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Your search keyword '"Gonzalez, L. P."' showing total 12 results
Start Over Author "Gonzalez, L. P." Topic astrophysics - high energy astrophysical phenomena
12 results on '"Gonzalez, L. P."'

1. Magnetized vector boson gas at any temperature

Author

Angulo, G. Quintero, González, L. C. Suárez, Martínez, A. Pérez, and Rojas, H. Pérez

Subjects
High Energy Physics - Phenomenology, Astrophysics - High Energy Astrophysical Phenomena, Condensed Matter - Quantum Gases
Abstract

We study the thermodynamic properties of a relativistic magnetized neutral vector boson gas at any temperature. By comparing the results with the low temperature and the non relativistic descriptions of this gas, we found that the fully relativistic case can be separated in two regimes according to temperature. For low temperatures, magnetic field effects dominate and the system shows a spontaneous magnetization, its pressure splits in two components and, eventually, a transversal magnetic collapse might occur. In the high temperature region, the gas behavior is led by pair production. The presence of antiparticles preserves the isotropy in the pressure, and increases the magnetization and the total pressure of the system by several orders. Astrophysical implications of those behaviors are discussed., Comment: 26 pages, 7 figures

Published
2020
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2. Luminous Type II supernovae for their low expansion velocities

Author

Rodríguez, Ó., Pignata, G., Anderson, J. P., Moriya, T. J., Clocchiatti, A., Förster, F., Prieto, J. L., Phillips, M. M., Burns, C. R., Contreras, C., Folatelli, G., Gutiérrez, C. P., Hamuy, M., Morrell, N. I., Stritzinger, M. D., Suntzeff, N. B., Benetti, S., Cappellaro, E., Elias-Rosa, N., Pastorello, A., Turatto, M., Maza, J., Antezana, R., Cartier, R., González, L., Haislip, J. B., Kouprianov, V., López, P., Marchi-Lasch, S., and Reichart, D.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We present optical and near-IR data of three Type II supernovae (SNe II), SN 2008bm, SN 2009aj, and SN 2009au. These SNe display the following common characteristics: signs of early interaction of the ejecta with circumstellar material (CSM), blue $B\!-\!V$ colours, weakness of metal lines, low expansion velocities, and $V$-band absolute magnitudes 2-3 mag brighter than those expected for normal SNe II based on their expansion velocities. Two more SNe reported in the literature (SN 1983K and LSQ13fn) share properties similar to our sample. Analysing this set of five SNe II, which are luminous for their low expansion velocities (LLEV), we find that their properties can be reproduced assuming ejecta-CSM interaction that lasts between 4-11 weeks post explosion. The contribution of this interaction to the radiation field seems to be the dominant component determining the observed weakness of metal lines in the spectra rather than the progenitor metallicity. Based on hydrodynamic simulations, we find that the interaction of the ejecta with a CSM of ~3.6 M$_\odot$ can reproduce the light curves and expansion velocities of SN 2009aj. Using data collected by the Chilean Automatic Supernova Search, we estimate an upper limit for the LLEV SNe II fraction to be 2-4 per cent of all normal SNe II. With the current data-set, it is not clear whether the LLEV events are a separated class of SNe II with a different progenitor system, or whether they are the extreme of a continuum mediated by CSM interaction with the rest of the normal SN II population., Comment: 20 pages, 15 figures, Accepted for publication to MNRAS

Published
2019
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3. Analysis of solar gamma rays and solar neutrons detected on March 7th and September 25th of 2011 by Ground Level Neutron Telescopes, SEDA-FIB and FERMI-LAT

Author

Muraki, Y., Valdes-Galicia, J. F., Gonzalez, L. X., Kamiya, K., Katayose, Y., Koga, K., Matsumoto, H., Masuda, S., Matsubara, Y., Nagai, Y., Ohnishi, M., Ozawa, S., Sako, T., Shibata, S., Takita, M., Tanaka, Y., Tsuchiya, H., Watanabe, K., and Zhang, J. L.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

At the 33rd ICRC, we reported the possible detection of solar gamma rays by a ground level detector and later re-examined this event. On March 7, 2011, the solar neutron telescope (SNT) located at Mt. Sierra Negra, Mexico (4,600 m) observed enhancements of the counting rate from 19:49 to 20:02 UT and from 20:50 to 21:01 UT. The statistical significance was 9.7sigma and 8.5sigma, respectively. This paper discusses the possibility of using this mountain detector to detect solar gamma rays. In association with this event, the solar neutron detector SEDA-FIB onboard the International Space Station has also detected solar neutrons with a statistical significance of 7.5sigma. The FERMI-LAT detector also observed high-energy gamma rays from this flare with a statistical significance of 6.7sigma. We thus attempted to make a unified model to explain this data. In this paper, we report on another candidate for solar gamma rays detected on September 25th, 2011 by the SNT located in Tibet (4,300 m) from 04:37 to 04:47 UT with a statistical significance of 8.0sigma (by the Li-Ma method)., Comment: 15 pages

Published
2017

4. Space Telescope and Optical Reverberation Mapping Project VI: reverberating Disk Models for NGC 5548

Author

Starkey, D., Horne, Keith, Fausnaugh, M. M., Peterson, B. M., Bentz, M. C., Kochanek, C. S., Denney, K. D., Edelson, R., Goad, M. R., De Rosa, G., Anderson, M. D., Arevalo, P., Barth, A. J., Bazhaw, C., Borman, G. A., Boroson, T. A., Bottorff, M. C., Brandt, W. N., Breeveld, A. A., Cackett, E. M., Carini, M. T., Croxall, K. V., Crenshaw, D. M., Bonta, E. Dalla, De Lorenzo-Caceres, A., Dietrich, M., Efimova, N. V., Ely, J., Evans, P. A., Filippenko, A. V., Flatland, K., Gehrels, N., Geier, S., Gelbord, J. M., Gonzalez, L., Gorjian, V., Grier, C. J., Grupe, D., Hall, P. B., Hicks, S., Horenstein, D., Hutchison, T., Im, M., Jensen, J. J., Joner, M. D., Jones, J., Kaastra, J., Kaspi, S., Kelly, B. C., Kennea, J. A., Kim, S. C., Kim, M., Klimanov, S. A., Korista, K. T., Kriss, G. A., Lee, J. C., Leonard, D. C., Lira, P., MacInnis, F., Manne-Nicholas, E. R., Mathur, S., McHardy, I. M., Montouri, C., Musso, R., Nazarov, S. V., Norris, R. P., Nousek, J. A., Okhmat, D. N., Pancoast, A., Parks, J. R., Pei, L., Pogge, R. W., Pott, J. -U., Rafter, S. E., Rix, H. W., Saylor, D. A., Schimoia, J. S., Schnulle, K., Sergeev, S. G., Siegel, M. H., Spencer, M., Sung, H. -I., Teems, K. G., Turner, C. S., Uttley, P., Vestergaard, M., Villforth, C., Weiss, Y., Woo, J. -H., Yan, H., Young, S., Zheng, W., and Zu, Y.

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - High Energy Astrophysical Phenomena
Abstract

We conduct a multiwavelength continuum variability study of the Seyfert 1 galaxy NGC 5548 to investigate the temperature structure of its accretion disk. The 19 overlapping continuum light curves (1158 to 9157 angstroms) combine simultaneous HST , Swift , and ground-based observations over a 180 day period from 2014 January to July. Light-curve variability is interpreted as the reverberation response of the accretion disk to irradiation by a central time-varying point source. Our model yields the disk inclination, i, temperature T1 at 1 light day from the black hole, and a temperature-radius slope, alpha. We also infer the driving light curve and find that it correlates poorly with both the hard and soft X-ray light curves, suggesting that the X-rays alone may not drive the ultraviolet and optical variability over the observing period. We also decompose the light curves into bright, faint, and mean accretion-disk spectra. These spectra lie below that expected for a standard blackbody accretion disk accreting at L/LEdd = 0.1, Comment: V2: Oops wrong title! V1: Accepted for publication in ApJ, 20 Pages, 11 Figures

Published
2016
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5. The HAWC Gamma-Ray Observatory: Observations of Cosmic Rays

Author

HAWC Collaboration, Abeysekara, A. U., Alfaro, R., Alvarez, C., Álvarez, J. D., Arceo, R., Arteaga-Velázquez, J. C., Solares, H. A. Ayala, Barber, A. S., Baughman, B. M., Bautista-Elivar, N., Belmont, E., BenZvi, S. Y., Berley, D., Rosales, M. Bonilla, Braun, J., Caballero-Lopez, R. A., Caballero-Mora, K. S., Carramiñana, A., Castillo, M., Cotti, U., Cotzomi, J., de la Fuente, E., De León, C., DeYoung, T., Hernandez, R. Diaz, Díaz-Vélez, J. C., Dingus, B. L., DuVernois, M. A., Ellsworth, R. W., Fernandez, A., Fiorino, D. W., Fraija, N., Galindo, A., Garfias, F., González, L. X., González, M. M., Goodman, J. A., Grabski, V., Gussert, M., Hampel-Arias, Z., Hui, C. M., Hüntemeyer, P., Imran, A., Iriarte, A., Karn, P., Kieda, D., Kunde, G. J., Lara, A., Lauer, R. J., Lee, W. H., Lennarz, D., Vargas, H. León, Linares, E. C., Linnemann, J. T., Longo, M., Luna-GarcIa, R., Marinelli, A., Martinez, H., Martinez, O., Martínez-Castro, J., Matthews, J. A. J., Miranda-Romagnoli, P., Moreno, E., Mostafá, M., Nava, J., Nellen, L., Newbold, M., Noriega-Papaqui, R., Oceguera-Becerra, T., Patricelli, B., Pelayo, R., Pérez-Pérez, E. G., Pretz, J., Rivière, C., Rosa-González, D., Salazar, H., Salesa, F., Sanchez, F. E., Sandoval, A., Santos, E., Schneider, M., Silich, S., Sinnis, G., Smith, A. J., Sparks, K., Springer, R. W., Taboada, I., Toale, P. A., Tollefson, K., Torres, I., Ukwatta, T. N., Villaseñor, L., Weisgarber, T., Westerhoff, S., Wisher, I. G., Wood, J., Yodh, G. B., Younk, P. W., Zaborov, D., Zepeda, A., and Zhou, H.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We describe measurements of GeV and TeV cosmic rays with the High-Altitude Water Cherenkov Gamma-Ray Observatory, or HAWC. The measurements include the observation of the shadow of the moon; the observation of small-scale and large-scale angular clustering of the TeV cosmic rays; the prospects for measurement of transient solar events with HAWC; and the observation of Forbush decreases with the HAWC engineering array and HAWC-30., Comment: Contributions to the 33rd International Cosmic Ray Conference, Rio de Janeiro, Brazil, July 2013

Published
2013

6. The HAWC Gamma-Ray Observatory: Dark Matter, Cosmology, and Fundamental Physics

Author

HAWC Collaboration, Abeysekara, A. U., Alfaro, R., Alvarez, C., Álvarez, J. D., Arceo, R., Arteaga-Velázquez, J. C., Solares, H. A. Ayala, Barber, A. S., Baughman, B. M., Bautista-Elivar, N., Belmont, E., BenZvi, S. Y., Berley, D., Rosales, M. Bonilla, Braun, J., Caballero-Lopez, R. A., Caballero-Mora, K. S., Carramiñana, A., Castillo, M., Cotti, U., Cotzomi, J., de la Fuente, E., De León, C., DeYoung, T., Hernandez, R. Diaz, Díaz-Vélez, J. C., Dingus, B. L., DuVernois, M. A., Ellsworth, R. W., Fernandez, A., Fiorino, D. W., Fraija, N., Galindo, A., Garfias, F., González, L. X., González, M. M., Goodman, J. A., Grabski, V., Gussert, M., Hampel-Arias, Z., Hui, C. M., Hüntemeyer, P., Imran, A., Iriarte, A., Karn, P., Kieda, D., Kunde, G. J., Lara, A., Lauer, R. J., Lee, W. H., Lennarz, D., Vargas, H. León, Linares, E. C., Linnemann, J. T., Longo, M., Luna-GarcIa, R., Marinelli, A., Martinez, H., Martinez, O., Martínez-Castro, J., Matthews, J. A. J., Miranda-Romagnoli, P., Moreno, E., Mostafá, M., Nava, J., Nellen, L., Newbold, M., Noriega-Papaqui, R., Oceguera-Becerra, T., Patricelli, B., Pelayo, R., Pérez-Pérez, E. G., Pretz, J., Rivière, C., Rosa-González, D., Salazar, H., Salesa, F., Sanchez, F. E., Sandoval, A., Santos, E., Schneider, M., Silich, S., Sinnis, G., Smith, A. J., Sparks, K., Springer, R. W., Taboada, I., Toale, P. A., Tollefson, K., Torres, I., Ukwatta, T. N., Villaseñor, L., Weisgarber, T., Westerhoff, S., Wisher, I. G., Wood, J., Yodh, G. B., Younk, P. W., Zaborov, D., Zepeda, A., and Zhou, H.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The High-Altitude Water Cherenkov Gamma Ray Observatory (HAWC) is designed to perform a synoptic survey of the TeV sky. The high energy coverage of the experiment will enable studies of fundamental physics beyond the Standard Model, and the large field of view of the detector will enable detailed studies of cosmologically significant backgrounds and magnetic fields. We describe the sensitivity of the full HAWC array to these phenomena in five contributions shown at the 33rd International Cosmic Ray Conference in Rio de Janeiro, Brazil (July 2013)., Comment: Contributions to the 33rd International Cosmic Ray Conference, Rio de Janeiro, Brazil, July 2013

Published
2013

7. The HAWC Gamma-Ray Observatory: Design, Calibration, and Operation

Author

HAWC Collaboration, Abeysekara, A. U., Alfaro, R., Alvarez, C., Álvarez, J. D., Arceo, R., Arteaga-Velázquez, J. C., Solares, H. A. Ayala, Barber, A. S., Baughman, B. M., Bautista-Elivar, N., Belmont, E., BenZvi, S. Y., Berley, D., Rosales, M. Bonilla, Braun, J., Caballero-Lopez, R. A., Caballero-Mora, K. S., Carramiñana, A., Castillo, M., Cotti, U., Cotzomi, J., de la Fuente, E., De León, C., DeYoung, T., Hernandez, R. Diaz, Díaz-Vélez, J. C., Dingus, B. L., DuVernois, M. A., Ellsworth, R. W., Fernandez, A., Fiorino, D. W., Fraija, N., Galindo, A., Garfias, F., González, L. X., González, M. M., Goodman, J. A., Grabski, V., Gussert, M., Hampel-Arias, Z., Hui, C. M., Hüntemeyer, P., Imran, A., Iriarte, A., Karn, P., Kieda, D., Kunde, G. J., Lara, A., Lauer, R. J., Lee, W. H., Lennarz, D., Vargas, H. León, Linares, E. C., Linnemann, J. T., Longo, M., Luna-GarcIa, R., Marinelli, A., Martinez, H., Martinez, O., Martínez-Castro, J., Matthews, J. A. J., Miranda-Romagnoli, P., Moreno, E., Mostafá, M., Nava, J., Nellen, L., Newbold, M., Noriega-Papaqui, R., Oceguera-Becerra, T., Patricelli, B., Pelayo, R., Pérez-Pérez, E. G., Pretz, J., Rivière, C., Rosa-González, D., Salazar, H., Salesa, F., Sanchez, F. E., Sandoval, A., Santos, E., Schneider, M., Silich, S., Sinnis, G., Smith, A. J., Sparks, K., Springer, R. W., Taboada, I., Toale, P. A., Tollefson, K., Torres, I., Ukwatta, T. N., Villaseñor, L., Weisgarber, T., Westerhoff, S., Wisher, I. G., Wood, J., Yodh, G. B., Younk, P. W., Zaborov, D., Zepeda, A., and Zhou, H.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

The High-Altitude Water Cherenkov Gamma Ray Observatory (HAWC) is under construction 4100 meters above sea level at Sierra Negra, Mexico. We describe the design and cabling of the detector, the characterization of the photomultipliers, and the timing calibration system. We also outline a next-generation detector based on the water Cherenkov technique., Comment: Contributions to the 33rd International Cosmic Ray Conference, Rio de Janeiro, Brazil, July 2013

Published
2013

8. The HAWC Gamma-Ray Observatory: Sensitivity to Steady and Transient Sources of Gamma Rays

Author

HAWC Collaboration, Abeysekara, A. U., Alfaro, R., Alvarez, C., Álvarez, J. D., Arceo, R., Arteaga-Velázquez, J. C., Solares, H. A. Ayala, Barber, A. S., Baughman, B. M., Bautista-Elivar, N., Belmont, E., BenZvi, S. Y., Berley, D., Rosales, M. Bonilla, Braun, J., Caballero-Lopez, R. A., Caballero-Mora, K. S., Carramiñana, A., Castillo, M., Cotti, U., Cotzomi, J., de la Fuente, E., De León, C., DeYoung, T., Hernandez, R. Diaz, Díaz-Vélez, J. C., Dingus, B. L., DuVernois, M. A., Ellsworth, R. W., Fernandez, A., Fiorino, D. W., Fraija, N., Galindo, A., Garfias, F., González, L. X., González, M. M., Goodman, J. A., Grabski, V., Gussert, M., Hampel-Arias, Z., Hui, C. M., Hüntemeyer, P., Imran, A., Iriarte, A., Karn, P., Kieda, D., Kunde, G. J., Lara, A., Lauer, R. J., Lee, W. H., Lennarz, D., Vargas, H. León, Linares, E. C., Linnemann, J. T., Longo, M., Luna-GarcIa, R., Marinelli, A., Martinez, H., Martinez, O., Martínez-Castro, J., Matthews, J. A. J., Miranda-Romagnoli, P., Moreno, E., Mostafá, M., Nava, J., Nellen, L., Newbold, M., Noriega-Papaqui, R., Oceguera-Becerra, T., Patricelli, B., Pelayo, R., Pérez-Pérez, E. G., Pretz, J., Rivière, C., Rosa-González, D., Salazar, H., Salesa, F., Sanchez, F. E., Sandoval, A., Santos, E., Schneider, M., Silich, S., Sinnis, G., Smith, A. J., Sparks, K., Springer, R. W., Taboada, I., Toale, P. A., Tollefson, K., Torres, I., Ukwatta, T. N., Villaseñor, L., Weisgarber, T., Westerhoff, S., Wisher, I. G., Wood, J., Yodh, G. B., Younk, P. W., Zaborov, D., Zepeda, A., and Zhou, H.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The High-Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory is designed to record air showers produced by cosmic rays and gamma rays between 100 GeV and 100 TeV. Because of its large field of view and high livetime, HAWC is well-suited to measure gamma rays from extended sources, diffuse emission, and transient sources. We describe the sensitivity of HAWC to emission from the extended Cygnus region as well as other types of galactic diffuse emission; searches for flares from gamma-ray bursts and active galactic nuclei; and the first measurement of the Crab Nebula with HAWC-30., Comment: Contributions to the 33rd International Cosmic Ray Conference, Rio de Janeiro, Brazil, July 2013

Published
2013

9. A Possible Detection of Solar Gamma-Rays by the Ground Level Detector

Author

Muraki, Y., Valdes-Galicia, J. F., Gonzalez, L. X., Koga, K., Matsumoto, H., Masuda, S., Matsubara, Y., Nagai, Y., Tanaka, Y., Sakai, T., Sako, T., Shibata, S., and Watanabe, K.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

On March 7, 2011 from 19:48:00 to 20:03:00 UT, the solar neutron telescope located at Mt. Sierra Negra, Mexico (4,600m) observed a 8.8sigma enhancement. In this paper, we would like to try to explain this enhancement by a hypothesis that a few GeV gamma-rays arrived at the top of the mountain produced by the Sun. We postulate that protons were accelerated at the shock front. They precipitate at the solar surface and produced those gamma-rays. If hypothesis is confirmed, this enhancement is the first sample of GeV gamma-rays observed by a ground level detector., Comment: 7 pages, 10 figures

Published
2013

10. Sensitivity of the High Altitude Water Cherenkov Detector to Sources of Multi-TeV Gamma Rays

Author

Abeysekara, A. U., Alfaro, R., Alvarez, C., Álvarez, J. D., Arceo, R., Arteaga-Velázquez, J. C., Solares, H. A. Ayala, Barber, A. S., Baughman, B. M., Bautista-Elivar, N., Belmont, E., BenZvi, S. Y., Berley, D., Rosales, M. Bonilla, Braun, J., Caballero-Lopez, R. A., Carramiñana, A., Castillo, M., Cotti, U., Cotzomi, J., de la Fuente, E., De León, C., DeYoung, T., Hernandez, R. Diaz, Diaz-Velez, J. C., Dingus, B. L., DuVernois, M. A., Ellsworth, R. W., Fernandez, A., Fiorino, D. W., Fraija, N., Galindo, A., Garcia-Luna, J. L., Garcia-Torales, G., Garfias, F., González, L. X., González, M. M., Goodman, J. A., Grabski, V., Gussert, M., Hampel-Arias, Z., Hui, C. M., Hüntemeyer, P., Imran, A., Iriarte, A., Karn, P., Kieda, D., Kunde, G. J., Lara, A., Lauer, R. J., Lee, W. H., Lennarz, D., Vargas, H. León, Linares, E. C., Linnemann, J. T., Longo, M., Luna-García, R., Marinelli, A., Martinez, O., Martínez-Castro, J., Matthews, J. A. J., Miranda-Romagnoli, P., Moreno, E., Mostafá, M., Nava, J., Nellen, L., Newbold, M., Noriega-Papaqui, R., Oceguera-Becerra, T., Patricelli, B., Pelayo, R., Pérez-Pérez, E. G., Pretz, J., Rivière, C., Rosa-González, D., Salazar, H., Salesa, F., Sandoval, A., Santos, E., Schneider, M., Silich, S., Sinnis, G., Smith, A. J., Sparks, K., Springer, R. W., Taboada, I., Toale, P. A., Tollefson, K., Torres, I., Ukwatta, T. N., Villaseñor, L., Weisgarber, T., Westerhoff, S., Wisher, I. G., Wood, J., Yodh, G. B., Younk, P. W., Zaborov, D., Zepeda, A., and Zhou, H.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The High Altitude Water Cherenkov (HAWC) observatory is an array of large water Cherenkov detectors sensitive to gamma rays and hadronic cosmic rays in the energy band between 100 GeV and 100 TeV. The observatory will be used to measure high-energy protons and cosmic rays via detection of the energetic secondary particles reaching the ground when one of these particles interacts in the atmosphere above the detector. HAWC is under construction at a site 4100 meters above sea level on the northern slope of the volcano Sierra Negra, which is located in central Mexico at 19 degrees N latitude. It is scheduled for completion in 2014. In this paper we estimate the sensitivity of the HAWC instrument to point-like and extended sources of gamma rays. The source fluxes are modeled using both unbroken power laws and power laws with exponential cutoffs. HAWC, in one year, is sensitive to point sources with integral power-law spectra as low as 5x10^-13 cm^-2 sec^-1 above 2 TeV (approximately 50 mCrab) over 5 sr of the sky. This is a conservative estimate based on simple event parameters and is expected to improve as the data analysis techniques are refined. We discuss known TeV sources and the scientific contributions that HAWC can make to our understanding of particle acceleration in these sources.

Published
2013
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11. On the sensitivity of the HAWC observatory to gamma-ray bursts

Author

HAWC collaboration, Abeysekara, A. U., Aguilar, J. A., Aguilar, S., Alfaro, R., Almaraz, E., Álvarez, C., Álvarez-Romero, J. de D., Álvarez, M., Arceo, R., Arteaga-Velázquez, J. C., Badillo, C., Barber, A., Baughman, B. M., Bautista-Elivar, N., Belmont, E., Benítez, E., BenZvi, S. Y., Berley, D., Bernal, A., Bonamente, E., Braun, J., Caballero-Lopez, R., Cabrera, I., Carramiñana, A., Carrasco, L., Castillo, M., Chambers, L., Conde, R., Condreay, P., Cotti, U., Cotzomi, J., D'Olivo, J. C., de la Fuente, E., De León, C., Delay, S., Delepine, D., DeYoung, T., Diaz, L., Diaz-Cruz, L., Dingus, B. L., Duvernois, M. A., Edmunds, D., Ellsworth, R. W., Fick, B., Fiorino, D. W., Flandes, A., Fraija, N. I., Galindo, A., García-Luna, J. L., García-Torales, G., Garfias, F., González, L. X., González, M. M., Goodman, J. A., Grabski, V., Gussert, M., Guzmán-Ceron, C., Hampel-Arias, Z., Harris, T., Hays, E., Hernandez-Cervantes, L., Hüntemeyer, P. H., Imran, A., Iriarte, A., Jimenez, J. J., Karn, P., Kelley-Hoskins, N., Kieda, D., Langarica, R., Lara, A., Lauer, R., Lee, W. H., Linares, E. C., Linnemann, J. T., Longo, M., Luna-García, R., Martínez, H., Martínez, J., Martínez, L. A., Martínez, O., Martínez-Castro, J., Martos, M., Matthews, J., McEnery, J. E., Medina-Tanco, G., Mendoza-Torres, J. E., Miranda-Romagnoli, P. A., Montaruli, T., Moreno, E., Mostafa, M., Napsuciale, M., Nava, J., Nellen, L., Newbold, M., Noriega-Papaqui, R., Oceguera-Becerra, T., Tapia, A. Olmos, Orozco, V., Pérez, V., Pérez-Pérez, E. G., Perkins, J. S., Pretz, J., Ramirez, C., Ramírez, I., Rebello, D., Rentería, A., Reyes, J., Rosa-González, D., Rosado, A., Ryan, J. M., Sacahui, J. R., Salazar, H., Salesa, F., Sandoval, A., Santos, E., Schneider, M., Shoup, A., Silich, S., Sinnis, G., Smith, A. J., Sparks, K., Springer, W., Suárez, F., Suarez, N., Taboada, I., Tellez, A. F., Tenorio-Tagle, G., Tepe, A., Toale, P. A., Tollefson, K., Torres, I., Ukwatta, T. N., Valdes-Galicia, J., Vanegas, P., Vasileiou, V., Vázquez, O., Vázquez, X., Villaseñor, L., Wall, W., Walters, J. S., Warner, D., Westerhoff, S., Wisher, I. G., Wood, J., Yodh, G. B., Zaborov, D., and Zepeda, A.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We present the sensitivity of HAWC to Gamma Ray Bursts (GRBs). HAWC is a very high-energy gamma-ray observatory currently under construction in Mexico at an altitude of 4100 m. It will observe atmospheric air showers via the water Cherenkov method. HAWC will consist of 300 large water tanks instrumented with 4 photomultipliers each. HAWC has two data acquisition (DAQ) systems. The main DAQ system reads out coincident signals in the tanks and reconstructs the direction and energy of individual atmospheric showers. The scaler DAQ counts the hits in each photomultiplier tube (PMT) in the detector and searches for a statistical excess over the noise of all PMTs. We show that HAWC has a realistic opportunity to observe the high-energy power law components of GRBs that extend at least up to 30 GeV, as it has been observed by Fermi LAT. The two DAQ systems have an energy threshold that is low enough to observe events similar to GRB 090510 and GRB 090902b with the characteristics observed by Fermi LAT. HAWC will provide information about the high-energy spectra of GRBs which in turn could help to understanding about e-pair attenuation in GRB jets, extragalactic background light absorption, as well as establishing the highest energy to which GRBs accelerate particles.

Published
2011
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12. The normal Type Ia SN 2003hv out to very late phases

Author

Leloudas, G., Stritzinger, M. D., Sollerman, J., Burns, C. R., Kozma, C., Krisciunas, K., Maund, J. R., Milne, P., Filippenko, A. V., Fransson, C., Ganeshalingam, M., Hamuy, M., Li, W., Phillips, M. M., Schmidt, B. P., Skottfelt, J., Taubenberger, S., Boldt, L., Fynbo, J. P. U., Gonzalez, L., Salvo, M., and Thomas-Osip, J.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

An extensive dataset for SN 2003hv that covers the flux evolution from maximum light to day +786 is presented. The data are combined with published nebular-phase infrared spectra, and the observations are compared to model light curves and synthetic nebular spectra. SN 2003hv is a normal Type Ia supernova (SN Ia) with photometric and spectroscopic properties consistent with its rarely observed B-band decline-rate parameter, Delta m_15 = 1.61 +- 0.02. The blueshift of the most isolated [Fe II] lines in the nebular-phase optical spectrum appears consistent with those observed in the infrared at similar epochs. At late times there is a prevalent color evolution from the optical toward the near-infrared bands. We present the latest-ever detection of a SN Ia in the near-infrared in Hubble Space Telescope images. The study of the ultraviolet/optical/infrared (UVOIR) light curve reveals that a substantial fraction of the flux is "missing" at late times. Between 300-700 days past maximum brightness, the UVOIR light curve declines linearly following the decay of radioactive Co56, assuming full and instantaneous positron trapping. At 700 days we detect a possible slowdown of the decline in optical bands, mainly in the V band. The data are incompatible with a dramatic infrared catastrophe. However, the idea that an infrared catastrophe occurred in the densest regions before 350 days can explain the missing flux from the UVOIR wavelengths and the flat-topped profiles in the near-infrared. We argue that such a scenario is possible if the ejecta are clumpy. The observations suggest that positrons are most likely trapped in the ejecta., Comment: 20 pages, 9 figures. Fixed typos found during proofs to match published version

Published
2009
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