Extraordinary Luminous Soft X-Ray Transient MAXI JO158-744 as an Ignition of a Nova on a Very Massive O-Ne White Dwarf
Extraordinary Luminous Soft X-Ray Transient MAXI JO158-744 as an Ignition of a Nova on a Very Massive O-Ne White Dwarf
复制标题
非凡的发光软 X 射线瞬态 MAXI JO158-744 作为超大质量邻氖白矮星上新星的点燃
DOI：
10.1088/0004-637x/779/2/118
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发表时间：
2013
影响因子：
4.9
通讯作者：
H. ; et al
中科院分区：
文献类型：
--
作者：
Morii;M. ; Tomida;H. ; Kimura;M. ; Suwa;F. ; Negoro;H. ; et al
2011年11月11日，我们通过全天X射线图像监视器（MAXI）观测到了一个非常明亮的软X射线瞬变，MAXI J 0158 − 744。该瞬变过程具有软X射线谱、短持续时间（1.3× 103 s< Δ Td < 1.10× 104 s）、快速上升（< 5.5× 103 s）和在0.7- 7.0keV波段内2× 1040 ergs-1的巨大峰值亮度等特征。通过Swift观测和中小孔径研究望远镜系统的光谱学，我们证实了瞬变是一次新星爆炸，发生在位于小麦哲伦云附近的一颗白色矮星和一颗Be星星的双星上。超软X射线源（SSS）阶段的早期开启（< 0.44天），大约一个月的短SSS阶段持续时间，以及在第三次MAXI扫描中发现的0.92 keV氖发射线，第一次探测后1296秒，表明爆炸涉及少量喷出物，并在一颗异常大质量的O-Ne白色上产生，接近或可能超过，这就是卡拉塞卡极限。我们认为MAXI探测到的巨大光度是由于火球阶段，这是新星爆炸中热核失控过程点火的直接表现。
We present the observation of an extraordinary luminous soft X-ray transient, MAXI J0158− 744, by the Monitor of All-sky X-ray Image (MAXI) on 2011 November 11. This transient is characterized by a soft X-ray spectrum, a short duration (1.3× 10 3 s< ΔT d< 1.10× 10 4 s), a rapid rise (< 5.5× 10 3 s), and a huge peak luminosity of 2× 10 40 erg s− 1 in 0.7–7.0 keV band. With Swift observations and optical spectroscopy from the Small and Moderate Aperture Research Telescope System, we confirmed that the transient is a nova explosion, on a white dwarf in a binary with a Be star, located near the Small Magellanic Cloud. An early turn-on of the super-soft X-ray source (SSS) phase (< 0.44 days), the short SSS phase duration of about one month, and a 0.92 keV neon emission line found in the third MAXI scan, 1296 s after the first detection, suggest that the explosion involves a small amount of ejecta and is produced on an unusually massive O–Ne white dwarf close to, or possibly over, the Chandrasekhar limit. We propose that the huge luminosity detected with MAXI was due to the fireball phase, a direct manifestation of the ignition of the thermonuclear runaway process in a nova explosion.