H2O masers in a jet-driven bow shock: episodic ejection from a massive young stellar object. Issue 1 (22nd April 2016)

• Record Type: Journal Article
• Authors: Burns, R. A.; Handa, T.; Nagayama, T.; Sunada, K.; Omodaka, T.
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 460:Issue 1(2016)
• Page Start: 283
• Page End: 290
• Publication Date: 2016-04-22
• Subjects: masers -- stars: individual: S255IR-SMA1 -- stars: massive -- ISM: jets and outflows; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stw958
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: We report the results of VERA (VLBI Exploration of Radio Astrometry) multi-epoch VLBI (very long baseline interferometry) 22 GHz water maser observations of S255IR-SMA1, a massive young stellar object located in the S255 star-forming region. By annual parallax the source distance was measured as D $= 1.78^{+0.12}_{-0.11}$ kpc and the source systemic motion was (μα cos δ, μδ ) = (−0.13 ± 0.20, −0.06 ± 0.27) mas yr −1 . Masers appear to trace a U-shaped bow shock whose morphology and proper motions are well reproduced by a jet-driven outflow model with a jet radius of about 6 au. The maser data, in the context of other works in the literature, reveal ejections from S255IR-SMA1 to be episodic, operating on time-scales of ∼1000 yr.