Related papers: Oxygen-rich disk in the V778 Cyg system resolved

Luminous water maser emission in the 6_(16)-5_(23) line at 22 GHz has been detected from two dozen galaxies. In all cases the emission is confined to the nucleus and has been found only in AGN, in particular, in Type 2 Seyferts and LINERs.…

Using the Green Bank Telescope, we conducted a ``snapshot'' survey for water maser emission toward the nuclei of 611 galaxies and detected eight new sources. The sample consisted of nearby (v < 5000 km/s) and luminous (M_B < -19.5)…

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…

We used the Very Long Baseline Array (VLBA) and the European VLBI Network (EVN) to perform phase-referenced VLBI observations of the three most powerful maser transitions associated with the high-mass star-forming region G28.87+0.07: the…

Between 1987 and 2023 we carried out single-dish monitoring campaigns of water-maser emission at 22 GHz in the circumstellar envelopes (CSEs) of four stars: RCas, oCet, RLeo and ChiCyg. The variability in integrated flux in RCas and oCet…

Circumstellar environments of oxygen-rich stars are among the strongest SiO maser emitters. Physical processes such as collisions, infrared pumping and overlaps favors the inversion of level population and produce maser emission at…

We present High Sensitivity Array observation of the water megamasers of NGC 1068. We obtain absolute astrometry with 0.3 mas precision that confirms the association of the disk masers with the nuclear radio continuum source S1. The new…

OH 231.8+4.2 is a well studied preplanetary nebula (pPN) around a binary stellar system that shows a remarkable bipolar outflow. To study the structure and kinematics of the inner 10-80 AU nebular regions we performed high-resolution…

We present the first VLBI maps of H2O maser emission (lambda 1.3cm) in the nucleus of the Circinus Galaxy, constructed from data obtained with the Australia Telescope Long Baseline Array. The maser emission traces a warped, edge-on…

We have conducted multi-epoch EVN observations of the 22.2 GHz water masers towards four high-mass star forming regions (Sh 2-255 IR, IRAS 23139+5939, WB89-234, and OMC2). The (three) observing epochs span a time range of 6 months. In each…

MERLIN measurements of 1.6-GHz OH masers associated with Orion-BN/KL are presented, and the data are compared with data on other masers, molecular lines, compact radio continuum sources and infrared sources in the region. OH masers are…

The results of high-resolution spectral-line observations of dense molecular gas are presented towards the nuclear region of the type 2 Seyfert galaxy NGC1068. MERLIN observations of the 22 GHz H2O maser were made for imaging the known…

We present five epochs of VLBI water maser observations around the massive protostar Cepheus A HW2 with 0.4 mas (0.3 AU) resolution. The main goal of these observations was to follow the evolution of the remarkable water maser…

We have observed 150 regions of massive star formation, selected originally by the presence of a water maser, in the J = 5-4, 3-2, and 2-1 transitions of CS, and 49 regions in the same transitions of C$^{34}$S. Over 90% of the 150 regions…

Water vapor maser emission in the 6_{16}-5_{23} transition towards the narrow-line Seyfert 1 (NLS1) galaxy NGC 4051 has been discovered during an ongoing single-dish extragalactic water maser survey. The Doppler-shifted maser components…

We have conducted VLBI observations of water maser and radio continuum emission in the nucleus of NGC 3079. The 22 GHz maser emission arises in compact clumps, distributed along an axis that is aligned with the major axis of the galactic…

Carbon is an essential element for life but how much can be delivered to young planets is still an open question. The chemical characterization of planet-forming disks is a crucial step in our understanding of the diversity and habitability…

Context. We report the results from the determination of stellar masses, carbon and oxygen abundances in the atmospheres of 107 stars from the CHEPS program. Our stars are drawn from a population with a significantly super-solar…

Abridged. The LINER galaxy TXS2226-184 is known to host a very luminous 22 GHz water maser, called a gigamaser at the time of its discovery. To date, the nature of this maser is still being debated, in particular, whether it is associated…

We present a study of the structure and dynamics of the star forming region B1-IRS (IRAS 03301+3057) using the properties of different molecules at high angular resolution (~4''). We have used VLA observations of NH3, CCS, and H2O masers at…