Journal
ASTROPHYSICAL JOURNAL LETTERS
Volume 705, Issue 2, Pages L109-L112Publisher
IOP PUBLISHING LTD
DOI: 10.1088/0004-637X/705/2/L109
Keywords
accretion, accretion disks; X-rays: binaries; X-rays: individual (HLX-1)
Categories
Funding
- CNRS
- CNES
- STFC
Ask authors/readers for more resources
The brightest ultra-luminous X-ray source, ESO 243-49 HLX-1, with a 0.2-10 keV X-ray luminosity of up to 10(42) erg s(-1), provides the strongest evidence to date for the existence of intermediate mass black holes (BHs). Although small-scale X-ray spectral variability has already been demonstrated, we have initiated a monitoring campaign with the X-ray Telescope (XRT) onboard the Swift satellite to search for luminosity-related spectral changes and to compare its behavior with the better-studied stellar mass BHs. In this Letter, we report a drop in the XRT count rate by a factor of similar to 8 which occurred simultaneously with a hardening of the X-ray spectrum. A second observation found that the source had re-brightened by a factor of similar to 21 which occurred simultaneously with a softening of the X-ray spectrum. This may be the first evidence for a transition between the low/hard and high/soft states.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available