Publication Date:
2015-05-23
Description:
We study the contribution of thermal and non-thermal processes to the inverse Compton emission of the radio galaxy M87 by modelling its broad-band emission. Through this we aim to derive insight into where within the AGN the X-ray, -ray and VHE emission is produced. We have analysed all available INTEGRAL IBIS/ISGRI (Imager on Board INTEGRAL Spacecraft/ INTEGRAL Soft Gamma-Ray Imager) data on M87, spanning almost 10 years, to set an upper limit to the average hard X-ray flux of f (20-60 keV) 3 x 10 –12 erg cm –2 s –1 , using several techniques beyond the standard analysis which are also presented here. We also analysed hard X-ray data from Suzaku /PIN taken late 2006 November, and we report the first hard X-ray detection of M87 with a flux of f (20-60 keV) = 10 –11 erg cm –2 s –1 . In addition we analyse data from Fermi /Large Area Telescope, INTEGRAL /Joint European Monitor in X-rays, and Suzaku /X-ray Imaging Spectrometer. We collected historical radio/IR/optical and VHE data and combined them with the X-ray and -ray data, to create broad-band spectral energy distributions (SEDs) for the average low-flux state and the flaring state. The resulting SEDs are modelled by applying a single-zone SSC model with a jet angle of = 15°. We also show that modelling the core emission of M87 using a single-zone synchrotron self-Compton model does represent the SED, suggesting that the core emission is dominated by a BL Lac-type AGN core. Using SED modelling we also show that the hard X-ray emission detected in 2006 is likely due to a flare of the jet knot HST-1, rather than being related to the core.
Print ISSN:
0035-8711
Electronic ISSN:
1365-2966
Topics:
Physics
Permalink