Related papers: VHE gamma-ray observations of Markarian 501

Multiwavelength Observations of a Flare from Markarian 501

We present multiwavelength observations of the BL Lacertae object Markarian 501 (Mrk 501) in 1997 between April 8 and April 19. Evidence of correlated variability is seen in very high energy (VHE, E > 350 GeV) gamma-ray observations taken…

Astrophysics · Physics 2009-10-30 M. Catanese , S. M. Bradbury , A. C. Breslin , J. H. Buckley , D. A. Carter-Lewis , M. F. Cawley , C. D. Dermer , D. J. Fegan , J. P. Finley , J. A. Gaidos , A. M. Hillas , W. N. Johnson , F. Krennrich , R. C. Lamb , R. W. Lessard , D. J. Macomb , J. E. McEnery , P. Moriarty , J. Quinn , A. J. Rodgers , H. J. Rose , F. W. Samuelson , G. H. Sembroski , R. Srinivasan , T. C. Weekes , J. Zweerink

Observations of the gamma-Ray Emission Above 250 Gev from the Blazars Markarian 501 and Markarian 421 by the Cat Cherenkov Atmospheric Imaging Telescope

The Very High Energy (VHE) gamma-ray emission of the closest BL Lacertae objects Markarian 501 and Markarian 421 has been observed by the CAT telescope in 1997 and 1998. In 1997 Mrk 501 exhibited a remarkable series of flares, with a VHE…

Astrophysics · Physics 2007-05-23 F. PIRON

VHE gamma-ray spectral properties of the blazars Mrk 501 and Mrk 421 from CAT observations in 1997 and 1998

The Very High Energy (VHE) gamma-ray emission of the BL Lacertae objects Markarian 501 and Markarian 421 has been observed by the CAT Imaging Atmospheric Cherenkov Telescope in 1997 and 1998. The spectrum extraction method is presented, and…

Astrophysics · Physics 2019-08-14 Frederic Piron

The Flux Variability of Markarian 501 in Very High Energy Gamma Rays

The BL Lacertae object Markarian 501 was identified as a source of gamma-ray emission at the Whipple Observatory in March 1995. Here we present a flux variability analysis on several times-scales of the 233 hour data set accumulated over…

Astrophysics · Physics 2009-10-31 J. Quinn , I. H. Bond , P. J. Boyle , S. M. Bradbury , A. C. Breslin , J. H. Buckley , A. M. Burdett , J. Bussons Gordo , D. A. Carter-Lewis , M. Catanese , M. F. Cawley , D. J. Fegan , J. P. Finley , J. A. Gaidos , T. Hall , A. M. Hillas , F. Krennrich , R. C. Lamb , R. W. Lessard , C. Masterson , J. E. McEnery , P. Moriarty , A. J. Rodgers , H. J. Rose , F. W. Samuelson , G. H. Sembroski , R. Srinivasan , V. V. Vassiliev , T. C. Weekes

Study of the Flux and Spectral Variations in the VHE Emission from the Blazar Markarian 501, with the MAGIC Telescope

The blazar Markarian 501 (Mrk 501) was observed above 100 GeV with the MAGIC Telescope during May, June and July 2005. The high sensitivity of the instrument made possible the detection of the source with high significance in each of the…

Astrophysics · Physics 2009-06-23 D. Paneque

Multi-wavelength Observations of Markarian 501

The very high energy (VHE; E > 100 GeV) gamma-ray blazar Markarian 501 has a history of extreme spectral variability and is an excellent laboratory for studying the physical processes within the jets of active galactic nuclei. A short term…

High Energy Astrophysical Phenomena · Physics 2019-08-13 Daniel Gall

Variable VHE gamma-ray emission from Markarian 501

The blazar Markarian 501 (Mrk 501) was observed at energies above 0.10 TeV with the MAGIC telescope from May through July 2005. The high sensitivity of the instrument enabled the determination of the flux and spectrum of the source on a…

Astrophysics · Physics 2010-11-11 J. Albert et al

Multiwavelength study of VHE emission from Markarian 501 using TACTIC observations during April-May, 2012

We have observed Markarian 501 in Very High Energy (VHE) gamma-ray wavelength band for 70.6 hours from 15 April to 30 May, 2012 using TACTIC telescope. Detailed analysis of $\sim$66.3 hours of clean data revealed the presence of a TeV…

Instrumentation and Methods for Astrophysics · Physics 2017-01-25 P Chandra , K K Singh , R C Rannot , K K Yadav , H Bhatt , A K Tickoo , B Ghosal , M Kothari , K K Gaur , A Goyal , H C Goyal , N Kumar , P Marandi , N Chouhan , S Sahayanathan , K Chanchalani , N K Agarwal , V K Dhar , S R Kaul , M K Koul , R Koul , K Venugopal , C K Bhat , C Borwankar , J Bhagwan , A C Gupta

Very High Energy outburst of Markarian 501 in May 2009

The very high energy (VHE; E $>$ 100 GeV) blazar Markarian 501 was observed between April 17 and May 5 (MJD 54938--54956), 2009, as part of an extensive multi-wavelength campaign from radio to VHE. Strong VHE $\gamma$-ray activity was…

High Energy Astrophysical Phenomena · Physics 2016-10-19 E. Aliu , S. Archambault , A. Archer , T. Arlen , T. Aune , A. Barnacka , B. Behera , M. Beilicke , W. Benbow , K. Berger , R. Bird , A. Bouvier , M. Böttcher , M. Buchovecky , J. H. Buckley , V. Bugaev , J. V Cardenzana , M. Cerruti , A. Cesarini , X. Chen , L. Ciupik , E. Collins-Hughes , M. P. Connolly , W. Cui , J. Dumm , J. D. Eisch , A. Falcone , S. Federici , Q. Feng , J. P. Finley , H. Fleischhack , P. Fortin , L. Fortson , A. Furniss , N. Galante , D. Gall , G. H. Gillanders , S. Griffin , S. T. Griffiths , J. Grube , G. Gyuk , M. Hütten , N. Håkansson , J. Holder , G. Hughes , T. B. Humensky , C. A. Johnson , P. Kaaret , P. Kar , N. Kelley-Hoskins , M. Kertzman , Y. Khassen , D. Kieda , M. Krause , H. Krawczynski , F. Krennrich , M. J. Lang , A. S Madhavan , G. Maier , S. McArthur , A. McCann , K. Meagher , J. Millis , P. Moriarty , R. Mukherjee , D. Nieto , A. O'Faoláin de Bhróithe , R. A. Ong , M. Orr , A. N. Otte , D. Pandel , N. Park , V. Pelassa , J. S. Perkins , A. Pichel , M. Pohl , A. Popkow , J. Quinn , K. Ragan , L. C. Reyes , P. T. Reynolds , E. Roache , J. Rousselle , A. C. Rovero , D. B. Saxon , G. H. Sembroski , K. Shahinyan , F. Sheidaei , C. Skole , A. W. Smith , D. Staszak , I. Telezhinsky , M. Theiling , N. W. Todd , J. V. Tucci , J. Tyler , A. Varlotta , V. V. Vassiliev , S. Vincent , S. P. Wakely , O. M. Weiner , A. Weinstein , R. Welsing , A. Wilhelm , D. A. Williams , B. Zitzer , M. G. Baring , J. Becerra Gónzalez , A. N. Cillis , D. Horan , D. Paneque

Detailed Multifrequency Study of a Rapid VHE Flare of Mrk501 in May 2009

We present observations of the gamma-ray blazar Markarian 501 between April 17 and May 5, 2009, with the Whipple 10-m telescope, VERITAS, the Fermi Large Area Telescope (LAT), Swift and RXTE as part of a 4.5-month multi-wavelength campaign.…

High Energy Astrophysical Phenomena · Physics 2019-08-15 Ana Pichel , David Paneque

Multi-wavelength Observations of VHE BL Lac Objects

We present multi-wavelength observations of the very high energy (VHE, E >250 GeV) gamma-ray sources Mrk 421 and Mrk 501. The VHE data presented here were taken with the Whipple Observatory 10m gamma-ray telescope. In the Mrk 421 campaign,…

Astrophysics · Physics 2019-08-14 M. Catanese

Very High Energy Gamma-Ray Emission from the Blazar Markarian 421

Very high energy gamma-ray emission from the BL Lac object Markarian 421 has been detected over three observing seasons on 59 nights between April 1992 and June 1994 with the Whipple 10-meter imaging Cherenkov telescope. During its initial…

Astrophysics · Physics 2009-10-28 M. S. Schubnell , C. W. Akerlof , S. Biller J. Buckley , D. A. Carter-Lewis , M. F. Cawley , M. Chantell , V. Connaughton , D. J. Fegan , S. Fennell , J. A. Gaidos , A. M. Hillas , A. D. Kerrick R. C. Lamb , D. I. Meyer , G. Mohanty , J. Rose , A. C. Rovero , G. Sembroski , T. C. Weekes , C. Wilson , J. Zweerink

Temporary EHBL-like behavior of Markarian 501 during July 2014 VHE flaring

Markarian 501, a BL Lac object well-known as a high energy gamma-ray source, has exhibited several epochs of very high energy (VHE) gamma-ray flaring events when its synchrotron peak frequency shifted above $10^{17}$ Hz, a signature of…

High Energy Astrophysical Phenomena · Physics 2026-04-08 Sarira Sahu , A. U. Puga Oliveros , D. I. Páez-Sánchez , G. Sánchez-Colón , Subhash Rajpoot , M. E. Iglesias Martínez , José Guerra Carmenate , P. Fernández de Córdoba , Gaetano Lambiase

TeV Observations of the Variability and Spectrum of Markarian 501

Markarian 501 is only the second extragalactic source to be detected with high statistical certainty at TeV energies; it is similar in many ways to Markarian 421. The Whipple Observatory gamma-ray telescope has been used to observe the AGN…

Astrophysics · Physics 2007-05-23 J. Quinn , I. H. Bond , P. J. Boyle , J. H. Buckley , S. M. Bradbury , A. C. Breslin , A. M. Burdett , J. Bussons Gordo , D. A. Carter-Lewis , M. Catanese , M. F. Cawley , D. J. Fegan , J. P. Finley , J. A. Gaidos , A. Hall , A. M. Hillas , F. Krennrich , R. C. Lamb , R. W. Lessard , C. Masterson , J. E. McEnery , G. Mohanty , P. Moriarty , A. J. Rodgers , H. J. Rose , F. W. Samuelson , G. H. Sembroski , R. Srinivasan , T. C. Weeke , J. Zweerink

Markarian 501 in X-ray bright state - RXTE observations

Mrk 501 has been in a state of very high flux in X-rays and VHE gamma-rays during 1997. In July 1997 near its hitherto maximum X-ray brightness intense multifrequency observations of Mrk 501 have been performed at radio, near infrared,…

Astrophysics · Physics 2016-08-30 G. Lamer , S. J. Wagner

VHE Gamma Rays from PKS 2155-304

The close X-ray selected BL Lac PKS 2155-304 has been observed using the University of Durham Mark 6 very high energy (VHE) gamma ray telescope during 1996 September/October/November and 1997 October/November. VHE gamma rays with energy >…

Astrophysics · Physics 2016-11-23 P. M. Chadwick , K. Lyons , T. J. L. McComb , K. J. Orford , J. L. Osborne , S. M. Rayner , S. E. Shaw , K. E. Turver , G. J. Wieczorek

Hour-Scale Multiwavelength Variability in Markarian 421

Markarian 421 was observed for about four days with BeppoSAX and the Whipple Observatory gamma-ray telescope in April 1998. A pronounced, well-defined, flare with hour-scale variability was observed simultaneously in X-rays and very high…

Astrophysics · Physics 2007-05-23 M. Catanese , I. H. Bond , S. M. Bradbury , A. C. Breslin , J. H. Buckley , A. M. Burdett , D. A. Carter-Lewis , M. F. Cawley , S. Dunlea , M. D'Vali , D. J. Fegan , S. J. Fegan , J. P. Finley , J. A. Gaidos , T. A. Hall , A. M. Hillas , D. Horan , J. Knapp , F. Krennrich , S. Le Bohec , R. W. Lessard , C. Masterson , P. Moriarty , J. Quinn , H. J. Rose , F. W. Samuelson , G. H. Sembroski , V. V. Vassiliev , T. C. Weekes , L. Maraschi , G. Fossati , F. Tavecchio , L. Chiappetti , A. Celotti , G. Ghisellini , P. Grandi , E. Pian , G. Tagliaferri , A. Treves

Spectral analysis of Markarian 421 and Markarian 501 with HAWC

The Hight Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory monitors the gamma-ray sky in the energy range from 100 GeV to 100 TeV and has detected two very high energy (VHE) blazars: Markarian 421 (Mrk 421) and Markarian 501 (Mrk 501)…

High Energy Astrophysical Phenomena · Physics 2019-08-13 S. Coutiño de León , A. Carramiñana , D. Rosa-González

A Rapid X-ray Flare from Markarian 501

We present X-ray observations of the BL Lacertae (BL Lac) object Markarian 501 (Mrk 501), taken with the Rossi X-ray Timing Explorer in 1998 May as part of a multi-wavelength campaign. The X-ray light curve shows a very rapid flare in which…

Astrophysics · Physics 2016-08-30 Michael Catanese , Rita M. Sambruna

Observations of TeV gamma rays from Markarian 501 at large zenith angles

TeV gamma rays from the blazar Markarian 501 have been detected with the University of Durham Mark 6 atmospheric Cerenkov telescope using the imaging technique at large zenith angles. Observations were made at zenith angles in the range 70…

Astrophysics · Physics 2008-11-26 P M Chadwick , K Lyons , T J L McComb , K J Orford , J L Osborne , S M Rayner , S E Shaw , K E Turver