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Related papers: On the Relationship of UC H II Regions and Class I…

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Context: NGC7538 is known to host a 6.7 and 12.2GHz methanol maser cospatial with a Ultra Compact (UC) HII region, IRS1. Aims: We report on the serendipitous discovery of two additional 6.7GHz methanol masers in the same region, not…

Astrophysics · Physics 2007-05-23 M. Pestalozzi , V. Minier , F. Motte , J. Conway

Hypercompact (HC) HII regions are, by nature, very young HII regions, associated with the earliest stages of massive star formation. They may represent the transition phase as an early B-type star grows into an O-type star. Unfortunately,…

Astrophysics of Galaxies · Physics 2015-05-28 Alvaro Sanchez-Monge , Jagadheep D. Pandian , Stan Kurtz

We present results of 13CO(1-0), C18O(1-0), and HCO+(1-0) map observations and N2H+2 (1-0) single point observations directed towards a sample of nine low-luminosity 6.7-GHz masers. N2H+ line emission has been detected from six out of nine…

Astrophysics of Galaxies · Physics 2015-05-19 Y. W. Wu , Y. Xu , J. Yang

The Australia Telescope Compact Array (ATCA) has been used to image class I methanol masers at 9.9, 25 (a series from J=2 to J=9), 84, 95 and 104 GHz located in the vicinity of IRAS 16547-4247 (G343.12-0.06), a luminous young stellar object…

We report the negative results from a search for 6.7 GHz methanol masers in the nearby spiral galaxy M33. We observed 14 GMCs in the central 4 kpc of the Galaxy, and found 3 sigma upper limits to the flux density of ~9 mJy in spectral…

Astrophysics · Physics 2009-11-13 P. F. Goldsmith , J. D. Pandian , A. A. Deshpande

The high-mass star-forming site G009.62+00.20E hosts the 6.7 GHz methanol maser source with the greatest flux density in the Galaxy which has been flaring periodically over the last ten years. We performed high-resolution astrometric…

Ten new class II methanol masers from the 6.7-GHz Methanol Multibeam survey catalogues III and IV were selected for a monitoring programme at both 6.7 and 12.2 GHz with the 26m Hartebeesthoek Radio Astronomy Observatory (HartRAO) radio…

Solar and Stellar Astrophysics · Physics 2015-12-29 J. P. Maswanganye , D. J. van der Walt , S. Goedhart , M. J. Gaylard

Eight new class II methanol masers selected from the 6.7 GHz Methanol Multibeam survey catalogues I and II were monitored at 6.7 GHz with the 26m Hartebeesthoek Radio Astronomy Observatory (HartRAO) radio telescope for three years and seven…

Solar and Stellar Astrophysics · Physics 2014-10-31 J. P. Maswanganye , M. J. Gaylard , S. Goedhart , D. J. van der Walt , R. S. Booth

Methanol masers at 6.7 GHz have been found exclusively towards high-mass star forming regions. Recently, some Class 0 protostars have been found to display conditions similar to what are found in hot cores that are associated with massive…

Astrophysics · Physics 2009-11-13 J. D. Pandian , S. Leurini , K. M. Menten , A. Belloche , P. F. Goldsmith

We report the results of a search for 6.7 GHz methanol (CH3OH) maser emission in OH megamaser galaxies at 0.11<z<0.27. No detections were made in the 25 objects observed down to rms noise levels of roughly 0.6 mJy in 150 kHz channels. The…

Astrophysics · Physics 2009-11-07 Jeremy Darling , Paul Goldsmith , Di Li , Riccardo Giovanelli

We report the detection of new 12.178, 12.229, 20.347, and 23.121 GHz methanol masers in the massive star-forming region G358.93-0.03, which are flaring on similarly short timescales (days) as the 6.668 GHz methanol masers also associated…

We have used the Australia Telescope Compact Array (ATCA) to search for continuum emission toward three strong 6.7-GHz methanol maser sources. For two of the sources, G339.88-1.26 and NGC 6334F (G351.42+0.64), we detect continuum emission…

Astrophysics · Physics 2015-06-24 S. P. Ellingsen , R. P. Norris , P. M. McCulloch

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 report results of 6.7 GHz methanol maser monitoring of 139 star-forming sites with the Torun 32 m radio telescope from June 2009 to February 2013. The targets were observed at least once a month, with higher cadences of 2-4 measurements…

Astrophysics of Galaxies · Physics 2017-12-20 Marian Szymczak , Mateusz Olech , Rafał Sarniak , Paweł Wolak , Anna Bartkiewicz

We have investigated the central region of NGC 253 for the presence of 84.5-GHz ($5_{-1}\rightarrow4_0$E) methanol emission using the Australia Telescope Compact Array. We present the second detection of 84.5-GHz class~I methanol maser…

Astrophysics of Galaxies · Physics 2018-11-21 Tiege P. McCarthy , Simon P. Ellingsen , Shari L. Breen , Maxim A. Voronkov , Xi Chen

We present the fourth portion of a Galactic Plane survey of methanol masers at 6668 MHz, spanning the longitude range 186 degrees to 330 degrees. We report 207 maser detections, 89 new to the survey. This completes the southern sky part of…

We present a survey of the polarization properties of mm-wavelength methanol masers, comprising both classes, and transitions from 84.5 to 157.0 GHz. Linear polarization is found in more than half of the observed objects, and circular…

Astrophysics · Physics 2009-11-10 Helmut Wiesemeyer , Clemens Thum , Malcolm Walmsley

VLBA and EVN radio observations of H2O masers at 22 GHz and methanol masers at 6.7 GHz have been used to obtain images of the maser spots in the infrared object GL2789, which is associated with the young stellar object V645Cyg. The position…

Astrophysics · Physics 2009-11-07 V. I. Slysh , M. A. Voronkov , I. E. Val'tts , V. Migenes

We have selected the positions of 54 6.7GHz methanol masers from the Methanol Multibeam Survey catalogue, covering a range of longitudes between $20^{\circ}$ and $34^{\circ}$ of the Galactic Plane. These positions were mapped in the J=3-2…

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
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