Statistical Properties of Molecular Clumps in the Galactic Center 50 km s$^{-1}$ Molecular Cloud

Дата и время публикации : 2012-04-25T02:17:10Z

Авторы публикации и институты :
Masato Tsuboi
Atsushi Miyazaki

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 16 pages, 5 figures, accepted for publication in PASJ
Первичная категория: astro-ph.GA

Все категории : astro-ph.GA

Краткий обзор статьи: We present the statistical properties of molecular clumps in the Galactic center 50 km s$^{-1}$ molecular cloud (GCM-0.02-0.07) based on observations of the CS $J=1-0$ emission line with the Nobeyama Millimeter Array. In the cloud, 37 molecular clumps with local thermal equilibrium (LTE) masses of $2times10^2-6times10^3 M_odot$ were identified by using the {it clumpfind} algorithm. The velocity widths of the molecular clumps are about five-fold those of Galactic disk molecular clouds with the same radius. The virial-theorem masses are three-fold the LTE masses. The mass and size spectra can be described by power laws of $dN/dMpropto M^{-2.6pm0.1}$ ($Mgtrsim 900M_odot$) and $dN/dRpropto R^{-5.9pm0.3}$ ($Rgtrsim 0.35$ pc), respectively. The statistical properties of the region interacting with the Sgr A East shell and those of the non-interacting part of the cloud are significantly different. The interaction probably makes the mass function steeper, from $dN/dMpropto M^{-2.0pm0.1}$ in the non-interacting part to $dN/dMpropto M^{-4.0pm0.2}$ in the interacting region. On the other hand, the interaction presumably truncates the size spectrum on the larger side of $Rsim 0.4$ pc.

Category: Physics