Author: "Murgia, S." - Searchworks@Jio Institute Digital Library Search Results

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1,808 results on '"Murgia, S."'

1. Search for gamma-ray emission from p-wave dark matter annihilation in the Galactic Center

Author: Johnson, C, Caputo, R, Karwin, C, Murgia, S, Ritz, S, and Shelton, J
Subjects: Fermi-LAT Collaboration, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics
Abstract: Indirect searches for dark matter through Standard Model products of its annihilation generally assume a cross-section which is dominated by a term independent of velocity (s-wave annihilation). However, in many DM models an s-wave annihilation cross-section is absent or helicity suppressed. To reproduce the correct DM relic density in these models, the leading term in the cross section is proportional to the DM velocity squared (p-wave annihilation). Indirect detection of such p-wave DM is difficult because the average velocities of DM in galaxies today are orders of magnitude slower than the DM velocity at the time of decoupling from the primordial thermal plasma, thus suppressing the annihilation cross-section today by some five orders of magnitude relative to its value at freeze out. Thus p-wave DM is out of reach of traditional searches for DM annihilations in the Galactic halo. Near the region of influence of a central supermassive black hole, such as Sgr A*, however, DM can form a localized over-density known as a "spike". In such spikes the DM is predicted to be both concentrated in space and accelerated to higher velocities, thereby allowing the γ-ray signature from its annihilation to potentially be detectable above the background. We use the Fermi Large Area Telescope to search for the γ-ray signature of p-wave annihilating DM from a spike around Sgr A* in the energy range 10 GeV-600 GeV. Such a signal would appear as a point source and would have a sharp line or box-like spectral features difficult to mimic with standard astrophysical processes, indicating a DM origin. We find no significant excess of γ rays in this range, and we place upper limits on the flux in γ-ray boxes originating from the Galactic Center. This result, the first of its kind, is interpreted in the context of different models of the DM density near Sgr A*.
Published: 2019

2. Measurement of the high-energy gamma-ray emission from the Moon with the Fermi Large Area Telescope

Author: Ackermann, M., Ajello, M., Albert, A., Atwood, W. B., Baldini, L., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bonino, R., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Costanza, F., Cuoco, A., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Favuzzi, C., Fegan, S. J., Focke, W. B., Franckowiak, A., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guiriec, S., Harding, A. K., Hewitt, J. W., Horan, D., Hou, X., Iafrate, G., Johannesson, G., Kamae, T., Kuss, M., Larsson, S., Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Magill, J., Maldera, S., Manfreda, A., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Murgia, S., Nuss, E., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Rainò, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reposeur, T., Sgrò, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Takahashi, H., Thayer, J. B., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Troja, E., Vianello, G., Winer, B. L., Wood, K. S., Yassine, M., Cerutti, F., Ferrari, A., and Sala, P. R.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment
Abstract: We have measured the gamma-ray emission spectrum of the Moon using the data collected by the Large Area Telescope onboard the Fermi satellite during its first 7 years of operation, in the energy range from 30 MeV up to a few GeV. We have also studied the time evolution of the flux, finding a correlation with the solar activity. We have developed a full Monte Carlo simulation describing the interactions of cosmic rays with the lunar surface. The results of the present analysis can be explained in the framework of this model, where the production of gamma rays is due to the interactions of cosmic-ray proton and helium nuclei with the surface of the Moon. Finally, we have used our simulation to derive the cosmic-ray proton and helium spectra near Earth from the Moon gamma-ray data., Comment: Published by PRD, 16 pages, 11 figures, corresponding authors: F. Loparco and M. N. Mazziotta
Published: 2016
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3. Search for extended gamma-ray emission from the Virgo galaxy cluster with Fermi-LAT

Author: Ackermann, M., Ajello, M., Albert, A., Atwood, W. B., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Conrad, J., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Favuzzi, C., Fegan, S. J., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Gustafsson, M., Hewitt, J. W., Hill, A. B., Horan, D., Jeltema, T. E., Jogler, T., Johnson, A. S., Kuss, M., Larsson, S., Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Maldera, S., Malyshev, D., Manfreda, A., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Sánchez-Conde, M., Schulz, A., Sgró, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Storm, E., Tajima, H., Takahashi, H., Thayer, J. B., Torres, D. F., Tosti, G., Troja, E., Vianello, G., Wood, K. S., Wood, M., Zaharijas, G., Zimmer, S., and Pinzke, A.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Phenomenology
Abstract: Galaxy clusters are one of the prime sites to search for dark matter (DM) annihilation signals. Depending on the substructure of the DM halo of a galaxy cluster and the cross sections for DM annihilation channels, these signals might be detectable by the latest generation of $\gamma$-ray telescopes. Here we use three years of Fermi Large Area Telescope (LAT) data, which are the most suitable for searching for very extended emission in the vicinity of nearby Virgo galaxy cluster. Our analysis reveals statistically significant extended emission which can be well characterized by a uniformly emitting disk profile with a radius of 3\deg that moreover is offset from the cluster center. We demonstrate that the significance of this extended emission strongly depends on the adopted interstellar emission model (IEM) and is most likely an artifact of our incomplete description of the IEM in this region. We also search for and find new point source candidates in the region. We then derive conservative upper limits on the velocity-averaged DM pair annihilation cross section from Virgo. We take into account the potential $\gamma$-ray flux enhancement due to DM sub-halos and its complex morphology as a merging cluster. For DM annihilating into $b\overline{b}$, assuming a conservative sub-halo model setup, we find limits that are between 1 and 1.5 orders of magnitude above the expectation from the thermal cross section for $m_{\mathrm{DM}}\lesssim100\,\mathrm{GeV}$. In a more optimistic scenario, we exclude $\langle \sigma v \rangle\sim3\times10^{-26}\,\mathrm{cm^{3}\,s^{-1}}$ for $m_{\mathrm{DM}}\lesssim40\,\mathrm{GeV}$ for the same channel. Finally, we derive upper limits on the $\gamma$-ray-flux produced by hadronic cosmic-ray interactions in the inter cluster medium. We find that the volume-averaged cosmic-ray-to-thermal pressure ratio is less than $\sim6\%$., Comment: 15 pages, 11 figures, 4 tables, accepted for publication in ApJ; corresponding authors: T. Jogler, S. Zimmer & A. Pinzke
Published: 2015
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4. Multiwavelength Evidence for Quasi-periodic Modulation in the Gamma-ray Blazar PG 1553+113

Author: The Fermi LAT collaboration, Ackermann, M., Ajello, M., Albert, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Gonzalez, J. Becerra, Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Conrad, J., Cutini, S., D'Ammando, F., De Angelis, A., De Palma, F., Desiante, R., Di Venere, L., Dominguez, A., Drell, P. S., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fuhrmann, L., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Godfrey, G., Green, D., Grenier, I. A., Grove, J. E., Guiriec, S., Harding, A. K., Hays, E., Hewitt, J. W., Hill, A. B., Horan, D., Jogler, T., Johannesson, G., Johnson, A. S., Kamae, T., Kuss, M., Larsson, S., Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Magill, J., Maldera, S., Manfreda, A., Max-Moerbeck, W., Mayer, M., Mazziotta, M. N., Mcenery, J. E., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nuss, E., Ohno, M., Ohsugi, T., Ojha, R., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Pearson, T. J., Perkins, J. S., Perri, M., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Raino', S., Rando, R., Razzano, M., Readhead, A., Reimer, A., Reimer, O., Schulz, A., Sgro', C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Thayer, J. B., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vianello, G., Wood, K. S., Wood, M., Zimmer, S., Berdyugin, A., Corbet, R. H. D., Hovatta, T., Lindfors, E., Nilsson, K., Reinthal, R., Sillanpaa, A., Stamerra, A., Takalo, L. O., and Valtonen, M. J.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report for the first time a gamma-ray and multi-wavelength nearly-periodic oscillation in an active galactic nucleus. Using the Fermi Large Area Telescope (LAT) we have discovered an apparent quasi-periodicity in the gamma-ray flux (E >100 MeV) from the GeV/TeV BL Lac object PG 1553+113. The marginal significance of the 2.18 +/-0.08 year-period gamma-ray cycle is strengthened by correlated oscillations observed in radio and optical fluxes, through data collected in the OVRO, Tuorla, KAIT, and CSS monitoring programs and Swift UVOT. The optical cycle appearing in ~10 years of data has a similar period, while the 15 GHz oscillation is less regular than seen in the other bands. Further long-term multi-wavelength monitoring of this blazar may discriminate among the possible explanations for this quasi-periodicity., Comment: 8 pages, 5 figures. Accepted to The Astrophysical Journal Letters. Corresponding authors: S. Ciprini (ASDC/INFN), S. Cutini (ASDC/INFN), S. Larsson (Stockholm Univ/KTH), A. Stamerra (INAF/SNS), D. J. Thompson (NASA GSFC)
Published: 2015
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5. PSR J1906+0722: An Elusive Gamma-ray Pulsar

Author: Clark, C. J., Pletsch, H. J., Wu, J., Guillemot, L., Ackermann, M., Allen, B., de Angelis, A., Aulbert, C., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Bock, O., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cecchi, C., Champion, D. J., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cuéllar, A., Cutini, S., D'Ammando, F., Desiante, R., Drell, P. S., Eggenstein, H. B., Favuzzi, C., Fehrmann, H., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guiriec, S., Harding, A. K., Hays, E., Hewitt, J. W., Hill, A. B., Horan, D., Hou, X., Jogler, T., Johnson, A. S., Jóhannesson, G., Kramer, M., Krauss, F., Kuss, M., Laffon, H., Larsson, S., Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Machenschalk, B., Manfreda, A., Marelli, M., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., de Palma, F., Paneque, D., Pesce-Rollins, M., Piron, F., Pivato, G., Rainò, S., Rando, R., Razzano, M., Reimer, A., Parkinson, P. M. Saz, Schaal, M., Schulz, A., Sgrò, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Thayer, J. B., Tibaldo, L., Torne, P., Torres, D. F., Tosti, G., Troja, E., Vianello, G., Wood, K. S., Wood, M., and Yassine, M.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report the discovery of PSR J1906+0722, a gamma-ray pulsar detected as part of a blind survey of unidentified Fermi Large Area Telescope (LAT) sources being carried out on the volunteer distributed computing system, Einstein@Home. This newly discovered pulsar previously appeared as the most significant remaining unidentified gamma-ray source without a known association in the second Fermi-LAT source catalog (2FGL) and was among the top ten most significant unassociated sources in the recent third catalog (3FGL). PSR J1906+0722 is a young, energetic, isolated pulsar, with a spin frequency of $8.9$ Hz, a characteristic age of $49$ kyr, and spin-down power $1.0 \times 10^{36}$ erg s$^{-1}$. In 2009 August it suffered one of the largest glitches detected from a gamma-ray pulsar ($\Delta f / f \approx 4.5\times10^{-6}$). Remaining undetected in dedicated radio follow-up observations, the pulsar is likely radio-quiet. An off-pulse analysis of the gamma-ray flux from the location of PSR J1906+0722 revealed the presence of an additional nearby source, which may be emission from the interaction between a neighboring supernova remnant and a molecular cloud. We discuss possible effects which may have hindered the detection of PSR J1906+0722 in previous searches and describe the methods by which these effects were mitigated in this survey. We also demonstrate the use of advanced timing methods for estimating the positional, spin and glitch parameters of difficult-to-time pulsars such as this., Comment: 7 pages, 4 figures, accepted for publication in Astrophysical Journal Letters
Published: 2015
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6. The NuMI Neutrino Beam

Author: Adamson, P., Anderson, K., Andrews, M., Andrews, R., Anghel, I., Augustine, D., Aurisano, A., Avvakumov, S., Ayres, D. S., Baller, B., Barish, B., Barr, G., Barrett, W. L., Bernstein, R. H., Biggs, J., Bishai, M., Blake, A., Bocean, V., Bock, G. J., Boehnlein, D. J., Bogert, D., Bourkland, K., Cao, S. V., Castromonte, C. M., Childress, S., Choudhary, B. C., Coelho, J. A. B., Cobb, J. H., Corwin, L., Crane, D., Cravens, J. P., Cronin-Hennessy, D., Ducar, R. J., de Jong, J. K., Devan, A. V., Devenish, N. E., Diwan, M. V., Erwin, A. R., Escobar, C. O., Evans, J. J., Falk, E., Feldman, G. J., Fields, T. H., Ford, R., Frohne, M. V., Gallagher, H. R., Garkusha, V., Gomes, R. A., Goodman, M. C., Gouffon, P., Graf, N., Gran, R., Grossman, N., Grzelak, K., Habig, A., Hahn, S. R., Harding, D., Harris, D., Harris, P. G., Hartnell, J., Hatcher, R., Hays, S., Heller, K., Holin, A., Huang, J., Hylen, J., Ibrahim, A., Indurthy, D., Irwin, G. M., Isvan, Z., Jaffe, D. E., James, C., Jensen, D., Johnstone, J., Kafka, T., Kasahara, S. M. S., Koizumi, G., Kopp, S., Kordosky, M., Kreymer, A., Lang, K., Laughton, C., Lefeuvre, G., Ling, J., Litchfield, P. J., Loiacono, L., Lucas, P., Mann, W. A., Marchionni, A., Marshak, M. L., Mayer, N., McGivern, C., Medeiros, M. M., Mehdiyev, R., Meier, J. R., Messier, M. D., Michael, D. G., Milburn, R. H., Miller, J. L., Miller, W. H., Mishra, S. R., Sher, S. Moed, Moore, C. D., Morfin, J., Mualem, L., Mufson, S., Murgia, S., Murtagh, M., Musser, J., Naples, D., Nelson, J. K., Newman, H. B., Nichol, R. J., Nowak, J. A., Connor, J. O, Oliver, W. P., Olsen, M., Orchanian, M., Osprey, S., Pahlka, R. B., Paley, J., Para, A., Patterson, R. B., Patzak, T., Pavlovic, Z., Pawloski, G., Perch, A., Peterson, E. A., Petyt, D. A., Pfutzner, M. M., Phan-Budd, S., Plunkett, R. K., Poonthottathil, N., Prieto, P., Pushka, D., Qiu, X., Radovic, A., Rameika, R. A., Ratchford, J., Rebel, B., Reilly, R., Rosenfeld, C., Rubin, H. A., Ruddick, K., Sanchez, M. C., Saoulidou, N., Sauer, L., Schneps, J., Schoo, D., Schreckenberger, A., Schreiner, P., Shanahan, P., Sharma, R., Smart, W., Smith, C., Sousa, A., Stefanik, A., Tagg, N., Talaga, R. L., Tassotto, G., Thomas, J., Thompson, J., Thomson, M. A., Tian, X., Timmons, A., Tinsley, D., Tognini, S. C., Toner, R., Torretta, D., Trostin, I., Tzanakos, G., Urheim, J., Vahle, P., Vaziri, K., Villegas, E., Viren, B., Vogel, G., Webber, R. C., Weber, A., Webb, R. C., Wehmann, A., White, C., Whitehead, L., Whitehead, L. H., Wojcicki, S. G., Wong-Squires, M. L., Yang, T., Yumiceva, F. X., Zarucheisky, V., and Zwaska, R.
Subjects: Physics - Accelerator Physics, High Energy Physics - Experiment
Abstract: This paper describes the hardware and operations of the Neutrinos at the Main Injector (NuMI) beam at Fermilab. It elaborates on the design considerations for the beam as a whole and for individual elements. The most important design details of individual components are described. Beam monitoring systems and procedures, including the tuning and alignment of the beam and NuMI long-term performance, are also discussed.
Published: 2015
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7. The Third Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope

Author: Ackermann, M., Ajello, M., Atwood, W., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Gonzalez, J., Bellazzini, R., Bissaldi, E., Blandford, R., Bloom, E., Bonino, R., Bottacini, E., Brandt, T., Bregeon, J., Britto, R., Bruel, P., Buehler, R., Buson, S., Caliandro, G., Cameron, R., Caragiulo, M., Caraveo, P., Casandjian, J., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Cheung, C., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L., Conrad, J., Cutini, S., D'Abrusco, R., D'Ammando, F., Angelis, A., Desiante, R., Digel, S., Venere, L., Drell, P., Favuzzi, C., Fegan, S., Ferrara, E., Finke, J., Focke, W., Franckowiak, A., Fuhrmann, L., Furniss, A., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I., Grove, J., Guiriec, S., Hewitt, J. W., Hill, A., Horan, D., J'ohannesson, G., Johnson, A., Johnson, W., Kataoka, J., Kuss, M., Mura, G., Larsson, S., Latronico, L., Leto, C., Li, J., Li, L., Longo, F., Loparco, F., Lott, B., Lovellette, M., Lubrano, P., Madejski, G., Mayer, M., Mazziotta, M., McEnery, J., Michelson, P., Mizuno, T., Moiseev, A., Monzani, M., Morselli, A., Moskalenko, I., Murgia, S., Nuss, E., Ohno, M., Ohsugi, T., Ojha, R., Omodei, N., Orienti, M., Orlando, E., Paggi, A., Paneque, D., Perkins, J., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T., Rain`o, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Romani, R., Salvetti, D., Schaal, M., Schinzel, F., Schulz, A., Sgr`o, C., Siskind, E., Sokolovsky, K., Spada, F., Spandre, G., Spinelli, P., Stawarz, L., Suson, D., Takahashi, H., Takahashi, T., Tanaka, Y., Thayer, J., Tibaldo, L., Torres, D., Torresi, E., Tosti, G., Troja, E., Uchiyama, Y., Vianello, G., Winer, B., Wood, K., and Zimmer, S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The third catalog of active galactic nuclei (AGNs) detected by the Fermi-LAT (3LAC) is presented. It is based on the third Fermi-LAT catalog (3FGL) of sources detected between 100 MeV and 300 GeV with a Test Statistic (TS) greater than 25, between 2008 August 4 and 2012 July 31. The 3LAC includes 1591 AGNs located at high Galactic latitudes (|b|>10{\deg}), a 71% increase over the second catalog based on 2 years of data. There are 28 duplicate associations, thus 1563 of the 2192 high-latitude gamma-ray sources of the 3FGL catalog are AGNs. Most of them (98%) are blazars. About half of the newly detected blazars are of unknown type, i.e., they lack spectroscopic information of sufficient quality to determine the strength of their emission lines. Based on their gamma-ray spectral properties, these sources are evenly split between flat-spectrum radio quasars (FSRQs) and BL~Lacs. The most abundant detected BL~Lacs are of the high-synchrotron-peaked (HSP) type. About 50% of the BL~Lacs have no measured redshifts. A few new rare outliers (HSP-FSRQs and high-luminosity HSP BL~Lacs) are reported. The general properties of the 3LAC sample confirm previous findings from earlier catalogs. The fraction of 3LAC blazars in the total population of blazars listed in BZCAT remains non-negligible even at the faint ends of the BZCAT-blazar radio, optical and X-ray flux distributions, which is a clue that even the faintest known blazars could eventually shine in gamma rays at LAT-detection levels. The energy-flux distributions of the different blazar populations are in good agreement with extrapolation from earlier catalogs., Comment: Accepted by ApJ. Updated to published version
Published: 2015
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8. Limits on Dark Matter Annihilation Signals from the Fermi LAT 4-year Measurement of the Isotropic Gamma-Ray Background

Author: The Fermi LAT Collaboration, Ackermann, M., Ajello, M., Albert, A., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonino, R., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cuoco, A., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Ferrara, E. C., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Guiriec, S., Gustafsson, M., Hewitt, J. W., Hou, X., Kamae, T., Kuss, M., Larsson, S., Latronico, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Malyshev, D., Massaro, F., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Negro, M., Nemmen, R., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Sanchez-Conde, M., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Strong, A. W., Suson, D. J., Tajima, H., Takahashi, H., Thayer, J. G., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Troja, E., Uchiyama, Y., Vianello, G., Werner, M., Winer, B. L., Wood, K. S., Wood, M., and Zaharijas, G.
Subjects: Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract: We search for evidence of dark matter (DM) annihilation in the isotropic gamma-ray background (IGRB) measured with 50 months of Fermi Large Area Telescope (LAT) observations. An improved theoretical description of the cosmological DM annihilation signal, based on two complementary techniques and assuming generic weakly interacting massive particle (WIMP) properties, renders more precise predictions compared to previous work. More specifically, we estimate the cosmologically-induced gamma-ray intensity to have an uncertainty of a factor ~20 in canonical setups. We consistently include both the Galactic and extragalactic signals under the same theoretical framework, and study the impact of the former on the IGRB spectrum derivation. We find no evidence for a DM signal and we set limits on the DM-induced isotropic gamma-ray signal. Our limits are competitive for DM particle masses up to tens of TeV and, indeed, are the strongest limits derived from Fermi LAT data at TeV energies. This is possible thanks to the new Fermi LAT IGRB measurement, which now extends up to an energy of 820 GeV. We quantify uncertainties in detail and show the potential this type of search offers for testing the WIMP paradigm with a complementary and truly cosmological probe of DM particle signals., Comment: Matches the JCAP published version. Corresponding authors: A. Franckowiak (afrancko@slac.stanford.edu), M. Gustafsson (michael.gustafsson@theorie.physik.uni-goettingen.de), M.A. Sanchez-Conde (sanchezconde@fysik.su.se), G. Zaharijas (gabrijela.zaharijas@ung.si)
Published: 2015
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9. Measurement of the high-energy gamma-ray emission from the Moon with the Fermi Large Area Telescope

Author: Ackermann, M, Ajello, M, Albert, A, Atwood, WB, Baldini, L, Barbiellini, G, Bastieri, D, Bellazzini, R, Bissaldi, E, Blandford, RD, Bonino, R, Bottacini, E, Bregeon, J, Bruel, P, Buehler, R, Caliandro, GA, Cameron, RA, Caragiulo, M, Caraveo, PA, Cavazzuti, E, Cecchi, C, Chekhtman, A, Chiang, J, Chiaro, G, Ciprini, S, Claus, R, Cohen-Tanugi, J, Costanza, F, Cuoco, A, Cutini, S, D’Ammando, F, de Angelis, A, de Palma, F, Desiante, R, Digel, SW, Di Venere, L, Drell, PS, Favuzzi, C, Fegan, SJ, Focke, WB, Franckowiak, A, Funk, S, Fusco, P, Gargano, F, Gasparrini, D, Giglietto, N, Giordano, F, Giroletti, M, Glanzman, T, Godfrey, G, Grenier, IA, Grove, JE, Guiriec, S, Harding, AK, Hewitt, JW, Horan, D, Hou, X, Iafrate, G, Jóhannesson, G, Kamae, T, Kuss, M, Larsson, S, Latronico, L, Li, J, Li, L, Longo, F, Loparco, F, Lovellette, MN, Lubrano, P, Magill, J, Maldera, S, Manfreda, A, Mayer, M, Mazziotta, MN, Michelson, PF, Mitthumsiri, W, Mizuno, T, Monzani, ME, Morselli, A, Murgia, S, Nuss, E, Omodei, N, Orlando, E, Ormes, JF, Paneque, D, Perkins, JS, Pesce-Rollins, M, Petrosian, V, Piron, F, Pivato, G, Rainò, S, Rando, R, Razzano, M, Reimer, A, Reimer, O, Reposeur, T, Sgrò, C, Siskind, EJ, Spada, F, and Spandre, G
Subjects: Fermi LAT Collaboration, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics
Abstract: We have measured the gamma-ray emission spectrum of the Moon using the data collected by the Large Area Telescope onboard the Fermi satellite during its first seven years of operation, in the energy range from 30 MeV up to a few GeV. We have also studied the time evolution of the flux, finding a correlation with the solar activity. We have developed a full Monte Carlo simulation describing the interactions of cosmic rays with the lunar surface. The results of the present analysis can be explained in the framework of this model, where the production of gamma rays is due to the interactions of cosmic-ray proton and helium nuclei with the surface of the Moon. Finally, we have used our simulation to derive the cosmic-ray proton and helium spectra near Earth from the Moon gamma-ray data.
Published: 2016

10. Gamma-ray flaring activity from the gravitationally lensed blazar PKS 1830-211 observed by Fermi LAT

Author: The Fermi LAT Collaboration, Abdo, A. A., Ackermann, M., Ajello, M., Allafort, A., Amin, M. A., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bonamente, E., Borgland, A. W., Bregeon, J., Brigida, M., Buehler, R., Bulmash, D., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Corbet, R. H. D., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Finke, J., Focke, W. B., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Grenier, I. A., Grove, J. E., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Hughes, R. E., Inoue, Y., Jackson, M. S., Jogler, T., Jòhannesson, G., Johnson, A. S., Kamae, T., Knödlseder, J., Kuss, M., Lande, J., Larsson, S., Latronico, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Mazziotta, M. N., Mehault, J., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reyes, L. C., Ritz, S., Romoli, C., Roth, M., Parkinson, P. M. Saz, Sgrò, C., Siskind, E. J., Spandre, G., Spinelli, P., Takahashi, H., Takeuchi, Y., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Tronconi, V., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Werner, M., Winer, B. L., and Wood, K. S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope routinely detects the highly dust-absorbed, reddened, and MeV-peaked flat spectrum radio quasar PKS 1830-211 (z=2.507). Its apparent isotropic gamma-ray luminosity (E>100 MeV) averaged over $\sim$ 3 years of observations and peaking on 2010 October 14/15 at 2.9 X 10^{50} erg s^{-1}, makes it among the brightest high-redshift Fermi blazars. No published model with a single lens can account for all of the observed characteristics of this complex system. Based on radio observations, one expects time delayed variability to follow about 25 days after a primary flare, with flux about a factor 1.5 less. Two large gamma-ray flares of PKS 1830-211 have been detected by the LAT in the considered period and no substantial evidence for such a delayed activity was found. This allows us to place a lower limit of about 6 on the gamma rays flux ratio between the two lensed images. Swift XRT observations from a dedicated Target of Opportunity program indicate a hard spectrum and with no significant correlation of X-ray flux with the gamma-ray variability. The spectral energy distribution can be modeled with inverse Compton scattering of thermal photons from the dusty torus. The implications of the LAT data in terms of variability, the lack of evident delayed flare events, and different radio and gamma-ray flux ratios are discussed. Microlensing effects, absorption, size and location of the emitting regions, the complex mass distribution of the system, an energy-dependent inner structure of the source, and flux suppression by the lens galaxy for one image path may be considered as hypotheses for understanding our results., Comment: 14 pages, 6 figures, 2 tables. Accepted by the The Astrophysical Journal. Corresponding authors: S. Ciprini (ASI ASDC & INAF OAR, Rome, Italy), S. Buson (INAF Padova & Univ. of Padova, Padova, Italy), J. Finke (NRL, Washington, DC, USA), F. D'Ammando (INAF IRA, Bologna, Italy)
Published: 2014
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11. The spectrum of isotropic diffuse gamma-ray emission between 100 MeV and 820 GeV

Author: The Fermi LAT collaboration, Ackermann, M., Ajello, M., Albert, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cuoco, A., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., Silva, E. do Couto e, Drell, P. S., Favuzzi, C., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Gustafsson, M., Hadasch, D., Hayashi, K., Hays, E., Hewitt, J. W., Ippoliti, P., Jogler, T., Jóhannesson, G., Johnson, A. S., Johnson, W. N., Kamae, T., Kataoka, J., Knödlseder, J., Kuss, M., Larsson, S., Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Manfreda, A., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Romani, R. W., Sánchez-Conde, M., Schaal, M., Schulz, A., Sgrò, C., Siskind, E. J., Spandre, G., Spinelli, P., Strong, A. W., Suson, D. J., Takahashi, H., Thayer, J. G., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vianello, G., Werner, M., Winer, B. L., Wood, K. S., Wood, M., Zaharijas, G., and Zimmer, S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The {\gamma}-ray sky can be decomposed into individually detected sources, diffuse emission attributed to the interactions of Galactic cosmic rays with gas and radiation fields, and a residual all-sky emission component commonly called the isotropic diffuse {\gamma}-ray background (IGRB). The IGRB comprises all extragalactic emissions too faint or too diffuse to be resolved in a given survey, as well as any residual Galactic foregrounds that are approximately isotropic. The first IGRB measurement with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope (Fermi) used 10 months of sky-survey data and considered an energy range between 200 MeV and 100 GeV. Improvements in event selection and characterization of cosmic-ray backgrounds, better understanding of the diffuse Galactic emission, and a longer data accumulation of 50 months, allow for a refinement and extension of the IGRB measurement with the LAT, now covering the energy range from 100 MeV to 820 GeV. The IGRB spectrum shows a significant high-energy cutoff feature, and can be well described over nearly four decades in energy by a power law with exponential cutoff having a spectral index of $2.32\pm0.02$ and a break energy of $(279\pm52)$ GeV using our baseline diffuse Galactic emission model. The total intensity attributed to the IGRB is $(7.2\pm0.6) \times 10^{-6}$ cm$^{-2}$ s$^{-1}$ sr$^{-1}$ above 100 MeV, with an additional $+15$%/$-30$% systematic uncertainty due to the Galactic diffuse foregrounds., Comment: Accepted by The Astrophysical Journal
Published: 2014
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12. Multifrequency Studies of the Peculiar Quasar 4C +21.35 During the 2010 Flaring Activity

Author: Ackermann, M., Ajello, M., Allafort, A., Antolini, E., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Bonamente, E., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Chaves, R. C. G., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cutini, S., D'Ammando, F., de Palma, F., Dermer, C. D., Silva, E. do Couto e, Donato, D., Drell, P. S., Favuzzi, C., Finke, J., Focke, W. B., Franckowiak, A., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Grenier, I. A., Guiriec, S., Hayashida, M., Hewitt, J. W., Horan, D., Hughes, R. E., Iafrate, G., Johnson, A. S., Knodlseder, J., Kuss, M., Lande, J., Larsson, S., Latronico, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Rainò, S., Razzano, M., Reimer, A., Reimer, O., Sanchez, D. A., Schulz, A., Sgrò, C., Siskind, E. J., Spandre, G., Spinelli, P., Stawarz, L., Takahashi, H., Takahashi, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, D. L., Wood, K. S., Aleksic, J., Ansoldi, S., Antonelli, L. A., Antoranz, P., Babic, A., Bangale, P., de Almeida, U. Barres, Barrio, J. A., Gonzalez, J. Becerra, Bednarek, W., Berger, K., Bernardini, E., Biland, A., Blanch, O., Bock, R. K., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carmona, E., Carosi, A., Fidalgo, D. Carreto, Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Da Vela, P., Dazzi, F., De Angelis, A., De Caneva, G., De Lotto, B., Mendez, C. Delgado, Doert, M., Dominguez, A., Prester, D. Dominis, Dorner, D., Doro, M., Einecke, S., Eisenacher, D., Elsaesser, D., Farina, E., Ferenc, D., Fonseca, M. V., Font, L., Frantzen, K., Fruck, C., Lopez, R. J. Garcia, Garczarczyk, M., Terrats, D. Garrido, Gaug, M., Giavitto, G., Godinovic, N., Munoz, A. Gonzalez, Gozzini, S. R., Hadasch, D., Herrero, A., Hildebrand, D., Hose, J., Hrupec, D., Idec, W., Kadenius, V., Kellermann, H., Knoetig, M. L., Kodani, K., Konno, Y., Krause, J., Kubo, H., Kushida, J., La Barbera, A., Lelas, D., Lewandowska, N., Lindfors, E., Lombardi, S., Lopez, M., Lopez-Coto, R., Lopez-Oramas, A., Lorenz, E., Lozano, I., Makariev, M., Mallot, K., Maneva, G., Mankuzhiyil, N., Mannheim, K., Maraschi, L., Marcote, B., Mariotti, M., Martinez, M., Mazin, D., Menzel, U., Meucci, M., Miranda, J. M., Mirzoyan, R., Moralejo, A., Munar-Adrover, P., Nakajima, D., Niedzwiecki, A., Nishijima, K., Nilsson, K., Nowak, N., Orito, R., Overkemping, A., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Paredes-Fortuny, X., Partini, S., Persic, M., Prada, F., Moroni, P. G. Prada, Prandini, E., Preziuso, S., Puljak, I., Reinthal, R., Rhode, W., Ribo, M., Rico, J., Garcia, J. Rodriguez, Rugamer, S., Saggion, A., Saito, T., Saito, K., Salvati, M., Satalecka, K., Scalzotto, V., Scapin, V., Schultz, C., Schweizer, T., Shore, S. N., Sillanpaa, A., Sitarek, J., Snidaric, I., Sobczynska, D., Spanier, F., Stamatescu, V., Stamerra, A., Steinbring, T., Storz, J., Sun, S., Suric, T., Takalo, L., Takami, H., Tavecchio, F., Temnikov, P., Terzic, T., Tescaro, D., Teshima, M., Thaele, J., Tibolla, O., Toyama, T., Treves, A., Vogler, P., Wagner, R. M., Zandanel, F., Zanin, R., Aller, M. F., Angelakis, E., Blinov, D. A., Djorgovski, S. G., Drake, A. J., Efimova, N. V., Gurwell, M. A., Homan, D. C., Jordan, B., Kopatskaya, E. N., Kovalev, Y. Y., Kurtanidze, O. M., Lahteenmaki, A., Larionov, V. M., Lister, M. L., Nieppola, E., Nikolashvili, M. G., Ros, E., Savolainen, T., Sigua, L. A., and Tornikoski, M.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract: The discovery of rapidly variable Very High Energy (VHE; E > 100 GeV) gamma-ray emission from 4C +21.35 (PKS 1222+216) by MAGIC on 2010 June 17, triggered by the high activity detected by the Fermi Large Area Telescope (LAT) in high energy (HE; E > 100 MeV) gamma-rays, poses intriguing questions on the location of the gamma-ray emitting region in this flat spectrum radio quasar. We present multifrequency data of 4C +21.35 collected from centimeter to VHE during 2010 to investigate the properties of this source and discuss a possible emission model. The first hint of detection at VHE was observed by MAGIC on 2010 May 3, soon after a gamma-ray flare detected by Fermi-LAT that peaked on April 29. The same emission mechanism may therefore be responsible for both the HE and VHE emission during the 2010 flaring episodes. Two optical peaks were detected on 2010 April 20 and June 30, close in time but not simultaneous with the two gamma-ray peaks, while no clear connection was observed between the X-ray an gamma-ray emission. An increasing flux density was observed in radio and mm bands from the beginning of 2009, in accordance with the increasing gamma-ray activity observed by Fermi-LAT, and peaking on 2011 January 27 in the mm regime (230 GHz). We model the spectral energy distributions (SEDs) of 4C +21.35 for the two periods of the VHE detection and a quiescent state, using a one-zone model with the emission coming from a very compact region outside the broad line region. The three SEDs can be fit with a combination of synchrotron self-Compton and external Compton emission of seed photons from a dust torus, changing only the electron distribution parameters between the epochs. The fit of the optical/UV part of the spectrum for 2010 April 29 seems to favor an inner disk radius of <6 gravitational radii, as one would expect from a prograde-rotating Kerr black hole., Comment: 46 pages, 10 figures, 4 tables. The Astrophysical Journal, Volume 786, Issue 2, article id. 157, 17 pp. Contact Authors: Filippo D'Ammando, Justin Finke, Davide Donato, Josefa Becerra Gonzalez, Tomislav Terzic. Figure 1 updated
Published: 2014
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13. Inferred cosmic-ray spectrum from ${\it Fermi}$-LAT $\gamma$-ray observations of the Earth's limb

Author: Collaboration, Fermi-LAT, Ackermann, M., Ajello, M., Albert, A., Allafort, A., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bloom, E. D., Bonamente, E., Bottacini, E., Bouvier, A., Brandt, T. J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chaves, R. C. G., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cutini, S., Dalton, M., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., Di Venere, L., Silva, E. do Couto e, Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Grove, J. E., Guiriec, S., Gustafsson, M., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hayashi, K., Hewitt, J. W., Horan, D., Hou, X., Hughes, R. E., Inoue, Y., Jackson, M. S., Jogler, T., Jóhannesson, G., Johnson, A. S., Kamae, T., Kawano, T., Knödlseder, J., Kuss, M., Lande, J., Larsson, S., Latronico, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Okumura, A., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ritz, S., Roth, M., Schaal, M., Schulz, A., Sgrò, C., Siskind, E. J., Spandre, G., Spinelli, P., Strong, A. W., Takahashi, H., Takeuchi, Y., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Tronconi, V., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, K. S., Wood, M., and Yang, Z.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Recent accurate measurements of cosmic-ray (CR) species by ATIC-2, CREAM, and PAMELA reveal an unexpected hardening in the proton and He spectra above a few hundred GeV, a gradual softening of the spectra just below a few hundred GeV, and a harder spectrum of He compared to that of protons. These newly-discovered features may offer a clue to the origin of high-energy CRs. We use the ${\it Fermi}$ Large Area Telescope observations of the $\gamma$-ray emission from the Earth's limb for an indirect measurement of the local spectrum of CR protons in the energy range $\sim 90~$GeV-$6~$TeV (derived from a photon energy range $15~$GeV-$1~$TeV). Our analysis shows that single power law and broken power law spectra fit the data equally well and yield a proton spectrum with index $2.68 \pm 0.04$ and $2.61 \pm 0.08$ above $\sim 200~$GeV, respectively., Comment: Accepted by PRL for publication; Contact authors: Stefan Funk, Warit Mitthumsiri, Igor Moskalenko; 2 figures
Published: 2014

14. Deep Broadband Observations of the Distant Gamma-ray Blazar PKS 1424+240

Author: Archambault, S., Aune, T., Behera, B., Beilicke, M., Benbow, W., Berger, K., Bird, R., Biteau, J., Bugaev, V., Byrum, K., Cardenzana, J. V, Cerruti, M., Chen, X., Ciupik, L., Connolly, M. P., Cui, W., Dumm, J., Errando, M., Falcone, A., Federici, S., Feng, Q., Finley, J. P., Fleischhack, H., Fortson, L., Furniss, A., Galante, N., Gillanders, G. H., Griffin, S., Griffiths, S. T., Grube, J., Gyuk, G., Hanna, D., Holder, J., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kertzman, M., Khassen, Y., Kieda, D., Krawczynski, H., Krennrich, F., Kumar, S., Lang, M. J., Madhavan, A. S, Maier, G., McCann, A., Meagher, K., Moriarty, P., Mukherjee, R., Nieto, D., de Bhroithe, A. O'Faolain, Ong, R. A., Otte, A. N., Park, N., Pohl, M., Popkow, A., Prokoph, H., Quinn, J., Ragan, K., Rajotte, J., Reyes, L. C., Reynolds, P. T., Richards, G. T., Roache, E., Sembroski, G. H., Shahinyan, K., Staszak, D., Telezhinsky, I., Tucci, J. V., Tyler, J., Varlotta, A., Vassiliev, V. V., Vincent, S., Wakely, S. P., Weinstein, A., Welsing, R., Wilhelm, A., Williams, D. A., Ackermann, M., Ajello, M., Albert, A., Baldini, L., Bastieri, D., Bellazzini, R., Bissaldi, E., Bregeon, J., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cavazzuti, E., Charles, E., Chiang, J., Ciprini, S., Claus, R., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., Di Venere, L., Drell, P. S., Favuzzi, C., Franckowiak, A., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Grenier, I. A., Guiriec, S., Jogler, T., Kuss, M., Larsson, S., Latronico, L., Longo, F., Loparco, F., Lubrano, P., Madejski, G. M., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Murgia, S., Nuss, E., Ohsugi, T., Ormes, J. F., Perkins, J. S., Piron, F., Pivato, G., Raino, S., Razzano, M., Reimer, A., Reimer, O., Ritz, S., Schaal, M., Sgro, C., Siskind, E. J., Spinelli, P., Takahashi, H., Tibaldo, L., Tinivella, M., Troja, E., Vianello, G., Werner, M., and Wood, M.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We present deep VERITAS observations of the blazar PKS 1424+240, along with contemporaneous Fermi Large Area Telescope, Swift X-ray Telescope and Swift UV Optical Telescope data between 2009 February 19 and 2013 June 8. This blazar resides at a redshift of $z\ge0.6035$, displaying a significantly attenuated gamma-ray flux above 100 GeV due to photon absorption via pair-production with the extragalactic background light. We present more than 100 hours of VERITAS observations from three years, a multiwavelength light curve and the contemporaneous spectral energy distributions. The source shows a higher flux of (2.1$\pm0.3$)$\times10^{-7}$ ph m$^{-2}$s$^{-1}$ above 120 GeV in 2009 and 2011 as compared to the flux measured in 2013, corresponding to (1.02$\pm0.08$)$\times10^{-7}$ ph m$^{-2}$s$^{-1}$ above 120 GeV. The measured differential very high energy (VHE; $E\ge100$ GeV) spectral indices are $\Gamma=$3.8$\pm$0.3, 4.3$\pm$0.6 and 4.5$\pm$0.2 in 2009, 2011 and 2013, respectively. No significant spectral change across the observation epochs is detected. We find no evidence for variability at gamma-ray opacities of greater than $\tau=2$, where it is postulated that any variability would be small and occur on longer than year timescales if hadronic cosmic-ray interactions with extragalactic photon fields provide a secondary VHE photon flux. The data cannot rule out such variability due to low statistics., Comment: ApJL accepted March 17, 2014
Published: 2014
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15. SEARCH FOR EXTENDED GAMMA-RAY EMISSION FROM THE VIRGO GALAXY CLUSTER WITH FERMI-LAT

Author: Ackermann, M, Ajello, M, Albert, A, Atwood, WB, Baldini, L, Barbiellini, G, Bastieri, D, Bechtol, K, Bellazzini, R, Bissaldi, E, Bloom, ED, Bonino, R, Bottacini, E, Brandt, TJ, Bregeon, J, Bruel, P, Buehler, R, Buson, S, Caliandro, GA, Cameron, RA, Caputo, R, Caragiulo, M, Caraveo, PA, Casandjian, JM, Cavazzuti, E, Cecchi, C, Charles, E, Chekhtman, A, Chiaro, G, Ciprini, S, Cohen-Tanugi, J, Conrad, J, Cutini, S, D’Ammando, F, de Angelis, A, de Palma, F, Desiante, R, Digel, SW, Di Venere, L, Drell, PS, Favuzzi, C, Fegan, SJ, Focke, WB, Franckowiak, A, Fukazawa, Y, Funk, S, Fusco, P, Gargano, F, Gasparrini, D, Giglietto, N, Giordano, F, Giroletti, M, Glanzman, T, Godfrey, G, Gomez-Vargas, GA, Grenier, IA, Guiriec, S, Gustafsson, M, Hewitt, JW, Hill, AB, Horan, D, Jeltema, TE, Jogler, T, Johnson, AS, Kuss, M, Larsson, S, Latronico, L, Li, J, Li, L, Longo, F, Loparco, F, Lovellette, MN, Lubrano, P, Maldera, S, Malyshev, D, Manfreda, A, Mayer, M, Mazziotta, MN, Michelson, PF, Mizuno, T, Monzani, ME, Morselli, A, Moskalenko, IV, Murgia, S, Nuss, E, Ohsugi, T, Orienti, M, Orlando, E, Ormes, JF, Paneque, D, Perkins, JS, Pesce-Rollins, M, Petrosian, V, Piron, F, Pivato, G, Porter, TA, Rainó, S, Rando, R, Razzano, M, and Reimer, A
Subjects: galaxies: clusters: individual, gamma-rays: galaxies: clusters, gamma-rays: general, astro-ph.HE, hep-ph, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics
Abstract: Galaxy clusters are one of the prime sites to search for dark matter (DM) annihilation signals. Depending on the substructure of the DM halo of a galaxy cluster and the cross sections for DM annihilation channels, these signals might be detectable by the latest generation of γ-ray telescopes. Here we use three years of Fermi-Large Area Telescope data, which are the most suitable for searching for very extended emission in the vicinity of the nearby Virgo galaxy cluster. Our analysis reveals statistically significant extended emission which can be well characterized by a uniformly emitting disk profile with a radius of 3 that moreover is offset from the cluster center. We demonstrate that the significance of this extended emission strongly depends on the adopted interstellar emission model (IEM) and is most likely an artifact of our incomplete description of the IEM in this region. We also search for and find new point source candidates in the region. We then derive conservative upper limits on the velocity-averaged DM pair annihilation cross section from Virgo. We take into account the potential γ-ray flux enhancement due to DM sub-halos and its complex morphology as a merging cluster. For DM annihilating into assuming a conservative sub-halo model setup, we find limits that are between 1 and 1.5 orders of magnitude above the expectation from the thermal cross section for mDM ≲ 100 GeV. In a more optimistic scenario, we exclude for mDM ≲ 40 GeV for the same channel. Finally, we derive upper limits on the γ-ray-flux produced by hadronic cosmic-ray interactions in the inter cluster medium. We find that the volume-averaged cosmic-ray-to-thermal pressure ratio is less than ∼6%.
Published: 2015

16. Updated search for spectral lines from Galactic dark matter interactions with pass 8 data from the Fermi Large Area Telescope

Author: Ackermann, M, Ajello, M, Albert, A, Anderson, B, Atwood, WB, Baldini, L, Barbiellini, G, Bastieri, D, Bellazzini, R, Bissaldi, E, Blandford, RD, Bloom, ED, Bonino, R, Bottacini, E, Brandt, TJ, Bregeon, J, Bruel, P, Buehler, R, Buson, S, Caliandro, GA, Cameron, RA, Caputo, R, Caragiulo, M, Caraveo, PA, Cecchi, C, Charles, E, Chekhtman, A, Chiang, J, Chiaro, G, Ciprini, S, Claus, R, Cohen-Tanugi, J, Conrad, J, Cuoco, A, Cutini, S, D'Ammando, F, De Angelis, A, De Palma, F, Desiante, R, Digel, SW, Di Venere, L, Drell, PS, Drlica-Wagner, A, Favuzzi, C, Fegan, SJ, Franckowiak, A, Fukazawa, Y, Funk, S, Fusco, P, Gargano, F, Gasparrini, D, Giglietto, N, Giordano, F, Giroletti, M, Godfrey, G, Gomez-Vargas, GA, Grenier, IA, Grove, JE, Guiriec, S, Gustafsson, M, Hewitt, JW, Hill, AB, Horan, D, Jóhannesson, G, Johnson, RP, Kuss, M, Larsson, S, Latronico, L, Li, J, Li, L, Longo, F, Loparco, F, Lovellette, MN, Lubrano, P, Malyshev, D, Mayer, M, Mazziotta, MN, McEnery, JE, Michelson, PF, Mizuno, T, Moiseev, AA, Monzani, ME, Morselli, A, Murgia, S, Nuss, E, Ohsugi, T, Orienti, M, Orlando, E, Ormes, JF, Paneque, D, Pesce-Rollins, M, Piron, F, Pivato, G, Rainò, S, Rando, R, Razzano, M, Reimer, A, Reposeur, T, Ritz, S, and Sánchez-Conde, M
Subjects: Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract: Dark matter in the Milky Way may annihilate directly into γ rays, producing a monoenergetic spectral line. Therefore, detecting such a signature would be strong evidence for dark matter annihilation or decay. We search for spectral lines in the Fermi Large Area Telescope observations of the Milky Way halo in the energy range 200 MeV-500 GeV using analysis methods from our most recent line searches. The main improvements relative to previous works are our use of 5.8 years of data reprocessed with the Pass 8 event-level analysis and the additional data resulting from the modified observing strategy designed to increase exposure of the Galactic center region. We search in five sky regions selected to optimize sensitivity to different theoretically motivated dark matter scenarios and find no significant detections. In addition to presenting the results from our search for lines, we also investigate the previously reported tentative detection of a line at 133 GeV using the new Pass 8 data.
Published: 2015

17. The First Pulse of the Extremely Bright GRB 130427A: A Test Lab for Synchrotron Shocks

Author: Preece, R., Burgess, J. Michael, von Kienlin, A., Bhat, P. N., Briggs, M. S., Byrne, D., Chaplin, V., Cleveland, W., Collazzi, A. C., Connaughton, V., Diekmann, A., Fitzpatrick, G., Foley, S., Gibby, M., Giles, M., Goldstein, A., Greiner, J., Gruber, D., Jenke, P., Kippen, R. M., Kouveliotou, C., McBreen, S., Meegan, C., Paciesas, W. S., Pelassa, V., Tierney, D., van der Horst, A. J., Wilson-Hodge, C., Xiong, S., Younes, G., Yu, H. -F., Ackermann, M., Ajello, M., Axelsson, M., Baldini, L., Barbiellini, G., Baring, M. G., Bastieri, D., Bellazzini, R., Bissaldi, E., Bonamente, E., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L. R., Conrad, J., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Franckowiak, A., Fukazawa, Y., Fusco, P., Gargano, F., Gehrels, N., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Granot, J., Grenier, I. A., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Iyyani, S., Jogler, T., Jóannesson, G., Kawano, T., Knödlseder, J., Kocevski, D., Kuss, M., Lande, J., Larsson, J., Larsson, S., Latronico, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mizuno, T., Monzani, M. E., Moretti, E., Morselli, A., Murgia, S., Nemmen, R., Nuss, E., Nymark, T., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Orienti, M., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Racusin, J. L., Rainò, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ritz, S., Roth, M., Ryde, F., Sartori, A., Scargle, J. D., Schulz, A., Sgrò, C., Siskind, E. J., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Takahashi, H., Thayer, J. G., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, K. S., and Zhu, S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Gamma-ray burst (GRB) 130427A is one of the most energetic GRBs ever observed. The initial pulse up to 2.5 s is possibly the brightest well-isolated pulse observed to date. A fine time resolution spectral analysis shows power-law decays of the peak energy from the onset of the pulse, consistent with models of internal synchrotron shock pulses. However, a strongly correlated power-law behavior is observed between the luminosity and the spectral peak energy that is inconsistent with curvature effects arising in the relativistic outflow. It is difficult for any of the existing models to account for all of the observed spectral and temporal behaviors simultaneously., Comment: This is the author's version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published online in Science Express on 21 November 2013 [DOI:10.1126/science.1242302] 15 pages, 4 figures and 1 table; includes supplementary online materials
Published: 2013
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18. Dark Matter Constraints from Observations of 25 Milky Way Satellite Galaxies with the Fermi Large Area Telescope

Author: Collaboration, The Fermi-LAT, Ackermann, M., Albert, A., Anderson, B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonamente, E., Bouvier, A., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., D'Ammando, F., de Angelis, A., Dermer, C. D., Digel, S. W., Silva, E. do Couto e, Drell, P. S., Drlica-Wagner, A., Essig, R., Favuzzi, C., Ferrara, E. C., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giroletti, M., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Gustafsson, M., Hayashida, M., Hays, E., Hewitt, J., Hughes, R. E., Jogler, T., Kamae, T., Knödlseder, J., Kocevski, D., Kuss, M., Larsson, ., Latronico, L., Garde, M. Llena, Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Martinez, G., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Orlando, E., Ormes, J. F., Perkins, J. S., Piron, F., Pivato, G., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ritz, S., Sànchez-Conde, M., Sehgal, N., Sgrò, C., Siskind, E. J., Spinelli, P., Strigari, L., Suson, D. J., Tajima, H., Takahashi, H., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, K. S., Wood, M., Zaharijas, G., and Zimmer, S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment
Abstract: The dwarf spheroidal satellite galaxies of the Milky Way are some of the most dark-matter-dominated objects known. Due to their proximity, high dark matter content, and lack of astrophysical backgrounds, dwarf spheroidal galaxies are widely considered to be among the most promising targets for the indirect detection of dark matter via gamma rays. Here we report on gamma-ray observations of 25 Milky Way dwarf spheroidal satellite galaxies based on 4 years of Fermi Large Area Telescope (LAT) data. None of the dwarf galaxies are significantly detected in gamma rays, and we present gamma-ray flux upper limits between 500 MeV and 500 GeV. We determine the dark matter content of 18 dwarf spheroidal galaxies from stellar kinematic data and combine LAT observations of 15 dwarf galaxies to constrain the dark matter annihilation cross section. We set some of the tightest constraints to date on the the annihilation of dark matter particles with masses between 2 GeV and 10 TeV into prototypical Standard Model channels. We find these results to be robust against systematic uncertainties in the LAT instrument performance, diffuse gamma-ray background modeling, and assumed dark matter density profile., Comment: 47 pages, 8 figure, and 8 tables. Contact authors: Johann Cohen-Tanugi, Jan Conrad, Alex Drlica-Wagner, Maja Llena Garde, and Nicola Mazziotta
Published: 2013
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19. Search for cosmic-ray induced gamma-ray emission in Galaxy Clusters

Author: Ackermann, M., Ajello, M., Albert, A., Allafort, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bloom, E. D., Bonamente, E., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cavazzuti, E., Chaves, R. C. G., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Franckowiak, A., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Gustafsson, M., Hadasch, D., Hayashida, M., Hewitt, J., Hughes, R. E., Jeltema, T. E., Jóhannesson, G., Johnson, A. S., Kamae, T., Kataoka, J., Knödlseder, J., Kuss, M., Lande, J., Larsson, S., Latronico, L., Garde, M. Llena, Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Rainò, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ruan, J., Sánchez-Conde, M., Schulz, A., Sgrò, C., Siskind, E. J., Spandre, G., Spinelli, P., Storm, E., Strong, A. W., Suson, D. J., Takahashi, H., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vianello, G., Vitale, V., Winer, B. L., Wood, K. S., Zimmer, S., Pfrommer, C., and Pinzke, A.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: Current theories predict relativistic hadronic particle populations in clusters of galaxies in addition to the already observed relativistic leptons. In these scenarios hadronic interactions give rise to neutral pions which decay into $\gamma$ rays, that are potentially observable with the Large Area Telescope (LAT) on board the Fermi space telescope. We present a joint likelihood analysis searching for spatially extended $\gamma$-ray emission at the locations of 50 galaxy clusters in 4 years of Fermi-LAT data under the assumption of the universal cosmic-ray model proposed by Pinzke & Pfrommer (2010). We find an excess at a significance of $2.7\sigma$ which upon closer inspection is however correlated to individual excess emission towards three galaxy clusters: Abell 400, Abell 1367 and Abell 3112. We discuss these cases in detail and conservatively attribute the emission to unmodeled background (for example, radio galaxies within the clusters). Through the combined analysis of 50 clusters we exclude hadronic injection efficiencies in simple hadronic models above 21% and establish limits on the cosmic-ray to thermal pressure ratio within the virial radius, $R_{200}$, to be below 1.2-1.4% depending on the morphological classification. In addition we derive new limits on the $\gamma$-ray flux from individual clusters in our sample., Comment: Manuscript version accepted for publication in ApJ with expanded set of CR models now including thermal ICM and flat CR profiles; 27 pages, 19 figures, 9 tables; Corresponding authors: S. Zimmer, zimmer@fysik.su.se; J. Conrad, conrad@fysik.su.se; C. Pfrommer, christoph.pfrommer@h-its.org; A. Pinzke, apinzke@fysik.su.se; O. Reimer, olr@slac.stanford.edu
Published: 2013
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20. Constraints on the Galactic Population of TEV Pulsar Wind Nebulae Using Fermi Large Area Telescope Observations

Author: Acero, F., Ackermann, M., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bloom, E. D., Bonamente, E., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chaves, R. C. G., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cutini, S., Dalton, M., D'Ammando, F., de Palma, F., Dermer, C. D., Di Venere, L., Silva, E. do Couto e, Drell, P. S., Drlica-Wagner, A., Falletti, L., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grégoire, T., Grenier, I. A., Grondin, M. -H., Grove, J. E., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hayashi, K., Hays, E., Hewitt, J., Hill, A. B., Horan, D., Hou, X., Hughes, R. E., Inoue, Y., Jackson, M. S., Jogler, T., Jóhannesson, G., Johnson, A. S., Kamae, T., Kawano, T., Kerr, M., Knödlseder, J., Kuss, M., Lande, J., Larsson, S., Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Marelli, M., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Nemmen, R., Nuss, E., Ohsugi, T., Okumura, A., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Roth, M., Rousseau, R., Parkinson, P. M. Saz, Schulz, A., Sgrò, C., Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Takeuchi, Y., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tibolla, O., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, K. S., and Yang, Z.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Pulsar wind nebulae (PWNe) have been established as the most populous class of TeV gamma-ray emitters. Since launch, the Fermi Large Area Telescope (LAT)identified five high-energy (100MeV
Published: 2013
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21. Detection of the Characteristic Pion-Decay Signature in Supernova Remnants

Author: collaboration, The Fermi-LAT, Ackermann, M., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Baring, M. G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Busetto, G., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Çelik, Ö., Charles, E., Chaty, S., Chaves, R. C. G., Chekhtman, A., Cheung, C. C., Chiang, J., Chiaro, G., Cillis, A. N., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L. R., Conrad, J., Corbel, S., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Silva, E. do Couto e, Drell, P. S., Drlica-Wagner, A., Falletti, L., Favuzzi, C., Ferrara, E. C., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M. -H., Grove, J. E., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hayashi, K., Hays, E., Hewitt, J., Hill, A. B., Hughes, R. E., Jackson, M. S., Jogler, T., Jóhannesson, G., Johnson, A. S., Kamae, T., Kataoka, J., Katsuta, J., Knödlseder, J., Kuss, M., Lande, J., Larsson, S., Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Madejski, G. M., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mignani, R. P., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Rainò, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ritz, S., Romoli, C., Sánchez-Conde, M., Schulz, A., Sgrò, C., Simeon, P. E., Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Stecker, F. W., Strong, A. W., Suson, D. J., Tajima, H., Takahashi, H., Takahashi, T., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Thorsett, S. E., Tibaldo, L., Tibolla, O., Tinivella, M., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Werner, M., Winer, B. L., Wood, K. S., Wood, M., Yamazaki, R., Yang, Z., and Zimmer, S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Galaxy Astrophysics
Abstract: Cosmic rays are particles (mostly protons) accelerated to relativistic speeds. Despite wide agreement that supernova remnants (SNRs) are the sources of galactic cosmic rays, unequivocal evidence for the acceleration of protons in these objects is still lacking. When accelerated protons encounter interstellar material, they produce neutral pions, which in turn decay into gamma rays. This offers a compelling way to detect the acceleration sites of protons. The identification of pion-decay gamma rays has been difficult because high-energy electrons also produce gamma rays via bremsstrahlung and inverse Compton scattering. We detected the characteristic pion-decay feature in the gamma-ray spectra of two SNRs, IC 443 and W44, with the Fermi Large Area Telescope. This detection provides direct evidence that cosmic-ray protons are accelerated in SNRs., Comment: To appear in Science Magazine on February 15th; contact authors: Stefan Funk, Takaaki Tanaka, Yasunobu Uchiyama
Published: 2013
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22. Binary Millisecond Pulsar Discovery via Gamma-Ray Pulsations

Author: Pletsch, H. J., Guillemot, L., Fehrmann, H., Allen, B., Kramer, M., Aulbert, C., Ackermann, M., Ajello, M., de Angelis, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Borgland, A. W., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Celik, Ö., Charles, E., Chaves, R. C. G., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cutini, S., D'Ammando, F., Dermer, C. D., Digel, S. W., Drell, P. S., Drlica-Wagner, A., Dubois, R., Dumora, D., Favuzzi, C., Ferrara, E. C., Franckowiak, A., Fukazawa, Y., Fusco, P., Gargano, F., Gehrels, N., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Grenier, I. A., Grondin, M. -H., Grove, J. E., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hartog, P. R. den, Hayashida, M., Hays, E., Hill, A. B., Hou, X., Hughes, R. E., Johannesson, G., Jackson, M. S., Jogler, T., Johnson, A. S., Johnson, W. N., Kataoka, J., Kerr, M., Knödlseder, J., Kuss, M., Lande, J., Larsson, S., Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., de Palma, F., Paneque, D., Perkins, J. S., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Ray, P. S., Razzano, M., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Romani, R. W., Romoli, C., Sanchez, D. A., Parkinson, P. M. Saz, Schulz, A., Sgro, C., Silva, E. do Couto e, Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Tibaldo, L., Tinivella, M., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Winer, B. L., Wood, K. S., Wood, M., Yang, Z., and Zimmer, S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Galaxy Astrophysics, General Relativity and Quantum Cosmology
Abstract: Millisecond pulsars, old neutron stars spun-up by accreting matter from a companion star, can reach high rotation rates of hundreds of revolutions per second. Until now, all such "recycled" rotation-powered pulsars have been detected by their spin-modulated radio emission. In a computing-intensive blind search of gamma-ray data from the Fermi Large Area Telescope (with partial constraints from optical data), we detected a 2.5-millisecond pulsar, PSR J1311-3430. This unambiguously explains a formerly unidentified gamma-ray source that had been a decade-long enigma, confirming previous conjectures. The pulsar is in a circular orbit with an orbital period of only 93 minutes, the shortest of any spin-powered pulsar binary ever found., Comment: 14 pages, 3 figures. Science Express (25 October 2012); in press
Published: 2012
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23. Multi-wavelength observations of blazar AO 0235+164 in the 2008-2009 flaring state

Author: Ackermann, M., Ajello, M., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bottacini, E., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cutini, S., D'Ammando, F., de Palma, F., Dermer, C. D., Silva, E. do Couto e, Drell, P. S., Drlica-Wagner, A., Dubois, R., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fortin, P., Fuhrmann, L., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Guiriec, S., Hadasch, D., Hayashida, M., Hughes, R. E., Itoh, R., Johannesson, G., Johnson, A. S., Katagiri, H., Kataoka, J., Knodlseder, J., Kuss, M., Lande, J., Larsson, S., Lee, S. -H., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Nishino, S., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ozaki, M., Paneque, D., Panetta, J. H., Pelassa, V., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Rastawicki, D., Razzano, M., Readhead, A., Reimer, A., Reimer, O., Reyes, L. C., Richards, J. L., Sbarra, C., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Szostek, A., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Winer, B. L., Wood, K. S., Yang, Z., Zimmer, S., Moderski, R., Nalewajko, K., Sikora, M., Villata, M., Raiteri, C. M., Aller, H. D., Aller, M. F., Arkharov, A. A., Benitez, E., Berdyugin, A., Blinov, D. A., Boettcher, M., Calle, O. J. A. Bravo, Buemi, C. S., Carosati, D., Chen, W. P., Diltz, C., Di Paola, A., Dolci, M., Efimova, N. V., Forn\', E., Gurwell, M. A., Heidt, J., Hiriart, D., Jordan, B., Kimeridze, G., Konstantinova, T. S., Kopatskaya, E. N., Koptelova, E., Kurtanidze, O. M., Lahteenmaki, A., Larionova, E. G., Larionova, L. V., Larionov, V. M., Leto, P., Lindfors, E., Lin, H. C., Morozova, D. A., Nikolashvili, M. G., Nilsson, K., Oksman, M., Roustazadeh, P., Sievers, A., Sigua, L. A., Sillanpaa, A., Takahashi, T., Takalo, L. O., Tornikoski, M., Trigilio, C., Troitsky, I. S., Umana, G., Angelakis, E., Krichbaum, T. P., Nestoras, I., Riquelme, D., Krips, M., Trippe, S., Arai, A., Kawabata, K. S., Sakimoto, K., Sasada, M., Sato, S., Uemura, M., Yamanaka, M., Yoshida, M., Belloni, T., Tagliaferri, G., Bonning, E. W., Isler, J., Urry, C. M., Hoversten, E., Falcone, A., Pagani, C., and Stroh, M.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The blazar AO 0235+164 (z = 0.94) has been one of the most active objects observed by Fermi Large Area Telescope (LAT) since its launch in Summer 2008. In addition to the continuous coverage by Fermi, contemporaneous observations were carried out from the radio to {\gamma} -ray bands between 2008 September and 2009 February. In this paper, we summarize the rich multi-wavelength data collected during the campaign (including F-GAMMA, GASP- WEBT, Kanata, OVRO, RXTE, SMARTS, Swift, and other instruments), examine the cross-correlation between the light curves measured in the different energy bands, and interpret the resulting spectral energy distributions in the context of well-known blazar emission models. We find that the {\gamma} -ray activity is well correlated with a series of near-IR/optical flares, accompanied by an increase in the optical polarization degree. On the other hand, the X-ray light curve shows a distinct 20 day high state of unusually soft spectrum, which does not match the extrapolation of the optical/UV synchrotron spectrum. We tentatively interpret this feature as the bulk Compton emission by cold electrons contained in the jet, which requires an accretion disk corona with an effective covering factor of 19% at a distance of 100 Rg . We model the broadband spectra with a leptonic model with external radiation dominated by the infrared emission from the dusty torus., Comment: 48 pages, 8 figures
Published: 2012
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24. Gamma-ray observations of the Orion Molecular Clouds with the Fermi Large Area Telescope

Author: Ackermann, M., Ajello, M., Allafort, A., Antolini, E., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Chekhtman, A., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Silva, E. do Couto e, Drell, P. S., Drlica-Wagner, A., Enoto, T., Falletti, L., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fukazawa, Y., Fukui, Y., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hayashi, K., Horan, D., Hou, X., Hughes, R. E., Jackson, M. S., Jóhannesson, G., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Kerr, M., Knödlseder, J., Kuss, M., Lande, J., Larsson, S., Lee, S. -H., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Makishima, K., Mazziotta, M. N., Mehault, J., Mitthumsiri, W., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Naumann-Godo, M., Nishino, S., Norris, J. P., Nuss, E., Ohno, M., Ohsugi, T., Okumura, A., Orienti, M., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pelassa, V., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Porter, T. A., Rainò, S., Razzano, M., Reimer, A., Reimer, O., Roth, M., Sadrozinski, H. F. -W., Sgrò, C., Siskind, E. J., Spandre, G., Spinelli, P., Strong, A. W., Takahashi, H., Takahashi, T., Tanaka, T., Thayer, J. G., Thayer, J. B., Tibolla, O., Tinivella, M., Torres, D. F., Tramacere, A., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Z., and Zimmer, S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Galaxy Astrophysics
Abstract: We report on the gamma-ray observations of giant molecular clouds Orion A and B with the Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope. The gamma-ray emission in the energy band between \sim100 MeV and \sim100 GeV is predicted to trace the gas mass distribution in the clouds through nuclear interactions between the Galactic cosmic rays (CRs) and interstellar gas. The gamma-ray production cross-section for the nuclear interaction is known to \sim10% precision which makes the LAT a powerful tool to measure the gas mass column density distribution of molecular clouds for a known CR intensity. We present here such distributions for Orion A and B, and correlate them with those of the velocity integrated CO intensity (WCO) at a 1{\deg} \times1{\deg} pixel level. The correlation is found to be linear over a WCO range of ~10 fold when divided in 3 regions, suggesting penetration of nuclear CRs to most of the cloud volumes. The Wco-to-mass conversion factor, Xco, is found to be \sim2.3\times10^20 cm-2(K km s-1)-1 for the high-longitude part of Orion A (l > 212{\deg}), \sim1.7 times higher than \sim1.3 \times 10^20 found for the rest of Orion A and B. We interpret the apparent high Xco in the high-longitude region of Orion A in the light of recent works proposing a non-linear relation between H2 and CO densities in the diffuse molecular gas. Wco decreases faster than the H2 column density in the region making the gas "darker" to Wco., Comment: 41 pages, 10 figures (Accepted to ApJ)
Published: 2012
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25. GeV Observations of Star-forming Galaxies with \textit{Fermi} LAT

Author: Fermi LAT Collaboration, Ackermann, M., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Bloom, E. D., Bonamente, E., Borgland, A. W., Bouvier, A., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Cillis, A. N., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cutini, S., De Palma, F., Dermer, C. D., Digel, S. W., Silva, E. Do Couto e, Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Fegan, S. J., Fortin, P., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Glanzman, T., Godfrey, G., Grenier, I. A., Guiriec, S., Gustafsson, M., Hadasch, D., Hayashida, M., Hays, E., Hughes, R. E., Jóhannesson, G., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Knödlseder, J., Kuss, M., Lande, J., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Martin, P., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nishino, S., Norris, J. P., Nuss, E., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ozaki, M., Parent, D., Persic, M., Pesce-Rollins, M., Petrosian, V., Pierbattista, M., Piron, F., Pivato, G., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Ritz, S., Roth, M., Sbarra, C., Sgrò, C., Siskind, E. J., Spandre, G., Spinelli, P., Stawarz, \{L}ukasz, Strong, A. W., Takahashi, H., Tanaka, T., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vandenbroucke, J., Vianello, G., Vitale, V., Waite, A. P., Wood, M., and Yang, Z.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Recent detections of the starburst galaxies M82 and NGC 253 by gamma-ray telescopes suggest that galaxies rapidly forming massive stars are more luminous at gamma-ray energies compared to their quiescent relatives. Building upon those results, we examine a sample of 69 dwarf, spiral, and luminous and ultraluminous infrared galaxies at photon energies 0.1-100 GeV using 3 years of data collected by the Large Area Telescope (LAT) on the \textit{Fermi Gamma-ray Space Telescope} (\textit{Fermi}). Measured fluxes from significantly detected sources and flux upper limits for the remaining galaxies are used to explore the physics of cosmic rays in galaxies. We find further evidence for quasi-linear scaling relations between gamma-ray luminosity and both radio continuum luminosity and total infrared luminosity which apply both to quiescent galaxies of the Local Group and low-redshift starburst galaxies (conservative $P$-values $\lesssim0.05$ accounting for statistical and systematic uncertainties). The normalizations of these scaling relations correspond to luminosity ratios of $\log(L_{0.1-100 \rm{GeV}}/L_{1.4 \rm{GHz}}) = 1.7 \pm 0.1_{\rm (statistical)} \pm 0.2_{\rm (dispersion)}$ and $\log(L_{0.1-100 \rm{GeV}}/L_{8-1000 \mu\rm{m}}) = -4.3 \pm 0.1_{\rm (statistical)} \pm 0.2_{\rm (dispersion)}$ for a galaxy with a star formation rate of 1 $M_{\odot}$ yr$^{-1}$, assuming a Chabrier initial mass function. Using the relationship between infrared luminosity and gamma-ray luminosity, the collective intensity of unresolved star-forming galaxies at redshifts $0
Published: 2012
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26. Constraints on the Galactic Halo Dark Matter from Fermi-LAT Diffuse Measurements

Author: collaboration, The Fermi-LAT, Ackermann, M., Ajello, M., Atwood, W. B., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cuoco, A., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Silva, E. do Couto e, Drell, P. S., Drlica-Wagner, A., Falletti, L., Favuzzi, C., Fegan, S. J., Focke, W. B., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Guiriec, S., Gustafsson, M., Hadasch, D., Hayashida, M., Horan, D., Hughes, R. E., Jackson, M. S., Jogler, T., Jóhannesson, G., Johnson, A. S., Kamae, T., Knödlseder, J., Kuss, M., Lande, J., Latronico, L., Lionetto, A. M., Garde, M. Llena, Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Norris, J. P., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Poon, H., Rainò, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Romoli, C., Sbarra, C., Scargle, J. D., Sgrò, C., Siskind, E. J., Spandre, G., Spinelli, P., Stawarz, Łukasz, Strong, A. W., Suson, D. J., Tajima, H., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Tibaldo, L., Tinivella, M., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Wallace, E., Wood, K. S., Wood, M., Yang, Z., Zaharijas, G., and Zimmer, S.
Subjects: Astrophysics - Cosmology and Extragalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract: We have performed an analysis of the diffuse gamma-ray emission with the Fermi Large Area Telescope in the Milky Way Halo region searching for a signal from dark matter annihilation or decay. In the absence of a robust dark matter signal, constraints are presented. We consider both gamma rays produced directly in the dark matter annihilation/decay and produced by inverse Compton scattering of the e+e- produced in the annihilation/decay. Conservative limits are derived requiring that the dark matter signal does not exceed the observed diffuse gamma-ray emission. A second set of more stringent limits is derived based on modeling the foreground astrophysical diffuse emission using the GALPROP code. Uncertainties in the height of the diffusive cosmic-ray halo, the distribution of the cosmic-ray sources in the Galaxy, the index of the injection cosmic-ray electron spectrum and the column density of the interstellar gas are taken into account using a profile likelihood formalism, while the parameters governing the cosmic-ray propagation have been derived from fits to local cosmic-ray data. The resulting limits impact the range of particle masses over which dark matter thermal production in the early Universe is possible, and challenge the interpretation of the PAMELA/Fermi-LAT cosmic ray anomalies as annihilation of dark matter., Comment: 23 pages, 7 figures, 3 tables. Contact authors: Jan Conrad, Alessandro Cuoco, Zhaoyu Yang, Gabrijela Zaharijas; v2: matches version published on ApJ
Published: 2012
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27. Fermi LAT Search for Dark Matter in Gamma-ray Lines and the Inclusive Photon Spectrum

Author: Collaboration, Fermi-LAT, Ackermann, M., Ajello, M., Albert, A., Baldini, L., Barbiellini, G., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Brigida, M., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., D'Ammando, F., de Palma, F., Dermer, C. D., Silva, E. do Couto e, Drell, P. S., Drlica-Wagner, A., Edmonds, Y., Essig, R., Favuzzi, C., Fegan, S. J., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Guiriec, S., Gustafsson, M., Hadasch, D., Hayashida, M., Horan, D., Hughes, R. E., Kamae, T., Knödlseder, J., Kuss, M., Lande, J., Lionetto, A. M., Garde, M. Llena, Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Prokhorov, D., Rainò, S., Rando, R., Razzano, M., Reimer, O., Roth, M., Sbarra, C., Scargle, J. D., Sgrò, C., Siskind, E. J., Snyder, A., Spinelli, P., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Winer, B. L., Wood, K. S., Yang, Z., and Zimmer, S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: Dark matter particle annihilation or decay can produce monochromatic gamma-ray lines and contribute to the diffuse gamma-ray background. Flux upper limits are presented for gamma-ray spectral lines from 7 to 200 GeV and for the diffuse gamma-ray background from 4.8 GeV to 264 GeV obtained from two years of Fermi Large Area Telescope data integrated over most of the sky. We give cross section upper limits and decay lifetime lower limits for dark matter models that produce gamma-ray lines or contribute to the diffuse spectrum, including models proposed as explanations of the PAMELA and Fermi cosmic-ray data., Comment: Accepted for publication in Physical Review D
Published: 2012
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28. Anisotropies in the diffuse gamma-ray background measured by the Fermi LAT

Author: Ackermann, M., Ajello, M., Albert, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bloom, E. D., Bonamente, E., Borgland, A. W., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cuoco, A., Cutini, S., D'Ammando, F., de Palma, F., Dermer, C. D., Digel, S. W., Silva, E. do Couto e, Drell, P. S., Drlica-Wagner, A., Dubois, R., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Fortin, P., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giroletti, M., Glanzman, T., Godfrey, G., Gomez-Vargas, G. A., Grégoire, T., Grenier, I. A., Grove, J. E., Guiriec, S., Gustafsson, M., Hadasch, D., Hayashida, M., Hayashi, K., Hou, X., Hughes, R. E., Jóhannesson, G., Johnson, A. S., Kamae, T., Knödlseder, J., Kuss, M., Lande, J., Latronico, L., Lemoine-Goumard, M., Linden, T., Lionetto, A. M., Garde, M. Llena, Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., McEnery, J. E., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Parent, D., Pavlidou, V., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Rainò, S., Rando, R., Reimer, A., Reimer, O., Roth, M., Sbarra, C., Schmitt, J., Sgrò, C., Siegal-Gaskins, J., Siskind, E. J., Spandre, G., Spinelli, P., Strong, A. W., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Winer, B. L., Wood, K. S., Wood, M., Yang, Z., Zimmer, S., and Komatsu, E.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics, High Energy Physics - Phenomenology
Abstract: The contribution of unresolved sources to the diffuse gamma-ray background could induce anisotropies in this emission on small angular scales. We analyze the angular power spectrum of the diffuse emission measured by the Fermi LAT at Galactic latitudes |b| > 30 deg in four energy bins spanning 1 to 50 GeV. At multipoles \ell \ge 155, corresponding to angular scales \lesssim 2 deg, angular power above the photon noise level is detected at >99.99% CL in the 1-2 GeV, 2-5 GeV, and 5-10 GeV energy bins, and at >99% CL at 10-50 GeV. Within each energy bin the measured angular power takes approximately the same value at all multipoles \ell \ge 155, suggesting that it originates from the contribution of one or more unclustered source populations. The amplitude of the angular power normalized to the mean intensity in each energy bin is consistent with a constant value at all energies, C_P/^2 = 9.05 +/- 0.84 x 10^{-6} sr, while the energy dependence of C_P is consistent with the anisotropy arising from one or more source populations with power-law photon spectra with spectral index \Gamma_s = 2.40 +/- 0.07. We discuss the implications of the measured angular power for gamma-ray source populations that may provide a contribution to the diffuse gamma-ray background., Comment: 28 pages, 20 figures; accepted for publication in Phys. Rev. D; Contact authors: A. Cuoco, E. Komatsu, T. Linden, M. N. Mazziotta, J. Siegal-Gaskins, V. Vitale
Published: 2012
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29. Search for Dark Matter Satellites using the FERMI-LAT

Author: The Fermi LAT Collaboration, Ackermann, M., Albert, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burnett, T. H., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Charles, E., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cutini, S., de Palma, F., Dermer, C. D., Digel, S. W., Silva, E. do Couto e, Drell, P. S., Drlica-Wagner, A., Essig, R., Falletti, L., Favuzzi, C., Fegan, S. J., Focke, W. B., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Guiriec, S., Gustafsson, M., Hadasch, D., Hayashida, M., Hou, X., Hughes, R. E., Johnson, R. P., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Knodlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S. -H., Lionetto, A. M., Garde, M. Llena, Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Pelassa, V., Pierbattista, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Ritz, S., Sadrozinski, H. F. -W., Sehgal, N., Sgro, C., Siskind, E. J., Spinelli, P., Strigari, L., Suson, D. J., Tajima, H., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Z., Zalewski, S., and Zimmer, S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: Numerical simulations based on the Lambda-CDM model of cosmology predict a large number of as yet unobserved Galactic dark matter satellites. We report the results of a Large Area Telescope (LAT) search for these satellites via the gamma-ray emission expected from the annihilation of weakly interacting massive particle (WIMP) dark matter. Some dark matter satellites are expected to have hard gamma-ray spectra, finite angular extents, and a lack of counterparts at other wavelengths. We sought to identify LAT sources with these characteristics, focusing on gamma-ray spectra consistent with WIMP annihilation through the $b \bar b$ channel. We found no viable dark matter satellite candidates using one year of data, and we present a framework for interpreting this result in the context of numerical simulations to constrain the velocity-averaged annihilation cross section for a conventional 100 GeV WIMP annihilating through the $b \bar b$ channel., Comment: 29 pages, 5 figures, 3 tables; Accepted by ApJ; Contact authors: Alex Drlica-Wagner, Ping Wang, Louie Strigari, and Elliott Bloom
Published: 2012
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30. Simultaneous multi-wavelength campaign on PKS 2005-489 in a high state

Author: Collaboration, The H. E. S. S., Collaboration, the Fermi LAT, Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., Barnacka, A., de Almeida, U. Barres, Bazer-Bachi, A. R., Becherini, Y., Becker, J., Behera, B., Bernlöhr, K., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Borrel, V., Brucker, J., Brun, F., Brun, P., Bulik, T., Büsching, I., Casanova, S., Cerruti, M., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L. -M., Clapson, A. C., Coignet, G., Conrad, J., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fiasson, A., Fontaine, G., Förster, A., Füßling, M., Gabici, S., Gallant, Y. A., Gast, H., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glück, B., Goret, P., Göring, D., Hague, J. D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jamrozy, M., Jung, I., Kastendieck, M. A., Katarzyński, K., Katz, U., Kaufmann, S., Keogh, D., Kerschhaggl, M., Khangulyan, D., Khélifi, B., Klochkov, D., Kluźniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Laffon, H., Lamanna, G., Lenain, J. -P., Lennarz, D., Lohse, T., Lopatin, A., Lu, C. -C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., Maxted, N., McComb, T. J. L., Medina, M. C., Méhault, J., Nguyen, N., Moderski, R., Moulin, E., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Olive, J-F., Wilhelmi, E. de Oña, Opitz, B., Ostrowski, M., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P. -O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S. M., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Ryde, F., Sahakian, V., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schönwald, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sikora, M., Skilton, J. L., Sol, H., Spengler, G., Stawarz, Ł., Steenkamp, R., Stegmann, C., Stinzing, F., Sushch, I., Szostek, A., Tam, P. H., Tavernet, J. -P., Terrier, R., Tibolla, O., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J. P., Viana, A., Vincent, P., Vivier, M., Völk, H. J., Volpe, F., Vorobiov, S., Vorster, M., Wagner, S. J., Ward, M., Wierzcholska, A., Zajczyk, A., Zdziarski, A. A., Zech, A., Zechlin, H. -S., Abdo, A. A., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bonamente, E., Borgland, A. W., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Cannon, A., Caraveo, P. A., Carrigan, S., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Çelik, Ö., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cutini, S., Dermer, C. D., de Palma, F., Silva, E. do Couto e, Drell, P. S., Dubois, R., Dumora, D., Escande, L., Favuzzi, C., Ferrara, E. C., Focke, W. B., Fortin, P., Frailis, M., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guiriec, S., Hadasch, D., Hays, E., Horan, D., Hughes, R. E., Jóhannesson, G., Johnson, A. S., Johnson, W. N., Kamae, T., Katagiri, H., Kataoka, J., Knödlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S. -H., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Makeev, A., Mazziotta, M. N., McConville, W., McEnery, J. E., Michelson, P. F., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Nishino, S., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pelassa, V., Pepe, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Sadrozinski, H. F. -W., Sanchez, D., Sander, A., Sgrò, C., Siskind, E. J., Smith, P. D., Spandre, G., Spinelli, P., Strickman, M. S., Suson, D. J., Takahashi, H., Takahashi, T., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Tramacere, A., Troja, E., Uehara, T., Usher, T. L., Vandenbroucke, J., Vianello, G., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Z., Ylinen, T., and Ziegler, M.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The high-frequency peaked BL Lac object PKS 2005-489 was the target of a multi-wavelength campaign with simultaneous observations in the TeV gamma-ray (H.E.S.S.), GeV gamma-ray (Fermi/LAT), X-ray (RXTE, Swift), UV (Swift) and optical (ATOM, Swift) bands. This campaign was carried out during a high flux state in the synchrotron regime. The flux in the optical and X-ray bands reached the level of the historical maxima. The hard GeV spectrum observed with Fermi/LAT connects well to the very high energy (VHE, E>100GeV) spectrum measured with H.E.S.S. with a peak energy between ~5 and 500 GeV. Compared to observations with contemporaneous coverage in the VHE and X-ray bands in 2004, the X-ray flux was ~50 times higher during the 2009 campaign while the TeV gamma-ray flux shows marginal variation over the years. The spectral energy distribution during this multi-wavelength campaign was fit by a one zone synchrotron self-Compton model with a well determined cutoff in X-rays. The parameters of a one zone SSC model are inconsistent with variability time scales. The variability behaviour over years with the large changes in synchrotron emission and small changes in the inverse Compton emission does not warrant an interpretation within a one-zone SSC model despite an apparently satisfying fit to the broadband data in 2009., Comment: published in A&A, 9pages, 4figures. Due to some style difficulties using the standard style file with the long author list, the abstract has been included manually. A version with the correct style can be found in the website http://www.lsw.uni-heidelberg.de/users/skaufman/publications/aa16170-10published.pdf
Published: 2011
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31. Constraints on the pMSSM from LAT Observations of Dwarf Spheroidal Galaxies

Author: Cotta, R. C., Drlica-Wagner, A., Murgia, S., Bloom, E. D., Hewett, J. L., and Rizzo, T. G.
Subjects: High Energy Physics - Phenomenology, Astrophysics - High Energy Astrophysical Phenomena
Abstract: We examine the ability for the Large Area Telescope (LAT) to constrain Minimal Supersymmetric Standard Model (MSSM) dark matter through a combined analysis of Milky Way dwarf spheroidal galaxies. We examine the Lightest Supersymmetric Particles (LSPs) for a set of ~71k experimentally valid supersymmetric models derived from the phenomenological-MSSM (pMSSM). We find that none of these models can be excluded at 95% confidence by the current analysis; nevertheless, many lie within the predicted reach of future LAT analyses. With two years of data, we find that the LAT is currently most sensitive to light LSPs (m_LSP < 50 GeV) annihilating into tau-pairs and heavier LSPs annihilating into b-bbar. Additionally, we find that future LAT analyses will be able to probe some LSPs that form a sub-dominant component of dark matter. We directly compare the LAT results to direct detection experiments and show the complementarity of these search methods., Comment: 24 pages, 9 figures, submitted to JCAP
Published: 2011
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32. Measurement of separate cosmic-ray electron and positron spectra with the Fermi Large Area Telescope

Author: The Fermi LAT Collaboration, Ackermann, M., Ajello, M., Allafort, A., Atwood, W. B., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bouvier, A., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cutini, S., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., Silva, E. do Couto e, Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fortin, P., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guiriec, S., Gustafsson, M., Hadasch, D., Harding, A. K., Hayashida, M., Hughes, R. E., Jóhannesson, G., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Knödlseder, J., Kuss, M., Lande, J., Latronico, L., Lemoine-Goumard, M., Garde, M. Llena, Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Madejski, G. M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Nolan, P. L., Norris, J. P., Nuss, E., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Ormes, E. Orlando J. F., Ozaki, M., Paneque, D., Parent, D., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Romani, R. W., Roth, M., Sadrozinski, H. F. -W., Sbarra, C., Schalk, T. L., Sgrò, C., Siskind, E. J., Spandre, G., Spinelli, P., Strong, A. W., Takahashi, H., Takahashi, T., Tanaka, T., Thayer, J. G., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Winer, B. L., Wood, K. S., Wood, M., Yang, Z., and Zimmer, S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We measured separate cosmic-ray electron and positron spectra with the Fermi Large Area Telescope. Because the instrument does not have an onboard magnet, we distinguish the two species by exploiting the Earth's shadow, which is offset in opposite directions for opposite charges due to the Earth's magnetic field. We estimate and subtract the cosmic-ray proton background using two different methods that produce consistent results. We report the electron-only spectrum, the positron-only spectrum, and the positron fraction between 20 GeV and 200 GeV. We confirm that the fraction rises with energy in the 20-100 GeV range. The three new spectral points between 100 and 200 GeV are consistent with a fraction that is continuing to rise with energy., Comment: 5 figures, 1 table, revtex 4.1, updated to match PRL published version
Published: 2011
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33. Constraining Dark Matter Models from a Combined Analysis of Milky Way Satellites with the Fermi Large Area Telescope

Author: Collaboration, The Fermi-LAT, Ackermann, M., Ajello, M., Albert, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burnett, T. H., Buson, S., Caliandro, G. A., Cameron, R. A., Canadas, B., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cutini, S., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., Silva, E. do Couto e, Drell, P. S., Drlica-Wagner, A., Falletti, L., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Guiriec, S., Gustafsson, M., Hadasch, D., Hayashida, M., Hays, E., Hughes, R. E., Jeltema, T. E., Johannesson, G., Johnson, R. P., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Knödlseder, J., Kuss, M., Lande, J., Latronico, L., Lionetto, A. M., Garde, M. Llena, Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Parent, D., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Porter, T. A., Profumo, S., Raino, S., Razzano, M., Reimer, A., Reimer, O., Ritz, S., Roth, M., Sadrozinski, H. F. -W., Sbarra, C., Scargle, J. D., Schalk, T. L., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Strigari, L., Suson, D. J., Tajima, H., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Troja, E., Uchiyama, Y., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Wood, M., Yang, Z., Zimmer, S., Kaplinghat, M., and Martinez, G. D.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Phenomenology
Abstract: Satellite galaxies of the Milky Way are among the most promising targets for dark matter searches in gamma rays. We present a search for dark matter consisting of weakly interacting massive particles, applying a joint likelihood analysis to 10 satellite galaxies with 24 months of data of the Fermi Large Area Telescope. No dark matter signal is detected. Including the uncertainty in the dark matter distribution, robust upper limits are placed on dark matter annihilation cross sections. The 95% confidence level upper limits range from about 1e-26 cm^3 s^-1 at 5 GeV to about 5e-23 cm^3 s^-1 at 1 TeV, depending on the dark matter annihilation final state. For the first time, using gamma rays, we are able to rule out models with the most generic cross section (~3e-26 cm^3 s^-1 for a purely s-wave cross section), without assuming additional boost factors., Comment: 6 pages, 2 figures; Contact authors: Johann Cohen-Tanugi, Jan Conrad, and Maja Llena Garde
Published: 2011
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34. The radio/gamma-ray connection in Active Galactic Nuclei in the era of the Fermi Large Area Telescope

Author: Ackermann, M., Ajello, M., Allafort, A., Angelakis, E., Axelsson, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bouvier, A., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Cannon, A., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Cheung, C. C., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cutini, S., de Palma, F., Dermer, C. D., Silva, E. do Couto e, Drell, P. S., Dubois, R., Dumora, D., Escande, L., Favuzzi, C., Fegan, S. J., Focke, W. B., Fortin, P., Frailis, M., Fuhrmann, L., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grandi, P., Grenier, I. A., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Healey, S. E., J, G., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Kn, J., Kuss, M., Lande, J., Lee, S. -H., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Makeev, A., Max-Moerbeck, W., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Nishino, S., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Pavlidou, V., Pelassa, V., Pepe, M., Pesce-Rollins, M., Pierbattista, M., Piron, F., Porter, T. A., Rain, S., Razzano, M., Readhead, A., Reimer, A., Reimer, O., Richards, J. L., Romani, R. W., Sadrozinski, H. F. -W., Scargle, J. D., Sgr, C., Siskind, E. J., Smith, P. D., Spandre, G., Spinelli, P., Strickman, M. S., Suson, D. J., Takahashi, H., Tanaka, T., Taylor, G. B., Thayer, J. G., Thayer, J. B., Thompson, D. J., Torres, D. F., Tosti, G., Tramacere, A., Troja, E., Vandenbroucke, J., Vianello, G., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Z., and Ziegler, M.
Subjects: Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract: We present a detailed statistical analysis of the correlation between radio and gamma-ray emission of the Active Galactic Nuclei (AGN) detected by Fermi during its first year of operation, with the largest datasets ever used for this purpose. We use both archival interferometric 8.4 GHz data (from the VLA and ATCA, for the full sample of 599 sources) and concurrent single-dish 15 GHz measurements from the Owens Valley Radio Observatory (OVRO, for a sub sample of 199 objects). Our unprecedentedly large sample permits us to assess with high accuracy the statistical significance of the correlation, using a surrogate-data method designed to simultaneously account for common-distance bias and the effect of a limited dynamical range in the observed quantities. We find that the statistical significance of a positive correlation between the cm radio and the broad band (E>100 MeV) gamma-ray energy flux is very high for the whole AGN sample, with a probability <1e-7 for the correlation appearing by chance. Using the OVRO data, we find that concurrent data improve the significance of the correlation from 1.6e-6 to 9.0e-8. Our large sample size allows us to study the dependence of correlation strength and significance on specific source types and gamma-ray energy band. We find that the correlation is very significant (chance probability <1e-7) for both FSRQs and BL Lacs separately; a dependence of the correlation strength on the considered gamma-ray energy band is also present, but additional data will be necessary to constrain its significance., Comment: Accepted for publications by ApJ. Contact authors: M. Giroletti, V. Pavlidou, A. Reimer
Published: 2011
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35. Gamma-Ray and Parsec-Scale Jet Properties of a Complete Sample of Blazars From the MOJAVE Program

Author: Lister, M. L., Aller, M., Aller, H., Hovatta, T., Kellermann, K. I., Kovalev, Y. Y., Meyer, E. T., Pushkarev, A. B., Ros, E., Ackermann, M., Antolini, E., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Boeck, M., Bonamente, E., Borgland, A. W., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Chang, C. S., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cutini, S., de Palma, F., Dermer, C. D., Silva, E. do Couto e, Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Finke, J., Focke, W. B., Fortin, P., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Horan, D., Hughes, R. E., Jóhannesson, G., Johnson, A. S., Kadler, M., Katagiri, H., Kataoka, J., Knödlseder, J., Kuss, M., Lande, J., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Mazziotta, M. N., McConville, W., McEnery, J. E., Mehault, J., Michelson, P. F., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Nishino, S., Nolan, P. L., Norris, J. P., Nuss, E., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ozaki, M., Paneque, D., Parent, D., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Rainò, S., Readhead, A., Reimer, A., Reimer, O., Richards, J. L., Ritz, S., Sadrozinski, H. F. -W., Sgrò, C., Shaw, M. S., Siskind, E. J., Spandre, G., Spinelli, P., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tosti, G., Tramacere, A., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., and Zimmer, S.
Subjects: Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract: We investigate the Fermi LAT gamma-ray and 15 GHz VLBA radio properties of a joint gamma-ray- and radio-selected sample of AGNs obtained during the first 11 months of the Fermi mission (2008 Aug 4 - 2009 Jul 5). Our sample contains the brightest 173 AGNs in these bands above declination -30 deg. during this period, and thus probes the full range of gamma-ray loudness (gamma-ray to radio band luminosity ratio) in the bright blazar population. The latter quantity spans at least four orders of magnitude, reflecting a wide range of spectral energy distribution (SED) parameters in the bright blazar population. The BL Lac objects, however, display a linear correlation of increasing gamma-ray loudness with synchrotron SED peak frequency, suggesting a universal SED shape for objects of this class. The synchrotron self-Compton model is favored for the gamma-ray emission in these BL Lacs over external seed photon models, since the latter predict a dependence of Compton dominance on Doppler factor that would destroy any observed synchrotron SED peak - gamma-ray loudness correlation. The high-synchrotron peaked (HSP) BL Lac objects are distinguished by lower than average radio core brightness temperatures, and none display large radio modulation indices or high linear core polarization levels. No equivalent trends are seen for the flat-spectrum radio quasars (FSRQ) in our sample. Given the association of such properties with relativistic beaming, we suggest that the HSP BL Lacs have generally lower Doppler factors than the lower-synchrotron peaked BL Lacs or FSRQs in our sample., Comment: 22 pages, 11 figures, 4 tables; accepted for publication in the Astrophysical Journal
Published: 2011
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36. Radio and Gamma-Ray Constraints on the Emission Geometry and Birthplace of PSR J2043+2740

Author: Noutsos, A., Abdo, A. A., Ackermann, M., Ajello, M., Ballet, J., Barbiellini, G., Baring, M. G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Bonamente, E., Borgland, A. W., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Buehler, R., Busetto, G., Caliandro, G. A., Cameron, R. A., Camilo, F., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Celik, O., Chaty, S., Chekhtman, A., Chiang, J., Ciprini, S., Claus, R., Cognard, I., Cohen-Tanugi, J., Colafrancesco, S., Cutini, S., Dermer, C. D., de Palma, F., Drell, P. S., Dumora, D., Espinoza, C. M., Favuzzi, C., Ferrara, E. C., Focke, W. B., Frailis, M., Freire, P. C. C., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Grandi, P., Grenier, I. A., Grove, J. E., Guillemot, L., Guiriec, S., Harding, A. K., Hughes, R. E., Jackson, M. S., Johannesson, G., Johnson, A. S., Johnson, T. J., Johnson, W. N., Johnston, S., Kamae, T., Katagiri, H., Kataoka, J., Knoedlseder, J., Kramer, M., Kuss, M., Lande, J., Lee, S. -H., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Lyne, A. G., Makeev, A., Marelli, M., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Nolan, P. L., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Panetta, J. H., Parent, D., Pelassa, V., Pepe, M., Persic, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Rain, S., Ray, P. S., Razzano, M., Reimer, A., Reimer, O., Reposeur, T., Romani, R. W., Sadrozinski, H. F. -W., Sander, A., Parkinson, P. M. Saz, Sgro, C., Siskind, E. J., Smith, D. A., Smith, P. D., Spandre, G., Spinelli, P., Stappers, B. W., Strickman, M. S., Suson, D. J., Takahashi, H., Tanaka, T., Theureau, G., Thompson, D. J., Thorsett, S. E., Tibolla, O., Torres, D. F., Tramacere, A., Usher, T. L., Vandenbroucke, J., Vianello, G., Vilchez, N., Villata, M., Vitale, V., von Kienlin, A., Waite, A. P., Wang, P., Watters, K., Weltevrede, P., Winer, B. L., Wood, K. S., and Ziegler, M.
Subjects: Astrophysics - Astrophysics of Galaxies
Abstract: We report on the first year of Fermi gamma-ray observations of pulsed high-energy emission from the old PSR J2043+2740. The study of the gamma-ray efficiency of such old pulsars gives us an insight into the evolution of pulsars' ability to emit in gammma rays as they age. The gamma-ray lightcurve of this pulsar above 0.1 GeV is clearly defined by two sharp peaks, 0.353+/-0.035 periods apart. We have combined the gamma-ray profile characteristics of PSR J2043+2740 with the geometrical properties of the pulsar's radio emission, derived from radio polarization data, and constrained the pulsar-beam geometry in the framework of a Two Pole Caustic and an Outer Gap model. The ranges of magnetic inclination and viewing angle were determined to be {alpha,zeta}~{52-57,61-68} for the Two Pole Caustic model, and {alpha,zeta}~{62-73,74-81} and {alpha,zeta}~{72-83,60-75} for the Outer Gap model. Based on this geometry, we assess possible birth locations for this pulsar and derive a likely proper motion, sufficiently high to be measurable with VLBI. At a characteristic age of 1.2 Myr, PSR J2043+2740 is the third oldest of all discovered, non-recycled, gamma-ray pulsars: it is twice as old as the next oldest, PSR J0357+32, and younger only than the recently discovered PSR J1836+5925 and PSR J2055+25, both of which are at least 5 and 10 times less energetic, respectively., Comment: 17 pages, 6 figures, Accepted for publication in ApJ
Published: 2010
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37. The Discovery of gamma-Ray Emission From The Blazar RGB J0710+591

Author: Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Bautista, M., Beilicke, M., Benbow, W., Böttcher, M., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Ciupik, L., Cui, W., Dickherber, R., Duke, C., Falcone, A., Finley, J. P., Finnegan, G., Fortson, L., Furniss, A., Galante, N., Gall, D., Gibbs, K., Gillanders, G. H., Godambe, S., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., Lamerato, A., LeBohec, S., Maier, G., McArthur, S., McCann, A., McCutcheon, M., Moriarty, P., Mukherjee, R., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Petry, D., Pichel, A., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Roustazadeh, P., Schroedter, M., Sembroski, G. H., Senturk, G. Demet, Smith, A. W., Steele, D., Swordy, S. P., Tešić, G., Theiling, M., Thibadeau, S., Varlotta, A., Vassiliev, V. V., Vincent, S., Wagner, R. G., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., Zitzer, B., Ackermann, M., Ajello, M., Antolini, E., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bouvier, A., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Carrigan, S., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Çelik, Ö., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Dermer, C. D., de Palma, F., Silva, E. do Couto e, Drell, P. S., Dubois, R., Dumora, D., Farnier, C., Favuzzi, C., Fegan, S. J., Fortin, P., Frailis, M., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giebels, B., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guiriec, S., Hays, E., Horan, D., Hughes, R. E., Jóhannesson, G., Johnson, A. S., Johnson, W. N., Kamae, T., Katagiri, H., Kataoka, J., Knödlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S. -H., Garde, M. Llena, Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Makeev, A., Mazziotta, M. N., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nolan, P. L., Norris, J. P., Nuss, E., Ohno, M., Ohsugi, T., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Pelassa, V., Pepe, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Ripken, J., Rodriguez, A. Y., Roth, M., Sadrozinski, H. F. -W., Sanchez, D., Sander, A., Scargle, J. D., Sgrò, C., Siskind, E. J., Smith, P. D., Spandre, G., Spinelli, P., Strickman, M. S., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Tramacere, A., Usher, T. L., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Z., Ylinen, T., and Ziegler, M.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: The high-frequency-peaked BL Lacertae object RGB J0710+591 was observed in the very high-energy (VHE; E > 100 GeV) wave band by the VERITAS array of atmospheric Cherenkov telescopes. The observations, taken between 2008 December and 2009 March and totaling 22.1 hr, yield the discovery of VHE gamma rays from the source. RGB J0710+591 is detected at a statistical significance of 5.5 standard deviations (5.5{\sigma}) above the background, corresponding to an integral flux of (3.9 +/- 0.8) x 10-12 cm-2 s-1 (3% of the Crab Nebula's flux) above 300 GeV. The observed spectrum can be fit by a power law from 0.31 to 4.6 TeV with a photon spectral index of 2.69 +/- 0.26stat +/- 0.20sys. These data are complemented by contemporaneous multiwavelength data from the Fermi Large Area Telescope, the Swift X-ray Telescope, the Swift Ultra-Violet and Optical Telescope, and the Michigan-Dartmouth-MIT observatory. Modeling the broadband spectral energy distribution (SED) with an equilibrium synchrotron self-Compton model yields a good statistical fit to the data. The addition of an external-Compton component to the model does not improve the fit nor brings the system closer to equipartition. The combined Fermi and VERITAS data constrain the properties of the high-energy emission component of the source over 4 orders of magnitude and give measurements of the rising and falling sections of the SED.
Published: 2010
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38. Constraints on Cosmological Dark Matter Annihilation from the Fermi-LAT Isotropic Diffuse Gamma-Ray Measurement

Author: collaboration, The Fermi-LAT, Abdo, A. A., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bouvier, A., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Burnett, T. H., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Carrigan, S., Casandjian, J. M., Cecchi, C., Elik, O. C., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cutini, S., Dermer, C. D., de Angelis, A., de Palma, F., Digel, S. W., Silva, E. do Couto e, Drell, P. S., Dubois, R., Dumora, D., Edmonds, Y., Farnier, C., Favuzzi, C., Fegan, S. J., Focke, W. B., Fortin, P., Frailis, M., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giordano, F., Glanzman, T., Godfrey, G., Grove, J. E., Guillemot, L., Guiriec, S., Gustafsson, M., Hadasch, D., Harding, A. K., Horan, D., Hughes, R. E., Johnson, A. S., Johnson, W. N., Kamae, T., Katagiri, H., Kataoka, J., Kawai, N., Kerr, M., Knodlseder, J., Kuss, M., Lande, J., Latronico, L., Garde, M. Llena, Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Makeev, A., Mazziotta, M. N., McEnery, J. E., Meurer, C., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Parent, D., Pelassa, V., Pepe, M., Pesce-Rollins, M., Piron, F., Raino, S., Rando, R., Reimer, A., Reimer, O., Reposeur, T., Rodriguez, A. Y., Roth, M., Sadrozinski, H. F. W., Sander, A., Parkinson, P. M. Saz, Scargle, J. D., Sellerholm, A., Sgro, C., Siskind, E. J., Smith, P. D., Spandre, G., Spinelli, P., Starck, J. L., Strickman, M. S., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. B., Thayer, J. G., Torres, D. F., Uchiyama, Y., Usher, T. L., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Ylinen, T., Zaharijas, G., and Ziegle, M.
Subjects: Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Phenomenology
Abstract: The first published Fermi large area telescope (Fermi-LAT) measurement of the isotropic diffuse gamma-ray emission is in good agreement with a single power law, and is not showing any signature of a dominant contribution from dark matter sources in the energy range from 20 to 100 GeV. We use the absolute size and spectral shape of this measured flux to derive cross section limits on three types of generic dark matter candidates: annihilating into quarks, charged leptons and monochromatic photons. Predicted gamma-ray fluxes from annihilating dark matter are strongly affected by the underlying distribution of dark matter, and by using different available results of matter structure formation we assess these uncertainties. We also quantify how the dark matter constraints depend on the assumed conventional backgrounds and on the Universe's transparency to high-energy gamma-rays. In reasonable background and dark matter structure scenarios (but not in all scenarios we consider) it is possible to exclude models proposed to explain the excess of electrons and positrons measured by the Fermi-LAT and PAMELA experiments. Derived limits also start to probe cross sections expected from thermally produced relics (e.g. in minimal supersymmetry models) annihilating predominantly into quarks. For the monochromatic gamma-ray signature, the current measurement constrains only dark matter scenarios with very strong signals., Comment: 29 pages, 7 figures, to be published in JCAP. Corresponding authors: Jan Conrad, Michael Gustafsson, Alexander Sellerholm, Gabrijela Zaharijas
Published: 2010
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39. Fermi LAT Search for Photon Lines from 30 to 200 GeV and Dark Matter Implications

Author: The Fermi LAT Collaboration, Abdo, A. A., Ackermann, M., Ajello, M., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Bloom, E. D., Bonamente, E., Borgland, A. W., Bouvier, A., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Burnett, T. H., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Carrigan, S., Casandjian, J. M., Cecchi, C., Elik, O. C., Chekhtman, A., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Dermer, C. D., de Angelis, A., de Palma, F., Digel, S. W., Silva, E. do Couto e, Drell, P. S., Drlica-Wagner, A., Dubois, R., Dumora, D., Edmonds, Y., Essig, R., Farnier, C., Favuzzi, C., Fegan, S. J., Focke, W. B., Fortin, P., Frailis, M., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giordano, F., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guillemot, L., Guiriec, S., Gustafsson, M., Hadasch, D., Harding, A. K., Horan, D., Hughes, R. E., Jackson, M. S., ohannesson, G. J ., Johnson, A. S., Johnson, R. P., Johnson, W. N., Kamae, T., Katagiri, H., Kataoka, J., Kawai, N., Kerr, M., dlseder, J. Kno ., Kuss, M., Lande, J., Latronico, L., Garde, M. Llena, Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Makeev, A., Mazziotta, M. N., McEnery, J. E., Meurer, C., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pelassa, V., Pepe, M., Pesce-Rollins, M., Piron, F., Rainó, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reposeur, T., Ripken, J., Ritz, S., Rodriguez, A. Y., Roth, M., Sadrozinski, H. F. -W., Sander, A., Parkinson, P. M. Saz, Scargle, J. D., Schalk, T. L., Sellerholm, A., Sgró, C., Siskind, E. J., Smith, D. A., Smith, P. D., Spandre, G., Spinelli, P., Starck, J. -L., Strickman, M. S., Suson, D. J., Tajima, H., Takahashi, H., Tanaka, T., Thayer, J. B., Thayer, J. G., Tibaldo, L., Torres, D. F., Uchiyama, Y., Usher, T. L., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Ylinen, T., and Ziegler, M.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Extragalactic Astrophysics, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: Dark matter (DM) particle annihilation or decay can produce monochromatic $\gamma$-rays readily distinguishable from astrophysical sources. $\gamma$-ray line limits from 30 GeV to 200 GeV obtained from 11 months of Fermi Large Area Space Telescope data from 20-300 GeV are presented using a selection based on requirements for a $\gamma$-ray line analysis, and integrated over most of the sky. We obtain $\gamma$-ray line flux upper limits in the range $0.6-4.5\times 10^{-9}\mathrm{cm}^{-2}\mathrm{s}^{-1}$, and give corresponding DM annihilation cross-section and decay lifetime limits. Theoretical implications are briefly discussed., Comment: 6 pages, 1 figure. Accepted for publication by The Physical Review Letters
Published: 2010
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40. Observations of Milky Way Dwarf Spheroidal galaxies with the Fermi-LAT detector and constraints on Dark Matter models

Author: Collaboration, Fermi-LAT, Abdo, A. A., Ackermann, M., Ajello, M., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Bloom, E. D., Bonamente, E., Borgland, A. W., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Burnett, T. H., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., de Angelis, A., de Palma, F., Digel, S. W., Silva, E. do Couto e, Drell, P. S., Drlica-Wagner, A., Dubois, R., Dumora, D., Farnier, C., Favuzzi, C., Fegan, S. J., Focke, W. B., Fortin, P., Frailis, M., Fukazawa, Y., Fusco, P., Gargano, F., Gehrels, N., Germani, S., Giebels, B., Giglietto, N., Giordano, F., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guillemot, L., Guiriec, S., Gustafsson, M., Harding, A. K., Hays, E., Horan, D., Hughes, R. E., Jackson, M. S., Jeltema, T. E., Johannesson, G., Johnson, A. S., Johnson, R. P., Johnson, W. N., Kamae, T., Katagiri, H., Kataoka, J., Kerr, M., Knodlseder, J., Kuss, M., Lande, J., Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Makeev, A., Mazziotta, M. N., McEnery, J. E., Meurer, C., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Moretti, E., Morselli, A., Moskalenko, I. V., Murgia, S., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Parent, D., Pelassa, V., Pepe, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Profumo, S., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Rodriguez, A. Y., Roth, M., Sadrozinski, H. F. -W., Sander, A., Parkinson, P. M. Saz, Scargle, J. D., Schalk, T. L., Sellerholm, A., Sgro, C., Siskind, E. J., Smith, D. A., Smith, P. D., Spandre, G., Spinelli, P., Strickman, M. S., Suson, D. J., Takahashi, H., Takahashi, T., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Tibaldo, L., Torres, D. F., Tramacere, A., Uchiyama, Y., Usher, T. L., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Ylinen, T., Ziegler, M., Bullock, James S., Kaplinghat, Manoj, and Martinez, Gregory D.
Subjects: Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Phenomenology
Abstract: We report on the observations of 14 dwarf spheroidal galaxies with the Fermi Gamma-Ray Space Telescope taken during the first 11 months of survey mode operations. The Fermi telescope provides a new opportunity to test particle dark matter models through the expected gamma-ray emission produced by pair annihilation of weakly interacting massive particles (WIMPs). Local Group dwarf spheroidal galaxies, the largest galactic substructures predicted by the cold dark matter scenario, are attractive targets for such indirect searches for dark matter because they are nearby and among the most extreme dark matter dominated environments. No significant gamma-ray emission was detected above 100 MeV from the candidate dwarf galaxies. We determine upper limits to the gamma-ray flux assuming both power-law spectra and representative spectra from WIMP annihilation. The resulting integral flux above 100 MeV is constrained to be at a level below around 10^-9 photons cm^-2 s^-1. Using recent stellar kinematic data, the gamma-ray flux limits are combined with improved determinations of the dark matter density profile in 8 of the 14 candidate dwarfs to place limits on the pair annihilation cross-section of WIMPs in several widely studied extensions of the standard model. With the present data, we are able to rule out large parts of the parameter space where the thermal relic density is below the observed cosmological dark matter density and WIMPs (neutralinos here) are dominantly produced non-thermally, e.g. in models where supersymmetry breaking occurs via anomaly mediation. The gamma-ray limits presented here also constrain some WIMP models proposed to explain the Fermi and PAMELA e^+e^- data, including low-mass wino-like neutralinos and models with TeV masses pair-annihilating into muon-antimuon pairs. (Abridged), Comment: 25 pages, 4 figures, accepted to ApJ, Corresponding authors: J. Cohen-Tanugi, C. Farnier, T.E. Jeltema, E. Nuss, and S. Profumo
Published: 2010
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41. Comparisons of the MINOS Near and Far Detector Readout Systems at a Test Beam

Author: Cabrera, A., Adamson, P., Barker, M., Belias, A., Boyd, S., Crone, G., Drake, G., Falk, E., Harris, P. G., Hartnell, J., Jenner, L., Kordosky, M., Lang, K., Litchfield, R. P., Michael, D., Miyagawa, P. S., Morse, R., Murgia, S., Nichol, R., Nicholls, T., Pearce, G. F., Petyt, D., Reyna, D., Saakyan, R., Shanahan, P., Smith, C., Symes, P., Tagg, N., Thomas, J., Vahle, P., and Weber, A.
Subjects: Physics - Instrumentation and Detectors
Abstract: MINOS is a long baseline neutrino oscillation experiment that uses two detectors separated by 734 km. The readout systems used for the two detectors are different and have to be independently calibrated. To verify and make a direct comparison of the calibrated response of the two readout systems, test beam data were acquired using a smaller calibration detector. This detector was simultaneously instrumented with both readout systems and exposed to the CERN PS T7 test beam. Differences in the calibrated response of the two systems are shown to arise from differences in response non-linearity, photomultiplier crosstalk, and threshold effects at the few percent level. These differences are reproduced by the Monte Carlo (MC) simulation to better than 1% and a scheme that corrects for these differences by calibrating the MC to match the data in each detector separately is presented. The overall difference in calorimetric response between the two readout systems is shown to be consistent with zero to a precision of 1.3% in data and 0.3% in MC with no significant energy dependence., Comment: 25 pages, 8 figures
Published: 2009
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42. SEARCH FOR COSMIC-RAY-INDUCED GAMMA-RAY EMISSION IN GALAXY CLUSTERS

Author: Ackermann, M, Ajello, M, Albert, A, Allafort, A, Atwood, WB, Baldini, L, Ballet, J, Barbiellini, G, Bastieri, D, Bechtol, K, Bellazzini, R, Bloom, ED, Bonamente, E, Bottacini, E, Brandt, TJ, Bregeon, J, Brigida, M, Bruel, P, Buehler, R, Buson, S, Caliandro, GA, Cameron, RA, Caraveo, PA, Cavazzuti, E, Chaves, RCG, Chiang, J, Chiaro, G, Ciprini, S, Claus, R, Cohen-Tanugi, J, Conrad, J, D'Ammando, F, de Angelis, A, de Palma, F, Dermer, CD, Digel, SW, Drell, PS, Drlica-Wagner, A, Favuzzi, C, Franckowiak, A, Funk, S, Fusco, P, Gargano, F, Gasparrini, D, Germani, S, Giglietto, N, Giordano, F, Giroletti, M, Godfrey, G, Gomez-Vargas, GA, Grenier, IA, Guiriec, S, Gustafsson, M, Hadasch, D, Hayashida, M, Hewitt, J, Hughes, RE, Jeltema, TE, Jóhannesson, G, Johnson, AS, Kamae, T, Kataoka, J, Knödlseder, J, Kuss, M, Lande, J, Larsson, S, Latronico, L, Garde, M Llena, Longo, F, Loparco, F, Lovellette, MN, Lubrano, P, Mayer, M, Mazziotta, MN, McEnery, JE, Michelson, PF, Mitthumsiri, W, Mizuno, T, Monzani, ME, Morselli, A, Moskalenko, IV, Murgia, S, Nemmen, R, Nuss, E, Ohsugi, T, Orienti, M, Orlando, E, Ormes, JF, Perkins, JS, Pesce-Rollins, M, Piron, F, Pivato, G, Rainò, S, Rando, R, Razzano, M, Razzaque, S, Reimer, A, Reimer, O, Ruan, J, and Sánchez-Conde, M
Subjects: galaxies: clusters: intracluster medium, gamma rays: galaxies: clusters, astro-ph.HE, astro-ph.CO, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics
Abstract: Current theories predict relativistic hadronic particle populations in clusters of galaxies in addition to the already observed relativistic leptons. In these scenarios hadronic interactions give rise to neutral pions which decay into γ rays that are potentially observable with the Large Area Telescope (LAT) on board the Fermi space telescope. We present a joint likelihood analysis searching for spatially extended γ-ray emission at the locations of 50 galaxy clusters in four years of Fermi-LAT data under the assumption of the universal cosmic-ray (CR) model proposed by Pinzke & Pfrommer. We find an excess at a significance of 2.7σ, which upon closer inspection, however, is correlated to individual excess emission toward three galaxy clusters: A400, A1367, and A3112. We discuss these cases in detail and conservatively attribute the emission to unmodeled background systems (for example, radio galaxies within the clusters).Through the combined analysis of 50 clusters, we exclude hadronic injection efficiencies in simple hadronic models above 21% and establish limits on the CR to thermal pressure ratio within the virial radius, R 200, to be below 1.25%-1.4% depending on the morphological classification. In addition, we derive new limits on the γ-ray flux from individual clusters in our sample. © 2014. The American Astronomical Society. All rights reserved.
Published: 2014

43. MULTIFREQUENCY STUDIES OF THE PECULIAR QUASAR 4C +21.35 DURING THE 2010 FLARING ACTIVITY

Author: Ackermann, M, Ajello, M, Allafort, A, Antolini, E, Barbiellini, G, Bastieri, D, Bellazzini, R, Bissaldi, E, Bonamente, E, Bregeon, J, Brigida, M, Bruel, P, Buehler, R, Buson, S, Caliandro, GA, Cameron, RA, Caraveo, PA, Cavazzuti, E, Cecchi, C, Chaves, RCG, Chekhtman, A, Chiang, J, Chiaro, G, Ciprini, S, Claus, R, Cohen-Tanugi, J, Conrad, J, Cutini, S, D'Ammando, F, de Palma, F, Dermer, CD, do Couto e Silva, E, Donato, D, Drell, PS, Favuzzi, C, Finke, J, Focke, WB, Franckowiak, A, Fukazawa, Y, Fusco, P, Gargano, F, Gasparrini, D, Gehrels, N, Giglietto, N, Giordano, F, Giroletti, M, Godfrey, G, Grenier, IA, Guiriec, S, Hayashida, M, Hewitt, JW, Horan, D, Hughes, RE, Iafrate, G, Johnson, AS, Knödlseder, J, Kuss, M, Lande, J, Larsson, S, Latronico, L, Longo, F, Loparco, F, Lovellette, MN, Lubrano, P, Mayer, M, Mazziotta, MN, McEnery, JE, Michelson, PF, Mizuno, T, Monzani, ME, Morselli, A, Moskalenko, IV, Murgia, S, Nemmen, R, Nuss, E, Ohsugi, T, Orienti, M, Orlando, E, Perkins, JS, Pesce-Rollins, M, Piron, F, Pivato, G, Porter, TA, Rainò, S, Razzano, M, Reimer, A, Reimer, O, Sanchez, DA, Schulz, A, Sgrò, C, Siskind, EJ, Spandre, G, Spinelli, P, Stawarz, Ł, Takahashi, H, Takahashi, T, Thayer, JG, Thayer, JB, Thompson, DJ, and Tinivella, M
Subjects: galaxies: active, gamma rays: general, quasars: general, quasars: individual, radiation mechanisms: non-thermal, astro-ph.HE, astro-ph.CO, astro-ph.GA, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics
Abstract: The discovery of rapidly variable Very High Energy (VHE; E > 100 GeV) γ -ray emission from 4C +21.35 (PKS 1222+216) by MAGIC on 2010 June 17, triggered by the high activity detected by the Fermi Large Area Telescope (LAT) in high energy (HE;E >100 MeV) γ -rays, poses intriguing questions on the location of the γ -ray emitting region in this flat spectrum radio quasar. We present multifrequency data of 4C +21.35 collected from centimeter to VHE during 2010 to investigate the properties of this source and discuss a possible emission model. The first hint of detection at VHE was observed by MAGIC on 2010 May 3, soon after a γ -ray flare detected by Fermi-LAT that peaked on April 29. The same emission mechanism may therefore be responsible for both the HE and VHE emission during the 2010 flaring episodes. Two optical peaks were detected on 2010 April 20 and June 30, close in time but not simultaneous with the two γ -ray peaks, while no clear connection was observed between the X-ray and γ -ray emission. An increasing flux density was observed in radio and mm bands from the beginning of 2009, in accordance with the increasing γ -ray activity observed by Fermi-LAT, and peaking on 2011 January 27 in the mm regime (230 GHz). We model the spectral energy distributions (SEDs) of 4C +21.35 for the two periods of the VHE detection and a quiescent state, using a one-zone model with the emission coming from a very compact region outside the broad line region. The three SEDs can be fit with a combination of synchrotron self-Compton and external Compton emission of seed photons from a dust torus, changing only the electron distribution parameters between the epochs. The fit of the optical/UV part of the spectrum for 2010 April 29 seems to favor an inner disk radius of
Published: 2014

44. Fermi LARGE AREA TELESCOPE OBSERVATIONS OF BLAZAR 3C 279 OCCULTATIONS BY THE SUN

Author: Barbiellini, G, Bastieri, D, Bechtol, K, Bellazzini, R, Blandford, RD, Borgland, AW, Bregeon, J, Bruel, P, Buehler, R, Buson, S, Caliandro, GA, Cameron, RA, Caraveo, PA, Cavazzuti, E, Cecchi, C, Chaves, RCG, Chekhtman, A, Cheung, CC, Chiang, J, Ciprini, S, Claus, R, Cohen-Tanugi, J, D'Ammando, F, de Angelis, A, Dermer, CD, Digel, SW, do Couto e Silva, E, Drell, PS, Drlica-Wagner, A, Favuzzi, C, Focke, WB, Franckowiak, A, Fukazawa, Y, Fusco, P, Gargano, F, Gasparrini, D, Germani, S, Giglietto, N, Giommi, P, Giordano, F, Giroletti, M, Glanzman, T, Godfrey, G, Grenier, IA, Grove, JE, Guiriec, S, Hadasch, D, Hayashida, M, Hays, E, Hughes, RE, Jackson, MS, Jogler, T, Knödlseder, J, Kuss, M, Lande, J, Larsson, S, Longo, F, Loparco, F, Lovellette, MN, Lubrano, P, Mazziotta, MN, Mehault, J, Michelson, PF, Mizuno, T, Moiseev, AA, Monte, C, Monzani, ME, Morselli, A, Moskalenko, IV, Murgia, S, Nemmen, R, Nuss, E, Ohsugi, T, Omodei, N, Orienti, M, Orlando, E, Paneque, D, Perkins, JS, Piron, F, Pivato, G, Prokhorov, D, Rainò, S, Razzano, M, Razzaque, S, Reimer, A, Reimer, O, Ritz, S, Romoli, C, Sánchez-Conde, M, Sanchez, DA, Sgrò, C, Siskind, EJ, Spandre, G, Spinelli, P, Takahashi, H, Tanaka, T, Tibaldo, L, Tinivella, M, Tosti, G, and Troja, E
Subjects: astroparticle physics, gamma rays: general, occultations, quasars: individual, Sun: X-rays, gamma rays, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics
Abstract: Observations of occultations of bright γ-ray sources by the Sun may reveal predicted pair halos around blazars and/or new physics, such as, e.g., hypothetical light dark matter particles-axions. We use Fermi Gamma-Ray Space Telescope (Fermi) data to analyze four occultations of blazar 3C 279 by the Sun on October 8 each year from 2008 to 2011. A combined analysis of the observations of these occultations allows a point-like source at the position of 3C 279 to be detected with significance of ≈3σ, but does not reveal any significant excess over the flux expected from the quiescent Sun. The likelihood ratio test rules out complete transparency of the Sun to the blazar γ-ray emission at a 3σ confidence level.
Published: 2014

45. Dark matter constraints from observations of 25 Milky Way satellite galaxies with the Fermi Large Area Telescope

Author: Ackermann, M, Albert, A, Anderson, B, Baldini, L, Ballet, J, Barbiellini, G, Bastieri, D, Bechtol, K, Bellazzini, R, Bissaldi, E, Bloom, ED, Bonamente, E, Bouvier, A, Brandt, TJ, Bregeon, J, Brigida, M, Bruel, P, Buehler, R, Buson, S, Caliandro, GA, Cameron, RA, Caragiulo, M, Caraveo, PA, Cecchi, C, Charles, E, Chekhtman, A, Chiang, J, Ciprini, S, Claus, R, Cohen-Tanugi, J, Conrad, J, D’Ammando, F, de Angelis, A, Dermer, CD, Digel, SW, do Couto e Silva, E, Drell, PS, Drlica-Wagner, A, Essig, R, Favuzzi, C, Ferrara, EC, Franckowiak, A, Fukazawa, Y, Funk, S, Fusco, P, Gargano, F, Gasparrini, D, Giglietto, N, Giroletti, M, Godfrey, G, Gomez-Vargas, GA, Grenier, IA, Guiriec, S, Gustafsson, M, Hayashida, M, Hays, E, Hewitt, J, Hughes, RE, Jogler, T, Kamae, T, Knödlseder, J, Kocevski, D, Kuss, M, Larsson, S, Latronico, L, Garde, M Llena, Longo, F, Loparco, F, Lovellette, MN, Lubrano, P, Martinez, G, Mayer, M, Mazziotta, MN, Michelson, PF, Mitthumsiri, W, Mizuno, T, Moiseev, AA, Monzani, ME, Morselli, A, Moskalenko, IV, Murgia, S, Nemmen, R, Nuss, E, Ohsugi, T, Orlando, E, Ormes, JF, Perkins, JS, Piron, F, Pivato, G, Porter, TA, Rainò, S, Rando, R, Razzano, M, Razzaque, S, Reimer, A, Reimer, O, Ritz, S, Sánchez-Conde, M, Sehgal, N, and Sgrò, C
Subjects: astro-ph.HE, hep-ex, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics
Abstract: The dwarf spheroidal satellite galaxies of the Milky Way are some of the most dark-matter-dominated objects known. Due to their proximity, high dark matter content, and lack of astrophysical backgrounds, dwarf spheroidal galaxies are widely considered to be among the most promising targets for the indirect detection of dark matter via γ rays. Here we report on γ-ray observations of 25 Milky Way dwarf spheroidal satellite galaxies based on 4 years of Fermi Large Area Telescope (LAT) data. None of the dwarf galaxies are significantly detected in γ rays, and we present γ-ray flux upper limits between 500 MeV and 500 GeV. We determine the dark matter content of 18 dwarf spheroidal galaxies from stellar kinematic data and combine LAT observations of 15 dwarf galaxies to constrain the dark matter annihilation cross section. We set some of the tightest constraints to date on the annihilation of dark matter particles with masses between 2 GeV and 10 TeV into prototypical standard model channels. We find these results to be robust against systematic uncertainties in the LAT instrument performance, diffuse γ-ray background modeling, and assumed dark matter density profile. © 2014 American Physical Society.
Published: 2014

46. P002 Adjuvant chemotherapy for resected early-stage triple negative breast cancer

Author: Solinas, C., primary, Bertaglia, V., additional, Parati, M.C., additional, Borgonovo, K., additional, De Silva, P., additional, Pretta, A., additional, Saba, G., additional, Migliari, M., additional, Bardanzellu, F., additional, Murgia, S., additional, D’Agata, A.P., additional, Cadoni, A., additional, Contu, F., additional, Cadeddu, M., additional, Sanna, G., additional, Luciani, A., additional, Novello, S., additional, Scartozzi, M., additional, Emens, L.A., additional, and Petrelli, F., additional
Published: 2023
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47. Development of a Sliding Vane Rotary Pump for Engine Cooling

Author: Cipollone, R., Di Battista, D., Contaldi, G., Murgia, S., and Mauriello, M.
Published: 2015
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48. Fermi-LAT Observations of the Gamma-Ray Burst GRB 130427A

Author: Ackermann, M., Ajello, M., Asano, K., Atwood, W. B., Axelsson, M., Baldini, L., Ballet, J., Barbiellini, G., Baring, M. G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Bonamente, E., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burgess, J. Michael, Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Chaplin, V., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cleveland, W., Cohen-Tanugi, J., Collazzi, A., Cominsky, L. R., Connaughton, V., Conrad, J., Cutini, S., D'Ammando, F., de Angelis, A., DeKlotz, M., de Palma, F., Dermer, C. D., Desiante, R., Diekmann, A., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Finke, J., Fitzpatrick, G., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gehrels, N., Germani, S., Gibby, M., Giglietto, N., Giles, M., Giordano, F., Giroletti, M., Godfrey, G., Granot, J., Grenier, I. A., Grove, J. E., Gruber, D., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Horan, D., Hughes, R. E., Inoue, Y., Jogler, T., Jóhannesson, G., Johnson, W. N., Kawano, T., Knödlseder, J., Kocevski, D., Kuss, M., Lande, J., Larsson, S., Latronico, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monzani, M. E., Moretti, E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Orienti, M., Paneque, D., Pelassa, V., Perkins, J. S., Pesoe-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Racusin, J. L, Rainò, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ritz, S., Roth, M., Ryde, F., Sartori, A., Parkinson, P. M. Saz, Scargle, J. D., Schulz, A., Sgrò, C., Siskind, E. J., Sonbas, E., Spandre, G., Spinelli, P., Tajima, H., Takahashi, H., Thayer, J. G., Thayer, J. A., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Winer, B. L., Wood, K. S., Yamazaki, R., Younes, G., Yu, H.-F., Zhu, S. J., Bhat, P. N., Briggs, M. S., Byrne, D., Foley, S., Goldstein, A., Jenke, P., Kippen, R. M., Kouveliotou, C., McBreen, S., Meegan, C., Paciesas, W. S., Preece, R., Rau, A., Tierney, D., van der Horst, A. J., von Kienlin, A., Wilson-Hodge, C., Xiong, S., Cusumano, G., La Parola, V., and Cummings, J. R.
Published: 2014
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49. Successful Secukinumab treatment of generalized pustular psoriasis and erythrodermic psoriasis

Author: Mugheddu, C., Atzori, L., Lappi, A., Pau, M., Murgia, S., and Rongioletti, F.
Published: 2017
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50. Experimental investigation and CFD numerical simulation of WGSR for hydrogen enrichment of high CO2 content syngas from an air-blown updraft coal gasifier

Author: Murgia, S., Cau, G., and Mura, G.
Published: 2012
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