ULTRACAM observations of two accreting white dwarf pulsators
ULTRACAM observations of two accreting white dwarf pulsators
复制标题
两个吸积白矮星脉动星的 ULTRACAM 观测
DOI：
10.1111/j.1365-2966.2008.14163.x
复制
发表时间：
2009
影响因子：
4.8
通讯作者：
Copperwheat C
中科院分区：
文献类型：
--
作者：
Copperwheat C
本文介绍了GW Librae(GW Lib)和SDSSJ161033.64−010223.3(SDSS1610)这两个激变变星的高时间分辨率观测，它们的周期变化归因于白矮星(WD)的非径向脉动。我们用超大型望远镜(VLT)上的ULTRACAM和SAAO 1.9米望远镜上的开普敦大学光度计观测了这两个系统的静态，并探测到了前人报道的强脉动模式。GW Lib中进一步的周期识别受到源的吸积驱动的闪烁的限制，但在SDSS1610的情况下，我们识别了几个额外的低幅度周期。在这两个源中，我们发现脉动模的振幅在较蓝的波长下更强。在SDSS1610的情况下，有证据表明这两个基色信号具有不同的颜色相关性，这表明它们可能是不同的球谐模式。我们还使用VLT上的ULTRACAM和威廉·赫歇尔望远镜上的辅助端口成像仪，在2007年矮新星爆发后的几个时期观察到了GW Lib。这是第一次在这种状态下观测到一颗包含脉动WD的矮新星。我们没有观察到任何周期性，这表明WD的加热要么完全切断了脉动，要么将它们在通量中的相对幅度降低到无法检测到的程度。在暴发11个月后，在利物浦望远镜上用RatCam进行的进一步观测仍然没有显示出以前观察到的脉动模式，但确实出现了两个新的周期信号，一个频率为74.86±0.68个周期d−1(P=1154 S)，银带幅度为2.20%±0.18，另一个频率为292.05±1.11个周期d−1(P=296 S)，银‘幅度为1.25%±0.18。除了WD脉动外，我们在静止状态下对GW Lib的观测还显示出光度上的较大幅度调制，周期约为2.1小时。这是以前观测到的，其来源尚不清楚：它与轨道周期无关。我们发现这种调制在我们的观察过程中会在相位和/或周期上发生变化。我们的数据支持这一结论，即这是一种与吸积有关的现象，起源于吸积盘。
In this paper, we present high time-resolution observations of GW Librae (GW Lib) and SDSS J161033.64−010223.3 (SDSS 1610) – two cataclysmic variables which have shown periodic variations attributed to non-radial pulsations of the white dwarf (WD). We observed both these systems in their quiescent states with ULTRACAM on the Very Large Telescope (VLT) and the University of Cape Town Photometer on the SAAO 1.9 m telescope, and detect the strong pulsations modes reported by previous authors. The identification of further periodicities in GW Lib is limited by the accretion-driven flickering of the source, but in the case of SDSS 1610 we identify several additional low-amplitude periodicities. In both the sources, we find the pulsation modes to be stronger in amplitude at bluer wavelengths. In the case of SDSS 1610, there is evidence to suggest that the two primary signals have a different colour dependence, suggesting that they may be different spherical harmonic modes. We additionally observed GW Lib during several epochs following its 2007 dwarf nova outburst, using ULTRACAM on the VLT and the Auxiliary Port Imager on the William Herschel Telescope. This is the first time a dwarf nova containing a pulsating WD has been observed in such a state. We do not observe any periodicities, suggesting that the heating of the WD had either switched-off the pulsations entirely, or reduced their relative amplitude in flux to the point where they are undetectable. Further observations 11 months after the outburst taken with RATCam on the Liverpool Telescope still do not show the pulsation modes previously observed, but do show the emergence of two new periodic signals, one with a frequency of 74.86 ± 0.68 cycles d−1(P= 1154 s) and ag′-band amplitude of 2.20 per cent ±0.18 and the other with a frequency of 292.05 ± 1.11 cycles d−1(P= 296 s) and ag′ amplitude of 1.25 per cent ±0.18. In addition to the WD pulsations, our observations of GW Lib in quiescence show a larger amplitude modulation in luminosity with a period of approximately 2.1 h. This has previously been observed, and its origin is unclear: it is unrelated to the orbital period. We find this modulation to vary over the course of our observations in phase and/or period. Our data support the conclusion that this is an accretion-related phenomenon, which originates in the accretion disc.
登录
查看更多内容
影响因子：
3.5
作者：
J. Patterson;G. Masi;M. Richmond;B. Martin;E. Beshore;D. Skillman;J. Kemp;T. Vanmunster;R. Rea;W. Allen;Stacey E. Davis;Tracy Davis;A. Henden;D. Starkey;J. Foote;A. Oksanen;L. Cook;R. Fried;D. Husar;R. Novák;T. Campbell;J. Robertson;T. Krajci;E. Pavlenko;N. Mirabal;P. Niarchos;O. Brettman;Stan Walker
通讯作者：
J. Patterson;G. Masi;M. Richmond;B. Martin;E. Beshore;D. Skillman;J. Kemp;T. Vanmunster;R. Rea;W. Allen;Stacey E. Davis;Tracy Davis;A. Henden;D. Starkey;J. Foote;A. Oksanen;L. Cook;R. Fried;D. Husar;R. Novák;T. Campbell;J. Robertson;T. Krajci;E. Pavlenko;N. Mirabal;P. Niarchos;O. Brettman;Stan Walker
Librae GW 中 2.09 小时的光度周期性
DOI：
--
发表时间：
2001
期刊：
影响因子：
--
作者：
P. Woudt;B. Warner
通讯作者：
B. Warner
DAV 白矮星的星震学
DOI：
--
发表时间：
1997
期刊：
影响因子：
--
作者：
P. Bradley
通讯作者：
P. Bradley
在灾变变星的白矮星初级中发现非径向脉动
DOI：
--
发表时间：
1998
期刊：
影响因子：
--
作者：
Van Zyl;Liza Marie.
通讯作者：
Liza Marie.
2001 年 7 月爆发后 Wz Sagittae 长期冷却的 Hst/stis 光谱和建模
DOI：
--
发表时间：
2006
期刊：
影响因子：
--
作者：
P. Godon;E. Sion;F. Cheng;K. Long;B. Gänsicke;P. Szkody
通讯作者：
P. Szkody