Bulletin of Taras Shevchenko National University of Kyiv. Astronomy, no. 56, p. 18-22 (2017)

Determining the upper limit on the black hole mass from NGC 4748 X-ray photometry

EFedorova, Ph.D
Astronomical Observatory of Taras Shevchenko National University of Kyiv, Kyiv


In this paper, we analyze all the available X-ray photometrical data of the narrow-line Seyfert 1 galaxy NGC 4748, namely XMM-Newton (EPIC and OM), INTEGRAL (ISGRI and JEM-X) as well as SWIFT (BAT and XRT) to estimate, if it’s possible,  the mass of the central black hole from the variability of the lightcurves. In the XMM/EPIC composite lightcurve, we found fast quasiperiodic variations of the 0.5-10.0 keV flux on a timescales of 103 seconds. These variations were interpreted as the result of the emission of a dense hot clump of matter orbiting the central black hole near the innermost stable trajectory. The structure function analysis of this lightcurve allowed us to put an upper limit to the mass of the central BH, as 6.23 * 107M¤.

Key words
Black hole.

Bentz, M. C., Katz, S., 2015, PASP, 127, 67;
Gallimore, J.F., Axon, D. J., Dea, C.P., Baum, S.A., Pedlar, A. 2006, AJ, 132, 2, 546
Grier, C.J., Martini, P., Watson, L.C., et al. 2013, ApJ, 773, 90
Hao, C. N., Xia Shude Mao, X.Y., Hong, W., Deng Z. G. 2005, AJ, 625, 78
Landi, R. et al. 2010, MNRAS, 403, 945
Mushotzky, R., Done, C., Pounds, K. A. 1993, Ann.Rev A&A, 31, 717
Osterbrock, D. E., De Robertis, M. M. 1985, PASP, 97, 1129
Pal, M. et al., 2016, MNRAS, 457, 875
Panessa, F., De Rosa, A., Bassani, L., et al. 2011, MNRAS, 417, 2426
Paturel, G.; Dubois, P., Petit, C., Woelfel, F. 2002, LEDA
Veron-Cetty, M.-P., Véron, P. 2006, A&A, 455, 773
Wang, T., Lu Y. 2001, A&A, 377, 52
Woo, J.H. et al. aph.1004.0252v2 2010

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DOI: https://doi.org/10.17721/BTSNUA.2017.56.18-22