X-ray and optical variability of the ultraluminous X-ray source NGC 1313 X-2
Abstract
We present an analysis of recent XMM-Newton and HST archive data of the ultraluminous X-ray source NGC 1313 X-2. Quasi-simultaneous observations taken with XMM-Newton, HST and VLT allow us to study both the X-ray light curve and its correlation with the optical emission of the two proposed ULX counterparts. At the end of December 2003 the source experienced a short, but intense flare, reaching a maximum luminosity of ~10^40 erg/s. At the same time, the optical flux of both the suggested counterparts did not show pronounced variations (<30%). Assuming that the ULX emission is isotropic and taking X-ray reprocessing into account, the optical data for one of the proposed counterparts are consistent with it being an early type, main sequence star of about 10-18 Msun losing matter through Roche-lobe overflow onto a ~120 Msun black hole at an orbital separation corresponding to a period of about 2 days.
Keywords
Cite
@article{arxiv.astro-ph/0612420,
title = {X-ray and optical variability of the ultraluminous X-ray source NGC 1313 X-2},
author = {P. Mucciarelli and L. Zampieri and A. Treves and R. Turolla and R. Falomo},
journal= {arXiv preprint arXiv:astro-ph/0612420},
year = {2015}
}
Comments
19 pages, 4 figures, accepted for pubblication on ApJ