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Recent observational studies suggest that Be stars most likely are formed through the process of mass transfer in binary systems. In view of the wide consensus that the origin of the magnetic field in stars with radiative envelopes involves…

Solar and Stellar Astrophysics · Physics 2026-05-07 S. Hubrig , S. P. Järvinen , M. Schöller , I. Ilyin

We study Hinode/SOT-FG observations of intensity fluctuations in Ca II H-line and G-band image sequences and their relation to simultaneous and co-spatial magnetic field measurements. We explore the G-band and H-line intensity oscillation…

Solar and Stellar Astrophysics · Physics 2015-06-05 J. K. Lawrence , A. C. Cadavid

A new methanol maser line 6(-1)-5(0)E at 133 GHz was detected with the 12-m Kitt Peak radio telescope using remote observation mode from Moscow. Moderately strong, narrow maser lines were found in DR21(OH), DR21-W, OMC-2, M8E, NGC2264,…

Astrophysics · Physics 2009-10-30 V. I. Slysh , S. V. Kalenskii , I. E. Val'tts , V. V. Golubev

We have used polarimetric imaging to study the magneto-ionic medium of the Galaxy, obtaining 1420 MHz images with an angular resolution of 1' over more than 40 square-degrees of sky around the W3/W4/W5/HB3 HII region/SNR complex in the…

Astrophysics · Physics 2009-10-31 A. D. Gray , T. L. Landecker , P. E. Dewdney , A. R. Taylor , A. G. Willis , M. Normandeau

Water fountain objects are generally defined as "evolved stars with low to intermediate initial mass accompanied by high-velocity molecular jets detectable in the 22.235 GHz H$_2$O maser line". They are the key objects of understanding the…

Astrophysics of Galaxies · Physics 2024-03-14 Xu-Jia Ouyang , Yong Zhang , Juan Li , Jun-ichi Nakashima , Xi Chen , Hai-Hua Qiao

We present a (sub)millimeter line survey of the methanol maser outflow located in the massive star-forming region DR21(OH) carried out with the Submillimeter Array (SMA) at 217/227 GHz and 337/347 GHz. We find transitions from several…

Solar and Stellar Astrophysics · Physics 2018-12-26 Ma. T. Orozco-Aguilera , Antonio Hernández-Gómez , Luis A. Zapata

We present the third instalment of a series of catalogues presenting 12.2-GHz methanol maser observations made towards each of the 6.7-GHz methanol masers detected in the Methanol Multibeam (MMB) Survey. The current portion of the catalogue…

We present the results of a monitoring campaign using the KAT-7 and HartRAO 26m telescopes, of hydroxyl, methanol and water vapour masers associated with the high-mass star forming region G9.62+0.20E. Periodic flaring of the main line…

Solar and Stellar Astrophysics · Physics 2019-03-20 S. Goedhart , R. van Rooyen , D. J. van der Walt , J. P. Maswanganye , A. Sanna , G. C. MacLeod , S. P. van den Heever

To investigate statistically whether magnetic fields in massive stars are ubiquitous or appear in stars with specific spectral classification, certain ages, or in a special environment, we acquired 41 new spectropolarimetric observations…

Context: Some O stars are suspected to have to have (weak) magnetic fields because of the observed cyclical variability in their UV wind-lines. However, direct detections of these magnetic fields using optical spectropolarimetry have proven…

We report the discovery of the Zeeman effect in the 44 GHz Class I methanol maser line. The observations were carried out with 22 antennas of the EVLA toward a star forming region in OMC-2. Based on our adopted Zeeman splitting factor of z…

Astrophysics of Galaxies · Physics 2015-05-27 A. P. Sarma , E. Momjian

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…

Astrophysics of Galaxies · Physics 2015-05-18 Shari Breen , James Caswell , Simon Ellingsen , Chris Phillips

We used the Very Long Baseline Array (VLBA) and the European VLBI Network (EVN) to perform phase-referenced VLBI observations of the three most powerful maser transitions associated with the high-mass star-forming region G28.87+0.07: the…

Solar and Stellar Astrophysics · Physics 2015-06-03 J. J. Li , L. Moscadelli , R. Cesaroni , R. S. Furuya , Y. Xu , T. Usuda , K. M. Menten , M. Pestalozzi , D. Elia , E. Schisano

In the framework of the Herschel/PRISMAS Guaranteed Time Key Program, the line of sight to the distant ultracompact HII region W51e2 has been observed using several selected molecular species. Most of the detected absorption features are…

Astrophysics of Galaxies · Physics 2014-07-02 B. Mookerjea , C. Vastel , G. E. Hassel , M. Gerin , J. Pety , P. F. Goldsmith , J. H. Black , T. Giesen , T. Harrison , C. M. Persson , J. Stutzki

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…

We present the first results from the MALT-45 (Millimetre Astronomer's Legacy Team - 45 GHz) Galactic Plane survey. We have observed 5 square-degrees ($l = 330 - 335$, $b = \pm0.5$) for spectral lines in the 7 mm band (42-44 and 48-49 GHz),…

We present Submillimeter Array (SMA) observations of the HCN\,(3--2) and HCO$^+$\,(3--2) molecular lines toward the W3(H$_2$O) and W3(OH) star-forming complexes. Infall and outflow motions in the W3(H$_2$O) have been characterized by…

Solar and Stellar Astrophysics · Physics 2016-01-27 Sheng-Li Qin , Peter Schilke , Jingwen Wu , Tie Liu , Yuefang Wu , Álvaro Sánchez-Monge , Ying Liu

We present Submillimeter Array observations of high frequency SiO masers around the supergiant VX Sgr and the semi-regular variable star W Hya. The J=5-4, v=1 28SiO and v=0 29SiO masers of VX Sgr are shown to be highly linearly polarized…

Solar and Stellar Astrophysics · Physics 2015-05-27 W. H. T. Vlemmings , E. M. L. Humphreys , R. Franco-Hernández

The interstellar hydride hydroxyl (OH) is a potential tracer of CO-dark molecular gas. We present new absorption line observations of OH at 18-cm wavelength towards four continuum sources. We compare these to the [CII] line at 1.9 THz…

We report new observations of molecular oxygen in absorption at z=0.685 in front of the radio source B0218+357. The lines at 56.3 and 118.7 GHz have been observed, redshifted to 33.4 and 70.5 GHz respectively, with the 12m at Kitt Peak, 43m…