arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1412.2175astro-ph.EPastro-ph.SR
收藏

FW候选原行星伴星的ALMA盘质量

An ALMA Disk Mass for the Candidate Protoplanetary Companion to FW Tau

Adam L. Kraus, Sean M. Andrews, Brendan P. Bowler, Gregory Herczeg, Michael J. Ireland, Michael C. Liu, Stanimir Metchev, Kelle L. Cruz

摘要:

我们目前ALMA观测FW Tau系统,一个密切的二元对M5恒星与宽轨道(300 AU投影分离)的亚恒星同伴。这颗伴星在光学和近红外波段非常微弱,呈红色,但拥有微弱的远红外过量和光学/近红外发射谱线,表明它是一个由气体和尘埃组成的原始吸积盘。成分分辨的1.3毫米连续辐射被发现只与伴星有关,其通量(1.78 +/- 0.03 mJy)表明尘埃质量为1-2 M_Earth。虽然这个质量库不足以形成一颗巨大的行星,但它足以产生一个类似于开普勒-42系外行星系统或伽利略卫星的系统。带着圆盘的FW Tau伴星的质量和几何形状仍然不清楚。近红外光谱显示深水带,表明比M5晚的光谱型,但大量的遮蔽阻止了有效温度(因此质量)的更准确测定。无论是在直射光下看到的一个带有“行星质量”的伴星,还是在边缘上的圆盘或封套散射的光下看到的一个棕矮星,都仍然是可能的。

英文摘要:

We present ALMA observations of the FW Tau system, a close binary pair of M5 stars with a wide-orbit (300 AU projected separation) substellar companion. The companion is extremely faint and red in the optical and near-infrared, but boasts a weak far-infrared excess and optical/near-infrared emission lines indicative of a primordial accretion disk of gas and dust. The component-resolved 1.3 mm continuum emission is found to be associated only with the companion, with a flux (1.78 +/- 0.03 mJy) that indicates a dust mass of 1-2 M_Earth. While this mass reservoir is insufficient to form a giant planet, it is more than sufficient to produce an analog of the Kepler-42 exoplanetary system or the Galilean satellites. The mass and geometry of the disk-bearing FW Tau companion remains unclear. Near-infrared spectroscopy shows deep water bands that indicate a spectral type later than M5, but substantial veiling prevents a more accurate determination of the effective temperature (and hence mass). Both a disk-bearing "planetary-mass" companion seen in direct light or a brown dwarf tertiary viewed in light scattered by an edge-on disk or envelope remain possibilities.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑