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1. Evidence for a correlation between the Si II 4000 width and Type Ia supernova color

Author

Nordin, J., Ostman, L., Goobar, A., Balland, C., Lampeitl, H., Nichol, R. C., Sako, M., Schneider, D. P., Smith, M., Sollerman, J., and Wheeler, J. C.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We study the pseudo equivalent width of the Si II 4000 feature of Type Ia supernovae in the redshift range 0.0024 < z < 0.634. We find that this spectral indicator correlates with the lightcurve color excess (SALT2 c) as well as previously defined spectroscopic subclasses (Branch types) and the evolution of the Si II 6150 velocity, i.e., the so called velocity gradient. Based on our study of 55 objects from different surveys, we find indications that the Si II 4000 spectral indicator could provide important information to improve cosmological distance measurements with Type Ia supernovae., Comment: 9 pages, 8 figures, 2 tables. Minor changes to match version accepted by the Astrophysical Journal

Published
2010
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2. NTT and NOT spectroscopy of SDSS-II supernovae

Author

Ostman, L., Nordin, J., Goobar, A., Amanullah, R., Smith, M., Sollerman, J., Stanishev, V., Stritzinger, M. D., Bassett, B. A., Davis, T. M., Edmondson, E., Frieman, J. A., Garnavich, P. M., Lampeitl, H., Leloudas, G., Marriner, J., Nichol, R. C., Romer, K., Sako, M., Schneider, D. P., and Zheng, C.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

Context. The SDSS-II Supernova Survey, conducted between 2005 and 2007, was designed to detect a large number of Type Ia supernovae (SNe Ia) around z~0.2, the redshift "gap" between low-z and high-z SN searches. The survey has provided multi-band photometric lightcurves for variable targets, and SN candidates were scheduled for spectroscopic observations, primarily to provide SN classification and accurate redshifts. We present SN spectra obtained in 2006 and 2007 using the NTT and the NOT. Aims. We provide an atlas of SN spectra in the range z =0.03-0.32 that complements the well-sampled lightcurves from SDSS-II in the forthcoming three-year SDSS SN cosmology analysis. The sample can, for example, be used for spectral studies of SNe Ia, which are critical for understanding potential systematic effects when SNe are used to determine cosmological distances. Methods. The spectra were reduced in a uniform manner, and special care was taken in estimating the uncertainties for the different processing steps. Host-galaxy light was subtracted when possible and the SN type fitted using the SuperNova IDentification code (SNID). We also present comparisons between spectral and photometric dating using SALT lightcurve fits to the photometry from SDSS-II, as well as the global distribution of our sample in terms of the lightcurve parameters: stretch and colour. Results. We report new spectroscopic data from 141 SNe Ia, mainly between -9 and +15 days from lightcurve maximum, including a few cases of multi-epoch observations. This homogeneous, host-galaxy subtracted, SN Ia spectroscopic sample is among the largest such data sets and unique in its redshift interval. The sample includes two potential SN 1991T-like SNe (SN 2006on and SN 2007ni) and one potential SN 2002cx-like SN (SN 2007ie). In addition, the new compilation includes spectra from 23 confirmed Type II and 8 Type Ib/c SNe., Comment: Accepted for publication in A&A

Published
2010
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3. First-year Sloan Digital Sky Survey-II (SDSS-II) supernova results: consistency and constraints with other intermediate-redshift datasets

Author

Lampeitl, H., Nichol, R. C., Seo, H. -J., Giannantonio, T., Shapiro, C., Bassett, B., Percival, W. J., Davis, T. M., Dilday, B., Frieman, J., Garnavich, P., Sako, M., Smith, M., Sollerman, J., Becker, A. C., Cinabro, D., Filippenko, A. V., Foley, R. J., Hogan, C. J., Holtzman, J. A., Jha, S. W., Konishi, K., Marriner, J., Richmond, M. W., Riess, A. G., Schneider, D. P., Stritzinger, M., van der Heyden, K. J., VanderPlas, J. T., Wheeler, J. C., and Zheng, C.

Subjects
Astrophysics - Cosmology and Extragalactic Astrophysics
Abstract

We present an analysis of the luminosity distances of Type Ia Supernovae from the Sloan Digital Sky Survey-II (SDSS-II) Supernova Survey in conjunction with other intermediate redshift (z<0.4) cosmological measurements including redshift-space distortions from the Two-degree Field Galaxy Redshift Survey (2dFGRS), the Integrated Sachs-Wolfe (ISW) effect seen by the SDSS, and the latest Baryon Acoustic Oscillation (BAO) distance scale from both the SDSS and 2dFGRS. We have analysed the SDSS-II SN data alone using a variety of "model-independent" methods and find evidence for an accelerating universe at >97% level from this single dataset. We find good agreement between the supernova and BAO distance measurements, both consistent with a Lambda-dominated CDM cosmology, as demonstrated through an analysis of the distance duality relationship between the luminosity (d_L) and angular diameter (d_A) distance measures. We then use these data to estimate w within this restricted redshift range (z<0.4). Our most stringent result comes from the combination of all our intermediate-redshift data (SDSS-II SNe, BAO, ISW and redshift-space distortions), giving w = -0.81 +0.16 -0.18(stat) +/- 0.15(sys) and Omega_M=0.22 +0.09 -0.08 assuming a flat universe. This value of w, and associated errors, only change slightly if curvature is allowed to vary, consistent with constraints from the Cosmic Microwave Background. We also consider more limited combinations of the geometrical (SN, BAO) and dynamical (ISW, redshift-space distortions) probes., Comment: 13 pages, 7 figures, accepted for publication in MNRAS

Published
2009
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4. First-Year Sloan Digital Sky Survey-II (SDSS-II) Supernova Results: Constraints on Non-Standard Cosmological Models

Author

Sollerman, J., Mörtsell, E., Davis, T. M., Blomqvist, M., Bassett, B., Becker, A. C., Cinabro, D., Filippenko, A. V., Foley, R. J., Frieman, J., Garnavich, P., Lampeitl, H., Marriner, J., Miquel, R., Nichol, R. C., Richmond, M. W., Sako, M., Schneider, D. P., Smith, M., Vanderplas, J. T., and Wheeler, J. C.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We use the new SNe Ia discovered by the SDSS-II Supernova Survey together with additional supernova datasets as well as observations of the cosmic microwave background and baryon acoustic oscillations to constrain cosmological models. This complements the analysis presented by Kessler et al. in that we discuss and rank a number of the most popular non-standard cosmology scenarios. When this combined data-set is analyzed using the MLCS2k2 light-curve fitter, we find that more exotic models for cosmic acceleration provide a better fit to the data than the Lambda-CDM model. For example, the flat DGP model is ranked higher by our information criteria tests than the standard model. When the dataset is instead analyzed using the SALT-II light-curve fitter, the standard cosmological constant model fares best. Our investigation also includes inhomogeneous Lemaitre-Tolman-Bondi (LTB) models. While our LTB models can be made to fit the supernova data as well as any other model, the extra parameters they require are not supported by our information criteria analysis., Comment: ApJ in press, updated references

Published
2009
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5. A Measurement of the Rate of type-Ia Supernovae at Redshift $z\approx$ 0.1 from the First Season of the SDSS-II Supernova Survey

Author

Dilday, Benjamin, Kessler, R., Frieman, J. A., Holtzman, J., Marriner, J., Miknaitis, G., Nichol, R. C., Romani, R., Sako, M., Bassett, B., Becker, A., Cinabro, D., DeJongh, F., Depoy, D. L., Doi, M., Garnavich, P. M., Hogan, C. J., Jha, S., Konishi, K., Lampeitl, H., Marshall, J. L., McGinnis, D., Prieto, J. L., Riess, A. G., Richmond, M. W., Schneider, D. P., Smith, M., Takanashi, N., Tokita, K., van der Heyden, K., Yasuda, N., Zheng, C., Barentine, J., Brewington, H., Choi, C., Crotts, A., Dembicky, J., Harvanek, M., Im, M., Ketzeback, W., Kleinman, S. J., Krzesiński, J., Long, D. C., Malanushenko, E., Malanushenko, V., McMillan, R. J., Nitta, A., Pan, K., Saurage, G., Snedden, S. A., Watters, S., Wheeler, J. C., and York, D.

Subjects
Astrophysics
Abstract

We present a measurement of the rate of type Ia supernovae (SNe Ia) from the first of three seasons of data from the SDSS-II Supernova Survey. For this measurement, we include 17 SNe Ia at redshift $z\le0.12$. Assuming a flat cosmology with $\Omega_m = 0.3=1-\Omega_\Lambda$, we find a volumetric SN Ia rate of $[2.93^{+0.17}_{-0.04}({\rm systematic})^{+0.90}_{-0.71}({\rm statistical})] \times 10^{-5} {\rm SNe} {\rm Mpc}^{-3} h_{70}^3 {\rm year}^{-1}$, at a volume-weighted mean redshift of 0.09. This result is consistent with previous measurements of the SN Ia rate in a similar redshift range. The systematic errors are well controlled, resulting in the most precise measurement of the SN Ia rate in this redshift range. We use a maximum likelihood method to fit SN rate models to the SDSS-II Supernova Survey data in combination with other rate measurements, thereby constraining models for the redshift-evolution of the SN Ia rate. Fitting the combined data to a simple power-law evolution of the volumetric SN Ia rate, $r_V \propto (1+z)^{\beta}$, we obtain a value of $\beta = 1.5 \pm 0.6$, i.e. the SN Ia rate is determined to be an increasing function of redshift at the $\sim 2.5 \sigma$ level. Fitting the results to a model in which the volumetric SN rate, $r_V=A\rho(t)+B\dot \rho(t)$, where $\rho(t)$ is the stellar mass density and $\dot \rho(t)$ is the star formation rate, we find $A = (2.8 \pm 1.2) \times 10^{-14} \mathrm{SNe} \mathrm{M}_{\sun}^{-1} \mathrm{year}^{-1}$, $B = (9.3^{+3.4}_{-3.1})\times 10^{-4} \mathrm{SNe} \mathrm{M}_{\sun}^{-1}$., Comment: 65 pages, 12 figures

Published
2008
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6. The Sloan Digital Sky Survey-II Supernova Survey: Search Algorithm and Follow-up Observations

Author

Sako, Masao, Bassett, B., Becker, A., Cinabro, D., DeJongh, F., Depoy, D. L., Dilday, B., Doi, M., Frieman, J. A., Garnavich, P. M., Hogan, C. J., Holtzman, J., Jha, S., Kessler, R., Konishi, K., Lampeitl, H., Marriner, J., Miknaitis, G., Nichol, R. C., Prieto, J. L., Riess, A. G., Richmond, M. W., Romani, R., Schneider, D. P., Smith, M., SubbaRao, M., Takanashi, N., Tokita, K., van der Heyden, K., Yasuda, N., Zheng, C., Barentine, J., Brewington, H., Choi, C., Dembicky, J., Harnavek, M., Ihara, Y., Im, M., Ketzeback, W., Kleinman, S. J., Krzesiński, J., Long, D. C., Malanushenko, E., Malanushenko, V., McMillan, R. J., Morokuma, T., Nitta, A., Pan, K., Saurage, G., and Snedden, S. A.

Subjects
Astrophysics
Abstract

The Sloan Digital Sky Survey-II Supernova Survey has identified a large number of new transient sources in a 300 sq. deg. region along the celestial equator during its first two seasons of a three-season campaign. Multi-band (ugriz) light curves were measured for most of the sources, which include solar system objects, Galactic variable stars, active galactic nuclei, supernovae (SNe), and other astronomical transients. The imaging survey is augmented by an extensive spectroscopic follow-up program to identify SNe, measure their redshifts, and study the physical conditions of the explosions and their environment through spectroscopic diagnostics. During the survey, light curves are rapidly evaluated to provide an initial photometric type of the SNe, and a selected sample of sources are targeted for spectroscopic observations. In the first two seasons, 476 sources were selected for spectroscopic observations, of which 403 were identified as SNe. For the Type Ia SNe, the main driver for the Survey, our photometric typing and targeting efficiency is 90%. Only 6% of the photometric SN Ia candidates were spectroscopically classified as non-SN Ia instead, and the remaining 4% resulted in low signal-to-noise, unclassified spectra. This paper describes the search algorithm and the software, and the real-time processing of the SDSS imaging data. We also present the details of the supernova candidate selection procedures and strategies for follow-up spectroscopic and imaging observations of the discovered sources., Comment: Accepted for publication in The Astronomical Journal (66 pages, 13 figures); typos corrected

Published
2007
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7. The Sloan Digital Sky Survey-II Supernova Survey: Technical Summary

Author

Frieman, Joshua A., Bassett, B., Becker, A., Choi, C., Cinabro, D., DeJongh, F., Depoy, D. L., Dilday, B., Doi, M., Garnavich, P. M., Hogan, C. J., Holtzman, J., Im, M., Jha, S., Kessler, R., Konishi, K., Lampeitl, H., Marriner, J., Marshall, J. L., McGinnis, D., Miknaitis, G., Nichol, R. C., Prieto, J. L., Riess, A. G., Richmond, M. W., Romani, R., Sako, M., Schneider, D. P., Smith, M., Takanashi, N., Tokita, K., van der Heyden, K., Yasuda, N., Zheng, C., Adelman-McCarthy, J., Annis, J., Assef, R. J., Barentine, J., Bender, R., Blandford, R. D., Boroski, W. N., Bremer, M., Brewington, H., Collins, C. A., Crotts, A., Dembicky, J., Eastman, J., Edge, A., Edmondson, E., Elson, E., Eyler, M. E., Filippenko, A. V., Foley, R. J., Frank, S., Goobar, A., Gueth, T., Gunn, J. E., Harvanek, M., Hopp, U., Ihara, Y., Ivezić, Ž., Kahn, S., Kaplan, J., Kent, S., Ketzeback, W., Kleinman, S. J., Kollatschny, W., Kron, R. G., Krzesiński, J., Lamenti, D., Leloudas, G., Lin, H., Long, D. C., Lucey, J., Lupton, R. H., Malanushenko, E., Malanushenko, V., McMillan, R. J., Mendez, J., Morgan, C. W., Morokuma, T., Nitta, A., Ostman, L., Pan, K., Rockosi, C. M., Romer, A. K., Ruiz-Lapuente, P., Saurage, G., Schlesinger, K., Snedden, S. A., Sollerman, J., Stoughton, C., Stritzinger, M., SubbaRao, M., Tucker, D., Vaisanen, P., Watson, L. C., Watters, S., Wheeler, J. C., Yanny, B., and York, D.

Subjects
Astrophysics
Abstract

The Sloan Digital Sky Survey-II (SDSS-II) has embarked on a multi-year project to identify and measure light curves for intermediate-redshift (0.05 < z < 0.35) Type Ia supernovae (SNe Ia) using repeated five-band (ugriz) imaging over an area of 300 sq. deg. The survey region is a stripe 2.5 degrees wide centered on the celestial equator in the Southern Galactic Cap that has been imaged numerous times in earlier years, enabling construction of a deep reference image for discovery of new objects. Supernova imaging observations are being acquired between 1 September and 30 November of 2005-7. During the first two seasons, each region was imaged on average every five nights. Spectroscopic follow-up observations to determine supernova type and redshift are carried out on a large number of telescopes. In its first two three-month seasons, the survey has discovered and measured light curves for 327 spectroscopically confirmed SNe Ia, 30 probable SNe Ia, 14 confirmed SNe Ib/c, 32 confirmed SNe II, plus a large number of photometrically identified SNe Ia, 94 of which have host-galaxy spectra taken so far. This paper provides an overview of the project and briefly describes the observations completed during the first two seasons of operation., Comment: Submitted to The Astronomical Journal (24 pages, 10 figures)

Published
2007
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8. A Study of the Type Ia/IIn Supernova 2005gj from X-ray to the Infrared: Paper I

Author

Prieto, J. L., Garnavich, P. M., Phillips, M. M., DePoy, D. L., Parrent, J., Pooley, D., Dwarkadas, V. V., Baron, E., Bassett, B., Becker, A., Cinabro, D., DeJongh, F., Dilday, B., Doi, M., Frieman, J. A., Hogan, C. J., Holtzman, J., Jha, S., Kessler, R., Konishi, K., Lampeitl, H., Marriner, J., Marshall, J. L., Miknaitis, G., Nichol, R. C., Riess, A. G., Richmond, M. W., Romani, R., Sako, M., Schneider, D. P., Smith, M., Takanashi, N., Tokita, K., van der Heyden, K., Yasuda, N., Zheng, C., Wheeler, J. C., Barentine, J., Dembicky, J., Eastman, J., Frank, S., Ketzeback, W., McMillan, R. J., Morrell, N., Folatelli, G., Contreras, C., Burns, C. R., Freedman, W. L., Gonzalez, S., Hamuy, M., Krzeminski, W., Madore, B. F., Murphy, D., Persson, S. E., Roth, M., and Suntzeff, N. B.

Subjects
Astrophysics
Abstract

We present extensive ugrizYHJK photometry and optical spectroscopy of SN 2005gj obtained by the SDSS-II and CSP Supernova Projects, which give excellent coverage during the first 150 days after the time of explosion. These data show that SN 2005gj is the second clear case, after SN 2002ic, of a thermonuclear explosion in a dense circumstellar environment. Both the presence of singly and doubly ionized iron-peak elements (FeIII and weak SII, SiII) near maximum light as well as the spectral evolution show that SN 2002ic-like events are Type Ia explosions. Independent evidence comes from the exponential decay in luminosity of SN 2005gj, pointing to an exponential density distribution of the ejecta. The interaction of the supernova ejecta with the dense circumstellar medium is stronger than in SN 2002ic: (1) the supernova lines are weaker; (2) the Balmer emission lines are more luminous; and (3) the bolometric luminosity is higher close to maximum light. The velocity evolution of the Halpha components suggest that the CSM around SN 2005gj is clumpy and it has a flatter density distribution compared with the steady wind solution, in agreement with SN 2002ic. An early X-ray observation with Chandra gives an upper-limit on the mass loss rate from the companion of < 2x10^{-4} Msun/yr., Comment: 63 pages, 16 figures, submitted to AJ

Published
2007

9. The Peculiar SN 2005hk: Do Some Type Ia Supernovae Explode as Deflagrations?

Author

Phillips, M. M., Li, W., Frieman, J. A., Blinnikov, S. I., DePoy, D., Prieto, J. L., Milne, P., Contreras, C., Folatelli, G., Morrell, N., Hamuy, M., Suntzeff, N. B., Roth, M., Gonzalez, S., Krzeminski, W., Filippenko, A. V., Freedman, W. L., Chornock, R., Jha, S., Madore, B. F., Persson, S. E., Burns, C. R., Wyatt, P., Murphy, D., Foley, R. J., Ganeshalingam, M., Serduke, F. J. D., Krisciunas, K., Bassett, B., Becker, A., Dilday, B., Eastman, J., Garnavich, P. M., Holtzman, J., Kessler, R., Lampeitl, H., Marriner, J., Frank, S., Marshall, J. L., Miknaitis, G., Sako, M., Schneider, D. P., van der Heyden, K., and Yasuda, Naoki

Subjects
Astrophysics
Abstract

We present extensive u'g'r'i'BVRIYJHKs photometry and optical spectroscopy of SN 2005hk. These data reveal that SN 2005hk was nearly identical in its observed properties to SN 2002cx, which has been called ``the most peculiar known type Ia supernova.'' Both supernovae exhibited high ionization SN 1991T-like pre-maximum spectra, yet low peak luminosities like SN 1991bg. The spectra reveal that SN 2005hk, like SN 2002cx, exhibited expansion velocities that were roughly half those of typical type Ia supernovae. The R and I light curves of both supernovae were also peculiar in not displaying the secondary maximum observed for normal type Ia supernovae. Our YJH photometry of SN 2005hk reveals the same peculiarity in the near-infrared. By combining our optical and near-infrared photometry of SN 2005hk with published ultraviolet light curves obtained with the Swift satellite, we are able to construct a bolometric light curve from ~10 days before to ~60 days after B maximum. The shape and unusually low peak luminosity of this light curve, plus the low expansion velocities and absence of a secondary maximum at red and near-infrared wavelengths, are all in reasonable agreement with model calculations of a 3D deflagration which produces ~0.25 M_sun of 56Ni., Comment: Accepted by PASP, to appear in April 2007 issue, 63 pages, 16 figures, 11 tables

Published
2006
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10. The Sloan Digital Sky Survey Monitor Telescope Pipeline

Author

Tucker, D. L., Kent, S., Richmond, M. W., Annis, J., Smith, J. A., Allam, S. S., Rodgers, C. T., Stute, J. L., Adelman-McCarthy, J. K., Brinkmann, J., Doi, M., Finkbeiner, D., Fukugita, M., Goldston, J., Greenway, B., Gunn, J. E., Hendry, J. S., Hogg, D. W., Ichikawa, S. -I., Ivezic, Z., Knapp, G. R., Lampeitl, H., Lee, B. C., Lin, H., McKay, T. A., Merrelli, A., Munn, J. A., Neilsen, Jr., E. H., Newberg, H. J., Richards, G. T., Schlegel, D. J., Stoughton, C., Uomoto, A., and Yanny, B.

Subjects
Astrophysics
Abstract

The photometric calibration of the Sloan Digital Sky Survey (SDSS) is a multi-step process which involves data from three different telescopes: the 1.0-m telescope at the US Naval Observatory (USNO), Flagstaff Station, Arizona (which was used to establish the SDSS standard star network); the SDSS 0.5-m Photometric Telescope (PT) at the Apache Point Observatory (APO), New Mexico (which calculates nightly extinctions and calibrates secondary patch transfer fields); and the SDSS 2.5-m telescope at APO (which obtains the imaging data for the SDSS proper). In this paper, we describe the Monitor Telescope Pipeline, MTPIPE, the software pipeline used in processing the data from the single-CCD telescopes used in the photometric calibration of the SDSS (i.e., the USNO 1.0-m and the PT). We also describe transformation equations that convert photometry on the USNO-1.0m u'g'r'i'z' system to photometry the SDSS 2.5m ugriz system and the results of various validation tests of the MTPIPE software. Further, we discuss the semi-automated PT factory, which runs MTPIPE in the day-to-day standard SDSS operations at Fermilab. Finally, we discuss the use of MTPIPE in current SDSS-related projects, including the Southern u'g'r'i'z' Standard Star project, the u'g'r'i'z' Open Star Clusters project, and the SDSS extension (SDSS-II)., Comment: 24 pages, 16 figures (1 color), accepted for publication in Astronomische Nachrichten

Published
2006
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11. Observations of the Crab Nebula with the HEGRA system of IACTs in convergent mode using a topological trigger

Author

Lucarelli, F., Konopelko, A., Aharonian, F., Hofmann, W., Kohnle, A., Lampeitl, H., and Fonseca, V.

Subjects
Astrophysics
Abstract

Routine observations of the Crab Nebula for a total of about 250 hrs, performed with the HEGRA stereoscopic system of 5 imaging atmospheric Cerenkov telescopes in the standard operational mode, have proven the energy threshold of the system to be 500 GeV for small zenith angles (< 20 deg). A topological trigger applied along with the convergent observational mode allows to reduce noticeably the energy threshold of the system down to 350 GeV. Here we present the relevant Monte Carlo simulations as well as the analysis results of 15 hrs Crab Nebula data taken in such an observational mode. From the Crab Nebula data, the final energy threshold was found to be 350 GeV. The estimated gamma ray flux from the Crab Nebula above 350 GeV is (8.1 +- 0.1(stat) +- 0.2(syst)) 10^(-11) ph cm^(-2) s^(-1), which is consistent with recent measurements reported by the STACEE, CELESTE, CAT, and Whipple groups., Comment: 18 pages, 9 figures, accepted for publication in "Astroparticle Physics"

Published
2002
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12. Monte Carlo studies on the sensitivity of the HEGRA imaging atmospheric Cerenkov telescope system in observations of extended gamma-ray sources

Author

Konopelko, A., Lucarelli, F., Lampeitl, H., and Hofmann, W.

Subjects
Astrophysics
Abstract

In this paper, we present the results of Monte Carlo simulations of atmospheric showers induced by diffuse gamma rays as detected by the high-energy gamma ray astronomy (HEGRA) system of five imaging atmospheric Cerenkov telescopes (IACTs). We have investigated the sensitivity of observations on extended gamma ray emission over the entire field of view of the instrument. We discuss a technique to search for extended gamma ray sources within the field of view of the instrument. We give estimates for HEGRA sensitivity of observations on extended TeV gamma ray sources., Comment: 21 pages, 7 figures, accepted for publication in "Journal of Physics G: Nuclear and Particle Physics"

Published
2002
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13. Search for point sources and diffuse emission from the Galactic plane with the HEGRA-IACT-system

Author

Lampeitl, H., Bernloehr, K., Daum, A., Hofmann, W., Konopelko, A., Puehlhofer, G., and HEGRA-Collaboration

Subjects
Astrophysics
Abstract

The HEGRA-IACT-system with a FoV of ~1.5 deg radius has been used for surveying one quater of the Galactic disc in respect to point sources, moderately extended sources and for diffuse emission in the energy range above 1 TeV. In total 140 h of good observation time were accumulated. No new source has been discoverd. Limits on the level of 20% or lower of the Crab flux on about 87 potential sources like SNR, Pulsars and EGRET sources are derived. A limit on the diffuse emission is given on the level of dPhi/dE(E=1 TeV) = 6.1 10^-15 ph cm-2 s-1 sr-1 Mev-1 resulting in a lower limit of 2.5 on the spectral index for the extrapolation of the meassured EGRET flux for the diffuse emission., Comment: 4 pages, 5 figures, 1 table, Submitted to ICRC, Hamburg

Published
2001

14. Measurement of the Cherenkov light spectrum and of the polarization with the HEGRA-IACT-system

Author

Doering, M., Bernloehr, K., Hermann, G., Hofmann, W., and Lampeitl, H.

Subjects
Astrophysics
Abstract

The HEGRA system of Imaging Atmospheric Cherenkov Telescopes (IACTs) detects Cherenkov light produced by air showers. The concept of stereoscopic observation with the five HEGRA telescopes allows the reconstruction of various shower parameters, for example the shower direction, the location of the shower core and the energy of cosmic rays. One of the telescopes was modified so that measurements of the spectrum and the polarization of Cherenkov light with the HEGRA system were possible. The experimental setup is described and preliminary results presented., Comment: submitted to ICRC Hamburg

Published
2001

15. Particle Identification by Multifractal Parameters in Gamma-Astronomy with the HEGRA-Cherenkov-Telescopes

Author

Schaefer, B. M., Hofmann, W., Lampeitl, H., and Hemberger, M.

Subjects
Astrophysics
Abstract

Cherenkov images of air showers can also be classified using multifractal and wavelet parameters, as compared to the conventional Hillas image parameters. This technique was applied to the images recorded by the cameras of the stereoscopic imaging air Cherenkov-telescopes operated by the HEGRA collaboration. With respect to the identification of particles, the performance of multifractal and wavelet parameters was examined using a data sample from the observation of the active galaxy Mkn 501 that showed a high gamma-ray flux. The multifractal parameters were also combined with the Hillas parameters using a neural network approach in order to further improve the gamma/hadron-separation., Comment: 16 Pages, 6 figures; Nucl. Instr. Meth., in press

Published
2001
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16. Improved energy resolution for VHE gamma-ray astronomy with systems of Cherenkov telescopes

Author

Hofmann, W., Lampeitl, H., Konopelko, A., and Krawczynski, H.

Subjects
Astrophysics
Abstract

We present analysis techniques to improve the energy resolution of stereoscopic systems of imaging atmospheric Cherenkov telescopes, using the HEGRA telescope system as an example. The techniques include (i) the determination of the height of the shower maximum, which is then taken into account in the energy determination, and (ii) the determination of the location of the shower core with the additional constraint that the direction of the gamma rays is known a priori. This constraint can be applied for gamma-ray point sources, and results in a significant improvement in the localization of the shower core, which translates into better energy resolution. Combining both techniques, the HEGRA telescopes reach an energy resolution between 9% and 12%, over the entire energy range from 1 TeV to almost 100 TeV. Options for further improvements of the energy resolution are discussed., Comment: 13 Pages, 7 figures, Latex. Astroparticle Physics, in press

Published
1999
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17. Comparison of techniques to reconstruct VHE gamma-ray showers from multiple stereoscopic Cherenkov images

Author

Hofmann, W., Jung, I., Konopelko, A., Krawczynski, H., Lampeitl, H., and Puehlhofer, G.

Subjects
Astrophysics
Abstract

For air showers observed simultaneously by more than two imaging atmospheric Cherenkov telescopes, the shower geometry is overconstrained by the images and image information should be combined taking into account the quality of the images. Different algorithms are discussed and tested experimentally using data obtained from observations of Mkn 501 with the HEGRA IACT system. Most of these algorithms provide an estimate of the accuracy of the reconstruction of shower geometry on an event-by-event basis, allowing, e.g., to select higher-quality subsamples for precision measurements., Comment: 14 Pages, 6 figures, Latex

Published
1999
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18. Characteristics of the Multi-Telescope Coincidence Trigger of the HEGRA IACT System

Author

Bulian, N., Daum, A., Hermann, G., Hess, M., Hofmann, W., Lampeitl, H., Puehlhofer, G., Koehler, C., Panter, M., Stein, M., Boerst, G., Rauterberg, G., Samorski, M., Sauerland, C., and Stamm, W.

Subjects
Astrophysics
Abstract

The HEGRA--collaboration is operating a system of imaging atmospheric Cherenkov telescopes to search for sources of TeV-gamma-rays. Air showers are observed in stereoscopic mode with several telescopes simultaneously. To trigger the telescope system a versatile two-level trigger scheme has been implemented, which allows a significant reduction of the energy threshold with respect to single telescopes. The technical implementation of this trigger scheme and the performance of the trigger system are described. Results include the dependence of single- and multi-telescope trigger rates on the trigger thresholds, on the orientation of the telescopes, and on the type of the primary particle., Comment: 17 Pages, 10 figures, Latex

Published
1997
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19. Statistical classification techniques for photometric supernova typing

Author

Newling, J., Varughese, M., Bassett, B., Campbell, H., Hlozek, R., Kunz, M., Lampeitl, H., Martin, B., Nichol, R., Parkinson, D., Smith, M., Newling, J., Varughese, M., Bassett, B., Campbell, H., Hlozek, R., Kunz, M., Lampeitl, H., Martin, B., Nichol, R., Parkinson, D., and Smith, M.

Abstract

Future photometric supernova surveys will produce vastly more candidates than can be followed up spectroscopically, highlighting the need for effective classification methods based on light curves alone. Here we introduce boosting and kernel density estimation techniques which have minimal astrophysical input, and compare their performance on 20 000 simulated Dark Energy Survey light curves. We demonstrate that these methods perform very well provided a representative sample of the full population is used for training. Interestingly, we find that they do not require the redshift of the host galaxy or candidate supernova. However, training on the types of spectroscopic subsamples currently produced by supernova surveys leads to poor performance due to the resulting bias in training, and we recommend that special attention be given to the creation of representative training samples. We show that given a typical non-representative training sample, S, one can expect to pull out a representative subsample of about 10 per cent of the size of S, which is large enough to outperform the methods trained on all of S

Published
2017

20. Variations of the TeV energy spectrum at different flux levels of Mkn 421 observed with the HEGRA system of Cherenkov telescopes

Author

Aharonian, F., Akhperjanian, A., Beilicke, M., Bernlöhr, K., Börst, H., Bojahr, H., Bolz, O., Coarasa, T., Contreras, J., Cortina, J., Costamante, L., Denninghoff, S., Fonseca, V., Girma, M., Götting, N., Heinzelmann, G., Hermann, G., Heusler, A., Hofmann, W., Horns, D., Jung, I., Kankanyan, R., Kestel, M., Kettler, J., Kohnle, A., Konopelko, A., Kornmeyer, H., Kranich, D., Krawczynski, H., Lampeitl, H., Lopez, M., Lorenz, E., Fabrizio Lucarelli, Mang, O., Meyer, H., Mirzoyan, R., Milite, M., Moralejo, A., Ona, E., Panter, M., Plyasheshnikov, A., Pühlhofer, G., Rauterberg, G., Reyes, R., Rhode, W., Ripken, J., Rowell, G., Sahakian, V., Samorski, M., Schilling, M., Siems, M., Sobzynska, D., Stamm, W., Tluczykont, M., Völk, H. J., Wiedner, C. A., Wittek, W., and Remillard, R. A.

Subjects
Physics, Photon, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Mid infrared, FOS: Physical sciences, HEGRA, Astronomy and Astrophysics, Astrophysics, Power law, Spectral line, Space and Planetary Science, Energy spectrum, Cherenkov radiation, Background radiation
Abstract

The nearby BL Lacertae (BL Lac) object Markarian~421 (Mkn~421) at a red shift z=0.031 was observed to undergo strong TeV Gamma-ray outbursts in the observational periods from December 1999 until May 2001. The time averaged energy spectrum is well described by a power law with an exponential cut-off energy at 3.6(+0.4-0.3)_{stat}(+0.9-0.8)_{sys} TeV. The energy spectra derived for different average flux levels ranging from 0.5 to 10 * 10^{-11}ph/cm**2/s follow a clear correlation of photon index and flux level. Generally, the energy spectra are harder for high flux levels. From January to April 2001 Mkn~421 showed rapid variability (doubling time as short as 20 minutes), accompanied with a spectral hardening with increasing flux level within individual nights. For two successive nights (MJD 51989-51991, March 21-23,2001), this correlation of spectral hardness and change in flux has been observed within a few hours. The cut-off energy for the Mkn~421 TeV spectrum remains within the errors constant for the different flux levels and differs by 2.6+/-0.6_stat+/-0.6_sys TeV from the value determined for Mkn~501. This indicates that the observed exponential cut-off in the energy spectrum of Mkn~421 is not solely caused by absorption of multi-TeV photons by pair-production processes with photons of the extragalactic near/mid infrared background radiation., Comment: 12 pages, 9 figures, submitted to Astronomy&Astrophysics

Published
2002
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21. THE CARNEGIE SUPERNOVA PROJECT: FIRST NEAR-INFRARED HUBBLE DIAGRAM TO z similar to 0.7

Author

Freedman, WL, Burns, CR, Phillips, MM, Wyatt, P, Persson, SE, Madore, BF, Contreras, C, Folatelli, G, Gonzalez, ES, Hamuy, M, Hsiao, E, Kelson, DD, Morrell, N, Murphy, DC, Roth, M, Stritzinger, M, Sturch, L, Suntzeff, NB, Astier, P, Balland, C, Bassett, B, Boldt, L, Carlberg, RG, Conley, AJ, Frieman, JA, Garnavich, PM, Guy, J, Hardin, D, Howell, DA, Kessler, R, Lampeitl, H, Marriner, J, Pain, R, Perrett, K, Regnault, N, Riess, AG, Sako, M, Schneider, DP, Sullivan, M, and Wood-Vasey, M

Published
2009

22. A Study of the Type Ia/IIn Supernova 2005gj from X-ray to the Infrared: Paper I

Author

Jose Prieto, Garnavich, P. M., Phillips, M. M., Depoy, D. L., Parrent, J., Pooley, D., Dwarkadas, V. V., Baron, E., Bassett, B., Becker, A., Cinabro, D., Dejongh, F., Dilday, B., Doi, M., Frieman, J. A., Hogan, C. J., Holtzman, J., Jha, S., Kessler, R., Konishi, K., Lampeitl, H., Marriner, J., Marshall, J. L., Miknaitis, G., Nichol, R. C., Riess, A. G., Richmond, M. W., Romani, R., Sako, M., Schneider, D. P., Smith, M., Takanashi, N., Tokita, K., Heyden, K., Yasuda, N., Zheng, C., Wheeler, J. C., Barentine, J., Dembicky, J., Eastman, J., Frank, S., Ketzeback, W., Mcmillan, R. J., Morrell, N., Folatelli, G., Contreras, C., Burns, C. R., Freedman, W. L., Gonzalez, S., Hamuy, M., Krzeminski, W., Madore, B. F., Murphy, D., Persson, S. E., Roth, M., and Suntzeff, N. B.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We present extensive ugrizYHJK photometry and optical spectroscopy of SN 2005gj obtained by the SDSS-II and CSP Supernova Projects, which give excellent coverage during the first 150 days after the time of explosion. These data show that SN 2005gj is the second clear case, after SN 2002ic, of a thermonuclear explosion in a dense circumstellar environment. Both the presence of singly and doubly ionized iron-peak elements (FeIII and weak SII, SiII) near maximum light as well as the spectral evolution show that SN 2002ic-like events are Type Ia explosions. Independent evidence comes from the exponential decay in luminosity of SN 2005gj, pointing to an exponential density distribution of the ejecta. The interaction of the supernova ejecta with the dense circumstellar medium is stronger than in SN 2002ic: (1) the supernova lines are weaker; (2) the Balmer emission lines are more luminous; and (3) the bolometric luminosity is higher close to maximum light. The velocity evolution of the Halpha components suggest that the CSM around SN 2005gj is clumpy and it has a flatter density distribution compared with the steady wind solution, in agreement with SN 2002ic. An early X-ray observation with Chandra gives an upper-limit on the mass loss rate from the companion of < 2x10^{-4} Msun/yr., 63 pages, 16 figures, submitted to AJ

Published
2007

23. Observations of H1426+428 with HEGRA -- Observations in 2002 and reanalysis of 1999&2000 data

Author

Aharonian, F., Akhperjanian, A., Beilicke, M., Bernlöhr, K., Börst, H. -G, Bojahr, H., Bolz, O., Coarasa, T., Contreras, J. L., Juan Cortina, Costamante, L., Denninghoff, S., Fonseca, M. V., Girma, M., Götting, N., Heinzelmann, G., Hermann, G., Heusler, A., Hofmann, W., Horns, D., Jung, I., Kankanyan, R., Kestel, M., Kohnle, A., Konopelko, A., Kornmeyer, H., Kranich, D., Lampeitl, H., Lopez, M., Lorenz, E., Lucarelli, F., Mang, O., Mazine, D., Meyer, H., Mirzoyan, R., Moralejo, A., Ona-Wilhelmi, E., Panter, M., Plyasheshnikov, A., Prahl, J., Pühlhofer, G., Los Reyes, R., Rhode, W., Ripken, J., Rowell, G., Sahakian, V., Samorski, M., Schilling, M., Siems, M., Sobzynska, D., Stamm, W., Tluczykont, M., Vitale, V., Völk, H. J., Wiedner, C. A., and Wittek, W.

Subjects
Physics, Astrophysics::High Energy Astrophysical Phenomena, Flux, HEGRA, Astronomy and Astrophysics, Astrophysics, Spectral line, Wavelength, Extragalactic background light, Space and Planetary Science, Absorption (electromagnetic radiation), Cherenkov radiation, BL Lac object
Abstract

The HEGRA system of imaging air Cherenkov telescopes has been used to observe the BL Lac object H1426+428 ($z=0.129$) for 217.5 hours in 2002. In this data set alone, the source is detected at a confidence level of $5.3~\sigma$, confirming this object as a TeV source. The overall flux level during the observations in 2002 is found to be a factor of $\approx 2.5$ lower than during the previous observations by HEGRA in 1999&2000. A new spectral analysis has been carried out, improving the signal-to-noise ratio at the expense of a slightly increased systematic uncertainty and reducing the relative energy resolution to $\Delta E/E\le 12 %$ over a wide range of energies. The new method has also been applied to the previously published data set taken in 1999 and 2000, confirming the earlier claim of a flattening of the energy spectrum between 1 and 5 TeV. The data set taken in 2002 shows again a signal at energies above 1 TeV. We combine the energy spectra as determined by the CAT and VERITAS groups with our reanalyzed result of the 1999&2000 data set and apply a correction to account for effects of absorption of high energy photons on extragalactic background light in the optical to mid infrared band. The shape of the inferred source spectrum is mostly sensitive to the characteristics of the extragalactic background light between wavelengths of 1 and 15~$\mu$m, Comment: 12 pages, 4 Figures, submitted to A&A

Published
2003

24. An unidentified TeV source in the vicinity of Cygnus OB2

Author

Aharonian, F., Akhperjanian, A., Beilicke, M., Bernlohr, K., Borst, H., Bojahr, H., Bolz, O., Coarasa, T., Contreras, J., Cortina, J., Denninghoff, S., Fonseca, V., Girma, M., Gotting, N., Heinzelmann, G., Hermann, G., Heusler, A., Hofmann, W., Horns, D., Jung, I., Kankanyan, R., Kestel, M., Kettler, J., Kohnle, A., Konopelko, A., Kornmeyer, H., Kranich, D., Krawczynski, H., Lampeitl, H., Lopez, M., Lorenz, E., Lucarelli, F., Magnussen, N., Mang, O., Meyer, H., Milite, M., Mirzoyan, R., Moralejo, A., Ona, E., Panter, M., Plyasheshnikov, A., Prahl, J., Puhlhofer, G., Rauterberg, G., Reyes, R., Rhode, W., Ripken, J., Rohring, A., Rowell, G. P., Sahakian, V., Samorski, M., Schilling, M., Schroder, F., Siems, M., Sobzynska, D., Stamm, W., Tluczykont, M., Volk, H. J., Wiedner, C. A., Wittek, W. (HEGRA Collaboration), Uchiyama, Yasunobu, and Takahashi, Tadayuki

Subjects
Physics, Astrophysics (astro-ph), Flux, HEGRA, FOS: Physical sciences, Astronomy and Astrophysics, Radius, Astrophysics, Particle acceleration, Stars, Pulsar, Space and Planetary Science, Cygnus OB2, Heliosphere
Abstract

著者人数：62名, Accepted: 2002-08-09, 資料番号: SA1002274000

Published
2002
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25. NTT and NOT spectroscopy of SDSS-II supernovae

Author

Östman, Linda, Nordin, Jakob, Goobar, Ariel, Amanullah, Rahman, Smith, M., Sollerman, Jesper, Stanishev, V., Stritzinger, M., Basset, B. A., Davis, T. M., Edmondson, E., Frieman, J. A., Garnavich, P. M., Lampeitl, H., Leloudas, G., Marriner, J., Nichol, R. C., Romer, K., Sako, M., Schneider, D. P., Zheng, C., Östman, Linda, Nordin, Jakob, Goobar, Ariel, Amanullah, Rahman, Smith, M., Sollerman, Jesper, Stanishev, V., Stritzinger, M., Basset, B. A., Davis, T. M., Edmondson, E., Frieman, J. A., Garnavich, P. M., Lampeitl, H., Leloudas, G., Marriner, J., Nichol, R. C., Romer, K., Sako, M., Schneider, D. P., and Zheng, C.

Abstract

Context. The Sloan Digital Sky Survey II (SDSS-II) Supernova Survey, conducted between 2005 and 2007, was designed to detect a large number of type Ia supernovae around z ~ 0.2, the redshift "gap" between low-z and high-z supernova searches. The survey has provided multi-band (ugriz) photometric lightcurves for variable targets, and supernova candidates were scheduled for spectroscopic observations, primarily to provide supernova classification and accurate redshifts. We present supernova spectra obtained in 2006 and 2007 using the New Technology Telescope (NTT) and the Nordic Optical Telescope (NOT). Aims: We provide an atlas of supernova spectra in the range z = 0.03-0.32 that complements the well-sampled lightcurves from SDSS-II in the forthcoming three-year SDSS supernova cosmology analysis. The sample can, for example, be used for spectral studies of type Ia supernovae, which are critical for understanding potential systematic effects when supernovae are used to determine cosmological distances. Methods: The spectra were reduced in a uniform manner, and special care was taken in estimating the uncertainties for the different processing steps. Host-galaxy light was subtracted when possible and the supernova type fitted using the SuperNova IDentification code (SNID). We also present comparisons between spectral and photometric dating using SALT lightcurve fits to the photometry from SDSS-II, as well as the global distribution of our sample in terms of the lightcurve parameters: stretch and colour. Results: We report new spectroscopic data from 141 type Ia supernovae, mainly between -9 and +15 days from lightcurve maximum, including a few cases of multi-epoch observations. This homogeneous, host-galaxy subtracted, type Ia supernova spectroscopic sample is among the largest such data sets and unique in its redshift interval. The sample includes two potential SN 1991T-like supernovae (SN 2006on and SN 2007ni) and one potential SN 2002cx-like supernova (SN 2007ie). I

Published
2011
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26. EVIDENCE FOR A CORRELATION BETWEEN THE Si II lambda 4000 WIDTH AND TYPE Ia SUPERNOVA COLOR

Author

Nordin, Jakob, Östman, Linda, Goobar, Ariel, Balland, C., Lampeitl, H., Nichol, R. C., Sako, M., Schneider, D. P., Smith, M., Sollerman, Jesper, Wheeler, J. C., Nordin, Jakob, Östman, Linda, Goobar, Ariel, Balland, C., Lampeitl, H., Nichol, R. C., Sako, M., Schneider, D. P., Smith, M., Sollerman, Jesper, and Wheeler, J. C.

Abstract

We study the pseudo-equivalent width of the Si II lambda 4000 feature of Type Ia supernovae (SNe Ia) in the redshift range 0.0024 <= z <= 0.634. We find that this spectral indicator correlates with the light curve color excess (SALT2c) as well as previously defined spectroscopic subclasses (Branch types) and the evolution of the Si II lambda 6150 velocity, i.e., the so-called velocity gradient. Based on our study of 55 objects from different surveys, we find indications that the Si II lambda 4000 spectral indicator could provide important information to improve cosmological distance measurements with SNe Ia., authorCount :11

Published
2011
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27. Measurement of the radial distribution of Cherenkov light generated by TeV gamma-ray air showers

Author

Aharonian, F. A., Akhperjanian, A. G., Barrio, J. A., Bernlöhr, K., Bojahr, H., Contreras, J. L., Juan Cortina, Daum, A., Deckers, T., Fonseca, V., Fraß, A., Gonzalez, J. C., Heinzelmann, G., Hemberger, M., Hermann, G., Heß, M., Heusler, A., Hofmann, W., Hohl, H., Holl, I., Horns, D., Ibarra, I., Kankanyan, R., Kestel, M., Kirstein, O., Köhler, C., Konopelko, A., Kornmayer, H., Kranich, D., Krawczynski, H., Lampeitl, H., Lindner, A., Lorenz, E., Magnussen, N., Meyer, H., Mirzoyan, R., Moralejo, A., Padilla, L., Panter, M., Petry, D., Plaga, R., Prahl, J., Prosch, C., Pühlhofer, G., Rauterberg, G., Rhode, W., Röhring, A., Samorski, M., Schmele, D., Schröder, F., Stamm, W., Ulrich, M., Völk, H. J., Wiebel-Sooth, B., Wiedner, C. A., Willmer, M., and Wirth, H.

Subjects
Physics, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Gamma ray, Astrophysics::Instrumentation and Methods for Astrophysics, HEGRA, FOS: Physical sciences, Astronomy and Astrophysics, IACT, Radial distribution, Astrophysics, Shower, Air shower, High Energy Physics::Experiment, Cherenkov radiation, Zenith
Abstract

Using air showers induced by TeV gamma-rays from Mrk 501, the radial distribution of Cherenkov light is investigated. The shower geometry is reconstructed from the stereoscopic shower images obtained with the telescopes of the HEGRA IACT system. We observe a change in the shape of the light pool with shower energy, and with zenith angle. Data are well reproduced by Monte-Carlo air shower simulations., Comment: 15 Pages, 8 figures, Latex

Published
1998
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28. The time structure of Cherenkov images generated by TeV gamma-rays and by cosmic rays

Author

Heß, M., Bernlöhra, K., Daum, A., Hemberger, M., Hermann, G., Hofmann, W., Lampeitl, H., Aharonian, F. A., Akhperjanian, A. G., Barrio, J. A., Beteta, J. J. G., Contreras, J. L., Juan Cortina, Deckers, T., Fernandez, J., Fonseca, V., Gonzalez, J. C., Heinzelmann, G., Heusler, A., Hohl, H., Holl, I., Horns, D., Kankanyan, R., Kestel, M., Kirstein, O., Köhler, C., Konopelko, A., Kornmayer, H., Kranich, D., Krawczynski, H., Lindner, A., Lorenz, E., Magnussen, N., Meyer, H., Mirzoyan, R., Moralejo, A., Padilla, L., Panter, M., Petry, D., Plaga, R., Prahl, J., Prosch, C., Pühlhofer, G., Rauterberg, G., Rhode, W., Röhring, A., Samorski, M., Sanchez, J. A., Schmele, D., Schröder, F., Stamm, W., Völk, H. J., Wiebel-Sooth, B., Wiedner, C. A., and Willmer, M.

Subjects
Physics, Photon, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Gamma ray, Astrophysics::Instrumentation and Methods for Astrophysics, HEGRA, FOS: Physical sciences, Astronomy and Astrophysics, Cosmic ray, Astrophysics, law.invention, Core (optical fiber), Telescope, Shower, law, Cherenkov radiation
Abstract

The time profiles of Cherenkov images of cosmic-ray showers and of gamma-ray showers are investigated, using data gathered with the HEGRA system of imaging atmospheric Cherenkov telescopes during the 1997 outbursts of Mrk 501. Photon arrival times are shown to vary across the shower images. The dominant feature is a time gradient along the major axis of the images. The gradient varies with the distance between the telescope and the shower core, and is maximal for large distances. The time profiles of cosmic-ray showers and of gamma-ray showers differ in a characteristic fashion. The main features of the time profiles can be understood in terms of simple geometrical models. Use of the timing information towards improved shower reconstruction and cosmic-ray suppression is discussed., Comment: 25 Pages, 16 figures, Latex

Published
1998
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29. The Sloan Digital Sky Survey monitor telescope pipeline

Author

Department of Physics, University of Michigan, 500 East University, Ann Arbor, MI 48109-1120, USA, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510, USA ; Dept. of Astronomy and Astrophysics, The University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637, USA, Physics Department, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623-5603, USA, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510, USA, Deptartment of Physics & Astronomy, Austin Peay State University, P.O. Box 4608, Clarksville, TN 37044 USA ; Los Alamos National Laboratory, ISR-4, MS D448, Los Alamos, NM 87545-0000, USA ; Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071, USA, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510, USA ; Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071, USA, Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071, USA, Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349, USA, Institute of Astronomy, School of Science, University of Tokyo, Osawa 2-21-1, Mitaka, Tokyo 181-0015, Japan, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA ; Princeton University Observatory, Peyton Hall, Princeton, NJ 08544, USA, Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwa, Kashiwa City, Chiba 277-8582, Japan, Princeton University Observatory, Peyton Hall, Princeton, NJ 08544, USA ; University of California at Berkeley, Depts. of Physics and Astronomy, 601 Campbell Hall, Berkeley, CA 94720, USA, Princeton University Observatory, Peyton Hall, Princeton, NJ 08544, USA, Department of Physics, New York University, 4 Washington Place, New York, NY 10003, USA, National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan, Princeton University Observatory, Peyton Hall, Princeton, NJ 08544, USA ; Department of Astronomy, University of Washington, Box 351580, Seattle WA 98195-1580 USA, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510, USA ; Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510, USA ; Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley CA 94720-8160, USA, Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15232, USA ; Dept. of Astronomy, 105-24, California Inst. of Tech., 1201 East California Boulevard, Pasadena, CA 91125, USA, US Naval Observatory, Flagstaff Station, P.O. Box 1149, Flagstaff, AZ 86002, USA, Dept. of Physics, Appl. Phys., Astron., Rensselaer Polytech. Inst., 100 Eighth Street, Troy, NY 12180-3590, USA, Princeton University Observatory, Peyton Hall, Princeton, NJ 08544, USA ; Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley CA 94720-8160, USA, Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101, USA, Kent, S., Richmond, M. W., Annis, J., Smith, J. A., Allam, S. S., Rodgers, C. T., Stute, J. L., Adelman-Mc Carthy, J. K., Brinkmann, J., Doi, M., Finkbeiner, D., Fukugita, M., Goldston, J., Greenway, B., Gunn, J. E., Hendry, J. S., Hogg, D. W., Ichikawa, S. -I., Ivezić, [zcaron]., Knapp, G. R., Lampeitl, H., Lee, B. C., Lin, H., McKay, T. A., Merrelli, A., Munn, J. A., Neilsen, E. H., Newberg, H. J., Richards, G. T., Schlegel, D. J., Stoughton, C., Uomoto, A., Yanny, B., Department of Physics, University of Michigan, 500 East University, Ann Arbor, MI 48109-1120, USA, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510, USA ; Dept. of Astronomy and Astrophysics, The University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637, USA, Physics Department, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623-5603, USA, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510, USA, Deptartment of Physics & Astronomy, Austin Peay State University, P.O. Box 4608, Clarksville, TN 37044 USA ; Los Alamos National Laboratory, ISR-4, MS D448, Los Alamos, NM 87545-0000, USA ; Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071, USA, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510, USA ; Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071, USA, Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071, USA, Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349, USA, Institute of Astronomy, School of Science, University of Tokyo, Osawa 2-21-1, Mitaka, Tokyo 181-0015, Japan, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA ; Princeton University Observatory, Peyton Hall, Princeton, NJ 08544, USA, Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwa, Kashiwa City, Chiba 277-8582, Japan, Princeton University Observatory, Peyton Hall, Princeton, NJ 08544, USA ; University of California at Berkeley, Depts. of Physics and Astronomy, 601 Campbell Hall, Berkeley, CA 94720, USA, Princeton University Observatory, Peyton Hall, Princeton, NJ 08544, USA, Department of Physics, New York University, 4 Washington Place, New York, NY 10003, USA, National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan, Princeton University Observatory, Peyton Hall, Princeton, NJ 08544, USA ; Department of Astronomy, University of Washington, Box 351580, Seattle WA 98195-1580 USA, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510, USA ; Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510, USA ; Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley CA 94720-8160, USA, Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15232, USA ; Dept. of Astronomy, 105-24, California Inst. of Tech., 1201 East California Boulevard, Pasadena, CA 91125, USA, US Naval Observatory, Flagstaff Station, P.O. Box 1149, Flagstaff, AZ 86002, USA, Dept. of Physics, Appl. Phys., Astron., Rensselaer Polytech. Inst., 100 Eighth Street, Troy, NY 12180-3590, USA, Princeton University Observatory, Peyton Hall, Princeton, NJ 08544, USA ; Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley CA 94720-8160, USA, Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101, USA, Kent, S., Richmond, M. W., Annis, J., Smith, J. A., Allam, S. S., Rodgers, C. T., Stute, J. L., Adelman-Mc Carthy, J. K., Brinkmann, J., Doi, M., Finkbeiner, D., Fukugita, M., Goldston, J., Greenway, B., Gunn, J. E., Hendry, J. S., Hogg, D. W., Ichikawa, S. -I., Ivezić, [zcaron]., Knapp, G. R., Lampeitl, H., Lee, B. C., Lin, H., McKay, T. A., Merrelli, A., Munn, J. A., Neilsen, E. H., Newberg, H. J., Richards, G. T., Schlegel, D. J., Stoughton, C., Uomoto, A., and Yanny, B.

Abstract

The photometric calibration of the Sloan Digital Sky Survey (SDSS) is a multi-step process which involves data from three different telescopes: the 1.0-m telescope at the US Naval Observatory (USNO), Flagstaff Station, Arizona (which was used to establish the SDSS standard star network); the SDSS 0.5-m Photometric Telescope (PT) at the Apache Point Observatory (APO), NewMexico (which calculates nightly extinctions and calibrates secondary patch transfer fields); and the SDSS 2.5-m telescope at APO (which obtains the imaging data for the SDSS proper). In this paper, we describe the Monitor Telescope Pipeline, MTPIPE, the software pipeline used in processing the data from the single-CCD telescopes used in the photometric calibration of the SDSS (i.e., the USNO 1.0-m and the PT). We also describe transformation equations that convert photometry on the USNO-1.0m u ′ g ′ r ′ i ′ z ′ system to photometry the SDSS 2.5m ugriz system and the results of various validation tests of the MTPIPE software. Further, we discuss the semi-automated PT factory, which runs MTPIPE in the day-to-day standard SDSS operations at Fermilab. Finally, we discuss the use of MTPIPE in current SDSS-related projects, including the Southern u ′ g ′ r ′ i ′ z ′ Standard Star project, the u ′ g ′ r ′ i ′ z ′ Open Star Clusters project, and the SDSS extension (SDSS-II). (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Published
2007

32. PHOTOMETRIC SUPERNOVA COSMOLOGY WITH BEAMS AND SDSS-II

Author

Hlozek R, Kunz M, Bassett B, Smith M, Newling J, Varughese M, Kessler R, Bernstein JP, Campbell H, Dilday B, Falck B, Frieman J, Kuhlmann S, Lampeitl H, Marriner J, Nichol RC, Riess AG, Sako M, and Schneider DP

Published
2012

33. NTT and NOT spectroscopy of SDSS-II supernovae

Author

Östman, L., primary, Nordin, J., additional, Goobar, A., additional, Amanullah, R., additional, Smith, M., additional, Sollerman, J., additional, Stanishev, V., additional, Stritzinger, M. D., additional, Bassett, B. A., additional, Davis, T. M., additional, Edmondson, E., additional, Frieman, J. A., additional, Garnavich, P. M., additional, Lampeitl, H., additional, Leloudas, G., additional, Marriner, J., additional, Nichol, R. C., additional, Romer, K., additional, Sako, M., additional, Schneider, D. P., additional, and Zheng, C., additional

Published
2010
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34. First-year Sloan Digital Sky Survey-II supernova results: consistency and constraints with other intermediate-redshift data sets

Author

Lampeitl, H., primary, Nichol, R. C., additional, Seo, H.-J., additional, Giannantonio, T., additional, Shapiro, C., additional, Bassett, B., additional, Percival, W. J., additional, Davis, T. M., additional, Dilday, B., additional, Frieman, J., additional, Garnavich, P., additional, Sako, M., additional, Smith, M., additional, Sollerman, J., additional, Becker, A.C., additional, Cinabro, D., additional, Filippenko, A. V., additional, Foley, R. J., additional, Hogan, C. J., additional, Holtzman, J. A., additional, Jha, S. W., additional, Konishi, K., additional, Marriner, J., additional, Richmond, M. W., additional, Riess, A. G., additional, Schneider, D. P., additional, Stritzinger, M., additional, van der Heyden, K. J., additional, VanderPlas, J. T., additional, Wheeler, J. C., additional, and Zheng, C., additional

Published
2010
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35. FIRST-YEAR SLOAN DIGITAL SKY SURVEY-II (SDSS-II) SUPERNOVA RESULTS: CONSTRAINTS ON NONSTANDARD COSMOLOGICAL MODELS

Author

Sollerman, J., primary, Mörtsell, E., additional, Davis, T. M., additional, Blomqvist, M., additional, Bassett, B., additional, Becker, A. C., additional, Cinabro, D., additional, Filippenko, A. V., additional, Foley, R. J., additional, Frieman, J., additional, Garnavich, P., additional, Lampeitl, H., additional, Marriner, J., additional, Miquel, R., additional, Nichol, R. C., additional, Richmond, M. W., additional, Sako, M., additional, Schneider, D. P., additional, Smith, M., additional, Vanderplas, J. T., additional, and Wheeler, J. C., additional

Published
2009
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36. The Sloan Digital Sky Survey monitor telescope pipeline

Author

Tucker, D.L., primary, Kent, S., additional, Richmond, M.W., additional, Annis, J., additional, Smith, J.A., additional, Allam, S.S., additional, Rodgers, C.T., additional, Stute, J.L., additional, Adelman-McCarthy, J.K., additional, Brinkmann, J., additional, Doi, M., additional, Finkbeiner, D., additional, Fukugita, M., additional, Goldston, J., additional, Greenway, B., additional, Gunn, J.E., additional, Hendry, J.S., additional, Hogg, D.W., additional, Ichikawa, S.-I., additional, Ivezić, Ž., additional, Knapp, G.R., additional, Lampeitl, H., additional, Lee, B.C., additional, Lin, H., additional, McKay, T.A., additional, Merrelli, A., additional, Munn, J.A., additional, Neilsen, E.H., additional, Newberg, H.J., additional, Richards, G.T., additional, Schlegel, D.J., additional, Stoughton, C., additional, Uomoto, A., additional, and Yanny, B., additional

Published
2006
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37. Observations of 14 young open star clusters with the HEGRA system of Cherenkov telescopes

Author

Aharonian, F., primary, Akhperjanian, A., additional, Beilicke, M., additional, Bernlöhr, K., additional, Börst, H.-G., additional, Bojahr, H., additional, Bolz, O., additional, Coarasa, T., additional, Contreras, J. L., additional, Cortina, J., additional, Denninghoff, S., additional, Fonseca, M. V., additional, Girma, M., additional, Götting, N., additional, Heinzelmann, G., additional, Hermann, G., additional, Heusler, A., additional, Hofmann, W., additional, Horns, D., additional, Jung, I., additional, Kankanyan, R., additional, Kestel, M., additional, Konopelko, A., additional, Kornmeyer, H., additional, Kranich, D., additional, Lampeitl, H., additional, Lopez, M., additional, Lorenz, E., additional, Lucarelli, F., additional, Mang, O., additional, Meyer, H., additional, Mirzoyan, R., additional, Moralejo, A., additional, Ona-Wilhelmi, E., additional, Panter, M., additional, Plyasheshnikov, A., additional, Pühlhofer, G., additional, de los Reyes, R., additional, Rhode, W., additional, Ripken, J., additional, Rowell, G., additional, Sahakian, V., additional, Samorski, M., additional, Schilling, M., additional, Siems, M., additional, Sobzynska, D., additional, Stamm, W., additional, Tluczykont, M., additional, Vitale, V., additional, Völk, H. J., additional, Wiedner, C. A., additional, and Wittek, W., additional

Published
2006
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38. The Crab Nebula and Pulsar between 500 GeV and 80 TeV: Observations with the HEGRA Stereoscopic Air Cerenkov Telescopes

Author

Aharonian, F., primary, Akhperjanian, A., additional, Beilicke, M., additional, Bernlohr, K., additional, Borst, H.‐G., additional, Bojahr, H., additional, Bolz, O., additional, Coarasa, T., additional, Contreras, J. L., additional, Cortina, J., additional, Denninghoff, S., additional, Fonseca, M. V., additional, Girma, M., additional, Gotting, N., additional, Heinzelmann, G., additional, Hermann, G., additional, Heusler, A., additional, Hofmann, W., additional, Horns, D., additional, Jung, I., additional, Kankanyan, R., additional, Kestel, M., additional, Kohnle, A., additional, Konopelko, A., additional, Kranich, D., additional, Lampeitl, H., additional, Lopez, M., additional, Lorenz, E., additional, Lucarelli, F., additional, Mang, O., additional, Mazin, D., additional, Meyer, H., additional, Mirzoyan, R., additional, Moralejo, A., additional, Ona‐Wilhelmi, E., additional, Panter, M., additional, Plyasheshnikov, A., additional, Puhlhofer, G., additional, de los Reyes, R., additional, Rhode, W., additional, Ripken, J., additional, Rowell, G., additional, Sahakian, V., additional, Samorski, M., additional, Schilling, M., additional, Siems, M., additional, Sobzynska, D., additional, Stamm, W., additional, Tluczykont, M., additional, Vitale, V., additional, Volk, H. J., additional, Wiedner, C. A., additional, and Wittek, W., additional

Published
2004
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39. Search for TeV gamma ray emission from the Andromeda galaxy

Author

Aharonian, F. A., primary, Akhperjanian, A. G., additional, Beilicke, M., additional, Bernlöhr, K., additional, Bojahr, H., additional, Bolz, O., additional, Börst, H., additional, Coarasa, T., additional, Contreras, J. L., additional, Cortina, J., additional, Denninghoff, S., additional, Fonseca, V., additional, Girma, M., additional, Götting, N., additional, Heinzelmann, G., additional, Hermann, G., additional, Heusler, A., additional, Hofmann, W., additional, Horns, D., additional, Jung, I., additional, Kankanyan, R., additional, Kestel, M., additional, Kettler, J., additional, Kohnle, A., additional, Konopelko, A., additional, Kornmeyer, H., additional, Kranich, D., additional, Krawczynski, H., additional, Lampeitl, H., additional, Lopez, M., additional, Lorenz, E., additional, Lucarelli, F., additional, Mang, O., additional, Meyer, H., additional, Mirzoyan, R., additional, Moralejo, A., additional, Ona, E., additional, Panter, M., additional, Plyasheshnikov, A., additional, Pühlhofer, G., additional, Rauterberg, G., additional, Reyes, R., additional, Rhode, W., additional, Ripken, J., additional, Röhring, A., additional, Rowell, G. P., additional, Sahakian, V., additional, Samorski, M., additional, Schilling, M., additional, Siems, M., additional, Sobzynska, D., additional, Stamm, W., additional, Tluczykont, M., additional, Völk, H. J., additional, Wiedner, C. A., additional, and Wittek, W., additional

Published
2003
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40. A search for TeV gamma-ray emission from SNRs, pulsars and unidentified GeV sources in the Galactic plane in the longitude range between $-2^\circ$ and $85^\circ$

Author

Aharonian, F. A., primary, Akhperjanian, A. G., additional, Beilicke, M., additional, Bernlöhr, K., additional, Bojahr, H., additional, Bolz, O., additional, Börst, H., additional, Coarasa, T., additional, Contreras, J. L., additional, Cortina, J., additional, Denninghoff, S., additional, Fonseca, V., additional, Girma, M., additional, Götting, N., additional, Heinzelmann, G., additional, Hermann, G., additional, Heusler, A., additional, Hofmann, W., additional, Horns, D., additional, Jung, I., additional, Kankanyan, R., additional, Kestel, M., additional, Kettler, J., additional, Kohnle, A., additional, Konopelko, A., additional, Kornmeyer, H., additional, Kranich, D., additional, Krawczynski, H., additional, Lampeitl, H., additional, Lopez, M., additional, Lorenz, E., additional, Lucarelli, F., additional, Mang, O., additional, Meyer, H., additional, Mirzoyan, R., additional, Moralejo, A., additional, Ona, E., additional, Panter, M., additional, Plyasheshnikov, A., additional, Pühlhofer, G., additional, Rauterberg, G., additional, Reyes, R., additional, Rhode, W., additional, Ripken, J., additional, Röhring, A., additional, Rowell, G. P., additional, Sahakian, V., additional, Samorski, M., additional, Schilling, M., additional, Siems, M., additional, Sobzynska, D., additional, Stamm, W., additional, Tluczykont, M., additional, Völk, H. J., additional, Wiedner, C. A., additional, and Wittek, W., additional

Published
2002
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42. Search for point sources of gamma radiation above 15 TeV with the HEGRA AIROBICC array

Author

Aharonian, F., primary, Akhperjanian, A., additional, Barrio, J. A., additional, Bernlöhr, K., additional, Börst, H., additional, Bojahr, H., additional, Bolz, O., additional, Contreras, J. L., additional, Cortina, J., additional, Denninghoff, S., additional, Fonseca, V., additional, Gebauer, H. J., additional, González, J., additional, Götting, N., additional, Heinzelmann, G., additional, Hermann, G., additional, Heusler, A., additional, Hofmann, W., additional, Horns, D., additional, Jung, I., additional, Kankanyan, R., additional, Kestel, M., additional, Kettler, J., additional, Kohnle, A., additional, Konopelko, A., additional, Kornmayer, H., additional, Kranich, D., additional, Krawczynski, H., additional, Lampeitl, H., additional, López, M., additional, Lorenz, E., additional, Lucarelli, F., additional, Magnussen, N., additional, Mang, O., additional, Meyer, H., additional, Mirzoyan, R., additional, Moralejo, A., additional, Oña, E., additional, Padilla, L., additional, Panter, M., additional, Plaga, R., additional, Plyasheshnikov, A., additional, Prahl, J., additional, Pühlhofer, G., additional, Rauterberg, G., additional, Röhring, A., additional, Rhode, W., additional, Rowell, G., additional, Sahakian, V., additional, Samorski, M., additional, Schilling, M., additional, Schmele, D., additional, Schröder, F., additional, Sevilla, I., additional, Siems, M., additional, Stamm, W., additional, Tluczykont, M., additional, Völk, H. J., additional, Wiedner, C. A., additional, and Wittek, W., additional

Published
2002
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43. TeV gamma rays from the blazar H 1426+428 and the diffuse extragalactic background radiation

Author

Aharonian, F., primary, Akhperjanian, A., additional, Barrio, J., additional, Beilicke, M., additional, Bernlöhr, K., additional, Börst, H., additional, Bojahr, H., additional, Bolz, O., additional, Contreras, J., additional, Cornils, R., additional, Cortina, J., additional, Denninghoff, S., additional, Fonseca, V., additional, Girma, M., additional, Gonzalez, J., additional, Götting, N., additional, Heinzelmann, G., additional, Hermann, G., additional, Heusler, A., additional, Hofmann, W., additional, Horns, D., additional, Jung, I., additional, Kankanyan, R., additional, Kestel, M., additional, Kettler, J., additional, Kohnle, A., additional, Konopelko, A., additional, Kornmeyer, H., additional, Kranich, D., additional, Krawczynski, H., additional, Lampeitl, H., additional, Lopez, M., additional, Lorenz, E., additional, Lucarelli, F., additional, Magnussen, N., additional, Mang, O., additional, Meyer, H., additional, Mirzoyan, R., additional, Moralejo, A., additional, Ona, E., additional, Padilla, L., additional, Panter, M., additional, Plaga, R., additional, Plyasheshnikov, A., additional, Pühlhofer, G., additional, Rauterberg, G., additional, Röhring, A., additional, Rhode, W., additional, Robrade, J., additional, Rowell, G., additional, Sahakian, V., additional, Samorski, M., additional, Schilling, M., additional, Schröder, F., additional, Sevilla, I., additional, Siems, M., additional, Stamm, W., additional, Tluczykont, M., additional, Völk, H. J., additional, Wiedner, C. A., additional, and Wittek, W., additional

Published
2002
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44. TeV gamma-ray observations of SS-433 and a survey of the surrounding field with the HEGRA IACT-System

Author

Aharonian, F., Akhperjanian, A., Beilicke, M., Bernlöhr, K., Börst, H.-G., Bojahr, H., Bolz, O., Coarasa, T., Contreras, J., Cortina, J., Denninghoff, S., Fonseca, V., Girma, M., Götting, N., Heinzelmann, G., Hermann, G., Heusler, A., Hofmann, W., Horns, D., Jung, I., Kankanyan, R., Kestel, M., Kohnle, A., Konopelko, A., Kranich, D., Lampeitl, H., Lopez, M., Lorenz, E., Lucarelli, F., Mang, O., Mazin, D., Meyer, H., Mirzoyan, R., Moralejo, A., Oña-Wilhelmi, E., Panter, M., Plyasheshnikov, A., Pühlhofer, G., Reyes, R. de los, Rhode, W., Ripken, J., Rowell, G. P., Sahakian, V., Samorski, M., Schilling, M., Siems, M., Sobzynska, D., Stamm, W., Tluczykont, M., Vitale, V., Völk, H. J., Wiedner, C. A., Wittek, W., Aharonian, F., Akhperjanian, A., Beilicke, M., Bernlöhr, K., Börst, H.-G., Bojahr, H., Bolz, O., Coarasa, T., Contreras, J., Cortina, J., Denninghoff, S., Fonseca, V., Girma, M., Götting, N., Heinzelmann, G., Hermann, G., Heusler, A., Hofmann, W., Horns, D., Jung, I., Kankanyan, R., Kestel, M., Kohnle, A., Konopelko, A., Kranich, D., Lampeitl, H., Lopez, M., Lorenz, E., Lucarelli, F., Mang, O., Mazin, D., Meyer, H., Mirzoyan, R., Moralejo, A., Oña-Wilhelmi, E., Panter, M., Plyasheshnikov, A., Pühlhofer, G., Reyes, R. de los, Rhode, W., Ripken, J., Rowell, G. P., Sahakian, V., Samorski, M., Schilling, M., Siems, M., Sobzynska, D., Stamm, W., Tluczykont, M., Vitale, V., Völk, H. J., Wiedner, C. A., and Wittek, W.

Abstract

We present results of a search for TeV γ-ray emission from the microquasar SS-433 and the surrounding region covering a ~$8^\circ$$\times$$8^\circ$field of view. Analysis of data taken with the HEGRA stereoscopic system of imaging atmospheric Čerenkov imaging telescopes reveals no evidence of steady or variable emission from any position. Observation times of over 100 h have been achieved in central parts of the field of view. We set 99% confidence level upper limits to a number of a-priori-chosen objects of interest, including SS-443 and its interaction regions, 32 pulsars, 3 supernova remnants and the GeV source GeV J1907+0537. Our upper limit of 3.2% Crab flux (for energies $E>0.8$TeV) for the eastern-lobe region e3of SS-433 permits, after comparison with X-ray fluxes, a lower limit of $B\geq19~\mu$G on the post-shocked magnetic field in this region. An ensemble upper limit at 0.3% Crab flux ($E>0.7$TeV) from a subset (11) of the 32 pulsars implies a maximum of 4.5% of the spin-down pulsar power is available for TeV γ-ray production. For one of the SNR in our FoV, 3C 396, recent Chandra observations suggest that a central pulsar-driven wind nebula may be the source of X-ray emission. Our upper limit implies that a maximum of 0.1% of the spin-down power from the central source of 3C 396 would be available for TeV γ-rays.

Published
2005
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45. Simultaneous X‐Ray and TeV Gamma‐Ray Observation of the TeV Blazar Markarian 421 during 2000 February and May

Author

Krawczynski, H., primary, Sambruna, R., additional, Kohnle, A., additional, Coppi, P. S., additional, Aharonian, F., additional, Akhperjanian, A., additional, Barrio, J., additional, Bernlohr, K., additional, Borst, H., additional, Bojahr, H., additional, Bolz, O., additional, Contreras, J., additional, Cortina, J., additional, Denninghoff, S., additional, Fonseca, V., additional, Gonzalez, J., additional, Gotting, N., additional, Heinzelmann, G., additional, Hermann, G., additional, Heusler, A., additional, Hofmann, W., additional, Horns, D., additional, Ibarra, A., additional, Jung, I., additional, Kankanyan, R., additional, Kestel, M., additional, Kettler, J., additional, Konopelko, A., additional, Kornmeyer, H., additional, Kranich, D., additional, Lampeitl, H., additional, Lorenz, E., additional, Lucarelli, F., additional, Magnussen, N., additional, Mang, O., additional, Meyer, H., additional, Mirzoyan, R., additional, Moralejo, A., additional, Padilla, L., additional, Panter, M., additional, Plaga, R., additional, Plyasheshnikov, A., additional, Puhlhofer, G., additional, Rauterberg, G., additional, Rohring, A., additional, Rhode, W., additional, Rowell, G., additional, Sahakian, V., additional, Samorski, M., additional, Schilling, M., additional, Schroder, F., additional, Siems, M., additional, Stamm, W., additional, Tluczykont, M., additional, Volk, H. J., additional, Wiedner, C. A., additional, and Wittek, W., additional

Published
2001
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46. A search for gamma-ray emission from the Galactic plane in the longitude range between $\mathsf{37}^\circ$ and $\mathsf{43}^\circ$

Author

Aharonian, F. A., primary, Akhperjanian, A. G., additional, Barrio, J. A., additional, Bernlöhr, K., additional, Bolz, O., additional, Börst, H., additional, Bojahr, H., additional, Contreras, J. L., additional, Cortina, J., additional, Denninghoff, S., additional, Fonseca, V., additional, Gonzalez, J. C., additional, Götting, N., additional, Heinzelmann, G., additional, Hermann, G., additional, Heusler, A., additional, Hofmann, W., additional, Horns, D., additional, Ibarra, A., additional, Iserlohe, C., additional, Jung, I., additional, Kankanyan, R., additional, Kestel, M., additional, Kettler, J., additional, Kohnle, A., additional, Konopelko, A., additional, Kornmeyer, H., additional, Kranich, D., additional, Krawczynski, H., additional, Lampeitl, H., additional, Lorenz, E., additional, Lucarelli, F., additional, Magnussen, N., additional, Mang, O., additional, Meyer, H., additional, Mirzoyan, R., additional, Moralejo, A., additional, Padilla, L., additional, Panter, M., additional, Plaga, R., additional, Plyasheshnikov, A., additional, Prahl, J., additional, Pühlhofer, G., additional, Rhode, W., additional, Röhring, A., additional, Rowell, G. P., additional, Sahakian, V., additional, Samorski, M., additional, Schilling, M., additional, Schröder, F., additional, Siems, M., additional, Stamm, W., additional, Tluczykont, M., additional, Völk, H. J., additional, Wiedner, C. A., additional, and Wittek, W., additional

Published
2001
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47. A study of Tycho's SNR at TeV energies with the HEGRA CT-System

Author

Aharonian, F. A., primary, Akhperjanian, A. G., additional, Barrio, J. A., additional, Bernlöhr, K., additional, Börst, H., additional, Bojahr, H., additional, Bolz, O., additional, Contreras, J. L., additional, Cortina, J., additional, Denninghoff, S., additional, Fonseca, V., additional, Gonzalez, J. C., additional, Götting, N., additional, Heinzelmann, G., additional, Hermann, G., additional, Heusler, A., additional, Hofmann, W., additional, Horns, D., additional, Ibarra, A., additional, Jung, I., additional, Kankanyan, R., additional, Kestel, M., additional, Kettler, J., additional, Kohnle, A., additional, Konopelko, A., additional, Kornmeyer, H., additional, Kranich, D., additional, Krawczynski, H., additional, Lampeitl, H., additional, Lorenz, E., additional, Lucarelli, F., additional, Magnussen, N., additional, Mang, O., additional, Meyer, H., additional, Mirzoyan, R., additional, Moralejo, A., additional, Padilla, L., additional, Panter, M., additional, Plaga, R., additional, Plyasheshnikov, A., additional, Prahl, J., additional, Pühlhofer, G., additional, Rauterberg, G., additional, Röhring, A., additional, Rhode, W., additional, Rowell, G. P., additional, Sahakian, V., additional, Samorski, M., additional, Schilling, M., additional, Schröder, F., additional, Stamm, W., additional, Tluczykont, M., additional, Völk, H. J., additional, Wiedner, C., additional, and Wittek, W., additional

Published
2001
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48. Evidence for TeV gamma ray emission from Cassiopeia A

Author

Aharonian, F., primary, Akhperjanian, A., additional, Barrio, J., additional, Bernlöhr, K., additional, Börst, H., additional, Bojahr, H., additional, Bolz, O., additional, Contreras, J., additional, Cortina, J., additional, Denninghoff, S., additional, Fonseca, V., additional, Gonzalez, J., additional, Götting, N., additional, Heinzelmann, G., additional, Hermann, G., additional, Heusler, A., additional, Hofmann, W., additional, Horns, D., additional, Ibarra, A., additional, Iserlohe, C., additional, Jung, I., additional, Kankanyan, R., additional, Kestel, M., additional, Kettler, J., additional, Kohnle, A., additional, Konopelko, A., additional, Kornmeyer, H., additional, Kranich, D., additional, Krawczynski, H., additional, Lampeitl, H., additional, Lopez, M., additional, Lorenz, E., additional, Lucarelli, F., additional, Magnussen, N., additional, Mang, O., additional, Meyer, H., additional, Mirzoyan, R., additional, Moralejo, A., additional, Ona, E., additional, Padilla, L., additional, Panter, M., additional, Plaga, R., additional, Plyasheshnikov, A., additional, Prahl, J., additional, Pühlhofer, G., additional, Rauterberg, G., additional, Röhring, A., additional, Rhode, W., additional, Rowell, G. P., additional, Sahakian, V., additional, Samorski, M., additional, Schilling, M., additional, Schröder, F., additional, Siems, M., additional, Stamm, W., additional, Tluczykont, M., additional, Völk, H. J., additional, Wiedner, C. A., additional, and Wittek, W., additional

Published
2001
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49. Search for a TeV gamma-ray halo of Mkn 501

Author

Aharonian, F. A., primary, Akhperjanian, A. G., additional, Barrio, J. A., additional, Bernlöhr, K., additional, Bolz, O., additional, Börst, H., additional, Bojahr, H., additional, Contreras, J. L., additional, Cortina, J., additional, Denninghoff, S., additional, Fonseca, V., additional, Gonzalez, J. C., additional, Götting, N., additional, Heinzelmann, G., additional, Hermann, G., additional, Heusler, A., additional, Hofmann, W., additional, Horns, D., additional, Ibarra, A., additional, Iserlohe, C., additional, Jung, I., additional, Kankanyan, R., additional, Kestel, M., additional, Kettler, J., additional, Kohnle, A., additional, Konopelko, A., additional, Kornmeyer, H., additional, Kranich, D., additional, Krawczynski, H., additional, Lampeitl, H., additional, Lorenz, E., additional, Lucarelli, F., additional, Magnussen, N., additional, Mang, O., additional, Meyer, H., additional, Mirzoyan, R., additional, Moralejo, A., additional, Padilla, L., additional, Panter, M., additional, Plaga, R., additional, Plyasheshnikov, A., additional, Prahl, J., additional, Pühlhofer, G., additional, Rhode, W., additional, Röhring, A., additional, Rowell, G. P., additional, Sahakian, V., additional, Samorski, M., additional, Schilling, M., additional, Schröder, F., additional, Siems, M., additional, Stamm, W., additional, Tluczykont, M., additional, Völk, H. J., additional, Wiedner, C., additional, and Wittek, W., additional

Published
2001
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50. The TeV Energy Spectrum of Markarian 501 Measured with the Stereoscopic Telescope System of HEGRA during 1998 and 1999

Author

Aharonian, F., primary, Akhperjanian, A., additional, Barrio, J., additional, Bernlohr, K., additional, Borst, H., additional, Bojahr, H., additional, Bolz, O., additional, Contreras, J., additional, Cortina, J., additional, Denninghoff, S., additional, Fonseca, V., additional, Gonzalez, J., additional, Gotting, N., additional, Heinzelmann, G., additional, Hermann, G., additional, Heusler, A., additional, Hofmann, W., additional, Horns, D., additional, Iserlohe, C., additional, Ibarra, A., additional, Jung, I., additional, Kankanyan, R., additional, Kestel, M., additional, Kettler, J., additional, Kohnle, A., additional, Konopelko, A., additional, Kornmeyer, H., additional, Kranich, D., additional, Krawczynski, H., additional, Lampeitl, H., additional, Lorenz, E., additional, Lucarelli, F., additional, Magnussen, N., additional, Mang, O., additional, Meyer, H., additional, Mirzoyan, R., additional, Moralejo, A., additional, Padilla, L., additional, Panter, M., additional, Plaga, R., additional, Plyasheshnikov, A., additional, Prahl, J., additional, Puhlhofer, G., additional, Rohring, A., additional, Rhode, W., additional, Rowell, G. P., additional, Sahakian, V., additional, Samorski, M., additional, Schilling, M., additional, Schroder, F., additional, Siems, M., additional, Stamm, W., additional, Tluczykont, M., additional, Volk, H., additional, Wiedner, C., additional, and Wittek, W., additional

Published
2001
Full Text
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