Related papers: Radio Continuum and Methanol Observations of DR21(…
The 6.7 GHz maser transition of methanol has been found exclusively towards massive star forming regions. A majority of the masers have been found to lack the presence of any associated radio continuum. This could be due to the maser…
We present a survey of the polarization properties of mm-wavelength methanol masers, comprising both classes, and transitions from 84.5 to 157.0 GHz. Linear polarization is found in more than half of the observed objects, and circular…
Results of observations of the maser sources toward the W33C region (G12.8-0.2) carried out on the 22-m radio telescope of the Pushchino Radio Astronomy Observatory in the 1.35-cm H2O line and on the Large radio telescope in Nancay (France)…
Methanol masers at 6.7 GHz are well known tracers of high-mass star-forming regions. However, their origin is still not clearly understood. We aimed to determine the morphology and velocity structure for a large sample of the maser emission…
The European VLBI Network (EVN) has been used to make phase referenced, wide-field (several arcminute) spectral line observations of the 6.7-GHz methanol maser emission towards W51. In the W51main region, the bulk of the methanol is offset…
We have selected the positions of 54 6.7GHz methanol masers from the Methanol Multibeam Survey catalogue, covering a range of longitudes between $20^{\circ}$ and $34^{\circ}$ of the Galactic Plane. These positions were mapped in the J=3-2…
The Australia Telescope Compact Array (ATCA) has been used to image class I methanol masers at 9.9, 25 (a series from J=2 to J=9), 84, 95 and 104 GHz located in the vicinity of IRAS 16547-4247 (G343.12-0.06), a luminous young stellar object…
We report the first detection of the ground-state rotational transition of the methylidyne cation CH+ towards the massive star-forming region DR21 with the HIFI instrument onboard the Herschel satellite. The line profile exhibits a broad…
We present an astrometry study of the radio source VLA 1 at the core of the HH 111 outflow using new data (2007) as well as archival observations (1992-1996). All data were taken at 3.6 cm with the Very Large Array in its most extended (A)…
We present upgraded Giant Metrewave Radio Telescope (uGMRT) observations of 0731+438, an \mbox{FR II} radio galaxy at a redshift of 2.429 with two lobes separated by 82 kpc. A blueshifted, faint and broad \mbox{H{\sc i}} 21 cm absorption…
The Australia Telescope Compact Array (ATCA) has been used for high angular resolution imaging of 71 southern class I methanol maser sources quasi-simultaneously at 36 and 44 GHz. The data reveal a high level of morphological and…
We present the results of the observations of the (J,K)=(1,1) and the (J,K)=(2,2) inversion transitions of the NH3 molecule toward a large sample of 40 regions with molecular or optical outflows, using the 37 m radio telescope of the…
At centimeter wavelengths, single-dish observations have suggested that the Sagittarius (Sgr) B2 molecular cloud at the Galactic Center hosts weak maser emission from several organic molecules, including CH$_2$NH, HNCNH, and HCOOCH$_3$.…
We present sensitive, high angular resolution ($0\rlap.{''}05$) VLA continuum observations made at 7 mm of the core of the HH 111/121 quadrupolar outflow. We estimate that at this wavelength the continuum emission is dominated by dust,…
We present high angular resolution (FWHM_beam < 0.2") observations of the 23.1-GHz methanol (CH_3OH) transition toward the massive-star forming region NGC 7538 IRS 1. The two velocity components previously reported by Wilson et al. are…
Intriguing work on observations of 4.83 GHz formaldehyde (H2CO) absorptions and 4.87 GHz H110a radio recombination lines (RRLs) towards 6.7 GHz methanol (CH3OH) maser sources is presented. Methanol masers provide ideal sites to probe the…
We made a detailed observational analysis of a well known hot molecular core lying in the high-mass star-forming region G31.41+0.31. This core is believed to contain deeply embedded massive stars and presents a velocity gradient that has…
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…
Context. Class II methanol masers at 6.7 and 12.2 GHz occur close to high-mass young stellar objects (HMYSOs). When they are observed simultaneously, such studies may contribute to refining the characterisation of local physical conditions.…
In the early days of methanol maser discoveries the 9(2)-10(1) A+ transition at 23.1 GHz was found to exhibit maser characteristics in the northern star-forming region W3(OH), and probable maser emission in two other sources. Attention…