Hard TeV spectra of blazars and the constraints to the IR intergalactic background

Abstract

Recent gamma-ray observations of the blazar 1ES 1101-232 (redshift z=0.186) reveal that the unabsorbed TeV spectrum is hard, with spectral index $\alpha \lesssim 0.5$ [$F(\nu )\propto {\nu }^{-\alpha }$]. We show that simple one-zone synchrotron self-Compton model can explain such hard spectra if we assume a power law energy distribution of the emitting electrons with a relatively high minimum energy. In this case the intrinsic TeV spectrum can be as hard as $F(\nu )\propto {\nu }^{1/3}$, while the predicted X-ray spectrum can still be much softer. The observations of 1ES 1101-232 can therefore be reconciled with relatively high intensities of the infrared background, even if some extreme background levels can indeed be excluded. We show that the other TeV sources (Mrk 421, Mrk 501 and PKS 2155-304) can be interpreted in the same framework, with a somewhat larger minimum energy.

arXiv comment5 pages, 3 figures, accepted for publication as a letter in MNRAS

References in corpus (11)

• The Cosmic Infrared Background: Measurements and Implications
• Constraints on the Physical Parameters of TeV Blazars
• Multiwavelength Observations of Strong Flares From the TeV-Blazar 1ES 1959+650
• Deep Galaxy Counts, Extragalactic Background Light, and the Stellar Baryon Budget
• Implications of Cosmological Gamma-Ray Absorption II. Modification of gamma-ray spectra
• BeppoSAX Observations of Unprecedented Synchrotron Activity in the BL Lac Object Mkn 501
• Simultaneous Constraints on the Spectrum of the Extragalactic Background Light and the Intrinsic Tev Spectra of Mrk 421, Mrk 501, and H1426+428
• Simultaneous X-Ray and TeV Gamma-Ray Observations of the TeV Blazar Markarian 421 during February and May 2000
• Multi-wavelength observations of PKS 2155-304 with H.E.S.S
• Correlation between the TeV and X-ray emission in high--energy peaked BL Lac objects
• The SED of the TeV BLLac 1ES 1426+428 after correction for the TeV--IR absorption

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