Multiwavelength detection of an ongoing FUOr-type outburst on a low-mass YSO
Multiwavelength detection of an ongoing FUOr-type outburst on a low-mass YSO
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DOI：
10.1093/mnrasl/slad201
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发表时间：
2023-12
影响因子：
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通讯作者：
Zhen Guo;‹. P. W. Lucas;R. Kurtev;J. Borissova;V. Elbakyan;C. Morris;A. Bayo;L. Smith;A. C. O. Garatti;C. Pe;D. Minniti;J. Jose;M. Ashraf;J. Alonso-Garc;N. Miller;H. Muthu;Hillenbrand Findeisen;C. Pe;Naylor Morrell
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作者：
Zhen Guo;‹. P. W. Lucas;R. Kurtev;J. Borissova;V. Elbakyan;C. Morris;A. Bayo;L. Smith;A. C. O. Garatti;C. Pe;D. Minniti;J. Jose;M. Ashraf;J. Alonso-Garc;N. Miller;H. Muthu;Hillenbrand Findeisen;C. Pe;Naylor Morrell
在主序前演化过程中，年轻星体（YSO）在幕式吸积过程中聚集了大部分质量。罕见的FUOR型事件是研究YSO爆发性质的宝贵实验室。在这里，我们提出了多波长检测的高振幅喷发源在年轻的疏散星团VdBH 221与正在进行的爆发，包括光学中红外时间序列和近红外光谱。最初的爆发有一个异常的振幅，在盖亚大于6.3等，在Ks为4.6等，峰值亮度高达16 L，峰值质量吸积率为1.4 × 10−5 M yr−1。该天体的光学到红外光谱能量分布与低质量星星（0.2 M质量）一致，具有适度的消光（AV < 2等）。光学和红外上升阶段之间的100-d的延迟被检测到，这表明一个由外向内的起源的不稳定性。这个天体的光谱特征显示出一个自发光的吸积盘，非常类似于FU Orionis，具有低的视线消光。最近，在整个波长范围内亮度逐渐增加，可能表明质量吸积速率的增强。
During the pre-main-sequence evolution, Young Stellar Objects (YSOs) assemble most of their mass during the episodic accretion process. The rarely seen FUOr-type events are valuable laboratories to investigate the outbursting nature of YSOs. Here, we present multiwavelength detection of a high-amplitude eruptive source in the young open cluster VdBH 221 with an ongoing outburst, including optical to mid-infrared time series and near-infrared spectra. The initial outburst has an exceptional amplitude of >6.3 mag in Gaia and 4.6 mag in Ks, with a peak luminosity up to 16 L⊙ and a peak mass accretion rate of 1.4 × 10−5 M⊙ yr−1. The optical to infrared spectral energy distribution of this object is consistent with a low-mass star (0.2 M⊙) with a modest extinction (AV < 2 mag). A 100-d delay between optical and infrared rising stages is detected, suggesting an outside-in origin of the instability. The spectroscopic features of this object reveal a self-luminous accretion disc, very similar to FU Orionis, with a low line-of-sight extinction. Most recently, there has been a gradual increase in brightness throughout the wavelength range, possibly suggesting an enhancement of the mass accretion rate.