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相关论文: Interstellar H$_2$O Masers from J Shocks

200 篇论文

We present the results of the first dedicated survey for 22 GHz H$_2$O maser emission in dwarf galaxies outside of the local group, with the aim of discovering disc masers. Studies of disc masers yield accurate and precise measurements of…

星系天体物理 · 物理学 2020-10-21 M. J. Rosenthal , I. Zaw

Aims.Molecular masers, including methanol and hydroxyl masers, and in particular the ones in excited rotational states (ex-OHmasers), are one of the most informative tools for studying star-forming regions. So, the discovery, of new maser…

星系天体物理 · 物理学 2021-08-04 O. Patoka , O. Antyufeyev , I. Shmeld , V. Bezrukovs , M. Bleiders , A. Orbidans , A. Aberfelds , V. Shulga

Class I methanol masers are believed to be produced in the shock-excited environment around star-forming regions. Many authors have argued that the appearance of various subsets of class I masers may be indicative of specific evolutionary…

OH (1720 MHz) masers serve as indicators of SNR - molecular cloud interaction sites. These masers are collisionally excited in warm (50-100K) shocked gas with densities of order 1e5 cm^-3 when the OH column density is in the range 1e16-1e17…

天体物理学 · 物理学 2009-11-13 Mark Wardle

The Australia Telescope Compact Array (ATCA) has been used to image class I methanol masers at 9.9, 25 (a series from J=2 to J=9), 84, 95 and 104 GHz located in the vicinity of IRAS 16547-4247 (G343.12-0.06), a luminous young stellar object…

天体物理学 · 物理学 2008-11-26 M. A. Voronkov , K. J. Brooks , A. M. Sobolev , S. P. Ellingsen , A. B. Ostrovskii , J. L. Caswell

The Australia Telescope Compact Array (ATCA) has been used to make the first extensive search for the class I methanol masers at 9.9 GHz. In total, 48 regions of high-mass star formation were observed. In addition to masers in W33-Met…

星系天体物理 · 物理学 2015-05-18 M. A. Voronkov , J. L. Caswell , S. P. Ellingsen , A. M. Sobolev

We present APEX 218 GHz observations of molecular emission in a complete sample of embedded protostars in the Ophiuchus star-forming region. To study the physical properties of the cores, we calculate H$_2$CO and c-C$_3$H$_2$ rotational…

太阳与恒星天体物理 · 物理学 2017-01-25 Johan E. Lindberg , Steven B. Charnley , Jes K. Jørgensen , Martin A. Cordiner , Per Bjerkeli

Our mid-infrared and near-infrared surveys over the last five years have helped to strengthen and clarify the relationships between water, methanol, and OH masers and the star formation process. Our surveys show that maser emission seems to…

天体物理学 · 物理学 2009-11-11 James M. De Buizer , James T. Radomski , Charles M. Telesco , Robert K. Pina

Recent observations from Herschel allow the identification of important mechanisms responsible for the heating of gas surrounding low-mass protostars and its subsequent cooling in the far-infrared (FIR). Shocks are routinely invoked to…

We have compared the occurrence of 6.7-GHz and 12.2-GHz methanol masers with 22-GHz water masers and 6035-MHz excited-state OH masers in the 100 square degree region of the southern Galactic plane common to the Methanol Multibeam (MMB) and…

We report the detection of maser emission from the $J=4-3$ transition of HC$_3$N at 36.4~GHz towards the nearby starburst galaxy NGC253. This is the first detection of maser emission from this transition in either a Galactic or…

星系天体物理 · 物理学 2017-05-31 Simon Ellingsen , Xi Chen , Shari Breen , Hai-Hua Qiao

We investigated the ALMA science verification data of Orion KL and found a spectral signature of the vibrationally excited H2O maser line at 232.68670 GHz (nu2=1, 5,5,0-6,4,3). This line has been detected in circumstellar envelopes of…

太阳与恒星天体物理 · 物理学 2015-06-11 Tomoya Hirota , Mi Kyoung Kim , Mareki Honma

Aims. Young stars interact vigorously with their surroundings, as evident from the highly rotationally excited CO (up to Eup=4000 K) and H2O emission (up to 600 K) detected by the Herschel Space Observatory in embedded low-mass protostars.…

太阳与恒星天体物理 · 物理学 2015-05-30 R. Visser , L. E. Kristensen , S. Bruderer , E. F. van Dishoeck , G. J. Herczeg , C. Brinch , S. D. Doty , D. Harsono , M. G. Wolfire

We use UV measurements of interstellar CO towards nearby stars to calculate the density in the diffuse molecular clouds containing the molecules responsible for the observed absorption. Chemical models and recent calculations of the…

星系天体物理 · 物理学 2015-06-16 Paul F. Goldsmith

Context. The high intensities and narrow bandwidths exhibited by some astronomical masers make them ideal tools for studying star-forming giant molecular clouds. The water maser transition $J_{K_{-1}K_{1}}=5_{32}-4_{41}$ at 620.701 GHz can…

星系天体物理 · 物理学 2014-09-05 S. C. Jones , M. Houde , M. Harwit , M. Kidger , A. Kraus , C. McCoey , A. Marston , G. Melnick , K. M. Menten , P. Morris , D. Teyssier , V. Tolls

Radio images of maser spots in the infrared source GL2789, connected with the young stellar object V645 Cyg, have been obtained as a result of the radio interferometric observations of H2O maser at 22 GHz and methanol maser at 6.7 GHz, with…

天体物理学 · 物理学 2007-05-23 I. E. Val'tts , V. I. Slysh , M. A. Voronkov , V. Migenes

Space-based mid-IR spectroscopy provides tracers of warm gas in star-forming regions that are inaccessible from the ground. Past mid-IR spectra of bright high-mass protostars in the hot-core phase typically showed strong absorption features…

A survey of the inner 8$^\circ \times 1^\circ$ of the Galactic plane toward the Galactic center has been carried out at the 1720 MHz transition of OH molecule using the VLA in its D configuration with a resolution of…

天体物理学 · 物理学 2009-05-20 F. Yusef-Zadeh , W. M. Goss , D. A. Roberts , B. Robinson , D. A. Frail

We present the results of a high sensitivity survey for 6.7 GHz methanol masers towards 22 GHz water maser using the 100 m Efflesberg telescope. A total of 89 sources were observed and 10 new methanol masers were detected. The new…

天体物理学 · 物理学 2010-01-28 Y. Xu , J. J. Li , K. Hachisuka , J. D. Pandian , K. M. Menten , C. Henkel

We present new observations of C-band continuum emission and masers to assess high-mass ($>$8 $M_\odot$) star formation at early evolutionary phases in the inner 200 pc of the Central Molecular Zone (CMZ) of the Galaxy. The continuum…