""Context. X-ray bright active galactic nuclei represent a unique astrophysical laboratory for studying accretion physics around supermassive black holes. Aims. 4U 1344-60 is a bright Seyfert galaxy which revealed relativistic reflection features in the archival XMM-Newton observation. Methods. We present the spectroscopic results of new data obtained with the Suzaku satellite and compare them with the previous XMM-Newton observation. Results. The X-ray continuum of 4U 1344-60 can be well described by a power-law component with the photon index approximate to 1.7 modified by a fully and a partially covering local absorbers. We measured a substantial decrease of the fraction of the partially absorbed radiation from around 45% in the XMM-Newton observation to less than 10% in the Suzaku observation while the power-law slope remains constant within uncertainties. The iron line in the Suzaku spectrum is relatively narrow, sigma = (0.08 +\\\/- 0.02) keV, without any suggestion for relativistic broadening. Regarding this, we interpret the iron line in the archival XMM-Newton spectrum as a narrow line of the same width plus an additional red-shifted emission around 6.1 keV. Conclusions. No evidence of the relativistic reflection is present in the Suzaku spectra. The detected red-shifted iron line during the XMM-Newton observation could be a temporary feature either due to locally enhanced emission or decreased ionisation in the innermost accretion flow. RI Bianchi, Stefano\\\/B-4804-2010 OI Bianchi, Stefano\\\/0000-0002-4622-4240""
Svoboda, J., Bianchi, S., Guainazzi, M., Matt, G., Piconcelli, E., Karas, V., et al. (2012). Active galaxy 4U 1344-60: did the relativistic line disappear?. ASTRONOMY & ASTROPHYSICS, 545, 148 [10.1051/0004-6361/201219500].
Active galaxy 4U 1344-60: did the relativistic line disappear?
BIANCHI, STEFANO;MATT, Giorgio;
2012-01-01
Abstract
""Context. X-ray bright active galactic nuclei represent a unique astrophysical laboratory for studying accretion physics around supermassive black holes. Aims. 4U 1344-60 is a bright Seyfert galaxy which revealed relativistic reflection features in the archival XMM-Newton observation. Methods. We present the spectroscopic results of new data obtained with the Suzaku satellite and compare them with the previous XMM-Newton observation. Results. The X-ray continuum of 4U 1344-60 can be well described by a power-law component with the photon index approximate to 1.7 modified by a fully and a partially covering local absorbers. We measured a substantial decrease of the fraction of the partially absorbed radiation from around 45% in the XMM-Newton observation to less than 10% in the Suzaku observation while the power-law slope remains constant within uncertainties. The iron line in the Suzaku spectrum is relatively narrow, sigma = (0.08 +\\\/- 0.02) keV, without any suggestion for relativistic broadening. Regarding this, we interpret the iron line in the archival XMM-Newton spectrum as a narrow line of the same width plus an additional red-shifted emission around 6.1 keV. Conclusions. No evidence of the relativistic reflection is present in the Suzaku spectra. The detected red-shifted iron line during the XMM-Newton observation could be a temporary feature either due to locally enhanced emission or decreased ionisation in the innermost accretion flow. RI Bianchi, Stefano\\\/B-4804-2010 OI Bianchi, Stefano\\\/0000-0002-4622-4240""I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
