论文标题
矮人银河系中充满活力的,快速升高的蓝色光学瞬态CSS161010的轻度相对论流出
A mildly relativistic outflow from the energetic, fast-rising blue optical transient CSS161010 in a dwarf galaxy
论文作者
论文摘要
我们在t = 69-531天提出了X射线和无线电观察结果。 CSS161010显示发光X射线($ l_x \ sim5 \ times 10^{39} \,\ rm {erg {erg \,s^{ - 1}} $)和无线电($l_ν\ sim10^{29}} {29} {29} \,\,\ rm rmg rm {erg rm {erg \ rm {erg,s^n} $} - 1} - 1}} { - 1} { - 1} { - { - { - { - { - { - { - { - { - { - { - 1} { - }无线电发射在短暂爆炸后约100天达到峰值,并迅速衰减。我们在从扩展的Blastwave的同步加速器发射的背景下解释了这些观察结果。 CSS161010在〜100天以速度$γβC\ ge0.55c $发射了一个轻度的相对论流出。这比非相关主义AT2018COW($γβC\ sim0.1c $)更快,并且更接近ZTF18ABVKWLA(63天时$γβC\ ge0.3c $)。 CSS161010的推断初始动能($ e_k \ gtrsim10^{51} $ erg)与长伽玛射线突发(GRB)相当($ \ sim0.01-0.1 \,\ rm {m _ {\ odot}} $)。这与缺乏观察到的伽马射线一致。发光的X射线是通过与同步加速器发射的不同发射成分产生的。 CSS161010位于矮星系中的〜150 mpc,带有恒星质量$ m _ {*} \ sim10^{7} {7} \,\ rm {m _ {\ odot}}} $和特定的恒星率$ SSFR \ sim 0.3 \,\,\ rmm rmm rmm rmm rmm rmm {gyr^ - 1该质量是从巨大恒星爆炸性瞬变的宿主 - 山脉中推断出的最低质量之一。我们对CSS161010的观察结果与发动机驱动的非球面爆炸一致,从富含H的恒星祖细胞的罕见进化路径中,我们不能排除在中心位于中心阶段的中间质量黑洞上发生恒星的潮汐破坏事件。不管物理机制如何,CSS161010都建立了新的稀有类别(速率$ <0.4 \%\%\%的局部核心偏曲超新星速率)H-富含相对论流出的H-rich瞬变。
We present X-ray and radio observations of the Fast Blue Optical Transient (FBOT) CRTS-CSS161010 J045834-081803 (CSS161010 hereafter) at t=69-531 days. CSS161010 shows luminous X-ray ($L_x\sim5\times 10^{39}\,\rm{erg\,s^{-1}}$) and radio ($L_ν\sim10^{29}\,\rm{erg\,s^{-1}Hz^{-1}}$) 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 blastwave. CSS161010 launched a mildly relativistic outflow with velocity $Γβc\ge0.55c$ at ~100 days. This is faster than the non-relativistic AT2018cow ($Γβc\sim0.1c$) and closer to ZTF18abvkwla ($Γβc\ge0.3c$ at 63 days). The inferred initial kinetic energy of CSS161010 ($E_k\gtrsim10^{51}$ erg) is comparable to that of long Gamma Ray Bursts (GRBs), but the ejecta mass that is coupled to the mildly relativistic outflow is significantly larger ($\sim0.01-0.1\,\rm{M_{\odot}}$). This is consistent with the lack of observed gamma-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 $M_{*}\sim10^{7}\,\rm{M_{\odot}}$ and specific star formation rate $sSFR\sim 0.3\,\rm{Gyr^{-1}}$. 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.