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Title: Understanding the nature of the blazar CGRaBS J0211+1051

The source CGRaBS J0211+1051 (MG1 J021114+1051, z = 0.20) flared up on 2011 January 23 in high-energy γ-rays as reported by the Large Area Telescope (LAT) on board Fermi. This event was followed by increased activity at the UV, optical, and radio frequencies as detected by the observing facilities worldwide. The source also showed a high and variable optical polarization based on which it was proposed to be a low-energy peaked BL Lac object (LBL). The present work reports first comprehensive multi-wavelength study of this source using data in the radio, optical, UV, X- and γ-rays, and optical polarization. Using these multi-wavelength data on the source, we have estimated various parameters and verified its classification vis-a-vis blazar sequence. Multi-waveband light curves are used to discuss the flaring events of 2011 January in an attempt to address the nature of the source and pinpoint the possible physical processes responsible for the emission. The light curves show variations in the high-energy γ-rays to be correlated with X-ray, UV, and optical variations, perhaps indicating their co-spatial origin. Our optical data, quasi-simultaneous with UV (Swift-UVOT) and X-ray (Swift-XRT) data, enabled us to trace the low-energy (synchrotron) component of the spectral energy distribution (SED) formore » CGRaBS J0211+1051 for the first time. The SED shows the synchrotron peak to lie at ∼1.35 × 10{sup 14} Hz, confirming that CGRaBS J0211+1051 is an LBL. Some other parameters, such as the local magnetic field (∼5.93 G) and black hole mass (∼2.4 × 10{sup 8} M {sub ☉}), are also estimated which are in agreement with their typical values for the blazars. Based on the present study, identification of the Fermi/LAT source, 2FGL J0211.2+1050, with its BL Lac counterpart CGRaBS J0211+1051 is confirmed.« less
Authors:
; ;  [1] ;  [2]
  1. Physical Research Laboratory, Ahmedabad 380009 (India)
  2. INAF, Osservatorio Astronomico di Brera, Via E. Bianchi 46, I-23807 Merate (Italy)
Publication Date:
OSTI Identifier:
22365338
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 791; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BL LACERTAE OBJECTS; BLACK HOLES; CLASSIFICATION; EMISSION; ENERGY SPECTRA; GALAXIES; MAGNETIC FIELDS; MASS; POLARIZATION; RADIOWAVE RADIATION; STELLAR FLARES; SYNCHROTRON RADIATION; TELESCOPES; VARIATIONS; VISIBLE RADIATION; WAVELENGTHS; X RADIATION