2004ApJ...602..850S -
Astrophys. J., 602, 850-859 (2004/February-3)
Discovery of a massive protostar near IRAS 18507+0121.
SHEPHERD D.S., NURNBERGER D.E.A. and BRONFMAN L.
Abstract (from CDS):
We have observed the massive star-forming region IRAS 18507+0121 at millimeter wavelengths in 3 mm continuum emission, H13CO+ (J=1-0) and SiO (v=0, J=2-1) line emission, and at near-infrared (NIR) wavelengths between 1.2 and 2.1 µm. Two compact molecular cores are detected: one north and one south, separated by ∼40". The northern molecular core contains a newly discovered, deeply embedded, B2 protostar surrounded by several hundred solar masses of warm gas and dust, G34.4+0.23 MM. Based on the presence of warm dust emission and the lack of detection at NIR wavelengths, we suggest that G34.4+0.23 MM may represent the relatively rare discovery of a massive protostar (e.g., analogous to a low-mass ``Class 0'' protostar). The southern molecular core is associated with an NIR cluster of young stars and an ultracompact H II region, G34.4+0.23, with a central B0.5 star. The fraction of NIR stars with excess infrared emission indicative of circumstellar material is greater than 50%, which suggests an upper limit on the age of the IRAS 18507+0121 star-forming region of 3 Myr.
Abstract Copyright:
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Journal keyword(s):
ISM: H II Regions - ISM: Molecules - Stars: Formation - Stars: Pre-Main-Sequence
VizieR on-line data:
<Available at CDS (J/ApJ/602/850): table1.dat>
Nomenclature:
Table 1: [SNB2004] NNN (Nos 1-146).
Simbad objects:
158
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