Investigating the temporal domain of massive ionized jets – I. A pilot study. Issue 1 (5th December 2017)

• Record Type: Journal Article
• Authors: Purser, S J D; Lumsden, S L; Hoare, M G; Cunningham, N
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 475:Issue 1(2018)
• Page Start: 2
• Page End: 19
• Publication Date: 2017-12-05
• Subjects: stars: formation -- stars: jets -- stars: massive -- stars: protostars -- radio continuum: general; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stx3131
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: We present sensitive (σ < 10 μJy beam − 1 ), radio continuum observations using the Australian Telescope Compact Array at frequencies of 6 and 9 GHz towards four massive young stellar objects (MYSOs). From a previous, less sensitive work, these objects are known to harbour ionized jets associated with radio lobes, which result from shock processes. In comparison with that work, further emission components are detected towards each MYSO. These include extended, direct, thermal emission from the ionized jet's stream, new radio lobes indicative of shocks close (<10 5 au) to the MYSO, three radio Herbig–Haro objects separated by up to 3.8 pc from the jet's launching site, and an IR-dark source coincident with CH3 OH maser emission. No significant, integrated flux variability is detected towards any jets or shocked lobes, and only one proper motion is observed ($1806\pm 596{\rm {\rm \, km}{\rm \, s}^{-1}{\, }}$ parallel to the jet axis of G310.1420+00.7583A). Evidence for precession is detected in all four MYSOs with precession periods and angles within the ranges 66–15 480 yr and 6°–36°, respectively. Should precession be the result of the influence from a binary companion, we infer orbital radii of 30–1800 au.