2006/10/19 by A. Wolter, G. Trinchieri, M. Colpi +1 · 2 citations
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Flux (metallurgy) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Luminosity #Physics #Supernova #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2006.11116.x
published as Mon.Not.Roy.Astron.Soc.373:1627-1632,2006 · 6 pages; 3 figure; accepted for publication in MNRAS
arxiv created 2006/10/19 · openalex publication_date 2006/11/17 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We report the first detection of flux variability in the most luminous X-ray source in the southern ring of the Cartwheel galaxy. XMM–Newton data show that the luminosity has varied over a time-scale of 6 months from L0.5−10 keV∼ 1.3 × 1041 erg s−1, consistent with the previous Chandra observation, to L0.5−10 keV≲ 6.4 × 1040 erg s−1. This fact provides the first evidence that the source is compact in nature and is not a collection of individual fainter sources, such as supernova remnants. The source has been repeatedly observed at the very high-luminosity level of L0.5−10 keV∼ 1.3 × 1041 erg s−1 for a period of at least 4 yr before dimming at the current level. It represents then the first example of an accreting object revealed in a long-lived state of extremely high luminosity.