SIMBAD references

2013A&A...550A..66K - Astronomy and Astrophysics, volume 550A, 66-66 (2013/2-1)

Fermi-LAT and Suzaku observations of the radio galaxy Centaurus B.

KATSUTA J., TANAKA Y.T., STAWARZ L., O'SULLIVAN S.P., CHEUNG C.C., KATAOKA J., FUNK S., YUASA T., ODAKA H., TAKAHASHI T. and SVOBODA J.

Abstract (from CDS):

CentaurusB is a nearby radio galaxy positioned in the southern hemisphere close to the Galactic plane. Here we present a detailed analysis of about 43 months of accumulated Fermi-LAT data of the γ-ray counterpart of the source initially reported in the 2nd Fermi-LAT catalog, and of newly acquired Suzaku X-ray data. We confirm its detection at GeV photon energies and analyze the extension and variability of the γ-ray source in the LAT dataset, in which it appears as a steady γ-ray emitter. The X-ray core of CentaurusB is detected as a bright source of a continuum radiation. We do not detect, however, any diffuse X-ray emission from the known radio lobes, with the provided upper limit only marginally consistent with the previously claimed ASCA flux. Two scenarios that connect the X-ray and γ-ray properties are considered. In the first one, we assume that the diffuse non-thermal X-ray emission component is not significantly below the derived Suzaku upper limit. In this case, modeling the inverse-Compton emission shows that the observed γ-ray flux of the source may in principle be produced within the lobes. This association would imply that efficient in-situ acceleration of the radiating electrons is occurring and that the lobes are dominated by the pressure from the relativistic particles. In the second scenario, with the diffuse X-ray emission well below the Suzaku upper limits, the lobes in the system are instead dominated by the magnetic pressure. In this case, the observed γ-ray flux is not likely to be produced within the lobes, but instead within the nuclear parts of the jet. By means of synchrotron self-Compton modeling, we show that this possibility could be consistent with the broad-band data collected for the unresolved core of CentaurusB, including the newly derived Suzaku spectrum.

Abstract Copyright:

Journal keyword(s): acceleration of particles - radiation mechanisms: non-thermal - X-rays: galaxies - gamma rays: galaxies - galaxies: jets - galaxies: individual: Centaurus B

Simbad objects: 12

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