X-ray outbursts from a new transient in NGC 55

	X-ray outbursts from a new transient in NGC 55
	Jithesh, V.; Wang, Zhongxiang
刊名	MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
	2015-04-01
卷号	448 期号:2 页码:1973-1978
关键词	X-rays: binaries X-rays: bursts X-rays: galaxies X-rays: general X-rays: individual: XMMU J001446.81-391123.48
英文摘要	We report the outbursts from a newly discovered X-ray transient in the Magellanic-type, SB(s) m galaxy NGC 55. The transient source, XMMU J001446.81-391123.48, was undetectable in the 2001 XMM-Newton and 2004 Chandra observations, but detected in a 2010 XMM-Newton observation at a significance level of 9 sigma in the 0.3-8 keV energy band. The XMM-Newton spectrum is consistent with a power law with photon index Gamma = 3.17(-0.20)(+0.22), but is better fitted with a kT(in) = 0.70 +/- 0.06 keV disc blackbody. The luminosity was similar to 10(38) erg s(-1), and the source displayed strong short-term X-ray variability. These results, combined with the hardness ratios of its emission, strongly suggest an X-ray binary nature for the source. The follow-up studies with Swift XRT (X-ray Telescope) observations revealed that the source exhibited recurrent outbursts with period about a month. The XRT spectra can be described by a power law (Gamma similar to 2.5-2.9) or a disc blackbody (kT(in) similar to 0.8-1.0 keV), and the luminosity was in a range of 10(38)-10(39) erg s(-1), with no evidence showing any significant changes of the spectral parameters in the observations. Based on the X-ray spectral and temporal properties, we conclude that XMMU J001446.81-391123.48 is a new transient X-ray binary in NGC 55, which possibly contains a black hole primary.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	RAPID BURSTER ; SPACED DATA ; XMM-NEWTON ; ROSAT PSPC ; CANDIDATE ; GALAXIES ; NOVAE ; TIME
收录类别	SCI
语种	英语
WOS记录号	WOS:000350274500074
公开日期	2015-08-18
内容类型	期刊论文
源URL	[http://119.78.226.72/handle/331011/18212]
专题	上海天文台_星系宇宙学重点实验室
作者单位	Chinese Acad Sci, Shanghai Astron Observ, Shanghai 200030, Peoples R China
推荐引用方式 GB/T 7714	Jithesh, V.,Wang, Zhongxiang. X-ray outbursts from a new transient in NGC 55[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2015,448(2):1973-1978.
APA	Jithesh, V.,&Wang, Zhongxiang.(2015).X-ray outbursts from a new transient in NGC 55.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,448(2),1973-1978.
MLA	Jithesh, V.,et al."X-ray outbursts from a new transient in NGC 55".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 448.2(2015):1973-1978.