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相关论文: CCS and NH3 emission associated with low-mass youn…

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Molecular maser lines are signposts of high-mass star formation, probing excitation and kinematics of very compact regions in the close environment of young stellar objects and providing useful targets for trigonometric parallax…

星系天体物理 · 物理学 2022-04-12 Y. T. Yan , C. Henkel , K. M. Menten , Y. Gong , J. Ott , T. L. Wilson , A. Wootten , A. Brunthaler , J. S. Zhang , J. L. Chen , K. Yang

We present new maser emission from ^{14}NH_3 (9,6) in NGC 7538. Our observations include the known spectral features near v_LSR = -60 km/s and -57 km/s and several more features extending to -46 km/s. In three epochs of observation spanning…

星系天体物理 · 物理学 2015-05-30 Ian M. Hoffman , Stella Seojin Kim

We have observed 150 regions of massive star formation, selected originally by the presence of a water maser, in the J = 5-4, 3-2, and 2-1 transitions of CS, and 49 regions in the same transitions of C$^{34}$S. Over 90% of the 150 regions…

天体物理学 · 物理学 2011-05-25 Rene Plume , D. T. Jaffe , Neal J. Evans , J. Martin-Pintado , J. Gomez-Gonzalez

We have carried out survey observations of molecular emission lines from HC$_{3}$N, N$_{2}$H$^{+}$, CCS, and cyclic-C$_{3}$H$_{2}$ in the 81$-$94 GHz band toward 17 high-mass starless cores (HMSCs) and 28 high-mass protostellar objects…

星系天体物理 · 物理学 2019-02-27 Kotomi Taniguchi , Masao Saito , T. K. Sridharan , Tetsuhiro Minamidani

We have observed several emission lines of two Nitrogen-bearing (C2H5CN and C2H3CN) and two Oxygen-bearing (CH3OCH3 and HCOOCH3) molecules towards a sample of well-known hot molecular cores (HMCs) in order to check whether the chemical…

天体物理学 · 物理学 2009-11-13 F. Fontani , I. Pascucci , P. Caselli , F. Wyrowski , R. Cesaroni , C. M. Walmsley

We present deep CCS and HC$_7$N observations of the L1495-B218 filaments in the Taurus molecular cloud obtained using the K-band focal plane array on the 100m Green Bank Telescope. We observed the L1495-B218 filaments in CCS $J_N$ =…

Aims. We observe the dense gas tracer CS in two nearby starburst galaxies to determine how the conditions of the dense gas varies across the circumnuclear regions in starburst galaxies. Methods. Using the IRAM-30m telescope, we mapped the…

星系天体物理 · 物理学 2015-06-10 G. Kelly , S. Viti , E. Bayet , R. Aladro , J. Yates

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

NH3 and CH3OH are key molecules in astrochemical networks leading to the formation of more complex N- and O-bearing molecules, such as CH3CN and HCOOCH3. Despite a number of recent studies, little is known about their abundances in the…

The 22.2 GHz water masers are often associated with the 6.7 GHz methanol masers but owing to the different excitation conditions they likely probe independent spatial and kinematic regions around the powering young massive star. We compared…

星系天体物理 · 物理学 2015-06-04 Anna Bartkiewicz , Marian Szymczak , Huib Jan van Langevelde

We report the detection of CO(2-1) and 3.1 mm and 1.3 mm continuum emission towards the extremely young starburst in NGC 5253, with data taken from the Owens Valley Millimeter Array. Faint CO emission originates in five molecular clouds…

天体物理学 · 物理学 2009-11-07 David S. Meier , Jean L. Turner , Sara C. Beck

The results of a maser survey toward ninety-nine protostars in the Orion molecular cloud complex are presented. The target sources are low-mass protostars identified from infrared observations. Single-dish observations were carried out in…

星系天体物理 · 物理学 2015-06-17 Miju Kang , Jeong-Eun Lee , Minho Choi , Yunhee Choi , Kee-Tae Kim , James Di Francesco , Yong-Sun Park

(Abridged) We have observed CS and C17O lines, and 1.2 mm cont. emission towards a sample of 130 high-mass protostellar candidates with DEC<-30 deg. This is the first step of the southern extension of a project started more than a decade…

天体物理学 · 物理学 2009-11-10 F. Fontani , M. T. Beltran , J. Brand , R. Cesaroni , L. Testi , S. Molinari , C. M. Walmsley

We present high-resolution spectral line and continuum VLBI and VLA observations of the nuclear region of NGC 253 at 22 GHz. While the water vapor masers in this region were detected on arcsecond and milliarcsecond scales, we could not…

宇宙学与河外天体物理 · 物理学 2009-04-09 A. Brunthaler , P. Castangia , A. Tarchi , C. Henkel , M. J. Reid , H. Falcke , K. M. Menten

Young massive clusters play an important role in the evolution of their host galaxies, and feedback from the high-mass stars in these clusters can have profound effects on the surrounding interstellar medium. The nuclear starburst in the…

We present observations of 1.2-mm dust continuum emission, made with the Swedish ESO Submillimeter Telescope, towards eighteen luminous IRAS point sources, all with colors typical of compact HII regions and associated with CS(2-1) emission,…

天体物理学 · 物理学 2011-02-11 Guido Garay , Diego Mardones , Kate J. Brooks , Liza Videla , Yanett Contreras

We present results of submillimeter observations of a low-mass young stellar objects (YSOs) condensation in the Cederblad 110 region of the Chamaeleon I dark cloud with Atacama Submillimeter Telescope Experiment. Our HCO+(J=4-3) map reveals…

We have mapped the water maser emission associated with the infrared centers IRS1 and IRS3 of the NGC 2071IR star forming region at four epochs over ~4 months with the Very Long Baseline Array (VLBA). We detected 269 maser features with ~1…

天体物理学 · 物理学 2009-11-07 Anil Seth , Lincoln Greenhill , Benjamin Holder

We report the most sensitive water maser survey towards Bok globules to date, using NASA's 70m antenna in Robledo de Chavela (Spain). We observed 207 positions within the CB catalog with a higher probability of harboring a young star, using…

天体物理学 · 物理学 2008-11-26 Jose F. Gomez , Itziar de Gregorio-Monsalvo , Olga Suarez , Thomas B. H. Kuiper

Six young bipolar outflows in regions of low-to-intermediate-mass star formation were observed in the 7_0-6_1A+, 8_0-7_1A+, and 5_{-1}-4_0E methanol lines at 44, 95, and 84 GHz, respectively. Narrow features were detected towards NGC…

天体物理学 · 物理学 2009-11-11 S. V. Kalenskii , V. G. Promyslov , V. I. Slysh , P. Bergman , A. Winnberg