中文
相关论文

相关论文: The Relationship between Class I and Class II Meth…

200 篇论文

The 22.2 GHz water masers are often associated with the 6.7 GHz methanol masers but owing to the different excitation conditions they likely probe independent spatial and kinematic regions around the powering young massive star. We compared…

星系天体物理 · 物理学 2015-06-04 Anna Bartkiewicz , Marian Szymczak , Huib Jan van Langevelde

The Australia Telescope Compact Array (ATCA) has been used to make the first full polarization observations of 6.7 GHz methanol masers. Linear polarization was detected towards all four sources observed, at levels between a few and 10%,…

天体物理学 · 物理学 2007-05-23 S. P. Ellingsen

We report the results of 10 years of monitoring of six regularly varying 6.7 GHz methanol masers using the Hartebeesthoek 26m telescope. Observations were done at intervals of 1--2 weeks, with faster sampling during flaring episodes. Four…

太阳与恒星天体物理 · 物理学 2013-11-08 S. Goedhart , J. P. Maswanganye , M. J. Gaylard , D. J. van der Walt

The Methanol MultiBeam survey (MMB) provides the most complete sample of Galactic massive young stellar objects (MYSOs) hosting 6.7GHz class II methanol masers. We characterise the properties of these maser sources using dust emission…

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…

太阳与恒星天体物理 · 物理学 2014-10-31 J. P. Maswanganye , M. J. Gaylard , S. Goedhart , D. J. van der Walt , R. S. Booth

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…

天体物理学 · 物理学 2009-11-13 M. Szymczak , A. Bartkiewicz , A. M. S. Richards

The Cygnus X complex is covered by the Global View of Star Formation in the Milky Way (GLOSTAR) survey, an unbiased radio-wavelength Galactic plane survey, in 4--8 GHz continuum radiation and several spectral lines. The GLOSTAR survey…

The ATCA has been used to measure positions with arcsecond accuracy for 379 masers at the 22-GHz transition of water. The principal observation targets were 202 OH masers of the variety associated with star formation regions (SFR)s in the…

星系天体物理 · 物理学 2015-05-18 Shari Breen , James Caswell , Simon Ellingsen , Chris Phillips

The 6.7 GHz methanol maser is exclusively associated with high-mass star formation. However, it remains unclear what structures harbour the methanol masers. Cepheus A is one of the closest regions of massive star formation, making it an…

太阳与恒星天体物理 · 物理学 2015-05-20 K. J. E. Torstensson , H. J. van Langevelde , W. H. T. Vlemmings , S. Bourke

We present accurate absolute astrometry of 6.7 GHz methanol masers detected in the Arecibo Methanol Maser Galactic Plane Survey using MERLIN and the Expanded Very Large Array (EVLA). We estimate the absolute astrometry to be accurate to…

太阳与恒星天体物理 · 物理学 2015-05-27 J. D. Pandian , E. Momjian , Y. Xu , K. M. Menten , P. F. Goldsmith

We report the discovery of 6.7 GHz methanol maser periodic flares in four massive star forming regions and the updated light curve for the known periodic source G22.357+0.066. The observations were carried out with the Torun 32 m radio…

星系天体物理 · 物理学 2015-06-23 M. Szymczak , P. Wolak , A. Bartkiewicz

We report the detection of the Zeeman effect in the 44 GHz Class I methanol maser line toward the star forming region DR21(OH). In a 219 Jy/beam maser centered at an LSR velocity of 0.83 km s$^{-1}$, we find a 20-$\sigma$ detection of…

星系天体物理 · 物理学 2017-01-18 E. Momjian , A. P. Sarma

The aim of this study is to investigate the distribution and excitation of the methanol gas around Cep A and to describe the physical conditions of the region. In addition the large scale abundance distribution is determined in order to…

Water masers are common in star-forming regions (SFRs), with the 22.235 GHz transition widely detected in both high- and low-mass protostars. In contrast, (sub)millimeter water maser transitions remain poorly studied, especially in low-mass…

星系天体物理 · 物理学 2025-09-17 P. K. Humire , C. Goddi , G. N. Ortiz-León , A. Hernández-Gómez , J-C Loison

We present the results of a 5-year monitoring program of 42 sources targeted at 6.7 GHz methanol masers, conducted from March 2017 to October 2022 using the Irbene 32 and 16 meter radio telescopes. Sources were observed with irregular…

星系天体物理 · 物理学 2023-10-13 A. Aberfelds , J. Šteinbergs , I. Shmeld , R. A. Burns

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…

天体物理学 · 物理学 2015-06-24 S. P. Ellingsen , R. P. Norris , P. M. McCulloch

We present results on simultaneous observations of Class~I methanol masers at 25, 36, and 44 GHz towards 22 Galactic targets carried out with the Effelsberg 100-m telescope. The study investigates relations between the hyperfine (HF)…

We present MERLIN observations of OH, water and methanol masers towards the young high mass stellar object IRAS 20126+4104. Emission from the 1665-MHz OH, 22-GHz H_2O and 6.7-GHz CH_3OH masers is detected and all originates very close to…

星系天体物理 · 物理学 2011-07-05 K. A. Edris , G. A. Fuller , R. J. Cohen , S. Etoka

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

We report the results of a blind search for 22-GHz water masers in two regions, covering approximately half a square degree, within the giant molecular cloud associated with RCW 106. The complete search of the two regions was carried out…