论文标题
W49N MCN-A：嵌入早期热分子芯中的大量质体的磁盘
W49N MCN-a: a disk accreting massive protostar embedded in an early-phase hot molecular core
论文作者
论文摘要
我们介绍了219-235 GHz连续体的ALMA档案数据，并以〜0分辨率为〜0的热分子核（HMC）W49N MCN-A（UCHII区J1）的线观测。3。尘埃连续发射，显示了1.的细长结构。在47.5摄氏度或较大的情况下，具有7,800AU的半径为7,800AU，CH3CN和11个分子线的排放量显示出一致的速度梯度。 R^0.44+-0.11对于2,400AU <r <14,000AU，使动态质量为mdyn = 57.0+24.5-17.1（r [au]/3，000）^1.88 msun，从尘埃中估算了910MSUNS（for TDUST = 180K）（r <70a）。 TDUST = 300K）r <1,700 AU。在r <（300-1,000）AU的自我填充磁盘也与整个HMC的总质量〜10^4 msun一致结果揭示了MCN-A在其中间半径上的结构和运动学。
We present ALMA archival data for 219-235 GHz continuum and line observations toward the hot molecular core (HMC) W49N MCN-a (UCHII region J1) at a resolution of ~0."3. The dust continuum emission, showing an elongated structure of 1."40x0."95 (PA=43.5deg) perpendicular to the outflow seen in SiO and SO, represents a rotating flattened envelope, or torus, with a radius of 7,800au inclined at 47.5deg or larger. The emissions from CH3CN and 11 molecular lines exhibit a consistent velocity gradient as a result of rotation. The magnitude of each velocity gradient is different, reflecting that each line samples a specific radial region. This allows us to derive a rotation curve as Vrot prop R^0.44+-0.11 for 2,400au < R < 14,000au, giving the dynamical mass as Mdyn = 57.0+24.5-17.1 (R [au]/3, 000)^1.88 Msun. The envelope mass independently estimated from the dustemission is 910Msun (for Tdust =180K) for R<7,800au and 32Msun (for Tdust=300K) for R<1,700 au. The dynamical mass formula agrees well with these mass estimates within an uncertainty of a factor of three in the latter. The envelope is self-gravitating and is unstable to form spiral arms and fragments, allowing rapid accretion to the inner radii with a rate of order 10^-2 Msun yr^-1, although inward motion was not detected. The envelope may become a non self-gravitating Keplerian disk at R<(300-1,000) au. The formula is also consistent with the total mass ~10^4 Msun of the entire HMC 0.15 pc (31,000 au) in radius. Multiple transitions of CH3CN, HNCO and CH3OH provide the rotation temperatures, suggesting that the central source of MCN-a has an intrinsic bolometric luminosity of ~10^6 Lsun. These results have revealed the structure and kinematics of MCN-a at its intermediate radii. With no broad-line H30alpha emission detected, MCN-a may be in the earliest phase of massive star formation.
