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相关论文: Galactic H2CO Densitometry I: Pilot survey of Ultr…

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We derive the molecular properties for a sample of 301 Galactic HII regions including 123 ultra compact (UC), 105 compact, and 73 diffuse nebulae. We analyze all sources within the BU-FCRAO Galactic Ring Survey (GRS) of 13CO emission known…

天体物理学 · 物理学 2009-11-13 L. D. Anderson , T. M. Bania , J. M. Jackson , D. P. Clemens , M. Heyer , R. Simon , R. Y. Shah , J. M. Rathborne

Observations of various molecular lines toward a disk region of a nearby galaxy are now feasible, and they are being employed as diagnostic tools to study star-formation activities there. However, the spatial resolution attainable for a…

星系天体物理 · 物理学 2019-07-17 Yuri Nishimura , Yoshimasa Watanabe , Nanase Harada , Kotaro Kohno , Satoshi Yamamoto

We present new 2 cm and 6 cm maps of H2CO, radio recombination lines, and the radio continuum in the W51 star forming complex acquired with Arecibo and the Green Bank Telescope at ~50" resolution. We use H2CO absorption to determine the…

The [CII] fine--structure line at 158um is an excellent tracer of the warm diffuse gas in the ISM and the interfaces between molecular clouds and their surrounding atomic and ionized envelopes. Here we present the initial results from…

We present the first results on the diffuse transition clouds observed in [CII] line emission at 158 microns (1.9 THz) towards Galactic longitudes near 340deg (5 LOSs) and 20deg (11 LOSs) as part of the GOT C+ survey. Out of the total 146…

星系天体物理 · 物理学 2015-05-19 T. Velusamy , W. D. Langer , J. L. Pineda , P. F. Goldsmith , D. Li. , H. W. Yorke

Aims: We searched for the molecular outflows from fifteen molecular clouds associated with ultra-compact and compact HII (UCHII/HII) regions and discussed possible gas heating mechanism. Methods: Mapping observations of CO $J=3-2$ and…

天体物理学 · 物理学 2009-11-13 Sheng-Li Qin , Jun-Jie Wang , Gang Zhao , Martin Miller , Jun-Hui Zhao

We present Green Bank Telescope (GBT) observations of the 3(12)-3(13) (29 GHz) and 4(13)-4(14) (48 GHz) transitions of the H2CO molecule toward a sample of 23 well-studied star-forming regions. Analysis of the relative intensities of these…

星系天体物理 · 物理学 2015-05-30 Patrick I. McCauley , Jeffrey G. Mangum , Alwyn Wootten

ABRIDGED: Context: HI and CO large scale surveys of the Milky Way trace the diffuse atomic clouds and the dense shielded regions of molecular hydrogen clouds. However, until recently, we have not had spectrally resolved C+ surveys to…

星系天体物理 · 物理学 2015-06-18 W. D. Langer , T. Velusamy , J. L. Pineda , K. Willacy , P. F. Goldsmith

We present high spatial and spectral resolution observations of sixteen Galactic compact and ultracompact H II regions in the [Ne II] 12.8 microns fine structure line. The small thermal width of the neon line and the high dynamic range of…

天体物理学 · 物理学 2009-11-13 Qingfeng Zhu , John H. Lacy , Daniel T. Jaffe , Matthew J. Richter , Thomas K. Greathouse

Context. The earliest phases of high-mass star formation are poorly understood. Aims. Our goal is to determine the physical conditions and kinematic structure of massive star-forming cloud clumps. Methods. We analyze H$_2$O 557 GHz line…

太阳与恒星天体物理 · 物理学 2014-10-15 Russell F. Shipman , Floris F. S van der Tak , Friedrich Wyrowski , Fabrice Herpin , Wilfred Frieswijk

Mon R2, at a distance of 830 pc, is the only ultracompact HII region (UC HII) where the photon-dominated region (PDR) between the ionized gas and the molecular cloud can be resolved with Herschel. HIFI observations of the abundant compounds…

The Galactic HII region G353.2+0.9 is excited by the massive open cluster Pismis-24. By analyzing (sub-)mm molecular-line and -continuum we study the detailed morphology of the gas and dust, as well as their physical parameters and their…

星系天体物理 · 物理学 2015-06-03 A. Giannetti , J. Brand , F. Massi , A. Tieftrunk , M. T. Beltran

We report single-dish multi-transition measurements of the 12^CO, HCN, and HCO^+ molecular line emission as well as HNC J=1-0 and HNCO in the two ultraluminous infra-red galaxies Arp220 and NGC6240. Using this new molecular line inventory,…

天体物理学 · 物理学 2009-03-27 T. R. Greve , P. P. Papadopoulos , Y. Gao , S. J. E. Radford

We investigate the star formation activity in the molecular complex associated with the Galactic HII region Sh2-90, using radio-continuum maps obtained at 1280 MHz and 610 MHz, Herschel Hi-GAL observations at 70 -- 500 microns, and deep…

太阳与恒星天体物理 · 物理学 2015-06-19 M. R. Samal , A. Zavagno , L. Deharveng , S. Molinari , D. K. Ojha , D. Paradis , J. Tigé , A. K. Pandey , D. Russeil

We present 3 mm observations obtained with the IRAM 30-m telescope for ten nearby gas-rich active galaxies spanning three orders of magnitude in infrared luminosity. Emission lines of HCO+(1-0), HCN(1-0), and C2H(1-0) were simultaneously…

宇宙学与河外天体物理 · 物理学 2015-05-30 Xuejian Jiang , Junzhi Wang , Qiusheng Gu

Hypercompact HII regions (HC) are regions of ionized gas associated with the early stages of high-mass star formation. With the aim of better understanding their characteristics, we studied five candidate HC HII regions. Here, we present…

星系天体物理 · 物理学 2026-05-12 I. T. Rodríguez-Esnard , S. Kurtz , J. D. Pandian , J. Franco , A. Sánchez-Monge , M. A. Trinidad , V. Migenes

We have carried out the largest and most unbiased search for hypercompact (HC) HII regions. Our method combines four interferometric radio continuum surveys (THOR, CORNISH, MAGPIS and White2005) with far-infrared and sub-mm Galactic Plane…

星系天体物理 · 物理学 2018-11-28 A. Y. Yang , M. A. Thompson , W. W. Tian , S. Bihr , H. Beuther , L. Hindson

We report on a study of the high-mass star formation in the the HII region W28A2 by investigating the molecular clouds extended over ~5-10 pc from the exciting stars using the 12CO and 13CO (J=1-0) and 12CO (J=2-1) data taken by the NANTEN2…

While the CO(1-0) transition is often used to deduce the total molecular hydrogen in galaxies, it is challenging to detect in low metallicity galaxies, in spite of the star formation taking place. In contrast, the [CII] 158 micron line is…

We present maps and spectra of the HCN(1-0) and HCO$^+$(1-0) lines in the extreme outer Galaxy, at galactocentric radii between 14 and 22 kpc, with the 13.7 meter Delingha telescope. The 9 molecular clouds were selected from a CO/$^{13}$CO…

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