Journal article

An active M star with X-ray double flares disguised as an ultra-luminous X-ray source

Jin-Cheng Guo, Ji-Feng Liu, Song Wang, Yue Wu, Yu-Xiang Qin

Research in Astronomy and Astrophysics | NATL ASTRONOMICAL OBSERVATORIES, CHIN ACAD SCIENCES | Published : 2016


Here we present research on an ultra-luminous X-ray source (ULX) candidate 2XMM J140229.91+542118.8. The X-ray light curves of this ULX candidate in M101 exhibit features of a flare star. More importantly, the Chandra light curve displays unusual X-ray double flares, which is comprised of two close peaks. The X-ray (0.3-11.0 keV) flux of the first peak was derived from the two-temperature APEC model as ∼ 1.1 ± 0.1 × 10-12 erg cm-2 s-1. The observed flux at its first peak increased by about two orders of magnitude in X-ray as compared to quiescence. The slope of the second fast decay phase is steeper than the slope of the first fast decay phase, indicating that the appearance of a second flar..

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University of Melbourne Researchers


Awarded by National Natural Science Foundation of China (NSFC)

Funding Acknowledgements

The authors would like to thank the anonymous referee for the helpful suggestions. The authors acknowledge the National Natural Science Foundation of China (NSFC) under grants 11333004 and 11403056. This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France.