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Related papers: Magnetic field in Cepheus A as deduced from OH mas…

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We present linear and circular polarization observations of the water masers in 4 distinct regions spread over 1x2 arcseconds around the HW2 high-mass young stellar object in the Cepheus A star-forming region. We find magnetic fields…

Astrophysics · Physics 2009-11-11 W. H. T. Vlemmings , P. J. Diamond , H. J. van Langevelde , J. M Torrelles

The southern maser site OH 300.969+1.147 has been studied using the Long Baseline Array of the Australia Telescope National Facility. The 1665- and 1667-MHz hydroxyl ground-state transitions were observed simultaneously. A series of maps…

Astrophysics of Galaxies · Physics 2015-05-13 J. L. Caswell , B. Hutawarakorn Kramer , J. E. Reynolds

We have identified and classified Zeeman pairs in the survey by Argon, Reid, & Menten of massive star-forming regions with 18 cm (2 Pi 3/2, J = 3/2) OH maser emission. We have found a total of more than 100 Zeeman pairs in more than 50…

Astrophysics · Physics 2009-11-10 Vincent L. Fish , Mark J. Reid , Alice L. Argon , Karl M. Menten

We present high angular resolution observations of OH maser emission towards the high-mass star forming region IRAS 06056+2131. The observations were carried out using the UK radio interferometer array, Multi-Element Radio Linked…

Solar and Stellar Astrophysics · Physics 2021-01-19 Mohamed Said darwish , Anita M. S. Richards , Sandra Etoka , Khaled Edris , Somaya Saad , Mohamed Beheary , Gary Fullar

We present the first maps of 4765-MHz OH masers in two star-forming regions Cepheus A and W75N, made with Multi-Element Radio Linked Interferometer Network. In Cep A the emission has an arc-like structure of size 40 mas with a clear…

Astrophysics · Physics 2009-09-29 A. Niezurawska , M. Szymczak , R. J. Cohen , A. M. S. Richards

We present VLBA observations of 1667 MHz OH maser emission from the massive star formation region G5.89-0.39. The observations were phase referenced allowing the absolute positions of the masers to be obtained. The 1667 MHz masers have…

Astrophysics · Physics 2008-11-26 D. P. Stark , W. M. Goss , E. Churchwell , V. L. Fish , I. M. Hoffman

From targeted observations of ground-state OH masers towards 702 Multibeam (MMB) survey 6.7-GHz methanol masers, between Galactic longitudes 186$^{\circ}$ through the Galactic centre to 20$^{\circ}$, made as part of the `MAGMO' project, we…

Astrophysics of Galaxies · Physics 2020-01-29 C. S. Ogbodo , J. A. Green , J. R. Dawson , S. L. Breen , S. A. Mao , N. M. McClure-Griffiths , T. Robishaw , L. Harvey-Smith , .

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

We present polarization observations of the 6.7-GHz methanol masers around the massive protostar Cepheus A HW2 and its associated disc. The data were taken with the Multi-Element Radio Linked Interferometer Network. The maser polarization…

Astrophysics of Galaxies · Physics 2015-05-18 W. H. T. Vlemmings , G. Surcis , K. J. E. Torstensson , H. J. van Langevelde

Context. Maser emission is a strong tool for studying high mass star forming regions and their evolutionary stages. OH masers in particular can trace the circumstellar material around protostars and determine their magnetic field strengths…

Astrophysics of Galaxies · Physics 2017-12-13 K. A. Edris , G. A. Fuller , S. Etoka , R. J. Cohen

We have observed six high-mass star-forming regions in the 2 Pi 3/2, J = 7/2 lines of OH using the GBT in order to investigate whether the magnetic field, and hence the density, measured in absorption differs from that implied by maser…

Astrophysics · Physics 2009-11-10 Vincent L. Fish , Mark J. Reid , Karl M. Menten

We aim to detect the magnetic field and infer its properties around four AGB stars using H$_2$O maser observations. The sample we observed consists of the following sources: the semi-regular variable RT Vir and the Mira variables AP Lyn, IK…

Solar and Stellar Astrophysics · Physics 2015-06-15 M. L. Leal-Ferreira , W. H. T. Vlemmings , A. Kemball , N. Amiri

OH 1612 and 1667 MHz masers from the well known object OH127.8+0.0 were mon- itored in full-polarization mode over a period of 6.5 years and mapped with MERLIN at one epoch. The OH variability pattern of the star is typical of extremely…

Astrophysics of Galaxies · Physics 2013-02-11 P. Wolak , M. Szymczak , E. Gerard

Full-polarization MERLIN and VLBA observations of the 1720-MHz maser emission from the OH molecule in the supernova remnant W44 are presented. Zeeman splitting has been directly resolved between right- and left-circularly polarized spectra…

Astrophysics · Physics 2009-11-10 Ian M. Hoffman , W. M. Goss , C. L. Brogan , M. J. Claussen

The massive star-forming region G11.904-0.141 is one of only 11 sources to show maser emission in the highly-excited 13441 MHz transition of OH. VLBA observations of the 1665, 1667, 4765, and 13441 MHz transitions of OH toward G11.904-0.141…

Astrophysics · Physics 2009-11-13 Vincent L. Fish

In an attempt to probe the magnetic field morphology near the massive young star Orion-IRc2, we mapped the linear polarization of its J=2-1 SiO masers, in both the v=0 and v=1 vibrational levels, with 0.5 arcsec resolution. The intense v=1…

Astrophysics · Physics 2009-11-10 R. L. Plambeck , M. C. H. Wright , R. Rao

Full-polarization MERLIN and VLBA observations of the 1720 MHz maser emission from the OH molecule in the supernova remnant W28 are presented. Zeeman splitting (|B| \approx 0.75 mG) has been directly resolved between right- and…

Astrophysics · Physics 2009-11-10 Ian M. Hoffman , W. M. Goss , C. L. Brogan , M. J. Claussen

The 1612 and 1667 MHz OH maser lines have been measured in all four Stokes parameters in 47 proto-planetary nebula (PPN) candidates. Out of 42 objects detected, 40 and 34 are 1612 and 1667 MHz emitters, respectively. The spectral extent of…

Astrophysics · Physics 2009-11-10 M. Szymczak , E. Gerard

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

MERLIN observations of 6.668-GHz methanol and both 6.031- and 6.035-GHz hydroxyl (OH) emission from the massive star-formation region ON1 are presented. These are the first methanol observations made in full polarization using 5 antennas of…

Astrophysics · Physics 2009-11-13 J. A. Green , A. M. S. Richards , W. H. T. Vlemmings , P. Diamond , R. J. Cohen
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