Detection of Gamma Rays with [ITAL]E[/ITAL] ] 300 GeV from Markarian 501

Quinn, J.; Akerlof, C.; Biller, S. D.; Buckley, J. H.; Carter‐Lewis, D. A.; Cawley, M. F.; Catanese, M.; Connaughton, V.; Fegan, D. J.; Finley, J. P.; Gaidos, J. A.; Hillas, A. M.; Lamb, R. C.; Krennrich, F.; Lessard, R. W.; McEnery, J. E.; Meyer, D. I.; Mohanty, G.; Rodgers, A. J.; Rose, H. J.; Schubnell, M.; Sembroski, G. H.; Weekes, T. C.; Wilson, C.; Zweerink, J.

doi:10.1086/309878

Cited by 340 publications

(108 citation statements)

References 7 publications

Supporting

Mentioning

103

Contrasting

Unclassified

Order By: Relevance

“…(Tluczykont 2010) are added (labels 4 and 5). Mrk 501 (z = 0.034, Moles et al 1987) is the second extragalactic VHE source detected (Quinn et al 1996) and is also observed by H.E.S.S. at large zenith angles.…”

Section: Blazar Samplementioning

confidence: 87%

Measurement of the EBL spectral energy distribution using the VHE γ-ray spectra of H.E.S.S. blazars

Abdalla¹,

Abramowski²,

Aharonian³

et al. 2017

A&A

View full text Add to dashboard Cite

Very high-energy γ rays (VHE, E 100 GeV) propagating over cosmological distances can interact with the low-energy photons of the extragalactic background light (EBL) and produce electron-positron pairs. The transparency of the Universe to VHE γ rays is then directly related to the spectral energy distribution (SED) of the EBL. The observation of features in the VHE energy spectra of extragalactic sources allows the EBL to be measured, which otherwise is very difficult. An EBL model-independent measurement of the EBL SED with the H.E.S.S. array of Cherenkov telescopes is presented. It was obtained by extracting the EBL absorption signal from the reanalysis of high-quality spectra of blazars. From H.E.S.S. data alone the EBL signature is detected at a significance of 9.5σ, and the intensity of the EBL obtained in different spectral bands is presented together with the associated γ-ray horizon.

show abstract

Section: Blazar Samplementioning

confidence: 87%

Measurement of the EBL spectral energy distribution using the VHE γ-ray spectra of H.E.S.S. blazars

Abdalla¹,

Abramowski²,

Aharonian³

et al. 2017

A&A

View full text Add to dashboard Cite

show abstract

“…Cuts were applied to the mean scaled width, mean scaled length, apparent altitude of the maximum Cherenkov emission (shower maximum), and θ, the angular distance between the position of Mrk 501 and the reconstructed origin of the event. The results were independently reproduced with two analysis packages (Cogan 2008;Prokoph 2013). The uncertainty on the energy calibration of VERITAS is estimated at 20%.…”

Section: Veritasmentioning

confidence: 99%

FIRSTNuSTAROBSERVATIONS OF MRK 501 WITHIN A RADIO TO TeV MULTI-INSTRUMENT CAMPAIGN

Furniss

Noda

Boggs

et al. 2015

ApJ

View full text Add to dashboard Cite

We report on simultaneous broadband observations of the TeV-emitting blazar Markarian 501 between 2013 April 1 and August 10, including the first detailed characterization of the synchrotron peak with Swift and NuSTAR. During the campaign, the nearby BL Lac object was observed in both a quiescent and an elevated state. The broadband campaign includes observations with NuSTAR, MAGIC, VERITAS, the Fermi Large Area Telescope, Swift X-ray Telescope and UV Optical Telescope, various ground-based optical instruments, including the GASP-WEBT program, as well as radio observations by OVRO, Metsähovi, and the F-Gamma consortium. Some of the MAGIC observations were affected by a sand layer from the Saharan desert, and had to be corrected using eventby-event corrections derived with a Light Detection and Ranging (LIDAR) facility. This is the first time that LIDAR information is used to produce a physics result with Cherenkov Telescope data taken during adverse atmospheric conditions, and hence sets a precedent for the current and future ground-based gamma-ray instruments. The NuSTAR instrument provides unprecedented sensitivity in hard X-rays, showing the source to display a spectral energy distribution (SED) between 3 and 79 keV consistent with a log-parabolic spectrum and hard X-ray variability on hour timescales. None (of the four extended NuSTAR observations) show evidence of the onset of inverse-Compton emission at hard X-ray energies. We apply a single-zone equilibrium synchrotron selfCompton (SSC) model to five simultaneous broadband SEDs. We find that the SSC model can reproduce the observed broadband states through a decrease in the magnetic field strength coinciding with an increase in the luminosity and hardness of the relativistic leptons responsible for the high-energy emission.

show abstract

“…Optical variability is often associated with color/spectral behavior in blazars, which can be used to explore the emission mechanism (e.g., Gu & Ai 2011 • ¢  , J2000, redshift z=0.034, HSP) is one of the brightest extragalactic sources in the X-ray/TeV sky, and the second extragalactic object to be identified as a very high energy γ-ray emitter (Abdo et al 2011). The flux and spectral variation of Mrk 501 have been extensively studied over the entire electromagnetic spectrum (e.g., Stickel et al 1993;Heidt & Wagner 1996;Quinn et al 1996;Catanese et al 1997;Pian et al 1998;Aharonian et al 1999aAharonian et al , 1999bXie et al 1999Xie et al , 2001Ghosh et al 2000;Xue & Cui 2005;Albert et al 2007;Gupta et al 2008;Rodig et al 2009;Abdo et al 2011;Neronov et al 2012;Aleksic et al 2015;Bartoli et al 2015;Shukla et al 2015;Wierzcholska et al 2015). In 1997, Mrk 501 went into a state with surprisingly high activity and strong variability and became more than a factor of 10 brighter (above 1 TeV) than the Crab Nebula (Aharonian et al 1999a(Aharonian et al , 1999b.…”

Section: Introductionmentioning

confidence: 99%

Multi-Color Optical Monitoring of MRK 501 From 2010 to 2015

Xiong¹,

Zhang²,

Zhang³

et al. 2016

ApJS

View full text Add to dashboard Cite

We have monitored the BL Lac object Mrk 501 in the optical V, R, and I bands from 2010 to 2015. For Mrk 501, the presence of a strong host galaxy component can affect the results of photometry. After subtracting the host galaxy contributions, the source shows intraday and long-term variabilities for optical flux and color indices. The average variability amplitudes of the V, R, and I bands are 22.05%, 22.25%, and 23.82%, respectively, and the value of the duty cycle is 14.87%. A minimal variability timescale of 106 minutes is detected. No significant time lag between the V and I bands is found on one night. The bluer-when-brighter (BWB) trend is dominant for Mrk 501 on intermediate, short, and intraday timescales, which supports the shock-in-jet model. For the long timescale, Mrk 501, in different states, can have different BWB trends. The corresponding results for non-correcting host galaxy contributions are also presented.

show abstract

Detection of Gamma Rays with [ITAL]E[/ITAL] ] 300 GeV from Markarian 501

Cited by 340 publications

References 7 publications

Measurement of the EBL spectral energy distribution using the VHE γ-ray spectra of H.E.S.S. blazars

Measurement of the EBL spectral energy distribution using the VHE γ-ray spectra of H.E.S.S. blazars

FIRSTNuSTAROBSERVATIONS OF MRK 501 WITHIN A RADIO TO TeV MULTI-INSTRUMENT CAMPAIGN

Multi-Color Optical Monitoring of MRK 501 From 2010 to 2015

Contact Info

Product

Resources

About