论文标题
HST对H $ _2 $ O 1.4 $ $ M $ M吸收频段的猎户座星云群的调查
HST survey of the Orion Nebula Cluster in the H$_2$O 1.4 $μ$m absorption band: I. A census of substellar and planetary mass objects
论文作者
论文摘要
为了在$ \ sim1 $ Myr Old Orion Nebula Cluster中获得恒星和子赛车人口的完整人口普查，降至几m $ _ {jup} $，我们使用了Hubble Space TeleScope的宽野外摄像头3的红外频道，并带有F139M和F130N备案。这些带通对应于$1.4μ$ m h $ _2 $ o吸收功能和相邻的无线连续体区域。 Out of $4,504$ detected sources, $3,352$ (about $75\%$) appear fainter than m$_{130}=14$ (Vega mag) in the F130N filter, a brightness corresponding to the hydrogen-burning limit mass (M$\simeq 0.072 M_\odot$) at $\sim 1$ Myr.但是，其中只有742美元的资源为负130m-139n颜色指数，表明吸收h $ _2 $ o蒸气，因此可以将其归类为善意的M和L矮人，其有效的温度为t $ \ sieldsim t $ 2850 $ k在假定的$ 1 $ myr $ 1 $ myr cluster cluster cluster lime k。 On our color-magnitude diagram, this population of sources with H$_2$O absorption appears clearly distinct from the larger background population of highly reddened stars and galaxies with positive F130M-F139N color index, and can be traced down to the sensitivity limit of our survey, m$_{130}\simeq 21.5$, corresponding to a $1$ Myr old $\simeq 3 $ m $ _ {jup} $，行星质量对象，大约2个视觉灭绝。 BT-SETTL家族的理论模型预测$ 1、2 $和$ 3 $ MYR（降至$ \ sim 1 $ M $ _ {JUP} $）的理论模型未能重现观察到的H $ _2 $ o _2 $ o color Index，M $ \ lysesim 20 $ 20 $ M $ _ {JUP} $。我们进行贝叶斯分析，以确定样品中每个子续集成员的灭绝，质量和有效温度以及其成员概率。
In order to obtain a complete census of the stellar and sub-stellar population, down to a few M$_{Jup}$ in the $\sim1$ Myr old Orion Nebula Cluster, we used the infrared channel of the Wide Field Camera 3 of the Hubble Space Telescope with the F139M and F130N filters. These bandpasses correspond to the $1.4 μ$m H$_2$O absorption feature and an adjacent line-free continuum region. Out of $4,504$ detected sources, $3,352$ (about $75\%$) appear fainter than m$_{130}=14$ (Vega mag) in the F130N filter, a brightness corresponding to the hydrogen-burning limit mass (M$\simeq 0.072 M_\odot$) at $\sim 1$ Myr. Of these, however, only $742$ sources have a negative F130M-139N color index, indicative of the presence of H$_2$O vapor in absorption, and can therefore be classified as bona-fide M and L dwarfs, with effective temperatures T$\lesssim 2850$ K at an assumed $1$ Myr cluster age. On our color-magnitude diagram, this population of sources with H$_2$O absorption appears clearly distinct from the larger background population of highly reddened stars and galaxies with positive F130M-F139N color index, and can be traced down to the sensitivity limit of our survey, m$_{130}\simeq 21.5$, corresponding to a $1$ Myr old $\simeq 3 $M$_{Jup}$, planetary mass object under about 2 magnitudes of visual extinction. Theoretical models of the BT-Settl family predicting substellar isochrones of $1, 2$ and $3$ Myr (down to $\sim 1 $M$_{Jup}$) fail to reproduce the observed H$_2$O color index at M$\lesssim 20 $M$_{Jup}$. We perform a Bayesian analysis to determine extinction, mass and effective temperature of each sub-stellar member of our sample, together with its membership probability.
