Details

Autor(en) / Beteiligte

• Patel, A L
• Urquhart, J S
• Yang, A Y
• Moore, T J T
• Menten, K M
• Thompson, M A
• Hoare, M G
• Irabor, T
• Breen, S L
• Smith, M D

Titel

SCOTCH − search for clandestine optically thick compact H iis

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2023-09, Vol.524 (3), p.4384-4402

Ort / Verlag

Oxford University Press

Erscheinungsjahr

2023

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• ABSTRACT This study uses archival high-frequency continuum data to expand the search for Hypercompact H ii regions and determine the conditions at which they appear, as this stage high mass star formation is short-lived and rare. We use 23 GHz continuum data taken towards methanol masers, which are an excellent signpost for very young embedded high-mass protostars. We have searched for high-frequency, optically thick radio sources to identify HC H ii region candidates. The data cover 128 fields that include 141 methanol masers identified by the Methanol Multibeam (MMB) survey. We have detected 68 high-frequency radio sources and conducted a multiwavelength analysis to determine their nature. This has identified 49 H ii regions, 47 of which are embedded in dense clumps fourteen of which do not have a 5 GHz radio counterpart. We have identified 13 methanol maser sites that are coincident with radio sources that have a steep positive spectral index. The majority of these are not detected in the mid-infrared and have been classified as protostellar or young stellar objects in the literature and we therefore consider to be good HC H ii region candidates, however, further work and higher resolution data are needed to confirm these candidates.