English
Related papers

Related papers: A Search for H2CO 6cm Emission toward Young Stella…

200 papers

We present (sub)millimeter imaging at 0.5'' resolution of the massive star-forming region G358.93-0.03 acquired in multiple epochs at 2 and 3 months following the recent flaring of its 6.7 GHz methanol maser emission. Using SMA and ALMA, we…

Accurate techniques which allow for the derivation of the spatial density in star formation regions are rare. A technique which has found application for the derivation of spatial densities in Galactic star formation regions utilizes the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Jeffrey G. Mangum , Jeremy Darling , Christian Henkel , Karl M. Menten

Class II methanol (CH$_{3}$OH) masers are amongst the clearest signposts of recent high-mass star formation (HMSF). A complete catalogue outlines the distribution of star formation in the Galaxy, the number of young star-forming cores, and…

High-mass protostars are deeply embedded in dust inside their natal cores and are not easily detectable. However, maser emission at centimeter wavelengths, owing to its high brightness, enables us to study gas kinematics in protostars'…

We present wide area radio (12 mm) Mopra Telescope observations of the complex and rich massive star forming region G305. Our goals are to determine the reservoir for star formation within G305 using NH3 to trace the dense molecular…

Astrophysics of Galaxies · Physics 2015-05-19 L. Hindson , M. A. Thompson , J. S. Urquhart , J. S. Clark , B. Davies

We report on EVN imaging of the 6.7 GHz methanol maser emission from the candidate high-mass protostar G23.657-0.127. The masers originate in a nearly circular ring of 127 mas radius and 12 mas width. The ring structure points at a central…

Astrophysics · Physics 2016-08-30 A. Bartkiewicz , M. Szymczak , H. J. van Langevelde

We present the first astronomical detection of the 14NH3 (J,K) = (10,6) line: nonthermal emission at several velocities in the Galactic star-forming region NGC 7538. Using the VLA we have imaged the (10,6) and (9,6) ammonia masers at…

Astrophysics of Galaxies · Physics 2015-06-11 Ian M. Hoffman

Methanol masers are associated with young high-mass stars and are an important tool for investigating the process of massive star formation. The recently discovered methanol maser ring in G23.657-00.127 provides an excellent ``laboratory''…

Astrophysics · Physics 2008-12-18 A. Bartkiewicz , A. Brunthaler , M. Szymczak , H. J. van Langevelde , M. J. Reid

A sensitive search for 6.7--GHz methanol maser emission has been made towards 10 galaxies that have yielded detectable microwave molecular--line transitions. These include several which show OH megamaser or superluminous \water\/ maser…

Astrophysics · Physics 2015-06-24 S. P. Ellingsen , R. P. Norris , J. B. Whiteoak , R. A. Vaile , P. M. McCulloch , M. Price

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 present a new 12CO(J=1-0)-line survey of the Andromeda galaxy, M31, covering the bright disk with the highest resolution to date (85 pc along the major axis), observed On-the-Fly (in italics) with the IRAM 30-m telescope. We discuss the…

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…

Astrophysics of Galaxies · Physics 2015-05-30 Patrick I. McCauley , Jeffrey G. Mangum , Alwyn Wootten

Using the IRAM 30-m telescope and the 15-m JCMT, we explore the value of para-formaldehyde (p-H_2CO) as a tracer of density and temperature of the molecular gas in external galaxies. The target of our observations are the lobes of the…

Astrophysics · Physics 2009-11-13 S. Mühle , E. R. Seaquist , C. Henkel

We report the first detection of an extragalactic millimeter wavelength H2O maser at 183 GHz towards NGC 3079 using the Submillimeter Array (SMA), and a tentative submillimeter wave detection of the 439 GHz maser towards the same source…

I present here the summary of results from a survey by De Buizer (2003) searching for outflows using near-infrared imaging. Targets were massive young stellar objects associated with methanol masers in linear distributions. Presently, it is…

Astrophysics · Physics 2007-05-23 James M. De Buizer

We present a survey of the formaldehyde emission in a sample of eight Class 0 protostars obtained with the IRAM and JCMT telescopes. The data have been analyzed with three different methods with increasing level of sophistication. We first…

Despite their carbon-rich photospheres, silicate carbon stars show evidence of oxygen-rich circumstellar material, which is considered to exist in disks. Silicate carbon stars represent interesting cases that allow us to study the possible…

Solar and Stellar Astrophysics · Physics 2013-10-18 K. Ohnaka , D. A. Boboltz , G. Mulitz-Schimel , H. Izumiura , M. Wittkowski

We present an analysis of the molecular and atomic gas emission in the rest-frame far-infrared and sub-millimetre, from the lensed z=2.3 sub-millimetre galaxy SMM J2135-0102. We obtain very high signal-to-noise detections of 11 transitions…

We report the discovery of 6.035GHz hydroxyl (OH) maser flares toward the massive star forming region IRAS18566+0408 (G37.55+0.20), which is the only region known to show periodic formaldehyde (4.8 GHz H2CO) and methanol (6.7 GHz CH3OH)…

Astrophysics of Galaxies · Physics 2015-06-04 A. A. Al-Marzouk , E. D. Araya , P. Hofner , S. Kurtz , H. Linz , L. Olmi

We report the results of a multi-epoch survey of water maser observations at 22.2 GHz with the Medicina radiotelescope from 44 bright rimmed clouds (BRCs) of the northern hemisphere identified by Sugitani et al. (1989) as potential sites of…

Astrophysics · Physics 2009-11-11 R. Valdettaro , F. Palla , J. Brand , R. Cesaroni