Related papers: The Rotating Molecular Structures and the Ionized …

W75N(B) is a massive star-forming region that contains three radio continuum sources (VLA 1, VLA 2, and VLA 3), which are thought to be three massive young stellar objects at three different evolutionary stages. VLA 1 is the most evolved…

Massive protostars generate strong radiation feedback, which may help set the mass they achieve by the end of the accretion process. Studying such feedback is therefore crucial for understanding the formation of massive stars. We report the…

We report the results of a wide field CO mapping in the region of IRAS 19312+1950. This IRAS object exhibits SiO/H$_2$O/OH maser emission, and is embedded in a chemically-rich molecular component, of which the origin is still unknown. In…

We present molecular line observations of the massive star forming region IRAS 17233-3606 aimed at studying the molecular core associated with the source. The observations were made using the Atacama Pathfinder Experiment telescope in the…

We present Submillimeter Array observations of the young stellar object IRAS 04579+4703 in the 1.3 mm continuum and in the 12CO(2-1), 13CO(2-1) and C18O(2-1) lines. The 1.3 mm continuum image reveals a flattened structure with a mass of 13…

We present ATCA observations of the H2O maser line and radio continuum at 18.0GHz and 22.8GHz, toward a sample of 192 massive star forming regions containing several clumps already imaged at 1.2mm. The main aim of this study is to…

We present continuum and molecular line (CO, C$^{18}$O, HCO$^+$) observations carried out with the Atacama Large Millimeter/submillimeter Array toward the "water fountain" star IRAS 15103-5754, an object that could be the youngest PN known.…

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)…

We have discovered 12 new molecular hydrogen emission-line objects (MHOs) in the vicinity of the candidate massive young stellar object Mol 121, in addition to five that were previously known. H2 2.12-micron/H2 2.25-micron flux ratios…

We report the first results of an ongoing survey at 22 GHz with the 100-m Effelsberg telescope to search for water maser emission in bright IRAS sources. We have detected water vapor emission in IC 342. The maser, associated with a star…

Aims: We searched for the molecular outflows from fifteen molecular clouds associated with ultra-compact and compact HII (UCHII/HII) regions and discussed possible gas heating mechanism. Methods: Mapping observations of CO $J=3-2$ and…

We present ALMA band 6/7 (1.3 mm/0.87 mm) and VLA Ka band (9 mm) observations toward NGC 2071 IR, an intermediate-mass star forming region. We characterize the continuum and associated molecular line emission towards the most luminous…

We have observed the Class 0 protostellar source IRAS 16293-2422 A in the C17O and H2CS lines as well as the 1.3 mm dust continuum with the Atacama Large Millimeter/submillimeter Array at an angular resolution of ~0."1 (14 au). The…

We study the molecular and the ionized gas in a possible precursor of an UC HII region to contribute to the understanding of how high-mass stars build-up their masses once they have reached the zero-age main secuence. We carried out…

We report observations of 6cm, 3.6cm, 1.3cm, and 7mm radio continuum, conducted with the Very Large Array towards IRAS18566+0408, one of the few sources known to harbor H2CO 6cm maser emission. Our observations reveal that the emission is…

An Australia Telescope Compact Array search for 22 GHz water masers towards 6.7 GHz class II methanol masers detected in the Methanol Multibeam (MMB) survey has resulted in the detection of extremely high velocity emission from one of the…

Massive stars form in dense and massive molecular cores. The exact formation mechanism is unclear, but it is possible that some massive stars are formed by processes similar to those that produce the low-mass stars, with accretion/ejection…

Methanol masers at 6.7~GHz are well-known signposts of high-mass star-forming regions. [...] We aim to understand the origin of the ring-like structures outlined by methanol maser emission in a number of sources. This emission could be, a…

We examine an Infrared Dark Cloud (IRDC) at high spatial resolution as a means to study rotation, outflow, and infall at the onset of massive star formation. Submillimeter Array observations combined with IRAM 30 meter data in 12CO(2--1)…

Using the Very Long Baseline Array and the European VLBI Network, we have observed 22.2 GHz H_2O and 1612 MHz OH masers in the "water fountain" source IRAS 18460-0151. The H_2O maser spectrum has a very wide line-of-sight velocity range…