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相关论文: HI-to-H2 Transition Layers in the Star-Forming Reg…

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Analyzing the Galactic plane CO survey with the Nobeyama 45-m telescope, we compared the spectral column density (SCD) of H$_2$ calculated for $^{12}$CO line using the current conversion factor $X_{\rm CO}$ to that for $^{13}$CO line under…

星系天体物理 · 物理学 2020-07-22 Yoshiaki Sofue , Mikito Kohno

HST spectroscopical observations of 8 HII galaxies are reported. Ly alpha emission was detected in 4 of them. We find that the velocity structure of the gas is the main determining factor for the escape of the Ly alpha photons, and not the…

天体物理学 · 物理学 2007-05-23 D. Kunth , J. Lequeux , J. M. Mas-Hesse , E. Terlevich , R. Terlevich

Measurements of molecular hydrogen (H_2) column densities are presented for the first six rotational levels (J=0 to 5) for 73 extragalactic targets observed with FUSE. All of these have a final signal-to-noise ratio larger than \snlimit,…

天体物理学 · 物理学 2009-11-11 B. P. Wakker

We suggest that Bipolar H{\sc ii} Regions may be the aftermath of collisions between clouds. Such a collision will produce a shock-compressed layer, and a star cluster can then condense out of the dense gas near the centre of the layer. If…

星系天体物理 · 物理学 2018-11-19 Anthony Whitworth , Oliver Lomax , Scott Balfour , Pierre Mège , Annie Zavagno , Lise Deharveng

We present Herschel PACS observations of the [CII] 158 micron emission line in a sample of 24 intermediate mass (9<logM$_\ast$/M$_\odot$<10) and low metallicity (0.4< Z/Z$_\odot$<1.0) galaxies from the xCOLD GASS survey. Combining them with…

Massive stars are formed in molecular clouds, and produce H II regions when they evolve onto the main sequence. The expansion of H II region can both suppress and promote star formation in the vicinity. M17 H II region is a giant cometary H…

星系天体物理 · 物理学 2023-06-22 Feng-Yao Zhu , Junzhi Wang , Yaoting Yan , Qing-Feng Zhu , Juan Li

We have carried out a submillimeter continuum and spectroscopic study of the W43 main complex, a massive star-forming region, which harbors a giant HII region. The maps reveal a filamentary structure containing ~50 fragments with masses of…

天体物理学 · 物理学 2011-09-30 Frederique Motte , Peter Schilke , Darek C. Lis

To investigate the environment of HII region Sh2-163 and search for evidence of triggered star formation in this region, we performed a multi-wavelength study of this HII region. Most of our data were taken from large-scale surveys: 2MASS,…

星系天体物理 · 物理学 2017-02-14 Naiping Yu , Jun-Jie Wang , Nan Li

We present and analyze deep Herschel/HIFI observations of the [CII] 158um, [CI] 609um, and [CI] 370um lines towards 54 lines-of-sight (LOS) in the Large and Small Magellanic clouds. These observations are used to determine the physical…

An independent analysis of the molecular hydrogen absorption system at z = 2.059 in the spectrum of the quasar J2123-0050 is presented. The H_2 system consists of two components (A and B) with column densities log N^A(H_2) = 17.94+/-0.01…

星系天体物理 · 物理学 2016-03-07 V. V. Klimenko , S. A. Balashev , A. V. Ivanchik , D. A. Varshalovich

Massive stars have a major influence on their environment yet their formation is difficult to study. W43 is a highly luminous galactic massive star forming region at a distance of 5.5 kpc and the MM1 part hosts a very massive dense core…

星系天体物理 · 物理学 2016-11-02 T. Jacq , J. Braine , F. Herpin , F. van der Tak , F. Wyrowski

We derive radial and vertical distributions of HI and H2 gas densities in our Galaxy by using the terminal velocity method. We calculate the molecular fraction (f_mol) defined as the ratio of the molecular hydrogen to total hydrogen gas…

天体物理学 · 物理学 2007-05-23 K. Imamura , Y. Sofue

We have discovered 12 new molecular hydrogen emission-line objects (MHOs) in the vicinity of the candidate massive young stellar object Mol 121, in addition to five that were previously known. H2 2.12-micron/H2 2.25-micron flux ratios…

星系天体物理 · 物理学 2015-06-12 G. Wolf-Chase , K. Arvidsson , M. Smutko , R. Sherman

We present an analysis of multi-wavelength observations from various datasets and Galactic plane surveys to study the star formation process in the W42 complex. A bipolar appearance of W42 complex is evident due to the ionizing feedback…

星系天体物理 · 物理学 2015-09-30 L. K. Dewangan , A. Luna , D. K. Ojha , B. G. Anandarao , K. K. Mallick , Y. D. Mayya

To investigate the presence of small scale structure in the spatial distribution of H2 molecules we have undertaken repeated FUSE UV observations of the runaway O9.5V star, HD34078. In this paper we present five spectra obtained between…

天体物理学 · 物理学 2009-11-10 P. Boisse , F. Le Petit , E. Rollinde , E. Roueff , G. Pineau des Forets , B. G. Anderson , C. Gry , P. Felenbok

Water is a key molecule in the star formation process, but its spatial distribution in star-forming regions is not well known. We study the distribution of dust continuum and H2O and 13CO line emission in DR21, a luminous star-forming…

星系天体物理 · 物理学 2019-08-14 F. F. S. van der Tak , M. G. Marseille , F. Herpin , F. Wyrowski

The large scale structure and physics of molecular gas in the Galactic center region is discussed based on the analysis of a 9' resolution survey of the Galactic center region in the J=1->0 line of C^18O. Emphasis is placed on the…

天体物理学 · 物理学 2007-05-23 G. Dahmen , S. Huettemeister , T. L. Wilson , R. Mauersberger

We investigated the star formation activities in the AFGL333 region, which is in the vicinity of the W4 expanding bubble, by conducting NH3 (1,1), (2,2), and (3,3) mapping observations with the 45 m Nobeyama Radio Telescope at an angular…

In order to interpret H2 (molecular hydrogen) quasar absorption line observations of damped Ly-alpha systems (DLAs) and sub-DLAs, we model their H2 abundance as a function of dust-to-gas ratio, including H2 self-shielding and dust…

天体物理学 · 物理学 2009-11-10 H. Hirashita , A. Ferrara

Three molecular clouds have been mapped in the nearby metal-poor dwarf irregular galaxy NGC 6822 using the Owens Valley Millimeter-Wave Interferometer. Based on upper limits to the virial masses of the clouds, the CO-to-H2 conversion factor…

天体物理学 · 物理学 2009-10-22 C. D. Wilson