A distance-limited sample of massive star-forming cores from the RMS survey

作者：Maud L T^*; Lumsden S L; Moore T J T; Mottram J C; Urquhart J S; Cicchini A

来源：Monthly Notices of the Royal Astronomical Society, 2015, 452(1): 637-655.

DOI：10.1093/mnras/stv1334

• stars: abundances
• stars: formation
• stars: massive
• stars: protostars

We analyse (CO)-O-18 (J = 3-2) data from a sample of 99 infrared (IR)-bright massive young stellar objects (MYSOs) and compact H II regions that were identified as potential molecular-outflow sources in the Red MSX Source survey. We extract a distance-limited (D < 6 kpc) sample shown to be representative of star formation covering the transition between the source types. At the spatial resolution probed, Larson-like relationships are found for these cores, though the alternative explanation, that Larson's relations arise where surface-density-limited samples are considered, is also consistent with our data. There are no significant differences found between source properties for the MYSOs and H II regions, suggesting that the core properties are established prior to the formation of massive stars, which subsequently have little impact at the later evolutionary stages investigated. There is a strong correlation between dust-continuum and (CO)-O-18-gas masses, supporting the interpretation that both trace the same material in these IR-bright sources. A clear linear relationship is seen between the independently established core masses and luminosities. The position of MYSOs and compact H II regions in the mass-luminosity plane is consistent with the luminosity expected from a cluster of protostars when using an similar to 40 per cent star formation efficiency and indicates that they are at a similar evolutionary stage, near the end of the accretion phase.

• 出版日期2015-9-1