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相关论文: Physical properties of outflows: Comparing CO and …

200 篇论文

We aim to characterize the outflow properties of a sample of early Class 0 phase low-mass protostars in Orion first identified by the Herschel Space Observatory. We also look for signatures of infall in key molecular lines. CO $J$=3-2 and…

星系天体物理 · 物理学 2020-10-14 Z. Nagy , A. Menechella , S. T. Megeath , J. J. Tobin , J. J. Booker , W. J. Fischer , P. Manoj , T. Stanke , A. Stutz , F. Wyrowski

We present a study of molecular outflows using six molecular lines (including 12CO/13CO/C18O/HCO+(J = 1-0) and SiO/CS(J = 2-1)) toward nine nearby high-mass star-forming regions with accurate known distances. This work is based on the…

星系天体物理 · 物理学 2021-03-10 De-Jian Liu , Ye Xu , Ying-Jie Li , Sheng Zheng , Deng-Rong Lu , Chao-Jie Hao , Ze-Hao Lin , Shuai-Bo Bian , Li-Ming Liu

We are aiming at the observational estimation of the relative contribution to the cooling by CO and H2O, as this provides decisive information for the understanding of the oxygen chemistry behind interstellar shock waves. Methods. The high…

We present the results of an outflow and infall survey towards a distance limited sample of 31 massive star forming regions drawn from the RMS survey. The presence of young, active outflows is identified from SiO (8-7) emission and the…

星系天体物理 · 物理学 2018-04-04 Nichol Cunningham , Stuart Lumsden , Toby Moore , Luke Maud , Ignacio. Mendigutia

We have observed 99 mid-infrared-bright, massive young stellar objects and compact HII regions drawn from the Red MSX source (RMS) survey in the J=3$-$2 transition of $^{12}$CO and $^{13}$CO, using the James Clerk Maxwell Telescope. 89…

太阳与恒星天体物理 · 物理学 2015-09-02 L. T. Maud , T. J. T. Moore , S. L. Lumsden , J. C. Mottram , J. S. Urquhart , M. G. Hoare

Large scale spectral maps of star forming regions enable the comparative study of the gas excitation around an ensemble of sources at a common frame of reference, providing direct insights in the multitude of processes involved. In this…

太阳与恒星天体物理 · 物理学 2020-09-09 Odysseas Dionatos , Lars. E. Kristensen , Mario Tafalla , Manuel Güdel , Magnus Persson

Low mass star-forming regions are more complex than the simple spherically symmetric approximation that is often assumed. We apply a more realistic infall/outflow physical model to molecular/continuum observations of three late Class 0…

星系天体物理 · 物理学 2013-08-26 J. M. C. Rawlings , M. P. Redman , P. B. Carolan

Previous numerical studies have shown that in protostellar outflows, the mass-velocity distribution $m(v)$ can be well described by a broken power law $\propto v^{- \gamma}$. On the other hand, recent observations of a sample of outflows…

During the formation of a star, material is ejected along powerful jets that impact the ambient material. This outflow phenomenon plays an important role in the regulation of star formation. Understanding the associated shocks and their…

星系天体物理 · 物理学 2011-08-19 A. Gusdorf , T. Giannini , D. R. Flower , B. Parise , R. Güsten , L. E. Kristensen

During the embedded stage of star formation, bipolar molecular outflows and UV radiation from the protostar are important feedback processes. Our aim is to quantify the feedback, mechanical and radiative, for a large sample of low-mass…

By studying 7 objects in the Lupus clouds we aim to test if a coherence exists between commonly used evolutionary tracers. We present ALMA observations of the continuum and molecular line emission that probe the dense gas and dust of cores…

Herschel-HIFI observations of water in the low-mass star-forming object L1448-MM, known for its prominent outflow, are presented, as obtained within the `Water in star-forming regions with Herschel' (WISH) key programme. Six H2-16O lines…

太阳与恒星天体物理 · 物理学 2015-05-28 L. E. Kristensen , E. F. van Dishoeck , M. Tafalla , R. Bachiller , B. Nisini , R. Liseau , U. A. Yildiz

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

Using the ASTE 10 m submillimeter telescope and the 1.4 m Infrared Survey Facility (IRSF), we performed an extensive outflow survey in the Orion Molecular Cloud -2 and -3 region. Our survey, which includes 41 potential star-forming sites,…

Intermediate mass protostarsprovide a bridge between theories of low- and high-mass star formation. Emerging molecular outflows can be used to determine the influence of fragmentation and multiplicity on protostellar evolution through the…

(Abridged) We use HIFI maps of the 987 GHz H2O 2(02)-1(11) emission to measure the sizes and shapes of 19 high-mass protostellar envelopes. To identify infall, we use HIFI spectra of the optically thin C18O 9-8 and H2O-18 1(11)-0(00) lines.…

星系天体物理 · 物理学 2019-05-29 Floris van der Tak , Russ Shipman , Thierry Jacq , Fabrice Herpin , Jonathan Braine , Friedrich Wyrowski

Changing physical conditions in the vicinity of protostars allow for a rich and interesting chemistry to occur. Heating and cooling of the gas allows molecules to be released from and frozen out on dust grains. These changes in physics,…

星系天体物理 · 物理学 2016-03-09 P. Bjerkeli , J. K. Jørgensen , C. Brinch

We examine how HI and metal absorption lines within low-redshift galaxy halos trace the dynamical state of circumgalactic gas, using cosmological hydrodynamic simulations that include a well-vetted heuristic model for galactic outflows. We…

宇宙学与河外天体物理 · 物理学 2015-06-17 Amanda Brady Ford , Romeel Davé , Benjamin D. Oppenheimer , Neal Katz , Juna A. Kollmeier , Robert Thompson , David H. Weinberg

The most usual tracer of molecular gas is line emission from CO. However, the reliability of that tracer has long been questioned in environments different from the Milky Way. We study the relationship between H2 and CO abundances using a…

星系天体物理 · 物理学 2015-05-18 S. C. O. Glover , M. -M. Mac Low

We review the known properties of molecular outflows from low- and high-mass young stars. General trends among outflows are identified, and the most recent studies on the morphology, kinematics, energetics, and evolution of molecular…