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Post Info TOPIC: Blazar 3C 279
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Quasar 3C279
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ATel 10121: Optical flare of the Quasar 3C279



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Blobrana


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RE: Blazar 3C 279
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Title: Gamma-Ray Blazars near Equipartition and the Location of the Gamma-Ray Emission Site in 3C 279
Authors: Charles D. Dermer, Matteo Cerruti, Benoit Lott, Catherine Boisson, Andreas Zech

Blazar spectral models generally have numerous unconstrained parameters, leading to ambiguous values for physical properties like Doppler factor delta or fluid magnetic field B'. To help remedy this problem, a few modifications of the standard leptonic blazar jet scenario are considered. First, a log-parabola function for the electron distribution is used. Second, analytic expressions relating energy loss and kinematics to blazar luminosity and variability, written in terms of equipartition parameters, imply delta, B', and the principal electron Lorentz factor gamma'_p. The external radiation field in a blazar is approximated by Ly alpha radiation from the broad line region (BLR) and ~0.1 eV infrared radiation from a dusty torus. When used to model 3C 279 SEDs from 2008 and 2009 reported by Hayashida et al. (2012), we derive delta ~ 20-30, B' ~ few G, and total (IR + BLR) external radiation field energy densities u 0.01 - 0.001 erg/cm³, implying an origin of the gamma-ray emission site in 3C 279 at the outer edges of the BLR. This is consistent with the gamma-ray emission site being located at a distance R <~ Gamma² c t_{var} ~ 0.1 (\Gamma/30)² (t_{var}/10^4 s) pc from the black hole powering 3C 279's jets, where t_{var} is the variability time scale of the radiation in the source frame. For low hadronic content, absolute jet powers of ~10% of the Eddington luminosity are calculated.

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Blobrana


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Telescope network zooms in on the heart of a distant quasar

An international team led by scientists from the Max-Planck-Institute for Radio Astronomy has succeeded in observing the heart of a distant quasar with unprecedented sharpness, or angular resolution. The observations, made by connecting radio telescopes on different continents, are a crucial step towards a dramatic scientific goal: to depict the supermassive black hole at the centre of our own galaxy and also the central black holes in other nearby galaxies.
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Blobrana


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3C 279
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Title: The Host Galaxy of 3C 279
Authors: K. Nilsson, T. Pursimo, C. Villforth, E. Lindfors, L. O. Takalo

We have obtained a deep i-band image of the blazar 3C 279 while the target was in a low optical state. Due to the faintness of the optical nucleus we have made the first detection of the host galaxy. The host galaxy has an apparent I-band magnitude of 18.4 ± 0.3 and an effective radius of (2.7 ± 1.1) arcsec. The luminosity of the host galaxy M_R = -23.8 is consistent with the luminosities of other radio-loud quasar host galaxies. Using the empirical correlation between bulge luminosity and central black hole mass M_bh we estimate log(M_bh/M_Sun) = 8.9 ± 0.5, broadly consistent with values obtained by photoionisation methods.

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The MAGIC (Major Atmospheric Gamma-ray Imaging Cherenkov) telescope has detected emission of very high energy gamma rays from the active nucleus of the 3C279 galaxy. The quasar's distance is more than five billion light years (roughly half the radius of the Universe) from the Earth, more than twice the distance of objects previously observed with this kind of radiation.

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Blazar 3C 279
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Title: Multifrequency Observations of the Blazar 3C 279 in January 2006
Authors: WEBT Collaboration: W. Collmar, M. Böttcher, T. Krichbaum, E. Bottacini, V. Burwitz, A. Cucchiara, D. Grupe, M. Gurwell, P. Kretschmar, K. Pottschmidt, M. Bremer, S. Leon, H. Ungerechts, P.Giommi, M. Capalbi

We report first results of a multifrequency campaign from radio to hard X-ray energies of the prominent gamma-ray blazar 3C 279, which was organised around an INTEGRAL ToO observation in January 2006, and triggered on its optical state. The variable blazar was observed at an intermediate optical state, and a well-covered multifrequency spectrum from radio to hard X-ray energies could be derived. The SED shows the typical two-hump shape, the signature of non-thermal synchrotron and inverse-Compton (IC) emission from a relativistic jet. By the significant exposure times of INTEGRAL and Chandra, the IC spectrum (0.3 - 100 keV) was most accurately measured, showing - for the first time - a possible bending. A comparison of this 2006 SED to the one observed in 2003, also centred on an INTEGRAL observation, during an optical low-state, reveals the surprising fact that - despite a significant change at the high-energy synchrotron emission (near-IR/optical/UV) - the rest of the SED remains unchanged. In particular, the low-energy IC emission (X- and hard X-ray energies) remains the same as in 2003, proving that the two emission components do not vary simultaneously, and provides strong constraints on the modelling of the overall emission of 3C 279.

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