GeV-TeV $\gamma$-ray energy spectral break of BL Lac objects

Abstract

In this paper, we compile the very-high-energy and high-energy spectral indices of 43 BL Lac objects from the literature. Based on a simple math model, $\Delta {\Gamma }_{obs}=\alpha \mathrm{z}+\beta$, we present evidence for the origin of an observed spectral break that is denoted by the difference between the observed very-high-energy and high-energy spectral indices, $\Delta {\Gamma }_{obs}$. We find by linear regression analysis that $\alpha \ne 0$ and $\beta \ne 0$. These results suggest that the extragalactic background light attenuation and the intrinsic curvature dominate on the GeV-TeV $\gamma$-ray energy spectral break of BL Lac objects. We argue that the extragalactic background light attenuation is an exclusive explanation for the redshift evolution of the observed spectral break.

arXiv comment8 pages, 5 figures, accepted for publication in APSS

References in corpus (57)

• The extragalactic optical-infrared background radiations, their time evolution and the cosmic photon-photon opacity
• The Cosmic Infrared Background: Measurements and Implications
• A low level of extragalactic background light as revealed by gamma-rays from blazars
• Semi-analytic modeling of the EBL and consequences for extragalactic gamma-ray spectra
• 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
• Implications of Cosmological Gamma-Ray Absorption II. Modification of gamma-ray spectra
• The Imprint of The Extragalactic Background Light in the Gamma-Ray Spectra of Blazars
• New constraints on the Mid-IR EBL from the HESS discovery of VHE gamma rays from 1ES 0229+200
• Stochastic Acceleration and the Evolution of Spectral Distributions in SSC Sources: A Self Consistent Modeling of Blazars' Flares
• The Extragalactic Background Light and the Gamma-ray Opacity of the Universe
• GeV breaks in blazars as a result of gamma-ray absorption within the broad-line region
• Indications for a pair-production anomaly from the propagation of VHE gamma-rays
• Detection of VHE gamma-ray emission from the distant blazar 1ES 1101-232 with H.E.S.S. and broadband characterisation
• Simultaneous Constraints on the Spectrum of the Extragalactic Background Light and the Intrinsic Tev Spectra of Mrk 421, Mrk 501, and H1426+428
• Discovery of Very High Energy gamma-rays from 1ES 1011+496 at z=0.212
• Discovery of VHE gamma-rays from the distant BL Lac 1ES 0347-121
• Discovery of Very High Energy $\gamma$-Rays from Markarian~180 Triggered by an Optical Outburst
• Multi-wavelength observations of PKS 2155-304 with H.E.S.S
• VERITAS Discovery of >200GeV Gamma-ray Emission from the Intermediate-frequency-peaked BL Lac Object W Comae
• Discovery of Very High Energy gamma-rays from the blazar S5 0716+714
• The Discovery of gamma-Ray Emission From The Blazar RGB J0710+591
• Discovery of very high energy gamma rays from PKS 1424+240 and multiwavelength constraints on its redshift
• Observation of very high energy gamma-rays from the AGN 1ES 2344+514 in a low emission state with the MAGIC telescope
• Discovery of Variability in the Very High Energy Gamma-Ray Emission of 1ES 1218+304 with VERITAS
• Discovery of VHE gamma-rays from the blazar 1ES 1215+303 with the MAGIC Telescopes and simultaneous multi-wavelength observations
• Rapid and multi-band variability of the TeV-bright active nucleus of the galaxy IC 310
• The curvature of spectral energy distribution of blazars
• Discovery of Very High Energy Gamma-Ray Emission from the BL Lac Object H2356-309 with the H.E.S.S. Cherenkov Telescopes
• Discovery of VHE gamma-rays from the high-frequency-peaked BL Lac object RGB J0152+017
• Intrinsic absorption in 3C 279 at GeV-TeV energies and consequences for estimates of the EBL
• Spectral analysis of Fermi-LAT blazars above 50 GeV
• Discovery of hard-spectrum γ-ray emission from the BL Lac object 1ES 0414+009
• Gamma-rays from Blazars and the Extragalactic Background Light
• PKS 2005-489 at VHE: Four Years of Monitoring with HESS and Simultaneous Multi-wavelength Observations
• TeV Gamma-ray Astronomy: A Summary
• Discovery of High-energy and Very High Energy Gamma-ray Emission from the Blazar RBS 0413
• On weak redshift dependence of gamma-ray spectra of distant blazars
• Evidence for a cosmological effect in γ-ray spectra of BL Lacs
• Discovery of a new TeV gamma-ray source: VER J0521+211
• Evidence for the Secondary Emission as the Origin of Hard Spectra in TeV Blazars
• H.E.S.S and Fermi-LAT discovery of gamma rays from the blazar 1ES 1312-423
• Discovery of VHE gamma-rays from the BL Lac object PKS 0548-322
• VERITAS detection of $\gamma$-ray flaring activity from the BL Lac object 1ES 1727+502 during bright moonlight observations
• Discovery of VHE gamma-ray emission from the BL Lac object B3 2247+381 with the MAGIC telescopes
• Investigating the peculiar emission from the new VHE gamma-ray source H1722+119
• Optical depth for VHE gamma-rays from distant sources from a generic EBL density
• Discovery of VHE γ-ray emission and multi-wavelength observations of the BL Lac object 1RXS J101015.9-311909
• The high-energy $\gamma$-ray emission of AP Librae
• Discovery of very high energy gamma-ray emission from the BL Lac object PKS 0301-243 with H.E.S.S
• Bethe-Heitler cascades as a plausible origin of hard spectra in distant TeV blazars
• A Simple Analytic Treatment of the Intergalactic Absorption Effect in Blazar Gamma-ray Spectra
• Discovery of very high energy gamma-ray emission from the blazar 1ES 1727+502 with the MAGIC Telescopes
• Insights into the emission of the blazar 1ES 1011+496 through unprecedented broadband observations during 2011 and 2012
• MAGIC detection of very high energy gamma-ray emission from the low-luminosity blazar 1ES 1741+196
• Derivation of a Relation for the Steepening of TeV Selected Blazar Gamma-ray Spectra with Energy and Redshift
• Discovery of Very High Energy Gamma Rays from 1ES 1440+122
• Very high-energy observations of the two high-frequency peaked BL Lac objects 1ES 1218+304 and H 1426+428

Cited by in corpus (2)

• The Intrinsic Properties of Multiwavelength Energy Spectra for Fermi Teraelectronvolt Blazars
• Testing CIBER cosmic infrared background measurements and axionlike particles with observations of TeV blazars