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We investigate the kinematics of high mass protostellar objects within the high mass star forming region IRAS 19410+2336. We performed high angular resolution observations of 6.7-GHz methanol and 22 GHz water masers using the MERLIN…

Astrophysics of Galaxies · Physics 2021-05-25 M. S. Darwish , K. A. Edris , A. M. S. Richards , S. Etoka , M. S. Saad , M. M. Beheary , G. A Fuller

We present the results of studies of a new class of 6.7 GHz methanol maser sources with a ring-like emission structure discovered recently with the EVN. We have used the VLA to search for water masers at 22 GHz and radio continuum at 8.4…

Astrophysics of Galaxies · Physics 2015-03-18 A. Bartkiewicz , M. Szymczak , H. J. van Langevelde , J. M. De Buizer , Y. Pihlström

The Korean very-long-baseline interferometry (VLBI) network (KVN) and VLBI Exploration of Radio Astrometry (VERA) Array (KaVA) is the first international VLBI array dedicated to high-frequency (23 and 43 GHz bands) observations in East…

The role of magnetic fields in the formation of high-mass stars is still under debate, and recent measurements of their orientation and strength by using polarized maser emissions are contributing new insights. Masers polarization, in…

Solar and Stellar Astrophysics · Physics 2015-06-04 G. Surcis , W. H. T. Vlemmings , H. J. van Langevelde , B. Hutawarakorn Kramer

22 GHz water and 6.7 GHz methanol masers are usually thought as signposts of early stages of high-mass star formation but little is known about their associations and the physical environments they occur in. The aim was to obtain accurate…

Astrophysics of Galaxies · Physics 2015-05-19 A. Bartkiewicz , M. Szymczak , Y. M. Pihlström , H. J. van Langevelde , A. Brunthaler , M. J. Reid

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 conducted Very Long Baseline Array (VLBA) observations of seven nearby narrow-line Seyfert 1 (NLS1) galaxies at 1.7 GHz (18cm) with milli-arcsecond resolution. This is the first systematic very long baseline interferometry (VLBI) study…

Astrophysics of Galaxies · Physics 2015-06-12 Akihiro Doi , Keiichi Asada , Kenta Fujisawa , Hiroshi Nagai , Yoshiaki Hagiwara , Kiyoaki Wajima , Makoto Inoue

The Australia Telescope Compact Array (ATCA) participated in a number of survey programs to search for and image common class I methanol masers (at 36 and 44 GHz) with high angular resolution. In this paper, we discuss spatial and velocity…

Astrophysics of Galaxies · Physics 2018-08-22 M. A. Voronkov , S. L. Breen , S. P. Ellingsen , C. H. Jordan

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…

Solar and Stellar Astrophysics · Physics 2016-12-07 Bridget McEwen , Loránt Sjouwerman , Ylva Pihlström

We report on the detection of 44 GHz Class I methanol (CH3OH) maser emission in the SgrA complex with the Expanded Very Large Array (EVLA). These EVLA observations show that the SgrA complex harbors at least four different tracers of…

Astrophysics of Galaxies · Physics 2015-05-28 Y. M. Pihlström , L. O. Sjouwerman , V. L. Fish

The class II methanol maser source G9.62+0.20E undergoes periodic flares at both 6.7 and 12.2 GHz. The flare starting in 2001 October was observed at seven epochs over three months using the VLBA at 12.2 GHz. High angular resolution images…

Astrophysics · Physics 2009-11-10 S. Goedhart , V. Minier , M. J. Gaylard , D. J. van der Walt

The first images of 6.7-GHz methanol masers in the massive star-forming regions DR21(OH) and DR21(OH)N are presented. By measuring the shapes, radial velocities and polarization properties of these masers it is possible to map out the…

Astrophysics · Physics 2009-11-13 L. Harvey-Smith , R. Soria-Ruiz , A. Duarte-Cabral , R. J. Cohen

Class I methanol masers are collisionally pumped and are generally correlated with outflows in star forming sites in the Galaxy. Using the VLA in its A-array configuration, we present a spectral line survey to identify methanol…

Astrophysics of Galaxies · Physics 2016-12-14 W. Cotton , F. Yusef-Zadeh

High-mass protostars are deeply embedded in dust inside their natal cores and are not easily detectable. However, maser emission at centimeter wavelengths, owing to its high brightness, enables us to study gas kinematics in protostars'…

We present a review of the properties of Class I methanol masers detected in low-mass star forming regions (LMSFRs). These masers, henceforth called LMMIs, are associated with postshock gas in the lobes of chemically active outflows in…

Astrophysics of Galaxies · Physics 2018-08-22 S. Kalenskii , S. Kurtz , P. Hofner , P. Bergman , C. M. Walmsley , P. Golysheva

We report the first sub-arcsecond VLA imaging of 6 GHz continuum, methanol maser, and excited-state hydroxyl maser emission toward the massive protostellar cluster NGC6334I following the recent 2015 outburst in (sub)millimeter continuum…

We present continent-scale VLBI - obtained with the European VLBI Network (EVN) at a wavelength of 18cm - of six distant, luminous submm-selected galaxies (SMGs). Our images have a synthesized beam width of ~30 milliarcsec FWHM - three…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 A. D. Biggs , J. D. Younger , R. J. Ivison

We have used the Australia Telescope Compact Array (ATCA) to make the first high resolution observations of a large sample of class~I methanol masers in the 95-GHz ($8_0$--$7_1$A$^+$) transition. The target sources consist of a…

Astrophysics of Galaxies · Physics 2018-03-28 Tiege P. McCarthy , Simon P. Ellingsen , Maxim A. Voronkov , Giuseppe Cimo

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.…

Astrophysics of Galaxies · Physics 2015-06-18 Y. M. Pihlström , L. O. Sjouwerman , D. A. Frail , M. J. Claussen , R. A. Mesler , B. C. McEwen

Milliarcsecond VLBI maps of regions containing 6.7 GHz methanol maser emission have lead to the recent discovery of ring-like distributions of maser spots and the plausible hypothesis that they may be tracing circumstellar disks around…

Solar and Stellar Astrophysics · Physics 2015-06-05 James M. De Buizer , Anna Bartkiewicz , Marian Szymczak