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相关论文: A highly variable methanol maser in G111.256-0.770

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We report on a large 44 GHz ($7_0-6_1$ A$^+$) methanol (CH$_3$OH) maser survey of the Galactic Center (GC). The Karl G. Jansky Very Large Array was used to search for CH$_3$OH maser emission covering a large fraction of the region around…

太阳与恒星天体物理 · 物理学 2016-12-07 Bridget McEwen , Loránt Sjouwerman , Ylva Pihlström

We present results of the investigations of the properties of the methanol $J_1 - J_0$ A$^{-+}$ line series motivated by the recent serendipitous detection of the maser emission in the $14_1 - 14_0$ A$^{-+}$ line at 349~GHz in S255IR-SMA1…

星系天体物理 · 物理学 2022-03-30 Svetlana V. Salii , Igor I. Zinchenko , Sheng-Yuan Liu , Andrej M. Sobolev , Artis Aberfelds , Yu-Nung Su

Intriguing work on observations of 4.83 GHz formaldehyde (H2CO) absorptions and 4.87 GHz H110a radio recombination lines (RRLs) towards 6.7 GHz methanol (CH3OH) maser sources is presented. Methanol masers provide ideal sites to probe the…

太阳与恒星天体物理 · 物理学 2015-06-18 Daniel. Okoh , Jarken. Esimbek , Jian. Jun. Zhou , Xin. Di. Tang , Augustine. Chukwude , Johnson. Urama , Pius. Okeke

We have conducted a Galactic plane survey of methanol masers at 6668 MHz using a 7-beam receiver on the Parkes telescope. Here we present results from the first part, which provides sensitive unbiased coverage of a large region around the…

We review the state of the Onsala blind survey of the galactic plane, searching for new 6.7 GHz methanol masers. We also describe preliminary results of millimeter follow-up observations of the new detections and high resolution…

天体物理学 · 物理学 2007-05-23 M. R. Pestalozzi , V. Minier , R. S. Booth , J. E. Conway

The NGC 2024 FIR 6 region was observed in the water maser line at 22 GHz and the methanol class I maser lines at 44, 95, and 133 GHz. The water maser spectra displayed several velocity components and month-scale time variabilities. Most of…

星系天体物理 · 物理学 2015-06-11 Minho Choi , Miju Kang , Do-Young Byun , Jeong-Eun Lee

The methanol molecule CH3OH has a complex microwave spectrum with a large number of very strong lines. This spectrum includes purely rotational transitions as well as transitions with contributions of the internal degree of freedom…

宇宙学与河外天体物理 · 物理学 2013-06-12 S. A. Levshakov , M. G. Kozlov , D. Reimers

High-amplitude variability in Young Stellar Objects (YSOs) is usually associated with episodic accretion events. It has not been observed so far in massive YSOs. Here, the high-amplitude variable star sample of ContrerasPe\~{n}a et…

太阳与恒星天体物理 · 物理学 2016-12-14 M. S. N. Kumar , C. Contreras-Pena , P. W. Lucas , M. A. Thompson

Variability in Young Stellar Objects (YSOs) is one of their primary characteristics. Long-term, multi-filter, high-cadence monitoring of large YSO samples is the key to understand the partly unusual light-curves that many of these objects…

In this contribution I will attempt to show that the study of galactic 6.7 and 12.2GHz methanol masers themselves, as opposed to the use of methanol masers as signposts, can yield important conclusions contributing to the understanding of…

天体物理学 · 物理学 2009-11-13 Michele Pestalozzi

We have used the Australian Long Baseline Array (LBA) to produce milliarcsecond images of five sites of methanol maser emission at 6.7 GHz. These are all sites that have linear morphologies at arcsecond resolutions, which have been…

天体物理学 · 物理学 2009-11-10 R. Dodson , R. Ojha , S. P. Ellingsen

We have used the Karl G. Jansky Very Large Array (VLA) to search for 36 GHz and 44 GHz methanol (CH3OH) lines in a sample of 21 Galactic supernova remnants (SNRs). Mainly the regions of the SNRs with 1720 MHz OH masers were observed.…

星系天体物理 · 物理学 2015-06-18 Y. M. Pihlström , L. O. Sjouwerman , D. A. Frail , M. J. Claussen , R. A. Mesler , B. C. McEwen

Radio images of maser spots in the infrared source GL2789, connected with the young stellar object V645 Cyg, have been obtained as a result of the radio interferometric observations of H2O maser at 22 GHz and methanol maser at 6.7 GHz, with…

天体物理学 · 物理学 2007-05-23 I. E. Val'tts , V. I. Slysh , M. A. Voronkov , V. Migenes

We report the first observations in a rare family of class II methanol maser transitions in both CH$_3$OH and $^{13}$CH$_3$OH toward three southern high-mass star formation regions, along with the first maser detected in the $^{13}$CH$_3$OH…

We present the results of the first complete survey of the Large and Small Magellanic Clouds for 6668-MHz methanol and 6035-MHz excited-state hydroxyl masers. In addition to the survey, higher-sensitivity targeted searches towards known…

Methanol masers which are traditionally divided into two classes provide possibility to study important parts of the star forming regions: Class~II masers trace vicinities of the massive YSOs while class~I masers are likely to trace more…

We observed 14 methanol transitions near lambda=2 mm in Galactic star-forming regions. Broad, quasi-thermal J(0)-J(-1)E methanol lines near 157 GHz were detected toward 73 sources. Together with the 6(-1)-5(0)E and 5(-2)-6(-1)E lines at 133…

天体物理学 · 物理学 2009-10-31 V. I. Slysh , S. V. Kalenskii , I. E. Val'tts , V. V. Golubev , K. Mead

We present a sensitive search for methanol line emission in evolved stars at 1 cm, aiming to detect, for the first time, methanol masers in this type of objects. Our sample comprised post-AGB stars and young planetary nebulae (PNe), whose…

星系天体物理 · 物理学 2014-03-05 J. F. Gomez , L. Uscanga , O. Suarez , J. R. Rizzo , I. de Gregorio-Monsalvo

The 6.7 GHz maser transition of methanol has been found exclusively towards massive star forming regions. A majority of the masers have been found to lack the presence of any associated radio continuum. This could be due to the maser…

星系天体物理 · 物理学 2015-05-19 J. D. Pandian , E. Momjian , Y. Xu , K. M. Menten , P. F. Goldsmith

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…

天体物理学 · 物理学 2009-11-13 P. F. Goldsmith , J. D. Pandian , A. A. Deshpande
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