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Title: SPECTRAL ANALYSIS OF FERMI -LAT BLAZARS ABOVE 50 GEV

Abstract

We present an analysis of the intrinsic (unattenuated by the extragalactic background light, EBL) power-law spectral indices of 128 extragalactic sources detected up to z ~ 2 with the Fermi-Large Area Telescope (LAT) at very high energies (VHEs, E ≥50 GeV). The median of the intrinsic index distribution is 2.20 (versus 2.54 for the observed distribution). We also analyze the observed spectral breaks (i.e., the difference between the VHE and high energy, HE, 100 MeV ≤ E ≤ 300 GeV, spectral indices). The Fermi-LAT has now provided a large sample of sources detected both at VHE and HE with comparable exposure that allows us to test models of extragalactic γ-ray photon propagation. We find that our data are compatible with simulations that include intrinsic blazar curvature and EBL attenuation. There is also no evidence of evolution with redshift of the physics that drives the photon emission in high-frequency synchrotron peak (HSP) blazars. This makes HSP blazars excellent probes of the EBL.

Authors:
 [1]; ORCiD logo [2]
  1. Clemson Univ., SC (United States); Univ. Complutense Madrid (Spain)
  2. Clemson Univ., SC (United States)
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1354852
Grant/Contract Number:  
AC02-76SF00515
Resource Type:
Accepted Manuscript
Journal Name:
The Astrophysical Journal. Letters (Online)
Additional Journal Information:
Journal Name: The Astrophysical Journal. Letters (Online); Journal Volume: 813; Journal Issue: 2; Journal ID: ISSN 2041-8213
Publisher:
Institute of Physics (IOP)
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS

Citation Formats

Domínguez, Alberto, and Ajello, Marco. SPECTRAL ANALYSIS OF FERMI -LAT BLAZARS ABOVE 50 GEV. United States: N. p., 2015. Web. doi:10.1088/2041-8205/813/2/L34.
Domínguez, Alberto, & Ajello, Marco. SPECTRAL ANALYSIS OF FERMI -LAT BLAZARS ABOVE 50 GEV. United States. https://doi.org/10.1088/2041-8205/813/2/L34
Domínguez, Alberto, and Ajello, Marco. Wed . "SPECTRAL ANALYSIS OF FERMI -LAT BLAZARS ABOVE 50 GEV". United States. https://doi.org/10.1088/2041-8205/813/2/L34. https://www.osti.gov/servlets/purl/1354852.
@article{osti_1354852,
title = {SPECTRAL ANALYSIS OF FERMI -LAT BLAZARS ABOVE 50 GEV},
author = {Domínguez, Alberto and Ajello, Marco},
abstractNote = {We present an analysis of the intrinsic (unattenuated by the extragalactic background light, EBL) power-law spectral indices of 128 extragalactic sources detected up to z ~ 2 with the Fermi-Large Area Telescope (LAT) at very high energies (VHEs, E ≥50 GeV). The median of the intrinsic index distribution is 2.20 (versus 2.54 for the observed distribution). We also analyze the observed spectral breaks (i.e., the difference between the VHE and high energy, HE, 100 MeV ≤ E ≤ 300 GeV, spectral indices). The Fermi-LAT has now provided a large sample of sources detected both at VHE and HE with comparable exposure that allows us to test models of extragalactic γ-ray photon propagation. We find that our data are compatible with simulations that include intrinsic blazar curvature and EBL attenuation. There is also no evidence of evolution with redshift of the physics that drives the photon emission in high-frequency synchrotron peak (HSP) blazars. This makes HSP blazars excellent probes of the EBL.},
doi = {10.1088/2041-8205/813/2/L34},
journal = {The Astrophysical Journal. Letters (Online)},
number = 2,
volume = 813,
place = {United States},
year = {Wed Nov 04 00:00:00 EST 2015},
month = {Wed Nov 04 00:00:00 EST 2015}
}

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Works referenced in this record:

Measurement of the extragalactic background light imprint on the spectra of the brightest blazars observed with H.E.S.S.
journal, January 2013


FERMI LARGE AREA TELESCOPE THIRD SOURCE CATALOG
journal, June 2015

  • Acero, F.; Ackermann, M.; Ajello, M.
  • The Astrophysical Journal Supplement Series, Vol. 218, Issue 2
  • DOI: 10.1088/0067-0049/218/2/23

The Imprint of the Extragalactic Background Light in the Gamma-Ray Spectra of Blazars
journal, November 2012


THE THIRD CATALOG OF ACTIVE GALACTIC NUCLEI DETECTED BY THE FERMI LARGE AREA TELESCOPE
journal, August 2015


A low level of extragalactic background light as revealed by γ-rays from blazars
journal, April 2006

  • Aharonian, F.; Akhperjanian, A. G.; Bazer-Bachi, A. R.
  • Nature, Vol. 440, Issue 7087
  • DOI: 10.1038/nature04680

Discovery of High-Energy and very high Energy γ-Ray Emission from the Blazar rbs 0413
journal, April 2012


THE EXTRAGALACTIC BACKGROUND LIGHT, THE HUBBLE CONSTANT, AND ANOMALIES: CONCLUSIONS FROM 20 YEARS OF TeV GAMMA-RAY OBSERVATIONS
journal, October 2015


Gamma-Rays from Blazars and the Extragalactic Background Light
journal, October 2013


Detection of the Cosmic γ-Ray Horizon from Multiwavelength Observations of Blazars
journal, May 2013


Extragalactic background light inferred from AEGIS galaxy-SED-type fractions: EBL from AEGIS galaxy-SED-type fractions
journal, October 2010


Axion-like particle imprint in cosmological very-high-energy sources
journal, November 2011

  • Domínguez, A.; Sánchez-Conde, M. A.; Prada, F.
  • Journal of Cosmology and Astroparticle Physics, Vol. 2011, Issue 11
  • DOI: 10.1088/1475-7516/2011/11/020

The extragalactic background light and the gamma-ray opacity of the universe
journal, March 2013


A new interpretation of the gamma-ray observations of distant active galactic nuclei
journal, March 2010


On weak Redshift Dependence of Gamma-Ray Spectra of Distant Blazars
journal, May 2012


Modeling the Extragalactic Background Light from Stars and dust
journal, February 2010


Semi-analytic modelling of the extragalactic background light and consequences for extragalactic gamma-ray spectra: Modelling of the EBL and gamma-ray spectra
journal, April 2012

  • Gilmore, Rudy C.; Somerville, Rachel S.; Primack, Joel R.
  • Monthly Notices of the Royal Astronomical Society, Vol. 422, Issue 4
  • DOI: 10.1111/j.1365-2966.2012.20841.x

The Cosmic Infrared Background: Measurements and Implications
journal, September 2001


RECONSTRUCTING THE γ-RAY PHOTON OPTICAL DEPTH OF THE UNIVERSE TO z ∼ 4 FROM MULTIWAVELENGTH GALAXY SURVEY DATA
journal, September 2012


Indications for a pair-production anomaly from the propagation of VHE gamma-rays
journal, February 2012


Star Formation History, dust Attenuation, and Extragalactic Background Light
journal, May 2015


Limits on the extragalactic background light in the Fermi era
journal, June 2012


Evidence for a cosmological effect in γ -ray spectra of BL Lacertae
journal, June 2013


Hints of the existence of axionlike particles from the gamma-ray spectra of cosmological sources
journal, June 2009


AN EMPIRICAL DETERMINATION OF THE INTERGALACTIC BACKGROUND LIGHT USING NEAR-INFRARED DEEP GALAXY SURVEY DATA OUT TO 5 μm AND THE GAMMA-RAY OPACITY OF THE UNIVERSE
journal, March 2014


TeV gamma rays from 3C 279 - A possible probe of origin and intergalactic infrared radiation fields
journal, May 1992

  • Stecker, F. W.; de Jager, O. C.; Salamon, M. H.
  • The Astrophysical Journal, Vol. 390
  • DOI: 10.1086/186369

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
journal, September 2006

  • Stecker, F. W.; Malkan, M. A.; Scully, S. T.
  • The Astrophysical Journal, Vol. 648, Issue 2
  • DOI: 10.1086/506188

DERIVATION OF A RELATION FOR THE STEEPENING OF TeV-SELECTED BLAZAR γ-RAY SPECTRA WITH ENERGY AND REDSHIFT
journal, January 2010


Stochastic Acceleration and the Evolution of Spectral Distributions in Synchro-Self-Compton Sources: a Self-Consistent Modeling of Blazars’ Flares
journal, September 2011


The Spectral Index Distribution of EGRET Blazars: Prospects for GLAST
journal, September 2007

  • Venters, Tonia M.; Pavlidou, Vasiliki
  • The Astrophysical Journal, Vol. 666, Issue 1
  • DOI: 10.1086/519487

The Spectral Index Distribution of EGRET Blazars: Prospects for GLAST
conference, January 2007

  • Venters, Tonia M.; Pavlidou, Vasiliki
  • THE FIRST GLAST SYMPOSIUM, AIP Conference Proceedings
  • DOI: 10.1063/1.2757293

Limits on the extragalactic background light in the Fermi era
conference, January 2012

  • Meyer, Manuel; Raue, Martin; Mazin, Daniel
  • HIGH ENERGY GAMMA-RAY ASTRONOMY: 5th International Meeting on High Energy Gamma-Ray Astronomy, AIP Conference Proceedings
  • DOI: 10.1063/1.4772332

The Third Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope
text, January 2015

  • Ackermann, Markus; Ajello, M.; Atwood, W. B.
  • Deutsches Elektronen-Synchrotron, DESY, Hamburg
  • DOI: 10.3204/pubdb-2016-00029

Axion-like particle imprint in cosmological very-high-energy sources
text, January 2011


On weak redshift dependence of gamma-ray spectra of distant blazars
text, January 2011


Limits on the extragalactic background light in the Fermi era
text, January 2012


Discovery of High-energy and Very High Energy Gamma-ray Emission from the Blazar RBS 0413
text, January 2012


Works referencing / citing this record:

GeV-TeV γ $\gamma $ -ray energy spectral break of BL Lac objects
journal, August 2018


Exploring the bulk of the BL Lacertae object population: II. Gamma-ray properties
journal, October 2018


Extreme HBL behavior of Markarian 501 during 2012
journal, December 2018


Measurement of the extragalactic background light using MAGIC and Fermi-LAT gamma-ray observations of blazars up to z = 1
journal, April 2019

  • Acciari, V. A.; Ansoldi, S.; Antonelli, L. A.
  • Monthly Notices of the Royal Astronomical Society, Vol. 486, Issue 3
  • DOI: 10.1093/mnras/stz943

Physics potential of the International Axion Observatory (IAXO)
text, January 2019


Leptonic and Hadronic Modeling of Fermi -LAT Hard Spectrum Quasars and Predictions for High-energy Polarization
journal, August 2018

  • Paliya, Vaidehi S.; Zhang, Haocheng; Böttcher, Markus
  • The Astrophysical Journal, Vol. 863, Issue 1
  • DOI: 10.3847/1538-4357/aad1f0

Identifying the 3FHL Catalog. I. Archival Swift Observations and Source Classification
journal, January 2019


Systematic Physical Characterization of the γ -Ray Spectra of 2FHL Blazars
journal, March 2019

  • van den Berg, Jacobus P.; Böttcher, Markus; Domínguez, Alberto
  • The Astrophysical Journal, Vol. 874, Issue 1
  • DOI: 10.3847/1538-4357/aafdfd

A New Measurement of the Hubble Constant and Matter Content of the Universe Using Extragalactic Background Light γ -Ray Attenuation
journal, November 2019


3FHL: The Third Catalog of Hard Fermi -LAT Sources
journal, September 2017

  • Ajello, M.; Atwood, W. B.; Baldini, L.
  • The Astrophysical Journal Supplement Series, Vol. 232, Issue 2
  • DOI: 10.3847/1538-4365/aa8221

Fermi -LAT Stacking Analysis Technique: An Application to Extreme Blazars and Prospects for their CTA Detection
journal, August 2019

  • Paliya, Vaidehi S.; Domínguez, A.; Ajello, M.
  • The Astrophysical Journal, Vol. 882, Issue 1
  • DOI: 10.3847/2041-8213/ab398a

Physics potential of the International Axion Observatory (IAXO)
journal, June 2019


Fermi-LAT Stacking Analysis Technique: An Application to Extreme Blazars and Prospects for their CTA Detection
text, January 2019

  • Paliya, Vaidehi Sharan; Domínguez, A.; Ajello, M.
  • Deutsches Elektronen-Synchrotron, DESY, Hamburg
  • DOI: 10.3204/pubdb-2019-03436

Measurement of the extragalactic background light using MAGIC and Fermi-LAT gamma-ray observations of blazars up to z = 1
text, January 2019

  • Acciari, V. A.; Ansoldi, S.; Antonelli, L. A.
  • Deutsches Elektronen-Synchrotron, DESY, Hamburg
  • DOI: 10.3204/pubdb-2019-03716

3FHL: The Third Catalog of Hard Fermi -LAT Sources
text, January 2017


Search for Spectral Irregularities due to Photon–Axionlike-Particle Oscillations with the Fermi Large Area Telescope
text, January 2016


The extreme HBL behaviour of Markarian 501 during 2012
text, January 2018

  • Ahnen, M. L.; Ansoldi, S.; Antonelli, L. A.
  • Deutsches Elektronen-Synchrotron, DESY, Hamburg
  • DOI: 10.3204/pubdb-2019-00102

Physics potential of the International Axion Observatory (IAXO)
text, January 2019


A new measurement of the Hubble constant and matter content of the Universe using extragalactic background light $\gamma$-ray attenuation
text, January 2019

  • Domínguez, Alberto; Wojtak, Radoslaw; Finke, Justin
  • Deutsches Elektronen-Synchrotron, DESY, Hamburg
  • DOI: 10.3204/pubdb-2020-00208

3FHL: The Third Catalog of Hard Fermi-LAT Sources
text, January 2017


Exploring the bulk of the BL Lac object population. II. Gamma-ray properties
text, January 2018


Systematic Physical Characterization of the Gamma-Ray Spectra of 2FHL Blazars
text, January 2019