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Related papers: Properties of $\mathrm{H_2O}$ masers and their ass…

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We report the discovery of widespread maser emission in non-metastable inversion transitions of NH$_3$ toward various parts of the Sagittarius B2 molecular cloud/star forming region complex: We detect masers in the $J,K = $ (6,3), (7,4),…

Astrophysics of Galaxies · Physics 2022-10-19 Y. T. Yan , C. Henkel , K. M. Menten , Y. Gong , H. Nguyen , J. Ott , A. Ginsburg , T. L. Wilson , A. Brunthaler , A. Belloche , J. S. Zhang , N. Budaiev , D. Jeff

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…

Astrophysics · Physics 2009-11-13 Sheng-Li Qin , Jun-Jie Wang , Gang Zhao , Martin Miller , Jun-Hui Zhao

We present a survey of OH maser emission towards a sample of high mass protostellar objects made using the Nancay and GBT telescopes.OH maser emission was detected towards 63 objects with 36 new detections. There are 56 star-forming regions…

Astrophysics · Physics 2009-11-13 K. A. Edris , G. A. Fuller , R. J . Cohen

The ionized core in the Sgr B2 Main star-forming region was imaged using the Submillimeter Array archival data observed for the H26$\alpha$ line and continuum emission at 0.86 millimeter with an angular resolution 0.3\arcsec. Eight…

Solar and Stellar Astrophysics · Physics 2015-05-30 Jun-Hui Zhao , M. C. H. Wright

We present results of continuum and spectral line observations with ALMA and 22 GHz water (H$_2$O) maser observations using KaVA and VERA toward a high-mass star-forming region, G25.82-0.17. Multiple 1.3 mm continuum sources are revealed,…

Methanol masers are often found in linear distributions, and it has been hypothesized that these masers are tracing circumstellar accretion disks around young massive stars. However, recent observations in H2 emission have shown what appear…

Astrophysics · Physics 2009-11-13 J. M. De Buizer , R. O. Redman , S. N. Longmore , J. Caswell , P. A. Feldman

At centimeter wavelengths, single-dish observations have suggested that the Sagittarius (Sgr) B2 molecular cloud at the Galactic Center hosts weak maser emission from several organic molecules, including CH$_2$NH, HNCNH, and HCOOCH$_3$.…

Astrophysics of Galaxies · Physics 2024-04-22 Ci Xue , Anthony Remijan , Alexandre Faure , Emmanuel Momjian , Todd R. Hunter , Ryan A. Loomis , Eric Herbst , Brett McGuire

The supergiant VX Sagittarii is a strong emitter of both H2O and SiO masers. However, previous VLBI observations have been performed separately, which makes it difficult to spatially trace the outward transfer of the material consecutively.…

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…

Astrophysics of Galaxies · Physics 2015-06-12 G. Wolf-Chase , K. Arvidsson , M. Smutko , R. Sherman

Abridged. Methods. We made use of the Karl G. Jansky Very Large Array (VLA) in the B configuration at K band, and in the A configuration at both Ku and C bands, in order to image the radio continuum emission towards 25 H$_2$O maser sites…

Solar and Stellar Astrophysics · Physics 2018-11-14 A. Sanna , L. Moscadelli , C. Goddi , V. Krishnan , F. Massi

We present wide-field near-IR images of Orion A. K and H2 1-0S(1) images of a contiguous 8 sqr degree region are compared to photometry from Spitzer and dust-continuum maps obtained with MAMBO and SCUBA. We also measure proper motions for…

Using the Very Large Array, we have detected weak OH maser emission near the Turner-Welch protostellar source in the W3 OH region. Unlike typical interstellar OH masers, which are associated with ultra-compact HII regions, our measured…

Astrophysics · Physics 2009-11-07 A. L. Argon , M. J. Reid , K. M. Menten

As the recent publication by Breen et al (2013) found Class II methanol masers are exclusively associated with high mass star forming regions. Based on the positions of the Class I and II methanol and H$_{2}$O masers, UC H II regions and…

Astrophysics of Galaxies · Physics 2014-11-19 Hontas Farmer

We present molecular line, H2O maser, radio continuum and near infrared maps of the bipolar outflow source AFGL5142. The high resolution of our molecular CO observations enables us to define the morphology of the large-scale bipolar outflow…

We have searched for 22 GHz H2O and 43/86/129 GHz SiO masers in bright IRAS point sources in the SMC and LMC, to test whether the kinematics of the mass loss from these stars depends on metallicity. H2O masers were detected in the red…

Astrophysics · Physics 2009-11-06 Jacco Th. van Loon , Albert A. Zijlstra , Valentin Bujarrabal , Lars-Ake Nyman

We present VLBI observations of the H$_2$O maser emission towards a selection of massive young stellar objects (YSOs). In one of these sources, IRAS20126+4104, the measured proper motions confirm that the water masers spots are tracing the…

Astrophysics · Physics 2007-05-23 M. J. Rioja , L. Moscadelli , R. Cesaroni

We present a model in which the 22 GHz H$_2$O masers observed in star-forming regions occur behind shocks propagating in dense regions (preshock density $n_0 \sim 10^6 - 10^8$ cm$^{-3}$). We focus on high-velocity ($v_s > 30$ km s$^{-1}$)…

Astrophysics of Galaxies · Physics 2015-06-16 David Hollenbach , Moshe Elitzur , Christopher F. McKee

A 22 GHz water maser survey was conducted towards 178 O-rich AGB stars with the aim of identifying maser emission associated with the Sagittarius stellar stream. In this survey, maser emissions were detected in 21 targets, of which 20 were…

Astrophysics of Galaxies · Physics 2022-09-14 Yuanwei Wu , Bo Zhang , Jingjing Li , Xing-Wu Zheng

We present an interferometric survey of the 44 GHz class I methanol maser transition toward a sample of 69 sources consisting of High Mass Protostellar Object candidates and Ultracompact (UC) H II regions. We found a 38% detection rate (16…

Astrophysics of Galaxies · Physics 2016-02-17 A. I. Gómez-Ruiz , S. E. Kurtz , E. D. Araya , P. Hofner , L. Loinard

We report the results of a sensitive search for 12.2 GHz methanol maser emission towards a sample of eight high-mass star formation regions in the Large Magellanic Clouds which have been detected in other maser transitions. We detected one…

Astrophysics of Galaxies · Physics 2015-05-14 S. P. Ellingsen , S. L. Breen , J. L. Caswell , L. J. Quinn , G. A. Fuller
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