A synchrotron self-Compton scenario for the very high energy gamma-ray emission of the radiogalaxy M87

Abstract

M87 is the first extragalactic source detected in the TeV range that is not a blazar. With the increasing performances of ground-based Cherenkov telescopes, we can now probe the variability in the gamma-ray flux at small timescales, thus putting strong constraints on the size of the emitting zone. A modification of standard emission models of TeV blazars appears necessary to account for the gamma-ray observations despite this misalignment. We explain TeV gamma-ray spectra and fast variability of M87 by invoking an emission zone close to the central supermassive black hole, which is filled with several plasma blobs moving in the large opening angle of the jet formation zone. We develop a new multi-blob synchrotron self-Compton (SSC) model with emitting blobs beyond the Alfven surface in the jet, at a distance of about 100 r_g from the central engine. This model is explicitly adapted to deal with large viewing angles and moderate values of the Lorentz factor inferred from (general relativistic) magnetohydrodynamic models of jet formation. This scenario can account for the recent gamma-ray observations of M87 made by the High Energy Stereoscopic System (H.E.S.S.) telescope array. We find individual blob radii of about 10^{14} cm, which is compatible with the variability on timescales of days recently reported by the H.E.S.S. collaboration and is of the order of the black hole gravitational radius. Predictions of the very high energy emission for three other sources with extended optical or X-ray jet which could be misaligned blazars still with moderate beaming are presented for one Seyfert 2 radiogalaxy, namely Cen A, one peculiar BL Lac, PKS 0521-36, and one quasar, 3C 273.

10 pages, 8 figures; accepted in A&A

References in corpus (40)

• Unified Schemes for Radio-Loud Active Galactic Nuclei
• A Unifying View of the Spectral Energy Distributions of Blazars
• A theoretical unifying scheme for gamma-ray bright blazars
• General Relativistic Magnetohydrodynamic Simulations of Jet Formation and Large-Scale Propagation from Black Hole Accretion Systems
• The supermassive black hole of M87 and the kinematics of its associated gaseous disk
• Intergalactic Photon Spectra from the Far IR to the UV Lyman Limit for $0<z<6$ and the Optical Depth of the Universe to High Energy Gamma-Rays
• Fast variability of TeV gamma-rays from the radio galaxy M 87
• The matter content of the jet in M87: evidence for an electron-positron jet
• Magnetic Driving of Relativistic Outflows in Active Galactic Nuclei. I. Interpretation of Parsec-Scale Accelerations
• Radio and X-ray observations of the jet in Centaurus A
• Rapid variability in the synchrotron self Compton model for blazars
• Chandra X-ray Imaging and Spectroscopy of the M87 Jet and Nucleus
• Is the Giant Radio Galaxy M87 a TeV Gamma-Ray Emitter?
• XMM-Newton observations of M87 and Its X-Ray Halo
• Black Hole Masses and Host Galaxy Evolution of Radio-loud Active Galactic Nuclei
• Chandra and XMM-Newton Observations of the Nucleus of Centaurus A
• The X-ray Emissions from the M87 Jet: Diagnostics and Physical Interpretation
• The BL Lac heart of Centaurus A
• The Blazar Sequence: Validity and Predictions
• 30 years of multi-wavelength observations of 3C 273
• Unveiling the Active Nucleus of Centaurus A
• BeppoSAX view of radio-loud Active Galactic Nuclei
• High Energy gamma-rays From FR I Jets
• Month-Timescale Optical Variability in the M87 Jet
• The supermassive black hole in Centaurus A: a benchmark for gas kinematical measurements
• Observations of Selected AGN with H.E.S.S
• Is the core of M87 the source of its TeV emission? Implications for unified schemes
• The mass of the black hole in 3C 273
• The bulk Lorentz factor crisis of TeV blazars : evidence for an inhomogeneous pileup energy distribution ?
• Ten milliparsec-scale structure of the nucleus region in Centaurus A
• Quasar X-ray jets: Gamma-ray diagnostics of the synchrotron and inverse Compton hypotheses, the case of 3C 273
• XMM-Newton observations of a sample of gamma-ray loud active galactic nuclei
• VLT Diffraction Limited Imaging and Spectroscopy in the NIR: Weighing the black hole in Centaurus A with NACO
• Absorption of Nuclear Gamma-rays on the Starlight Radiation in FR I Sources: the Case of Centaurus A
• A historic jet-emission minimum reveals hidden spectral features in 3C 273
• Are Cen a and M87 Tev Gamma-Ray Sources?
• INTEGRAL and RXTE Observations of Centaurus A
• Bulk Motion of Ultrarelativistic Conical Blazar Jets
• Influence of the jet opening angle on the derived kinematical parameters of blazar jets having uniform and stratified bulk motion
• Is Thermal Expansion Driving the Initial Gas Ejection in NGC 6251?

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• Radio Imaging of the Very-High-Energy Gamma-Ray Emission Region in the Central Engine of a Radio Galaxy
• Discovery of very high energy gamma-ray emission from Centaurus A with H.E.S.S
• 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
• High-Sensitivity 86GHz (3.5mm) VLBI Observations of M87: Deep Imaging of the Jet Base at a 10 Schwarzschild-Radius Resolution
• Fast TeV variability from misaligned minijets in the jet of M87
• Fermi Large Area Telescope View of the Core of the Radio Galaxy Centaurus A
• 230 GHz VLBI observations of M87: event-horizon-scale structure at the enhanced very-high-energy $\gamma$-ray state in 2012
• Very High Energy Gamma-Ray Observations of a Strong Flaring Activity in M87 in 2008 February
• Observation of gamma-ray emission from the galaxy M87 above 250 GeV with VERITAS
• Locating the gamma-ray emission region of the flat spectrum radio quasar PKS 1510-089
• Seyfert 2 galaxies in the GeV band: jets and starburst
• A lepto-hadronic model for high-energy emission from FR I radiogalaxies
• VERITAS Observations of day-scale flaring of M87 in 2010 April
• Active Galactic Nuclei under the scrutiny of CTA
• Interpretation of the flares of M87 at TeV energies in the cloud-jet interaction scenario
• Resolving acceleration to very high energies along the Jet of Centaurus A
• A strong radio brightening at the jet base of M87 during the elevated very-high-energy gamma-ray state in 2012
• Contemporaneous observations of the radio galaxy NGC 1275 from radio to very high energy gamma-rays
• VERITAS 2008 - 2009 monitoring of the variable gamma-ray source M87
• Evidence for a second component in the high-energy core emission from Centaurus A?
• The $\gamma$-ray spectrum of the core of Centaurus A as observed with H.E.S.S. and Fermi-LAT
• Monitoring of the radio galaxy M87 during a low emission state from 2012 to 2015 with MAGIC
• Determination of the intrinsic velocity field in the M87 jet
• Radio Galaxies at VHE energies
• MAGIC observations of the giant radio galaxy M87 in a low-emission state between 2005 and 2007
• VLBI Observations of the Jet in M87 During the Very-High-Energy Gamma-ray Flare in April 2010
• Fermi-LAT Observation of Non-Blazar AGNs
• Non-thermal Processes in Black-Hole-Jet Magnetospheres
• Rapid Gamma-ray variability of NGC 1275
• One-zone SSC model for the core emission of Centaurus A revisited
• Broadband Multi-wavelength Properties of M87 during the 2018 EHT Campaign including a Very High Energy Flaring Episode
• Long-term monitoring of PKS 2155$-$304 with ATOM and H.E.S.S.: investigation of optical/$\gamma$-ray correlations in different spectral states
• Magnetospheric Gamma-Ray Emission in Active Galactic Nuclei
• Modeling the Spectral Energy Distribution of the radio galaxy IC310
• Neutrino, $\gamma$-ray and cosmic ray fluxes from the core of the closest radio galaxies
• Locating the gamma-ray emission region in the brightest Fermi-LAT Flat Spectrum Radio Quasars
• "Leading blob" model in a stochastic acceleration scenario: the case of the 2009 flare of Mkn~501
• A Two Zone Synchrotron Model for the Knots in the M87 Jet
• Probing the central black hole in M87 with gamma-rays
• The complex gamma-ray behaviour of the Radio Galaxy M87
• RadioAstron Space VLBI Imaging of the jet in M87: I. Detection of high brightness temperature at 22 GHz
• Correlation of $\gamma$-ray and high-energy cosmic ray fluxes from the giant lobes of Centaurus A
• 3C66B as a TeV radiogalaxy
• Gamma-rays from the IC $e^{\pm }$ pair cascade in the radiation field of an accretion disk: Application to CenA
• Curvature in the very-high energy gamma-ray spectrum of M87
• The Fermi/LAT sky as seen by INTEGRAL/IBIS
• An original constraint on the Hubble constant: h>0.74
• Very high-energy gamma-ray signature of ultrahigh-energy cosmic-ray acceleration in Centaurus A
• TeV Gamma Ray Astronomy
• Physical conditions in nearby active galaxies correlated with ultra-high-energy cosmic rays detected by the Pierre Auger Observatory
• Interpreting correlated observations of cosmic rays and gamma-rays from Centaurus A with a proton blazar inspired model
• A two-fluid model for black-hole accretion flows: Particle acceleration, outflows, and TeV emission
• The Kinematics and Ionization of Nuclear Gas Clouds in Centaurus A
• Probing IC/CMB Interpretation for the X-ray knots of AGN through VHE observations
• SSC scenario for TeV emission from non-blazar AGNs
• A New Gamma-ray Emitting Population of FR0 Radio Galaxies
• The H.E.S.S. Extragalactic Sky
• A strong radio brightening at the jet base of M87 during the elevated very-high-energy gamma-ray state in 2012
• Distributed accelerators in the jet of Centaurus A: the origin of the spectral hardening of very high energy gamma-rays