Related papers: A Multi-Epoch, Simultaneous Water and Methanol Mas…
Single-dish spectra and interferometric maps of (sub)mm lines of H2O-18 and HDO are used to study the chemistry of water in eight regions of high-mass star formation. The spectra indicate HDO excitation temperatures of ~110 K and column…
We have used the NASA Tidbinbilla 70-m antenna to search for emission from the 2(1)-3(0)E 19.9-GHz transition of methanol. The search was targeted towards 22 star formation regions which exhibit maser emission in the 107.0-GHz 3(1)-4(0)A+…
We report phase-referencing VLBA observations of H2O masers near the star-forming region W3(OH) to measure their parallax and absolute proper motions. The measured annual parallax is 0.489 +/- 0.017 milli-arcseconds (2.04 +/- 0.07 kpc),…
Spectra, taken with the heterodyne instrument, HIFI, aboard the Herschel Space Observatory, of O-rich asymptotic giant branch (AGB) stars which form part of the guaranteed time key program HIFISTARS are presented. The aim of this program is…
We analyzed the 3-mm wavelength spectral line survey of 408 ATLASGAL clumps observed with the IRAM 30m-telescope, focusing on the class I methanol masers with frequencies near 84, 95 and 104.3 GHz. We detect narrow, maser-like features…
We present high-resolution Karl G. Jansky Very Large Array observations of the 22 GHz $\mathrm{H_2O}$ maser line in the extended Sagittarius B2 cloud. We detect 499 $\mathrm{H_2O}$ masers across the observed velocities between -39 and 172…
We report the detection of water maser emission from four nearby galaxies hosting ultradense HII (UDHII) regions, He 2-10, the Antennae galaxies (NGC 4038/4039), NGC 4214, and NGC 5253, with the Green Bank Telescope. Our detection rate is…
We have used the Australia Telescope Compact Array to undertake the first high-resolution observations of the 19.9-GHz methanol maser transition. The emission is coincident with the location of the targeted 6.7-GHz methanol masers to within…
We report the result of an on-going survey for 22 GHz H2O maser emission towards infrared luminous galaxies. The observed galaxies were selected primarily from the IRAS bright galaxy sample. The survey has resulted in the detection of one…
We present results of a multi-epoch monitoring program on variability of 6$\,$cm formaldehyde (H$_2$CO) masers in the massive star forming region NGC$\,$7538$\,$IRS$\,$1 from 2008 to 2015 conducted with the GBT, WSRT, and VLA. We found that…
Recent studies have shown that 6.7 GHz methanol maser flares can be a powerful tool for verifying the mechanisms of maser production and even the specific signatures of accretion rate changes in the early stages of high-mass star formation.…
We present $\sim1-4"$ resolution Very Large Array (VLA) observations of four CH$_3$OH $J_2-J_1$-$E$ 25~GHz transitions ($J$=3, 5, 8, 10) along with 1.3~cm continuum toward 20 regions of active massive star formation containing Extended…
We have used the Australia Telescope National Facility Mopra 22-m antenna to search for 37.7-GHz (7(-2) - 8(-1}E) methanol masers towards a sample of thirty six class II methanol masers. The target sources are the most luminous class II…
Aims. We report the discovery of periodic maser variability of an unusual pattern in the high-mass young stellar object G26.598-0.024. Methods. A ten-year monitoring of the 6.7 GHz methanol maser was carried out with the Torun 32 m radio…
{The variability study of 6.7\,GHz methanol masers has become a useful way to improve our understanding of the physical conditions in high-mass star-forming regions.} {Based on the single-dish monitoring using the Irbene telescopes, we…
We derive accurate proper motions of the CH3OH 12 GHz masers towards the W3(OH) UCHII region, employing seven epochs of VLBA observations spanning a time interval of about 10 yr. The achieved velocity accuracy is of the order of 0.1 km/s,…
Recently, a relationship between the water maser detection rate and far infrared (FIR) flux densities has been established as a result of two 22 GHz maser surveys in a complete sample of galaxies (Dec>-30 degree) with 100 micron flux…
Context: High-mass young stellar objects (HMYSOs) can undergo accretion episodes that strongly affect the star evolution, the dynamics of the disk, and its chemical evolution. Recently reported extraordinary bursts in the methanol maser…
Our present understanding of high-mass star formation still remains very schematic. In particular, it is not yet clear how much of the difference between low-mass and high-mass star formation occurs during the earliest star formation…
Context: Maser emission from the H2O molecule probes the warm, inner circumstellar envelopes of oxygen-rich red giant and supergiant stars. Multi-maser transition studies can be used to put constraints on the density and temperature of the…