Water masers in the massive protostar IRAS 20126+4104: ejection and deceleration

Abstract

We report on the first multi-epoch, phase referenced VLBI observations of the water maser emission in a high-mass protostar associated with a disk-jet system. The source under study, IRAS 20126+4104, has been extensively investigated in a large variety of tracers, including water maser VLBA data acquired by us three years before the present observations. The new findings fully confirm the interpretation proposed in our previous study, namely that the maser spots are expanding from a common origin coincident with the protostar. We also demonstrate that the observed 3-D velocities of the maser spots can be fitted with a model assuming that the spots are moving along the surface of a conical jet, with speed increasing for increasing distance from the cone vertex. We also present the results of single-dish monitoring of the water maser spectra in IRAS 20126+4104. These reveal that the peak velocity of some maser lines decreases linearly with time. We speculate that such a deceleration could be due to braking of the shocks from which the maser emission originates, due to mass loading at the shock front or dissipation of the shock energy.

arXiv comment11 pages, 8 figures. Accepted for publication in A&A

References in corpus (4)

• VLBI astrometry of circumstellar OH masers; proper motions and parallaxes of four AGB stars
• The Masers Towards IRAS 20126+4104
• Long-term study of water masers associated with Young Stellar Objects. II: Analysis
• EVN observations of water masers towards the high-mass young stellar object in AFGL 5142

Cited by in corpus (34)

• A near IR imaging survey of intermediate and high-mass young stellar outflow candidates
• Methanol and water masers in IRAS 20126+4104: The distance, the disk, and the jet
• The diversity of methanol maser morphologies from VLBI observations
• A wide-angle outflow with the simultaneous presence of a high-velocity jet in the high-mass Cepheus A HW2 system
• The RMS Survey: H2O masers towards a sample of southern hemisphere massive YSO candidates and ultra compact HII regions
• A Hot and Massive Accretion Disk around the High-Mass Protostar IRAS 20126+4104
• Radio Continuum and Methanol Observations of DR21(OH)
• Associations of water and methanol masers at milli-arcsec angular resolution in two high-mass young stellar objects
• Tracing the base of protostellar wind(s) towards the high-mass star forming region AFGL 5142: VLA continuum and VLBA water maser observations
• European VLBI Network imaging of 6.7 GHz methanol masers
• A multi-transition molecular line study of inward motions towards massive star-forming cores
• Collapse of turbulent massive cores with ambipolar diffusion and hybrid radiative transfer II. Outflows
• The Complex Mid-Infrared Structure at the Heart of IRAS 20126+4104
• New signposts of massive star formation in the S235A-B region
• Submillimeter Array Observations of 321 GHz Water Maser Emission in Cepheus A
• Protostellar Outflows at the EarliesT Stages (POETS). III. H2O masers tracing disk-winds and jets near luminous YSOs
• A Highly collimated Water Maser Bipolar Outflow in the Cepheus A HW3d Massive Young Stellar Object
• Water maser variability in a high-mass YSO outburst -- VERA and ALMA observations of S255 NIRS 3
• A collimated jet and an infalling-rotating disk in G192.16-3.84 traced by H2O maser emission
• Testing the Evolutionary Sequence of High Mass Protostars with CARMA
• H${}_2$O maser emission from bright rimmed clouds in the northern hemisphere
• Protostellar Outflows at the EarliesT Stages (POETS). IV. Statistical properties of the 22 GHz H2O masers
• Probing the magnetic fields of massive star forming regions with methanol maser polarisation
• A search for radio jets from massive young stellar objects. Association of radio jets with H2O and CH3OH masers
• The magnetic field at milliarcsecond resolution around IRAS20126+4104
• The SOUL view of IRAS20126+4104. Kinematics and variability of the H${}_2$ jet from a massive protostar
• Unbiased water and methanol maser surveys of NGC 1333
• Multiple outflows in the high-mass cluster forming region, G25.82-0.17
• A Herschel study of the high-mass protostar IRAS20126+4104
• Proper motion study of the 6.7 GHz methanol maser rings. I. A sample of sources with little variation
• A kinematic study of the disc-outflow system around a high-mass protostar G59.783+0.065 probed by methanol and water masers
• Search for High-Mass Protostellar Objects in Cold IRAS Sources
• Characterising the high-mass star forming region IRAS 18144-1723 through methanol maser observations
• Evidence for a bloated massive protostar in IRAS20126+4104