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Related papers: Total linear polarization in the OH maser W75N: VL…

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We have observed the OH (1720 MHz) line in five galactic SNRs with the VLA to measure their magnetic field strengths using the Zeeman effect. We detected all 12 of the bright ($S_{\nu} > 200$ mJy) OH (1720 MHz) masers previously detected by…

Astrophysics · Physics 2009-10-31 C. L. Brogan , D. A. Frail , W. M. Goss , T. H. Troland

We used the Submillimeter Array to image the SiO maser emission in the $v=1$, \$J=5-4$ transition associated with the peculiar red supergiant VY Canis Majoris. We identified seven maser components and measured their relative positions and…

Astrophysics · Physics 2009-11-10 Hiroko Shinnaga , James M. Moran , Ken H. Young , Paul T. P. Ho

Class I methanol masers are found to be good tracers of the interaction between outflows from massive young stellar objects with their surrounding media. Although polarization observations of Class II methanol masers have been able to…

Astrophysics of Galaxies · Physics 2017-01-16 Ji-hyun Kang , Do-Young Byun , Kee-Tae Kim , Jongsoo Kim , Aran Lyo , W. H. T. Vlemmings

We have done a statistical analysis of Very Long Baseline Array (VLBA) data of water masers in the star-forming regions (SFRs) Cepheus A and W75 N, using correlation functions to study the spatial clustering and Doppler-velocity…

Astrophysics of Galaxies · Physics 2015-05-18 L. Uscanga , J. Cantó , J. F. Gómez , G. Anglada , J. M. Torrelles , N. A. Patel , A. C. Raga , S. Curiel

OH 231.8+4.2 is a well studied preplanetary nebula (pPN) around a binary stellar system that shows a remarkable bipolar outflow. To study the structure and kinematics of the inner 10-80 AU nebular regions we performed high-resolution…

Astrophysics · Physics 2009-11-13 J. -F. Desmurs , J. Alcolea , V. Bujarrabal , C. Sanchez Contreras , F. Colomer

IRAS20126+4104 is a well studied B0.5 protostar that is surrounded by a ~1000 au Keplerian disk and is where a large-scale outflow originates. Both 6.7-GHz CH3OH masers and 22-GHz H2O masers have been detected toward this young stellar…

Solar and Stellar Astrophysics · Physics 2014-03-05 G. Surcis , W. H. T. Vlemmings , H. J. van Langevelde , L. Moscadelli , B. Hutawarakorn Kramer

Spectra of 6.7 GHz methanol masers from 21 pointings of known star-forming regions are reported. The C-band observations, using the Green Bank Telescope in full Stokes mode, have measured how polarization properties vary across the maser…

Astrophysics of Galaxies · Physics 2026-05-19 Paul Fallon , Derck P. Smits

We present the first ALMA dust polarization observations towards the high-mass star-forming regions W51 e2, e8, and W51 North in Band 6 (230 GHz) with a resolution around 0.26" ($\sim5$mpc). Polarized emission in all three sources is…

Astrophysics of Galaxies · Physics 2018-03-21 Patrick M. Koch , Ya-Wen Tang , Paul T. P. Ho , Hsi-Wei Yen , Yu-Nung Su , Shigehisa Takakuwa

An accurate polarization calibration is essential for a spectral data analysis and Zeeman splitting measurements. Two anomalies challenge our understanding of OH megamasers in IRAS 02524+2046: an unexplained 1667/1665 MHz flux-ratio…

Astrophysics of Galaxies · Physics 2026-04-08 L. G. Hou , X. Y. Gao , Tao Hong , J. L. Han

This paper examines the detailed sub-milliarcsecond polarization properties of an individual SiO maser feature displaying a rotation in polarization electric vector position angle of approximately \pi/2 across the feature. Such rotations…

Solar and Stellar Astrophysics · Physics 2015-05-30 A. J. Kemball , P. J. Diamond , L. Richter , I. Gonidakis , R. Xue

Context: Ground-state OH maser emission from late-type stars is usually polarized and remains a powerful probe of the magnetic field structure in the outer regions of circumstellar envelopes if observed with high angular and spectral…

Astrophysics of Galaxies · Physics 2011-10-11 Paweł Wolak , Marian Szymczak , Eric Gérard

Using the VLA, a series of high velocity resolution observations have been made of the M82 starburst at 1.6 GHz. These observations follow up on previous studies of the main line OH maser emission in the central kiloparsec of this starburst…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-09 M. K. Argo , A. Pedlar , R. J. Beswick , T. W. B. Muxlow , D. M. Fenech

We present VLA observations in the hydroxyl line OH(1720 MHz) towards the supernova remnant W28. These high resolution images show a more extensive distribution of 1720 MHz emission than had previously been suspected from earlier…

Astrophysics · Physics 2009-10-22 D. A. Frail , W. M. Goss , V. I. Slysh

We have observed the OH 1612-MHz maser emission towards the proto-planetary nebula candidate OH17.7-2.0 that underwent a very strong and unusual outburst in 2003. Phase-referencing data were obtained with the EVN in order to localize the…

Astrophysics · Physics 2009-04-16 M. Szymczak , A. Bartkiewicz , E. Gerard

We present 250~GHz continuum and H29alpha line data toward W49N:A2, a hypercompact HII region ionized by an O9 star. The data obtained with ALMA at a resolution of ~0"05 (600 au) confirmed the presence of an ionized ring with a radius…

Solar and Stellar Astrophysics · Physics 2023-01-04 Ryosuke Miyawaki , Masahiko Hayashi , Tetsuo Hasegawa

Aims.Molecular masers, including methanol and hydroxyl masers, and in particular the ones in excited rotational states (ex-OHmasers), are one of the most informative tools for studying star-forming regions. So, the discovery, of new maser…

Astrophysics of Galaxies · Physics 2021-08-04 O. Patoka , O. Antyufeyev , I. Shmeld , V. Bezrukovs , M. Bleiders , A. Orbidans , A. Aberfelds , V. Shulga

We report VLA HI Zeeman observations toward the W49A star-forming region and the SNR W49B. Line of sight magnetic fields (Blos) of 60 to 300 muG at 25" resolution were detected toward W49A at velocities of ~4 and ~7 km/s. The Blos values…

Astrophysics · Physics 2009-10-31 C. L. Brogan , T. H. Troland

H$_2$O maser emission associated with the massive star formation region W49N were observed with the Space-VLBI mission RadioAstron. The procedure for processing of the maser spectral line data obtained in the RadioAstron observations is…

Astrophysics of Galaxies · Physics 2020-01-15 N. N. Shakhvorostova , A. M. Sobolev , J. M. Moran , A. V. Alakoz , H. Imai , V. Y. Avdeev

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

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
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