Observation of gamma-ray emission from the galaxy M87 above 250 GeV with VERITAS

Abstract

The multiwavelength observation of the nearby radio galaxy M87 provides a unique opportunity to study in detail processes occurring in Active Galactic Nuclei from radio waves to TeV gamma-rays. Here we report the detection of gamma-ray emission above 250 GeV from M87 in spring 2007 with the VERITAS atmospheric Cherenkov telescope array and discuss its correlation with the X-ray emission. The gamma-ray emission is measured to be point-like with an intrinsic source radius less than 4.5 arcmin. The differential energy spectrum is fitted well by a power-law function: dPhi/dE=(7.4+-1.3_{stat}+-1.5_{sys})(E/TeV)^{-2.31+-0.17_{stat}+-0.2_{sys}} 10^{-9}m^{-2}s^{-1}TeV^{-1}. We show strong evidence for a year-scale correlation between the gamma-ray flux reported by TeV experiments and the X-ray emission measured by the ASM/RXTE observatory, and discuss the possible short-time-scale variability. These results imply that the gamma-ray emission from M87 is more likely associated with the core of the galaxy than with other bright X-ray features in the jet.

arXiv comment10 pages, 7 figures, accepted for publication in The Astrophysical Journal

References in corpus (28)

• Unified Schemes for Radio-Loud Active Galactic Nuclei
• Observations of the Crab Nebula with H.E.S.S
• First Results from the All-Sky Monitor on the Rossi X-ray Timing Explorer
• Structured jets in TeV BL Lac objects and radiogalaxies
• The supermassive black hole of M87 and the kinematics of its associated gaseous disk
• Fast variability of TeV gamma-rays from the radio galaxy M 87
• Filaments, Bubbles, and Weak Shocks in the Gaseous Atmosphere of M87
• The First VERITAS Telescope
• The Crab Nebula and Pulsar between 500 GeV and 80 TeV: Observations with the HEGRA stereoscopic air Cherenkov telescopes
• Multiwavelength Observations of Markarian 421 in March 2001: an Unprecedented View on the X-ray/TeV Correlated Variability
• Production of TeV gamma-radiation in the vicinity of the supermassive black hole in the giant radiogalaxy M87
• Is the Giant Radio Galaxy M87 a TeV Gamma-Ray Emitter?
• Spine-sheath layer radiative interplay in subparsec-scale jets and the TeV emission from M87
• Dynamics and High Energy Emission of the Flaring HST-1 Knot in the M 87 Jet
• Superluminal Radio Features in the M87 Jet and the Site of Flaring TeV Gamma-ray Emission
• Observations of Mkn 421 with the MAGIC Telescope
• The Outburst of HST-1 in the M87 Jet
• Time Dependent Modeling of the Markarian 501 X-ray and TeV Gamma-Ray Data Taken During March and April, 1997
• Detection of Neutralino Annihilation Photons from External Galaxies
• The X-ray Emissions from the M87 Jet: Diagnostics and Physical Interpretation
• Discovery of Spectral Variability of Markarian 421 at TeV Energies
• A synchrotron self-Compton scenario for the very high energy gamma-ray emission of the radiogalaxy M87
• Variable VHE gamma-ray emission from non-blazar AGNs
• Correlation between the TeV and X-ray emission in high--energy peaked BL Lac objects
• High Energy gamma-rays From FR I Jets
• Is the core of M87 the source of its TeV emission? Implications for unified schemes
• Transitive X-ray spectrum and PeV gamma-ray cutoff in the M87 jet: Electron "Pevatron"
• The Continuing Saga of the Explosive Event(s) in the M87 Jet: Is M87 a Blazar?

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• Fermi Large Area Telescope Gamma-Ray Detection of the Radio Galaxy M87
• The 2010 very high energy gamma-ray flare & 10 years of multi-wavelength observations of M 87
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• Fermi Large Area Telescope View of the Core of the Radio Galaxy Centaurus A
• New two-sided bound on the isotropic Lorentz-violating parameter of modified Maxwell theory
• Role of line-of-sight cosmic ray interactions in forming the spectra of distant blazars in TeV gamma rays and high-energy neutrinos
• Variability Timescales in the M87 Jet: Signatures of E-Squared Losses, Discovery of a Quasi-period in HST-1, and the Site of TeV Flaring
• Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign
• Very High Energy Gamma-Ray Observations of a Strong Flaring Activity in M87 in 2008 February
• Detection of very-high energy γ-ray emission from NGC 1275 by the MAGIC telescopes
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• VERITAS 2008 - 2009 monitoring of the variable gamma-ray source M87
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• Monitoring of the radio galaxy M87 during a low emission state from 2012 to 2015 with MAGIC
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• Modification of the gamma-ray spectra by internal absorption in OVV blazars: The example cases of 3C 273 and 3C 279
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• Ruling out thermal dark matter with a black hole induced spiky profile in the M87 galaxy
• Broadband Multi-wavelength Properties of M87 during the 2018 EHT Campaign including a Very High Energy Flaring Episode
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• VERITAS Upper Limit on the VHE Emission from the Radio Galaxy NGC 1275
• Search for multi-flare neutrino emissions in 10 years of IceCube data from a catalog of sources
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• Hadronuclear interactions in the jet of low TeV luminosity AGN: Implications for the low-state very-high-energy gamma-ray emission
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• 3C66B as a TeV radiogalaxy
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• High-Energy Gamma Rays and Neutrinos from Nearby Radio Galaxies
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• Constraining the cosmic-ray pressure in the inner Virgo Cluster using H.E.S.S. observations of M 87
• Time dependent gamma-ray production in the anisotropic IC $e^{\pm }$ pair cascade initiated by electrons in active galaxies
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• Highlight Talk: Recent Results from VERITAS
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• One of Everything: The Breakthrough Listen Exotica Catalog
• Constraining eV-scale axion-like particle dark matter: insights from the M87 Galaxy
• Neutrino production from photo-hadronic interactions of the gamma flux from Active Galactic Nuclei with their gas content
• Simultaneously unveiling the EBL and intrinsic spectral parameters of gamma-ray sources with Hamiltonian Monte Carlo
• Explaining the Origin of TeV Gamma Rays from M87 During High and Low States
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• Very high energy neutrino expectation from Fanaroff-Riley I sources
• Monitoring radio galaxies at TeV energies with HAWC
• Axion-like Particles and their Possible Impact on the Very High-Energy Spectrum of M87 Observed by LHAASO
• The Study of X-Ray Flux Variability of M87