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Title: Fermi Large Area Telescope observations of the active galaxy 4C +55.17: Steady, hard gamma-ray emission and its implications

Journal Article · · The Astrophysical Journal
 [1];  [2];  [3];  [4];  [5];  [6];  [7];  [8];  [1];  [9];  [7];  [1];  [6];  [10];  [11];  [12];  [7]
  1. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); Univ. of Maryland, College Park, MD (United States)
  2. Univ. degli Studi di Torino, Torino (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Torino (Italy); Univ. of Pennsylvania, Philadelphia, PA (United States); Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)
  3. Nicolaus Copernicus Astronomical Center, Warsaw (Poland)
  4. Institute of Space and Astronautical Science, Kanagawa (Japan); Jagiellonian Univ., Krakow (Poland)
  5. National Academy of Science, Washington, D.C. (United States); Naval Research Lab., Washington, D.C. (United States)
  6. Stanford Univ., Stanford, CA (United States)
  7. Univ. of California, Santa Cruz, CA (United States)
  8. Istituto Nazionale di Fisica Nucleare, Pisa (Italy)
  9. Naval Research Lab., Washington, D.C. (United States)
  10. Univ. di Bologna, Bologna (Italy); Istituto di Radioastronomia INAF, Bologna (Italy)
  11. Univ. of Chicago, Chicago, IL (United States)
  12. Istituto di Radioastronomia INAF, Bologna (Italy)
+ Show Author Affiliations

Here, we report Fermi Large Area Telescope (LAT) observations and broadband spectral modeling of the radio-loud active galaxy 4C +55.17 (z = 0.896), formally classified as a flat-spectrum radio quasar. Using 19 months of all-sky survey Fermi-LAT data, we detect a γ-ray continuum extending up to an observed energy of 145 GeV, and furthermore we find no evidence of γ-ray variability in the source over its observed history. We illustrate the implications of these results in two different domains. First, we investigate the origin of the steady γ-ray emission, where we re-examine the common classification of 4C +55.17 as a quasar-hosted blazar and consider instead its possible nature as a young radio source. We analyze and compare constraints on the source physical parameters in both blazar and young radio source scenarios by means of a detailed multiwavelength analysis and theoretical modeling of its broadband spectrum. Second, we show that the γ-ray spectrum may be formally extrapolated into the very high energy (VHE, ≥100 GeV) range at a flux level detectable by the current generation of ground-based Cherenkov telescopes. This enables us to place constraints on models of extragalactic background light within LAT energies and features the source as a promising candidate for VHE studies of the universe at an unprecedented redshift of z = 0.896.

Research Organization:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
AC02-76SF00515
OSTI ID:
1357198
Journal Information:
The Astrophysical Journal, Vol. 738, Issue 2; ISSN 0004-637X
Publisher:
Institute of Physics (IOP)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 32 works
Citation information provided by
Web of Science

References (97)

FERMI /LARGE AREA TELESCOPE BRIGHT GAMMA-RAY SOURCE LIST journal June 2009
BRIGHT ACTIVE GALACTIC NUCLEI SOURCE LIST FROM THE FIRST THREE MONTHS OF THE FERMI LARGE AREA TELESCOPE ALL-SKY SURVEY journal July 2009
FERMI LARGE AREA TELESCOPE FIRST SOURCE CATALOG journal May 2010
THE FIRST CATALOG OF ACTIVE GALACTIC NUCLEI DETECTED BY THE FERMI LARGE AREA TELESCOPE journal April 2010
FERMI LARGE AREA TELESCOPE CONSTRAINTS ON THE GAMMA-RAY OPACITY OF THE UNIVERSE journal October 2010
The Sixth Data Release of the Sloan Digital Sky Survey
  • Adelman‐McCarthy, Jennifer K.; Agüeros, Marcel A.; Allam, Sahar S.
  • The Astrophysical Journal Supplement Series, Vol. 175, Issue 2 https://doi.org/10.1086/524984
journal April 2008
A low level of extragalactic background light as revealed by γ-rays from blazars journal April 2006
THE EVOLUTION OF SWIFT /BAT BLAZARS AND THE ORIGIN OF THE MeV BACKGROUND journal June 2009
The Swift BAT X‐Ray Survey. III. X‐Ray Spectra and Statistical Properties journal January 2008
Very-High-Energy Gamma Rays from a Distant Quasar: How Transparent Is the Universe? journal June 2008
Magic Discovery of very high Energy Emission from the fsrq pks 1222+21 journal February 2011
THE LARGE AREA TELESCOPE ON THE FERMI GAMMA-RAY SPACE TELESCOPE MISSION journal May 2009
Flat-spectrum symmetric objects with ∼1 kpc sizes – I. The candidates journal April 2006
Unification of the Radio and Optical Properties of Gigahertz Peak Spectrum and Compact Steep‐Spectrum Radio Sources journal August 1997
Radio, millimeter-submillimeter, and infrared spectra of flat-spectrum extragalactic radio sources journal August 1994
The MAGIC-II gamma-ray stereoscopic telescope system
  • Tridon, D. Borla; Schweizer, T.; Goebel, F.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 623, Issue 1 https://doi.org/10.1016/j.nima.2010.03.028
journal November 2010
On the Depolarization of Discrete Radio Sources by Faraday Dispersion journal July 1966
The Swift X-Ray Telescope journal October 2005
The relationship between infrared, optical, and ultraviolet extinction journal October 1989
A revised catalogue of EGRET ${\sf \gamma}$-ray sources journal July 2008
Jets and accretion processes in active galactic nuclei: further clues journal April 1997
Spectral Irradiance Calibration in the Infrared. XIV. The Absolute Calibration of 2MASS journal August 2003
Characteristic Ultraviolet/Optical Timescales in Active Galactic Nuclei journal July 2001
On the Soft X‐Ray Spectra of γ‐Loud Blazars journal May 1997
Accretion disk Model of Short-Timescale Intermittent Activity in Young Radio Sources journal May 2009
The evolution of compact steep spectrum sources journal January 1993
Jet Interaction and the Evolution of Compact Symmetric Radio Sources journal November 1997
Simultaneous Constraints on the Spectrum of the Extragalactic Background Light and the Intrinsic TeV Spectra of Markarian 421, Markarian 501, and H1426+428 journal January 2005
The Second Extension of the International Celestial Reference Frame: ICRF-EXT.1 journal June 2004
Modeling the Extragalactic Background Light from Stars and dust journal February 2010
Extragalactic optical-infrared background radiation, its time evolution and the cosmic photon-photon opacity journal June 2008
A high signal-to-noise ratio composite quasar spectrum journal May 1991
Fueling the central engine of radio galaxies: I. The molecular/dusty disk of 4C 31.04 journal May 2007
The Swift Gamma‐Ray Burst Mission journal August 2004
A METHOD FOR SETTING UPPER LIMITS TO THE EXTRAGALACTIC BACKGROUND LIGHT WITH FERMI -LAT AND TeV OBSERVATIONS OF BLAZARS journal April 2010
GeV gamma-ray attenuation and the high-redshift UV background journal November 2009
Polarimetry of Compact Symmetric Objects journal May 2007
The Third EGRET Catalog of High‐Energy Gamma‐Ray Sources journal July 1999
The Cosmic Infrared Background: Measurements and Implications journal September 2001
The VLBA Imaging and Polarimetry Survey at 5 GHz journal March 2007
Relation Between Millimeter Wavelengths Emission and High-Energy Emission for Active Galactic Nuclei journal November 1998
A survey of polarization in the JVAS/CLASS flat-spectrum radio source surveys - I. The data and catalogue production journal March 2007
Observations of flat-spectrum radio sources at λ850 μm from the James Clerk Maxwell Telescope II. April 2000 to June 2005 journal January 2010
Multiwavelength Observations of the Powerful Gamma‐Ray Quasar PKS 1510−089: Clues on the Jet Composition journal January 2008
On the dynamical evolution of hotspots in powerful radio-loud active galactic nuclei: Dynamical evolution of hotspots in AGNs journal June 2006
Mini-radio lobes in AGN core illumination and their hadronic gamma-ray afterlight: Hadronic gamma-ray emission from young radio lobes journal December 2010
New prediction of extragalactic GeV γ-ray emission from radio lobes of young AGN jets journal May 2009
Extragalactic MeV γ-ray emission from cocoons of young radio galaxies journal March 2007
Implications of cosmological gamma-ray absorption: II. Modification of gamma-ray spectra journal January 2004
The Relation Between agn Gamma-Ray Emission and Parsec-Scale Radio jets journal April 2009
Seven-frequency VLBI Observations of the GHz-Peaked-Spectrum Source OQ 208 journal October 2007
High‐Frequency VLBA Total and Polarized Intensity Images of Gamma‐Ray Bright Blazars journal September 2002
The Likelihood Analysis of EGRET Data journal April 1996
A Quantitative Evaluation of Potential Radio Identifications for 3EG EGRET Sources journal August 2001
Numerical simulations of radiation from blazar jets journal August 2003
Klein-Nishina effects in the spectra of non-thermal sources immersed in external radiation fields journal November 2005
The Cosmic Lens All-Sky Survey - I. Source selection and observations journal May 2003
High Galactic latitude Fermi sources of γ -rays with energies above 100 GeV journal April 2011
The Compact Steep‐Spectrum and Gigahertz Peaked‐Spectrum Radio Sources journal May 1998
Constraints on Radio Source Evolution from the Compact Steep Spectrum and GHz Peaked Spectrum Radio Sources journal January 1997
Are young radio sources in equipartition? journal July 2008
Obscuration of the Parsec‐Scale Jets in the Compact Symmetric Object 1946+708 journal August 1999
Physical Parameters in the Hot Spots and Jets of Compact Symmetric Objects journal April 2002
Observational Gamma-ray Cosmology
  • Primack, Joel R.
  • HIGH ENERGY GAMMA-RAY ASTRONOMY: 2nd International Symposium on High Energy Gamma-Ray Astronomy, AIP Conference Proceedings https://doi.org/10.1063/1.1878394
conference January 2005
The Statistics and Ages of Compact Symmetric Objects journal April 1996
Flux density monitoring of radio sources with detected or supposed γ -ray emission journal July 1998
Intermittent Radio Galaxies and Source Statistics journal October 1997
The interstellar extinction law from 1 to 13 microns journal January 1985
The Swift Ultra-Violet/Optical Telescope journal October 2005
Multi-frequency VLBA observations of compact sources from the Peacock and Wall catalogue journal April 2005
Absorption of High‐Energy Gamma Rays by Interactions with Extragalactic Starlight Photons at High Redshifts and the High‐Energy Gamma‐Ray Background journal February 1998
Maps of Dust Infrared Emission for Use in Estimation of Reddening and Cosmic Microwave Background Radiation Foregrounds journal June 1998
The Sloan Digital Sky Survey Quasar Catalog. IV. Fifth Data Release journal May 2007
10.8-GHz flux density variations among a complete sample of sources from the NRAO-Bonn 84 survey
  • Seielstad, G. A.; Pearson, T. J.; Readhead, A. C. S.
  • Publications of the Astronomical Society of the Pacific, Vol. 95 https://doi.org/10.1086/131261
journal January 1983
X-ray emission from GPS and CSS sources journal February 2009
X‐Ray Cluster Associated with the z = 1.063 CSS Quasar 3C 186: The Jet is Not Frustrated journal October 2005
X‐Ray Properties of the Gigahertz Peaked and Compact Steep Spectrum Sources journal September 2008
The 300 kpc Long X‐Ray Jet in PKS 1127−145, z = 1.18 Quasar: Constraining X‐Ray Emission Models journal March 2007
Comptonization of diffuse ambient radiation by a relativistic jet: The source of gamma rays from blazars? journal January 1994
3C 454.3 Reveals the Structure and Physics of Its “Blazar Zone” journal March 2008
On the evolution of young radio-loud AGN journal December 2000
Evolution of and High‐Energy Emission from GHz‐Peaked Spectrum Sources journal June 2008
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
FERMI LARGE AREA TELESCOPE DETECTION OF BRIGHT γ-RAY OUTBURSTS FROM THE PECULIAR QUASAR 4C +21.35 journal April 2011
Chandra and Hubble Space Telescope Observations of Gamma‐Ray Blazars: Comparing Jet Emission at Small and Large Scales journal June 2007
Characteristics of EGRET Blazars in the VLBA Imaging and Polarimetry Survey (VIPS) journal December 2007
Twenty years monitoring of extragalactic sources at 22, 37 and 87 GHz journal October 2004
Fifteen years monitoring of extragalactic radio sources at 22, 37 and 87 GHz journal November 1998
24 year monitoring of extragalactic sources at 22 and 37 GHz journal August 2005
Radio continuum spectra of gigahertz-peaked spectrum galaxies journal April 2007
Unified Schemes for Radio-Loud Active Galactic Nuclei journal June 1995
Studies of kiloparsec-scale, steep-spectrum radio cores. I VLA maps journal January 1984
A catalogue of quasars and active nuclei: 12th edition journal August 2006
Variability of extragalactic sources at 2.7 GHz. IV Evidence for weak extended emission and for rapid variability journal June 1981
Two-sided ejection in powerful radio sources: The compact symmetric objects journal September 1994
Hubble Space Telescope Sample of Radio-loud Quasars: Ultraviolet Spectra of the First 31 Quasars journal July 1995
FIVE-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE OBSERVATIONS: SOURCE CATALOG journal February 2009

Cited By (8)

Identification of activity peaks in time-tagged data with a scan-statistics driven clustering method and its application to gamma-ray data samples journal July 2018
Mojave. x. Parsec-Scale jet Orientation Variations and Superluminal Motion in Active Galactic Nuclei journal October 2013
Search for very high energy gamma-rays from the z = 0.896 quasar 4C +55.17 with the MAGIC telescopes journal March 2014
Leptonic and Hadronic Modeling of Fermi -LAT Hard Spectrum Quasars and Predictions for High-energy Polarization journal August 2018
FIRST DETECTION IN GAMMA-RAYS OF A YOUNG RADIO GALAXY: FERMI -LAT OBSERVATIONS OF THE COMPACT SYMMETRIC OBJECT PKS 1718−649 journal April 2016
Search for very high energy gamma-rays from the z = 0.896 quasar 4C +55.17 with the MAGIC telescopes text January 2014
Gamma-Ray and Parsec-Scale Jet Properties of a Complete Sample of Blazars From the MOJAVE Program text January 2011
Identification of activity peaks in time-tagged data with a scan-statistics driven clustering method and its application to gamma-ray data samples text January 2018

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Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
galaxies: active
galaxies: individual (4C+55.17)
galaxies: jets
gamma rays: galaxies
radiation mechanisms: non-thermal