摘要： We successfully detected a molecular outflow with a scale of 370-450 pc in the central region of the starburst galaxy NGC 3628 through deep CO(1-0) observations by using the Nobeyama Millimeter Array (NMA). The mass of the outflowing molecular gas is ~2.8 x 10 super(7) M sub([middot in circle]), and the outflow velocity is ~90 + or - 10 km s super(-1). The expansion timescale of the outflow is 3.3-6.8 Myr, and the molecular gas mass flow rate is 4.1-8.5 M sub([middot in circle]) yr super(-1). It requires mechanical energy of (1.8-2.8) x 10 super(54) erg to create this sub-kpc scale molecular outflow. In order to understand the evolution of the molecular outflow, we compare the physical properties between the molecular outflow observed from our NMA CO(1-0) data and the plasma gas from the soft X-ray emission of the Chandra X-ray Observatory archival data. We found that the distribution between the molecular outflow and the strong plasma outflow seems to be in a similar region. In this region, the ram pressure and the thermal pressure of the plasma outflow are 10 super(-(8-10)) dyn cm super(-2), and the thermal pressure of molecular outflow is 10 super(-(11-13)) dyn cm super(-2). This implies that the molecular outflow is still expanding outward. The molecular gas consumption timescale is estimated as 17-27 Myr, and the total starburst timescale is 20-34 Myr. The evolutionary parameter is 0.11-0.25, suggesting that the starburst activity in NGC 3628 is still in a young stage. 出版者： Bristol: IOP 出版日期： 2012-06-10 出處： The Astrophysical journal, 2012-06, Vol.752 (1), p.38-14 資源來源： IoP Science journals 版權： 2015 INIST-CNRS 識別號： ISSN: 0004-637X 識別號： EISSN: 1538-4357 識別號： DOI: 10.1088/0004-637X/752/1/38 識別號： CODEN: ASJOAB
