A Mildly Relativistic Outflow from the Energetic, Fast-rising Blue Optical Transient CSS161010 in a Dwarf Galaxy
A Mildly Relativistic Outflow from the Energetic, Fast-rising Blue Optical Transient CSS161010 in a Dwarf Galaxy
复制标题
DOI：
10.3847/2041-8213/ab8cc7
复制
发表时间：
2020-03
期刊：
影响因子：
--
通讯作者：
D. Coppejans;R. Margutti;R. Margutti;G. Terreran;A. Nayana;A. Nayana;E. Coughlin;T. Laskar;K. Alexander;M. Bietenholz;D. Caprioli;P. Chandra;M. Drout;M. Drout;D. Frederiks;C. Frohmaier;K. Hurley;C. Kochanek;M. MacLeod;A. Meisner;P. Nugent;A. Ridnaia;D. Sand;D. Svinkin;C. Ward;C. Ward;Sheng Yang;Sheng Yang;Sheng Yang;A. Baldeschi;I. Chilingarian;I. Chilingarian;Y. Dong;C. Esquivia;C. Esquivia;W. Fong;C. Guidorzi;P. Lundqvist;D. Milisavljevic;K. Paterson;D. Reichart;B. Shappee;M. Stroh;S. Valenti;B. Zauderer;B. Zauderer;B. Zhang
中科院分区：
文献类型：
--
作者：
D. Coppejans;R. Margutti;R. Margutti;G. Terreran;A. Nayana;A. Nayana;E. Coughlin;T. Laskar;K. Alexander;M. Bietenholz;D. Caprioli;P. Chandra;M. Drout;M. Drout;D. Frederiks;C. Frohmaier;K. Hurley;C. Kochanek;M. MacLeod;A. Meisner;P. Nugent;A. Ridnaia;D. Sand;D. Svinkin;C. Ward;C. Ward;Sheng Yang;Sheng Yang;Sheng Yang;A. Baldeschi;I. Chilingarian;I. Chilingarian;Y. Dong;C. Esquivia;C. Esquivia;W. Fong;C. Guidorzi;P. Lundqvist;D. Milisavljevic;K. Paterson;D. Reichart;B. Shappee;M. Stroh;S. Valenti;B. Zauderer;B. Zauderer;B. Zhang
我们提出了在t = 69-531天的快蓝光学瞬变CRTS-CSS 161010 J 045834 - 081803（CSS 161010）的X射线和射电观测。CSS 161010显示了X射线（Lx = 1039 erg s−1）和射电（L v = 1029 erg s−1 Hz−1）的发光。无线电辐射在瞬变爆炸后100天达到峰值，并迅速衰减。我们解释这些意见的背景下，同步辐射从一个不断扩大的冲击波。CSS 161010在100天后发射了一个速度为Γβc ≥ 0.55c的温和相对论外流。这比非相对论性AT 2018奶牛（Γβc ≥ 0.1c）更快，更接近ZTF 18 abvkwla（63天时Γβc ≥ 0.3c）。CSS 161010的推断初始动能（Ek = 1051 erg）与长伽马射线暴相当，但与温和相对论外流耦合的喷出物质量明显更大（）。这与观测到的γ射线的缺乏是一致的。发光的X射线是由与同步加速器无线电发射不同的发射组件产生的。CSS 161010位于一个矮星系中，距离150 Mpc，恒星质量M*<$107 M <$，比星星形成速率sSFR <$0.3 Gyr−1。这个质量是从大质量恒星爆炸瞬变的宿主星系中推断出的最低质量之一。我们对CSS 161010的观测结果与发动机驱动的非球面爆炸相一致，该爆炸来自一个罕见的富氢恒星祖先的演化路径，但我们不能排除位于中心的中等质量黑洞上的恒星潮汐破裂事件。无论物理机制如何，CSS 161010确定了一类新的稀有（率< 0.4%的本地核心坍缩超新星率）富氢瞬变的存在，可以发射温和的相对论流出。
We present X-ray and radio observations of the Fast Blue Optical Transient CRTS-CSS161010 J045834−081803 (CSS161010 hereafter) at t = 69–531 days. CSS161010 shows luminous X-ray (Lx ∼ 5 × 1039 erg s−1) and radio (Lν ∼ 1029 erg s−1 Hz−1) emission. The radio emission peaked at ∼100 days post-transient explosion and rapidly decayed. We interpret these observations in the context of synchrotron emission from an expanding blast wave. CSS161010 launched a mildly relativistic outflow with velocity Γβc ≥ 0.55c at ∼100 days. This is faster than the non-relativistic AT 2018cow (Γβc ∼ 0.1c) and closer to ZTF18abvkwla (Γβc ≥ 0.3c at 63 days). The inferred initial kinetic energy of CSS161010 (Ek ≳ 1051 erg) is comparable to that of long gamma-ray bursts, but the ejecta mass that is coupled to the mildly relativistic outflow is significantly larger ( ). This is consistent with the lack of observed γ-rays. The luminous X-rays were produced by a different emission component to the synchrotron radio emission. CSS161010 is located at ∼150 Mpc in a dwarf galaxy with stellar mass M* ∼ 107 M⊙ and specific star formation rate sSFR ∼ 0.3 Gyr−1. This mass is among the lowest inferred for host galaxies of explosive transients from massive stars. Our observations of CSS161010 are consistent with an engine-driven aspherical explosion from a rare evolutionary path of a H-rich stellar progenitor, but we cannot rule out a stellar tidal disruption event on a centrally located intermediate-mass black hole. Regardless of the physical mechanism, CSS161010 establishes the existence of a new class of rare (rate < 0.4% of the local core-collapse supernova rate) H-rich transients that can launch mildly relativistic outflows.