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Related papers: Interstellar H$_2$O Masers from J Shocks

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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

(Abridged) H2 is the most abundant molecule in the Universe. Thanks to its widely spaced energy levels, it predominantly lights up in warm gas, T > 100 K, such as shocked regions, and it is one of the key targets of JWST observations. These…

Astrophysics of Galaxies · Physics 2023-07-11 L. E. Kristensen , B. Godard , P. Guillard , A. Gusdorf , G. Pineau des Forets

Interstellar shocks, a key element of stellar feedback processes, shape the structure of the interstellar medium (ISM) and are essential for the chemistry, thermodynamics, and kinematics of interstellar gas. Powerful, high-velocity shocks…

Astrophysics of Galaxies · Physics 2023-06-28 Daniel R. Rybarczyk , Snezana Stanimirovic , Antoine Gusdorf

Context. Water vapor emission at 22 GHz from masers associated with star-forming regions is highly variable. Aims. We present a database of up to 20 years of monitoring of a sample of 43 masers within star-forming regions. The sample covers…

We investigate the temperature distribution of CO-dark molecular hydrogen (H2) in a series of disk galaxies simulated using the AREPO moving-mesh code. In conditions similar to those in the Milky Way, we find that H2 has a flat temperature…

Astrophysics of Galaxies · Physics 2016-08-31 Simon C. O. Glover , Rowan J. Smith

We have used the Australia Telescope Compact Array to undertake the first high-resolution observations of the 19.9-GHz methanol maser transition. The emission is coincident with the location of the targeted 6.7-GHz methanol masers to within…

Astrophysics of Galaxies · Physics 2015-06-16 Vasaant Krishnan , Simon Ellingsen , Maxim Voronkov , Shari Breen

Herschel-HIFI spectra of H2O towards low-mass protostars show a distinct velocity component not seen in observations from the ground of CO or other species. The aim is to characterise this component in terms of excitation conditions and…

Solar and Stellar Astrophysics · Physics 2015-06-16 L. E. Kristensen , E. F. van Dishoeck , A. O. Benz , S. Bruderer , R. Visser , S. F. Wampfler

We present deep spectroscopic (3600 - 24700 A) X-shooter observations of the bright Herbig-Haro object HH1, one of the best laboratories to study the chemical and physical modifications caused by protostellar shocks on the natal cloud. We…

Solar and Stellar Astrophysics · Physics 2015-10-26 T. Giannini , S. Antoniucci , B. Nisini , F. Bacciotti , L. Podio

Methanol masers at 6.7 GHz are the brightest of class II methanol masers and have been found exclusively towards massive star forming regions. These masers can thus be used as a unique tool to probe the early phases of massive star…

Astrophysics of Galaxies · Physics 2020-01-08 Sonu Tabitha Paulson , Jagadheep D. Pandian

OH megamasers (OHMs) emit primarily in the main lines at 1667 and 1665 MHz, and differ from their Galactic counterparts due to their immense luminosities, large linewidths and 1667/1665 MHz flux ratios, which are always greater than one. We…

Astrophysics · Physics 2009-11-13 Philip Lockett , Moshe Elitzur

We present results from high-resolution three-dimensional simulations of turbulent interstellar gas that self-consistently follow its coupled thermal, chemical and dynamical evolution, with a particular focus on the formation and…

Solar and Stellar Astrophysics · Physics 2015-05-13 S. C. O. Glover , C. Federrath , M. -M. Mac Low , R. S. Klessen

We present a study of the high rotational bands (J > 2) of H2 toward 4 early type galactic stars: HD 73882, HD 192639, HD 206267, and HD 207538. In each case, the velocity dispersion - characterized by the spectrum fitting parameter b -…

Astrophysics · Physics 2009-11-10 S. Lacour , V. Ziskin , G. Hebrard , C. Oliveira , M. K. Andre , R. Ferlet , A. Vidal-Madjar

The collisionally pumped, ground-state 1720 MHz maser line of OH is widely recognized as a tracer for shocked regions and observed in star forming regions and supernova remnants. Whereas some lines of excited states of OH have been detected…

We found that in regions of high mass star formation the CS emission correlates well with the dust continuum emission and is therefore a good tracer of the total mass while the N$_2$H$^+$ distribution is frequently very different. This is…

We report results of EVN interferometric study of two star-forming regions L1206 and GL2789 in the brightest methanol maser line at 6.7 GHz. Using measured absolute positions both methanol masers were identified with protostars which are…

Astrophysics · Physics 2007-05-23 M. A. Voronkov , V. I. Slysh

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,…

This work presents a detailed study of the gas kinematics towards the "Hot Molecular Core" (HMC) G31.41+0.31 via multi-epoch VLBI observations of the H2O 22 GHz and CH3OH 6.7 GHz masers, and single-epoch VLBI of the OH 1.6 GHz masers. Water…

Solar and Stellar Astrophysics · Physics 2015-06-12 Luca Moscadelli , Jing Jing Li , Riccardo Cesaroni , Alberto Sanna , Ye Xu , Qizhou Zhang

Triggered star formation around HII regions could be an important process. The Galactic HII region RCW 79 is a prototypical object for triggered high-mass star formation. We take advantage of Herschel data from the surveys HOBYS, "Evolution…

Despite its major role in the evolution of the interstellar medium, the formation of high-mass stars (M > 10 Msol) is still poorly understood. Two types of massive star cluster precursors, the so-called Massive Dense Cores (MDCs), have been…

Astrophysics of Galaxies · Physics 2015-05-19 M. G. Marseille , F. F. S. van der Tak , F. Herpin , T. Jacq

We report the first detection of a radio-continuum and molecular jet associated with a dominant blue-shifted maser source, G353.273+0.641. A radio jet is extended 3000 au along NW-SE direction. H$_{2}$O masers are found to be clustered in…

Solar and Stellar Astrophysics · Physics 2015-06-11 Kazuhito Motogi , Kazuo Sorai , Kotaro Niinuma , Koichiro Sugiyama , Mareki Honma , Kenta Fujisawa