The host galaxy and Fermi-LAT counterpart of HESS J1943+213

Abstract

The very-high energy (VHE, E > 100 GeV) gamma-ray sky shows diverse Galactic and extragalactic source populations. For some sources the astrophysical object class could not be identified so far. The nature (Galactic or extragalactic) of the VHE gamma-ray source HESS J1943+213 is explored. We specifically investigate the proposed near-infrared counterpart 2MASS J19435624+2118233 of HESS J1943+213 and investigate the implications of a physical association. We present K-band imaging from the 3.5 meter CAHA telescope of 2MASS J19435624+2118233. Furthermore, 5 years of Fermi-LAT data were analyzed to search for a high-energy (HE, 100 MeV <E< 100 GeV) counterpart. The CAHA observations revealed that the near-infrared counterpart is extended with an intrinsic half light radius of 2" - 2.5" . These observations also show a smooth, centrally concentrated light profile that is typical of a galaxy, and thus point toward an extragalactic scenario for the VHE gamma-ray source, assuming that the near-infrared source is the counterpart of HESS J1943+213. A high-Sersic index profile provides a better fit than an exponential profile, indicating that the surface brightness profile of 2MASS J19435624+2118233 follows that of a typical, massive elliptical galaxy more closely than that of a disk galaxy. With Fermi-LAT a HE counterpart is found with a power law spectrum above 1 GeV. This gamma-ray spectrum shows a rather sharp break between the HE and VHE regimes. The infrared and HE data strongly favor an extragalactic origin of HESS J1943+213 The source is most likely located at a redshift between 0.03 and 0.45 according to extension and EBL attenuation arguments.

References in corpus (30)

• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission
• Detailed Decomposition of Galaxy Images. II. Beyond Axisymmetric Models
• Fermi Large Area Telescope Second Source Catalog
• A Cosmology Calculator for the World Wide Web
• The extragalactic optical-infrared background radiations, their time evolution and the cosmic photon-photon opacity
• Studies in Astronomical Time Series Analysis. VI. Bayesian Block Representations
• The 70 Month Swift-BAT All-Sky Hard X-Ray Survey
• The H.E.S.S. survey of the Inner Galaxy in very high-energy gamma-rays
• The Fermi Large Area Telescope On Orbit: Event Classification, Instrument Response Functions, and Calibration
• Fermi-LAT Observations of Markarian 421: the Missing Piece of its Spectral Energy Distribution
• Teraelectronvolt Astronomy
• Spectroscopy of The Largest Ever Gamma-ray Selected BL Lac Sample
• Insights Into the High-Energy Gamma-ray Emission of Markarian 501 from Extensive Multifrequency Observations in the Fermi Era
• The UKIRT Infrared Deep Sky Survey First Data Release
• The Mauna Kea Observatories Near-Infrared Filter Set. III. Isophotal Wavelengths and Absolute Calibration
• Measurement of the extragalactic background light imprint on the spectra of the brightest blazars observed with H.E.S.S
• Identification of the infrared non-thermal emission in Blazars
• Fermi observations of TeV-selected AGN
• Fermi Observations of the Very Hard Gamma-ray Blazar PG 1553+113
• Evidence for a cosmological effect in γ-ray spectra of BL Lacs
• HESS J1943+213: a candidate extreme BL Lacertae object
• H.E.S.S and Fermi-LAT discovery of gamma rays from the blazar 1ES 1312-423
• Extreme Blazars Studied with Fermi-LAT and Suzaku: 1ES 0347-121 and Blazar Candidate HESS J1943+213
• Discovery of high and very high-energy emission from the BL Lac object SHBL J001355.9-185406
• Near-Infrared Observations of BL Lacertae Host Galaxies
• The PSR J1124-5916 wind nebula in the near-infrared
• VLBI search for the radio counterpart of HESS J1943+213
• The HI absorption distance of HESS J1943+213 favours its extragalactic nature

Cited by in corpus (11)

• The Third Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope
• The H.E.S.S. Galactic plane survey
• Optical polarization of high-energy BL Lac objects
• Multi-TeV flaring from high energy blazars: An evidence of the photohadronic process
• HESS J1943+213: An Extreme Blazar Shining Through The Galactic Plane
• Extreme & High Synchrotron Peaked Blazars at the limit of Fermi-LAT detectability: the $\gamma$-ray spectrum of 1BIGB sources
• EVN Observations of HESS J1943+213: Evidence for an Extreme TeV BL Lac Object
• Model-independent Redshift Estimation of BL Lac Objects through VHE Observations
• HESS J1943+213: a non-classical high-frequency-peaked BL Lac object
• Resolving the Host Galaxy of a Distant Blazar with LBT/LUCI1 + ARGOS
• VERITAS and VLBA Observations of HESS J1943+213