论文标题
发现异常振幅的中红外质恒星爆发
Discovery of a mid-infrared protostellar outburst of exceptional amplitude
论文作者
论文摘要
我们报告了在年轻恒星物体（YSO）中发现的中红外爆发，幅度接近8 mag，$λ$$ \ $ 4.6 $μ$ m。 WISEA J142238.82-611553.7是23个高度可变的明智来源之一，在搜索红外云（IRDC）时发现。它位于小型IRDC G313.671-0.309（D $ \ $ \ $ 2.6 kpc）中，Herschel/Higal调查是一个紧凑的，巨大的云核，可能会被事件衡量。 2004年，Spitzer的前爆发数据表明，这是I级YSO，观察到弱的2.12 $ $ m h $ _2 $ _2 $在2019年采用的无特色红色连续体频谱中（低于K $ _S $的高峰低于峰值）。 Spitzer，Wise和VVV数据表明，爆发始于2006年，持续$> $ 13年，从2010--2014起的峰值相当平坦。几个$ \ times 10^2 $ lsun的爆发光度与积聚率mdot $ \大约10^{ - 4} $ msun/yr一致，可与经典的fu orionis事件相媲美。 2010年的4.6美元$ $ m的峰值意味着T = 800-1000 K和圆盘径向位置r $ \ $ \ $ \ $ 4.5 au用于发射区域。颜色演化表明随后的进展进展。在热不稳定性或MRI模型中，明显没有更热的物质可能是由于最内部的盘完全掩盖了，例如通过边缘圆盘视图。或者，盘片段化/插入片段模型可能更自然地解释了中红外峰，尽管这尚不清楚。
We report the discovery of a mid-infrared outburst in a Young Stellar Object (YSO) with an amplitude close to 8 mag at $λ$$\approx$4.6 $μ$m. WISEA J142238.82-611553.7 is one of 23 highly variable WISE sources discovered in a search of Infrared Dark Clouds (IRDCs). It lies within the small IRDC G313.671-0.309 (d$\approx$2.6 kpc), seen by the Herschel/HiGal survey as a compact, massive cloud core that may have been measurably warmed by the event. Pre-outburst data from Spitzer in 2004 suggest that it is a class I YSO, a view supported by observation of weak 2.12 $μ$m H$_2$ emission in an otherwise featureless red continuum spectrum taken in 2019 (6 mag below the peak in K$_s$). Spitzer, WISE and VVV data indicate that the outburst began by 2006 and has a duration $>$13 yr, with a fairly flat peak from 2010--2014. The outburst luminosity of a few $\times 10^2$ Lsun is consistent with an accretion rate Mdot $\approx 10^{-4}$ Msun/yr, comparable to a classical FU Orionis event. The 4.6 $μ$m peak in 2010 implies T = 800-1000 K and a disc radial location R$\approx$4.5 au for the emitting region. The colour evolution suggests subsequent progression outward. The apparent absence of the hotter matter expected in thermal instability or MRI models may be due to complete obscuration of the innermost disc, e.g. by an edge-on disc view. Alternatively, disc fragmentation/infalling fragment models might more naturally explain a mid-infrared peak, though this is not yet clear.
