Details

Autor(en) / Beteiligte

• Goddi, C.
• Moscadelli, L.
• Sanna, A.
• Cesaroni, R.
• Minier, V.

Titel

Associations of H2O and CH3OH masers at milli-arcsec angular resolution in two high-mass YSOs

Ist Teil von

• Astronomy and astrophysics (Berlin), 2007-01, Vol.461 (3), p.1027-1035

Ort / Verlag

Les Ulis: EDP Sciences

Erscheinungsjahr

2007

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Context.While high-angular resolution observations have clarified that water masers originate from shocks associated with protostellar jets, different environments have been proposed in several sources to explain the origin of CH3OH masers. Aims.We wish to investigate the nature of the CH3OH maser birthplace in SFRs and the association between the H2O and CH3OH maser emission in the same YSO. Methods.We have conducted phase-reference VLBI observations of H2O and CH3OH masers toward two high-mass SFRs, Sh 2-255 IR and AFGL 5142. Results.In Sh 2-255 IR water masers are aligned along a direction close to the orientation of the molecular outflow observed on angular scales of 1–10 arcsec, tracing possibly the disk-wind emerging from the disk atmosphere. In AFGL 5142 water masers trace expansion at the base of a protostellar jet, whilst methanol masers are more probably tracing infalling than outflowing gas. Conclusions.The results for AFGL 5142 suggest that water and methanol masers trace different kinematic structures in the circumstellar gas.