相关论文: Water masers in the massive protostar IRAS 20126+4…

IRAS 20126+4104 is one of the best candidates for a high-mass (proto)star surrounded by an accretion disk. Such a fact may be used to set constraints on theories of high-mass star formation, but requires confirmation that the mass and…

We imaged the protostars of the nearby region NGC1333 IRAS 4 in the water maser line at 22.2 GHz by using the VLBA in phase referencing at milliarcsecond scale over four epochs spaced by one month to measure proper motions. We measure the…

Based on the long-term monitoring data of the water maser since 2019.0 to 2021.0 allowed us detecting in IRAS 16293-2422 two powerful phenomena lasted about year at radial velocities near 6 and 8 km s$^{-1}$. In both cases, powerful short…

Multi-epoch VLBI observations measure 3D water maser motions in protostellar outflows, enabling analysis of inclination and velocity. However, these analyses assume that water masers and shock surfaces within outflows are co-propagating. We…

We conducted a 4 epoch 3 month VLBA proper motion study of H$_2$O masers toward an intermediate-mass class 0 source IRAS 20050+2720 MMS1 (d=700 pc). From milli-arcsecond (mas) resolution VLBA images, we found two groups of H2O maser spots…

We have performed observations of water maser emission towards a sample of low-mass protostars, in order to investigate the properties of jets associated with the earliest stages of star formation and their interaction with the surrounding…

We have mapped the water maser emission associated with the infrared centers IRS1 and IRS3 of the NGC 2071IR star forming region at four epochs over ~4 months with the Very Long Baseline Array (VLBA). We detected 269 maser features with ~1…

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…

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…

We present MERLIN observations of OH, water and methanol masers towards the young high mass stellar object IRAS 20126+4104. Emission from the 1665-MHz OH, 22-GHz H_2O and 6.7-GHz CH_3OH masers is detected and all originates very close to…

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…

We report the results of multi-epoch VLBA observations of the 22.2GHz water maser emission associated with the "water fountain" IRAS 18286-0959. We suggest that this object is the second example of a highly collimated bipolar precessing…

VLBI multi-epoch water maser observations are a powerful tool to study the dense, warm shocked gas very close to massive protostars. The very high-angular resolution of these observations allow us to measure the proper motions of the masers…

Aims: We report the discovery and analysis of a periodic methanol maser in the massive protostar IRAS 20216+4104. Methods: To obtain the light curve, we used the 6.7 GHz methanol maser spectra collected between 2000-2003 and 2009-2023 with…

Understanding the launching mechanism of winds and jets remains one of the fundamental challenges in astrophysics. The Protostellar Outflows at the EarliesT Stages (POETS) survey has recently mapped the 3D velocity field of the protostellar…

From measuring the annual parallax of water masers over one and a half years with VERA, we present the trigonometric parallax and corresponding distance of another newly identified water maser source in the region of IRAS 20231+3440 as…

This article focuses on NGC7538 IRS1, one of the most luminous and studied HC HII regions in the northern hemisphere. Our aim is to identify the young stellar objects (YSOs) embedded within the ionized gas and study their kinematic…

Ejection activities in S255IR-SMA1 and AFGL 5142 were investigated by multi-epoch VLBI observations of 22 GHz water masers, tracing bowshocks leading collimated jets. The history of ejections, revealed by the 3D maser motions and…

Water masers have been observed in several high redshift active galactic nuclei, including the gravitationally lensed quasar MG 0414+0534. This quasar is lensed into four images, and the water maser is detected in two of them. The…

We present VLBI observations of the H$_2$O maser emission towards a selection of massive young stellar objects (YSOs). In one of these sources, IRAS20126+4104, the measured proper motions confirm that the water masers spots are tracing the…