论文标题
在两个非常金属缺陷的紧凑型矮星系DDO 68和PHL 293B中，候选发光蓝色变化星的十年时间监视
Decade-long time-monitoring of candidate Luminous Blue Variable Stars in the two very metal-deficient compact dwarf galaxies DDO 68 and PHL 293B
论文作者
论文摘要
我们已经研究了两个低金属蓝色紧凑型矮星系中候选发光蓝色可变星（CLBV）的光谱时间变化，DDO 68和PHL 293B。位于HII区域3的DDO 68中的LBV显示出爆发，在2008 - 2010年期间，Halpha的发光度增加了1000次。 HI和HEI线的广泛发射显示了P Cygni曲线，相对恒定的终端速度约为800 km/s，达到〜2x10^38 ERG/s的最大发光度L（HALPHA），FWHM的FWHM为〜1000-1200 km/s。另一方面，自2001年在PHL 293B中发现CLBV以来，该银河系中HI和HEI发射线的宽和纳尔通量比的通量和较大的核糖通量比在16年中一直保持恒定，并且变化很小。宽HALPHA成分的光度在〜2x10^38 erg/s和〜10^39 erg/s之间变化，FWHM在〜500-1500 km/s的范围内变化。尽管最近几年的宽阔的核糖量比降低了，但直到2020年底降低了，直到2020年底，异常持久的P Cygni特征才能清晰可见。从P Cygni剖面测量了〜800 km/s的末端速度，类似于DDO 68中的速度，尽管后者比PHL 293B高3.7金属缺陷。 PHL 293B中宽HALPHA光度的相对恒定性表明，这是由于LBV/SN IIN型的长期恒星瞬态。
We have studied the spectral time variations of candidate luminous blue variable stars (cLBV) in two low-metallicity blue compact dwarf galaxies, DDO 68 and PHL 293B. The LBV in DDO 68, located in HII region #3, shows an outburst, with an increase of more than 1000 times in Halpha luminosity during the period 2008-2010. The broad emission of the HI and HeI lines display a P Cygni profile, with a relatively constant terminal velocity of ~800 km/s, reaching a maximum luminosity L(Halpha) of ~2x10^38 erg/s, with a FWHM of ~1000-1200 km/s. On the other hand, since the discovery of a cLBV in 2001 in PHL 293B, the fluxes of the broad components and the broad-to-narrow flux ratios of the HI and HeI emission lines in this galaxy have remained nearly constant over 16 years, with small variations. The luminosity of the broad Halpha component varies between ~2x10^38 erg/s and ~10^39 erg/s, with the FWHM varying in the range ~500-1500 km/s. Unusually persistent P Cygni features are clearly visible until the end of 2020 despite a decrease of the broad-to-narrow flux ratio in the most recent years. A terminal velocity of ~800 km/s is measured from the P Cygni profile, similar to the one in DDO 68, although the latter is 3.7 more metal-deficient than PHL 293B. The relative constancy of the broad Halpha luminosity in PHL 293B suggests that it is due to a long-lived stellar transient of type LBV/SN IIn.
