English
Related papers

Related papers: Models of class II methanol masers based on improv…

200 papers

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…

Astrophysics · Physics 2009-11-11 James M. De Buizer , James T. Radomski , Charles M. Telesco , Robert K. Pina

The Australia Telescope Compact Array has been used to search for 22-GHz water masers towards the 119 6.7-GHz methanol masers detected in the Methanol Multi-Beam survey between Galactic longitudes 6 and 20 degrees; we find water masers…

Solar and Stellar Astrophysics · Physics 2015-06-22 A. M. Titmarsh , S. P. Ellingsen , S. L. Breen , J. L. Caswell , M. A. Voronkov

We argue that the periodic variability of Class II methanol masers can be explained by variations of the dust temperature in the accretion disk around proto-binary star with at least one massive component. The dust temperature variations…

Astrophysics of Galaxies · Physics 2014-08-27 S. Yu. Parfenov , A. M. Sobolev

The near infrared (1-2um) and the thermal infrared (3-25um) trace many of the environments in which masers are thought to reside, including shocks, outflows, accretion disks, and the dense medium near protostars. After a number of recent…

Astrophysics · Physics 2009-11-13 James De Buizer

Recently, a comparison between the locations of 6.7-GHz methanol masers and dust continuum emission has renewed speculation that these masers can be associated with evolved stars. The implication of such a scenario would be profound,…

Class I CH$_3$OH masers trace interstellar shocks. They have received little attention mostly as a consequence of their low luminosities; this situation has changed recently and Class I masers are now routinely used as signposts of…

Astrophysics of Galaxies · Physics 2016-07-13 S. Leurini , K. M. Menten , C. M. Walmsley

The collisional pumping of CH3OH and OH masers in non-dissociative C-type shock waves is studied. The chemical processes responsible for the evolution of molecule abundances in the shock wave are considered in detail. The large velocity…

Astrophysics of Galaxies · Physics 2021-12-15 A. V. Nesterenok

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

We report the result of a systematic methanol observation toward IRAS 19312+1950. The properties of the SiO, H2O and OH masers of this object are consistent with those of mass-losing evolved stars, but some other properties are difficult to…

Solar and Stellar Astrophysics · Physics 2015-08-06 Jun-ichi Nakashima , Andrej M. Sobolev , Svetlana V. Salii , Yong Zhang , Bosco H. K. Yung , Shuji Deguchi

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

We present a review of the properties of Class I methanol masers detected in low-mass star forming regions (LMSFRs). These masers, henceforth called LMMIs, are associated with postshock gas in the lobes of chemically active outflows in…

Astrophysics of Galaxies · Physics 2018-08-22 S. Kalenskii , S. Kurtz , P. Hofner , P. Bergman , C. M. Walmsley , P. Golysheva

The Australia Telescope Compact Array (ATCA) has been used for high angular resolution imaging of 71 southern class I methanol maser sources quasi-simultaneously at 36 and 44 GHz. The data reveal a high level of morphological and…

Astrophysics of Galaxies · Physics 2015-06-18 M. A. Voronkov , J. L. Caswell , S. P. Ellingsen , J. A. Green , S. L. Breen

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…

Astrophysics of Galaxies · Physics 2015-05-18 M. A. Voronkov , J. L. Caswell , S. P. Ellingsen , A. M. Sobolev

We characterize the molecular environment of candidate massive young stellar objects (MYSOs) signposted by methanol masers. Single pixel observations of 10 transitions of HCO^+, CO and CS isotopomers were carried out, using the IRAM 30m…

Astrophysics · Physics 2009-11-13 M. Szymczak , A. Bartkiewicz , A. M. S. Richards

Maser lines from different molecular species, including water, hydroxyl, and methanol, are common observational phenomena associated with massive star forming regions. In particular, the methanol maser appears as an ideal tool to study the…

Astrophysics of Galaxies · Physics 2014-06-04 L. Olmi , E. D. Araya , P. Hofner , S. Molinari , J. Morales Ortiz , L. Moscadelli , M. Pestalozzi

We present observations of methanol lines in a sample of Class 0 low mass protostars. Using a 1-D radiative transfer model, we derive the abundances in the envelopes. In two sources of the sample, the observations can only be reproduced by…

Astrophysics · Physics 2007-05-23 S. Maret , C. Ceccarelli , A. G. G. M. Tielens , E. Caux , B. Lefloch , A. Faure , A. Castets , D. R. Flower

Class I methanol masers are collisionally pumped and are generally correlated with outflows in star forming sites in the Galaxy. Using the VLA in its A-array configuration, we present a spectral line survey to identify methanol…

Astrophysics of Galaxies · Physics 2016-12-14 W. Cotton , F. Yusef-Zadeh

Context: Methanol masers of Class I (collisionally-pumped) and Class II (radiatively-pumped) have been studied in great detail in our Galaxy in a variety of astrophysical environments such as shocks and star-forming regions and are helpful…

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

The collisional pumping of H_2^{16}O and H_2^{18}O masers in hot dense gas-dust clouds has been simulated numerically. New data on the rate coefficients for collisional transitions from Faure et al. (2007) were used in the calculations. The…

High Energy Astrophysical Phenomena · Physics 2011-07-19 Aleksandr Nesterenok , Dmitry Varshalovich