arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1612.04830astro-ph.HE
收藏

iPTF发现发光类星体的快速“开启”

iPTF Discovery of the Rapid "Turn On" of a Luminous Quasar

S. Gezari, T. Hung, S. B. Cenko, N. Blagorodnova, Lin Yan, S. R. Kulkarni, K. Mooley, A. K. H. Kong, T. M. Cantwell, P. C. Yu, Y. Cao, C. Fremling, J. D. Neill,… 展开作者

S. Gezari, T. Hung, S. B. Cenko, N. Blagorodnova, Lin Yan, S. R. Kulkarni, K. Mooley, A. K. H. Kong, T. M. Cantwell, P. C. Yu, Y. Cao, C. Fremling, J. D. Neill, C. C. Ngeow, P. E. Nugent, P. Wozniak

摘要:

我们提出了一个无线电安静的类星体在z=0.237发现“打开”的中间帕洛玛瞬态工厂(iPTF)。瞬态,iPTF 16 bco,由iPTF在星系核中检测到,具有低电离发射线区域(LINER)的弱窄线发射特征的档案SDSS光谱。我们的后续光谱显示了宽巴耳末线的戏剧性出现,以及12年后发光(L_bol~10^45 erg/s)的1型类星体的幂律连续特征。我们从2009年到2012年使用PTF进行的光度监测,以及2011年和2015年XMM-Newton Slew Survey的偶然X射线观测,将状态变化限制在iPTF检测之前不到500天。相对于其他外观变化的类星体,第1类星体的H α与[OIII]5007的宽线比增强,这也暗示了在类星体中观察到的最快的状态变化。我们认为,从紫外线和X射线连续通量的增亮推断,爱丁顿比增加>10更可能是由于一个内在的变化,在一个预先存在的吸积盘的吸积率,比外部机制,如可变的遮蔽,微透镜,或恒星的潮汐破坏。然而,进一步的监测将有助于更好地约束推动这种状态变化的机制。类星体的快速“启动”比吸积盘的粘性下降时间尺度要短得多,并且需要一个盘的不稳定性,这种不稳定性可以在不到一年的时间尺度上围绕一个~10^8 M的黑洞发展。

英文摘要:

We present a radio-quiet quasar at z=0.237 discovered "turning on" by the intermediate Palomar Transient Factory (iPTF). The transient, iPTF 16bco, was detected by iPTF in the nucleus of a galaxy with an archival SDSS spectrum with weak narrow-line emission characteristic of a low-ionization emission line region (LINER). Our follow-up spectra show the dramatic appearance of broad Balmer lines and a power-law continuum characteristic of a luminous (L_bol~10^45 erg/s) type 1 quasar 12 years later. Our photometric monitoring with PTF from 2009-2012, and serendipitous X-ray observations from the XMM-Newton Slew Survey in 2011 and 2015, constrain the change of state to have occurred less than 500 days before the iPTF detection. An enhanced broad Halpha to [OIII]5007 line ratio in the type 1 state relative to other changing-look quasars also is suggestive of the most rapid change of state yet observed in a quasar. We argue that the >10 increase in Eddington ratio inferred from the brightening in UV and X-ray continuum flux is more likely due to an intrinsic change in the accretion rate of a pre-existing accretion disk, than an external mechanism such as variable obscuration, microlensing, or the tidal disruption of a star. However, further monitoring will be helpful in better constraining the mechanism driving this change of state. The rapid "turn on" of the quasar is much shorter than the viscous infall timescale of an accretion disk, and requires a disk instability that can develop around a ~10^8 M_sun black hole on timescales less than a year.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑