Soft gamma-ray sources detected by INTEGRAL (2009)
Petry, D., Beckmann, V., Halloin, H., Strong, A.
We aim to exploit the available INTEGRAL/SPI data to provide time-averaged spectra of the brightest soft gamma-ray sources. Employing a maximum-likelihood fit technique for our SPI data analysis, we...
Aliu, E., Arlen, T., Beilicke, M., Benbow, W., Boltuch, D., ...
HESS J0632+057 is one of only two unidentified very-high-energy gamma-ray sources which appear to be point-like within experimental resolution. It is possibly associated with the massive Be star MWC...
VERITAS OBSERVATIONS OF A VERY HIGH ENERGY gamma-RAY FLARE FROM THE BLAZAR 3C 66A (2009)
Acciari, V. A., Aliu, E., Arlen, T., Beilicke, M., Benbow, W., Bottcher, M., ...
VERITAS Observations of a Very High Energy Gamma-ray Flare from the Blazar 3C 66A (2009)
Aliu, E., Arlen, T., Beilicke, M., Benbow, W., Bottcher, M., ...
The intermediate-frequency peaked BL Lacertae (IBL) object 3C 66A is detected during 2007 - 2008 in VHE (very high energy: E > 100 GeV) gamma-rays with the VERITAS stereoscopic array of imaging...
Discovery of Very High Energy Gamma-Ray Radiation from the Bl Lac 1es 0806+524 (2009)
Acciari, V., Aliu, E., Arlen, T., Bautista, M., Beilicke, M., Benbow, W., ...
Discovery of Very High-Energy Gamma-Ray Radiation from the BL Lac 1ES 0806+524 (2008)
Aliu, E., Arlen, T., Bautista, M., Beilicke, M., Benbow, W., ...
The high-frequency-peaked BL-Lacertae object \objectname{1ES 0806+524}, at redshift z=0.138, was observed in the very-high-energy (VHE) gamma-ray regime by VERITAS between November 2006 and April...
Aliu, E., Beilicke, M., Benbow, W., Boettcher, M., Bradbury, S. M., ...
We report the detection of very high-energy gamma-ray emission from the intermediate-frequency-peaked BL Lacertae object W Comae (z=0.102) by VERITAS. The source was observed between January and...
Lichti, G. G., Bottacini, E., Ajello, M., Charlot, P., Collmar, W., Falcone, A., ...
We report the results of a multi-wavelength campaign on the blazar Mrk 421 during outburst. We observed four strong flares at X-ray energies that were not seen at other wavelengths (partially because...
Fossati, G., Buckley, J. H., Bond, I. H., Bradbury, S. M., Carter-Lewis, D. A., Chow, Y. C. K., ...
We present a detailed analysis of week-long simultaneous observations of the blazar Mrk 421 at 2-60 keV X-rays (RXTE) and TeV gamma-rays (Whipple and HEGRA) in 2001. Accompanying optical monitoring...
Acciari, V. A., Aliu, E., Beilicke, M., Benbow, W., Bottcher, M., Bradbury, S. M., ...
We report the detection of very high energy gamma- ray emission from the intermediate- frequency- peaked BL Lacertae object W Comae (z = 0.102) by VERITAS. The source was observed between 2008...
A Search for High Energy (2007)
The BL Lac object Markarian 421 was observed in 1994 and 1995 using the two imaging Cherenkov telescopes of the HEGRA experiment on the Canary island La Palma. No significant excess was found in the...
Observations of Very High Energy Gamma-Radiation from Markarian 421 (2007)
This article intends to summarize the observational data on the first extragalactical object to be discovered as a VHE Gamma-ray source, the BL Lac object Mkn 421. After a historical overview, the...
Fl-Radiation From, D. Petry, S. M. Bradbury, A. Konopelko, J. Fernandez, F. Aharonian, ...
A detection of fl-rays from Mkn 421 at energies above 1 TeV is reported. The preliminary results presented here are based on 37.2 hours of ON-Source observations with Telescope 1 (CT1) and 60.0 hours...
Cherenkov Telescope, D. Petry, D. Kranich
Gamma-Hadron separation in Imaging Atmospheric Cherenkov Telescope (IACT) data started by parametrizing shape and orientation of the shower images and applying cuts to them which were...
Fl-Rays From, D. Petry, S. M. Bradbury, A. Konopelko, J. Fernandez, F. Aharonian, ...
. A detection of fl-rays from Mkn 421 at energies above 1 TeV is reported, based on observations made in December 1994 - May 1995 with the first two HEGRA Cherenkov telescopes. From the image...
Fossati, G., Buckley, J. H., Bond, I. H., Bradbury, S. M., Carter-Lewis, D. A., Chow, Y. C. K., ...
(Abridged) We present a detailed analysis of week-long simultaneous observations of the blazar Mrk421 at 2-60 keV X-rays (RXTE) and TeV gamma-rays (Whipple and HEGRA) in 2001. The unprecedented...
Focal Plane Instrumentation of VERITAS (2007)
Nagai, VERITAS Collaboration: T., McKay, R., Sleege, G., Petry, D.
VERITAS is a new atmospheric Cherenkov imaging telescope array to detect very high energy gamma rays above 100 GeV. The array is located in southern Arizona, USA, at an altitude of 1268m above sea...
INTEGRAL and Multiwavelength Observations of the Blazar Mrk 421 during an Active Phase (2007)
Lichti, G. G., Bottacini, E., Charlot, P., Collmar, W., Horan, D., Von Kienlin, A., ...
A ToO observation of the TeV-emitting blazar Mrk 421 with INTEGRAL was triggered in June 2006 by an increase of the RXTE count rate to more than 30 mCrab. The source was then observed with all...
Very High Energy Observations of Gamma-Ray Burst Locations with the Whipple Telescope (2007)
Horan, D., Atkins, R. W., Badran, H. M., Blaylock, G., Bradbury, S. M., Buckley, J. H., ...
Gamma-ray burst (GRB) observations at very high energies (VHE, E > 100 GeV) can impose tight constraints on some GRB emission models. Many GRB afterglow models predict a VHE component similar to that...
Very high energy observations of gamma-ray burst locations with the whipple telescope (2007)
Horan, D., Atkins, R. W., Badran, H. M., Blaylock, G., Bradbury, S. M., Buckley, J. H., ...
Gamma-ray burst (GRB) observations at very high energies (VHE; E > 100 GeV) can impose tight constraints on some GRB emission models. Many GRB afterglow models predict a VHE component similar to that...
The Whipple Observatory 10 m gamma-ray telescope, 1997-2006 (2007)
Kildea, J., Atkins, R. W., Badran, H. M., Blaylock, G., Bond, I. H., Bradbury, S. M., ...
Details are presented of the Whipple Observatory's 10 m atmospheric Cherenkov telescope and camera, as it evolved during the period 1997 until 2006. The design of the telescope and camera's optical...
Very high energy observations of gamma-ray burst locations with the whipple telescope (2007)
Horan, D., Atkins, R. W., Badran, H. M., Blaylock, G., Bradbury, S. M., Buckley, J. H., ...
Gamma-ray burst (GRB) observations at very high energies (VHE; E > 100 GeV) can impose tight constraints on some GRB emission models. Many GRB afterglow models predict a VHE component similar to that...
INTEGRAL and multiwavelength observations of the blazar Mrk 421 during an active phase (2007)
Lichti, G. G., Bottachini, E., Charlot, P., Collmar, W., Horan, D., Von Kienlin, A., ...
The Whipple Observatory 10 m gamma-ray telescope, 1997-2006 (2007)
Kildea, J., Atkins, R. W., Badran, H. M., Blaylock, G., Bond, I. H., Bradbury, S. M., ...
The first VERITAS telescope (2006)
Holder, J., Atkins, R. W., Badran, H. M., Blaylock, G., Bradbury, S. M., Buckley, J. H., ...
The first atmospheric Cherenkov telescope of VERITAS (the Very Energetic Radiation Imaging Telescope Array System) has been in operation since February 2005. We present here a technical description...
Daniel, M. K., Badran, H. M., Bond, I. H., Boyle, P. J., Bradbury, S. M., Buckley, J. H., ...
The blazar 1ES 1959+650 was observed in a flaring state with the Whipple 10 m Imaging Atmospheric Cerenkov Telescope in 2002 May. A spectral analysis has been carried out on the data from that time...
A survey of unidentified egret sources at very high energies (2005)
Fegan, S. J., Badran, H. M., Bond, I. H., Boyle, P. J., Bradbury, S. M., Buckley, J. H., ...
The Whipple Observatory 10 m γ-ray telescope has been used to survey the error boxes of EGRET unidentified sources in an attempt to find counterparts at energies of 350 GeV and above....
Daniel, M. K., Badran, H. M., Bond, I. H., Boyle, P. J., Bradbury, S. M., Buckley, J. H., ...
The blazar 1ES 1959+650 was observed in a flaring state with the Whipple 10 m Imaging Atmospheric Cerenkov Telescope in 2002 May. A spectral analysis has been carried out on the data from that time...
A survey of unidentified egret sources at very high energies (2005)
Fegan, S. J., Badran, H. M., Bond, I. H., Boyle, P. J., Bradbury, S. M., Buckley, J. H., ...
The Whipple Observatory 10 m γ-ray telescope has been used to survey the error boxes of EGRET unidentified sources in an attempt to find counterparts at energies of 350 GeV and above....
Falcone, A. D., Bond, I. H., Boyle, P. J., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D., ...
Blazars have traditionally been separated into two broad categories based on their optical emission characteristics. Blazars with faint or no emission lines are referred to as BL Lacertae objects (...
Constraints on the very high energy emission from BL Lacertae objects (2004)
Horan, D., Badran, H. M., Bond, I. H., Boyle, P. J., Bradbury, S. M., Buckley, J. H., ...
We present results from observations of 29 BL Lacertae objects, taken with the Whipple Observatory 10 m gamma-ray telescope between 1995 and 2000. The observed objects are mostly at low redshift (z
Tev Gamma-ray observations of the galactic center (2004)
Kosack, K., Badran, H. M., Bond, I. H., Boyle, P. J., Bradbury, S. M., Buckley, J. H., ...
We report a possible detection of TeV gamma rays from the Galactic center by the Whipple 10 m gamma-ray telescope. Twenty-six hours of data were taken over an extended period from 1995 through 2003...
Observation of M87 at 400 GeV with the Whipple 10 meter telescope (2004)
Le Bohec, S., Badran, H. M., Bond, I. H., Boyle, P. J., Bradbury, S. M., Buckley, J. H., ...
We present results from observations taken with the Whipple 10 m very high energy gamma-ray telescope with maximal sensitivity at 400 GeV during 39 hr between 2000 and 2003 in the direction of the...
VERITAS: the Very Energetic Radiation Imaging Telescope Array System (2004)
Krennrich, F., Bond, I. H., Boyle, P. J., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D., ...
The Very Energetic Radiation Imaging Telescope Array System (VERITAS) is the major next generation imaging atmospheric Cherenkov gamma-ray telescope in the western hemisphere and will be located in...
Holder, J., Bond, I. H., Boyle, P. J., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D. A., ...
We present the first strong detection of very high energy gamma-rays from the close (z=0.048) X-ray-selected BL Lacertae object 1ES 1959+650. Observations were made with the Whipple 10 m telescope on...
Search for high-energy gamma rays from an X-ray-selected blazar sample (2003)
Perez, I. D., Bond, I. H., Boyle, P. J., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D. A., ...
Our understanding of blazars has been greatly increased in recent years by extensive multiwavelength observations, particularly in the radio, X-ray, and gamma-ray regions. Over the past decade the...
Recent Results from the VERITAS Collaboration (2002)
Krennrich, F., Bond, I. H., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D. A., Cui, W., ...
A decade after the discovery of TeV gamma-rays from the blazar Mrk 421 (Punch et al. 1992), the list of TeV blazars has increased to five BL Lac objects: Mrk 421 (Punch et al. 1992; Petry et al....
The TeV spectrum of H1426+428 (2002)
Petry, D., Bond, I. H., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D. A., Cui, W., ...
The BL Lac object H1426+428 was recently detected as a high energy gamma-ray source by the VERITAS collaboration (Horan et al. 2002). We have reanalyzed the 2001 portion of the data used in the...
Discovery of Spectral Variability of Markarian 421 at TeV Energies (2002)
Krennrich, F., Bond, I. H., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D. A., Cui, W., ...
The detection of spectral variability of the gamma-ray blazar Mrk 421 at TeV energies is reported. Observations with the Whipple Observatory 10m gamma-ray telescope taken in 2000/2001 revealed...
Johnson, Rodger K., Petry, D., Miller, Phillip S., Fisher, R.
The Nebraska Index Line excels in reproduction and is being used in industry breeding programs. However, because it has been selected only for litter size since 1981, growth and carcass merit of...
Gutowski,G. A., Stys,A., Petry,D., Pierce,R.
The Defense Mapping Agency (DMA) produces digital data bases for the DoD which are used by many systems developed for the generation of real-world simulation data. In the past, Level 1 (First...
Large zenith angle observations with the high-resolution GRANITE III camera (2001)
Petry, D., Collaboration, The VERITAS
The GRANITE III camera of the Whipple Cherenkov Telescope at the Fred Lawrence Whipple Observatory on Mount Hopkins, Arizona (2300 m a.s.l.) has the highest angular resolution of all cameras used on...
Cutoff in the TeV Energy Spectrum of Markarian 421 During Strong Flares in 2001 (2001)
Krennrich, F., Badran, H. M., Bond, I. H., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D. A., ...
Exceptionally strong and long lasting flaring activity of the blazar Markarian 421 (Mrk 421) occurred between January and March 2001. Based on the excellent signal-to-noise ratio of the data we...
We present a compilation of data on the 22 tentatively identified gamma-ray sources from the Third EGRET Catalog which may be detected by the next-generation imaging atmospheric Cherenkov telescopes.
Multiwavelength observations of Mkn 501 during the 1997 high state (2000)
Petry, D., Boettcher, M., Connaughton, V., Lahteenmaki, A., Pursimo, T., Raiteri, C. M., ...
During the observation period 1997, the nearby Blazar Mkn 501 showed extremely strong emission and high variability. We examine multiwavelength aspects of this event using radio, optical, soft and...
The MAGIC Telescope - Prospects for GRB research (1999)
The Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) Telescope collaboration is constructing a large Cherenkov telescope (17 m diameter) for the exploration of the gamma-ray energy regime above...
TeV Gamma-ray Observations of the Crab and Mkn 501 during Moonshine and Twilight (1999)
Kranich, D., Mirzoyan, R., Petry, D., Raubenheimer, B. C.
TeV Gamma-ray signals from the Crab Nebula and Mkn 501 were detected with the HEGRA CT1 imaging Cerenkov telescope during periods when the moon was shining and during twilight. This was accomplished...
Search for gamma-ray bursts above 20 TeV with the HEGRA AIROBICC Cherenkov array (1998)
Padilla, HEGRA Collaboration: L., Funk, B., Krawczynski, H., Contreras, J. L., Moralejo, A., Aharonian, F., ...
A search for gamma-ray bursts (GRBs) above 20 TeV within the field of view (1 sr) of the HEGRA AIROBICC Cherenkov array (29N, 18W, 2200 m a.s.l.) has been performed using data taken between March...
Kranich, D., Deckers, T., Lorenz, E., Petry, D., Rauterberg, G., Collaboration, The HEGRA
Since February 1997 the BL Lac object Mkn 501 is in a ``high state'' of gamma-ray emission. The HEGRA collaboration has studied Mkn 501 with their air Cherenkov telescopes on La Palma. Here we report...
Petry, D., Bradbury, S. M., Konopelko, A., Kranich, D., Raubenheimer, B. C., Collaboration, The HEGRA
The HEGRA 5 m^2 air Cherenkov telescope (CT1) was used to search for gamma-ray emission above 1.5 TeV from a series of low redshift AGN (Mkn 421, Mkn 501, MS 0116+319, PKS 2209+236, NGC 315 and W...
A Multi-frequency campaign on the gamma-ray loud blazar W Comae (1997)
Maisack, M., Mannheim, K., Geckeler, R. D., Hillas, M., Katajainen, S., Marshall, F., ...
We report preliminary results of a multi-frequency campaign on the TeV candidate blazar W Comae (z=0.102). Flux limits by Whipple and HEGRA show that the TeV flux must be considerably below an E^-2...
Detection of Gamma-Rays above 1.5 TeV from Mkn 501 (1996)
Bradbury, S. M., Deckers, T., Petry, D., Konopelko, A.
A detection of TeV $\gamma$-rays from Mkn 501 is reported, based on observations made between March and August 1996 with the first HEGRA Cherenkov telescope (CT1). From the image analysis, 351 excess...
Detection of VHE Gamma-rays from Mkn 421 with the HEGRA Cherenkov Telescopes (1996)
Petry, D., Bradbury, S. M., Konopelko, A., Fernandez, J.
A detection of Gamma-rays from Mkn 421 at energies above 1 TeV is reported, based on observations made in December 1994 - May 1995 with the first two HEGRA Cherenkov telescopes. >From the image...
The OPAL silicon strip microvertex detector with two coordinate readout (1994)
Allport, P P, Batley, J Richard, Beck, G A, Carter, A A, Carter, J R, De Jong, S, ...
The OPAL silicon strip microvertex detector with two coordinate readout (1994)
OPAL Collaboration, Allport, P P, Batley, J R, Beck, G A, Carter, A A, Carter, J R, ...
ECO, the European Gamma-Ray Observatory: Low-threshold Telescopes at La Palma
Baixeras,C., Bendarek,W., Bigongiari,C., Biland,A., Blanch,O., Bock,R. K., ...
In this note we present the substantial physics potential made available by lowering the threshold for ground-based gamma-ray astronomy in the coming decade. We discuss the technologies needed to...
ECO, the European Gamma-Ray Observatory: Low-threshold Telescopes at La Palma
Baixeras, C., Bendarek, W., Bigongiari, C., Biland, A., Blanch, O., Bock, R. K., ...
In this note we present the substantial physics potential made available by lowering the threshold for ground-based gamma-ray astronomy in the coming decade. We discuss the technologies needed to...