FIRST RESULTS FROM A 1.3 cm EXPANDED VERY LARGE ARRAY SURVEY OF MASSIVE PROTOSTELLAR OBJECTS: G35.03+0.35

Journal Article · Tue Sep 20 04:00:00 EDT 2011 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/739/1/L16· OSTI ID:21565449

Brogan, C L; Hunter, T R; Friesen, R K; Indebetouw, R ^[1]; Cyganowski, C J ^[2]

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1. NRAO, 520 Edgemont Road, Charlottesville, VA 22903 (United States)
2. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

We have performed a 1.3 cm survey of 24 massive young stellar objects (MYSOs) using the Expanded Very Large Array. The sources in the sample exhibit a broad range of massive star formation signposts including infrared dark clouds (IRDCs), ultra-compact H II (UC H II) regions, and extended 4.5 {mu}m emission in the form of extended green objects (EGOs). In this work, we present results for G35.03+0.35 which exhibits all of these phenomena. We simultaneously image the 1.3 cm NH{sub 3} (1,1) through (6,6) inversion lines, four CH{sub 3}OH transitions, two H recombination lines, plus continuum at 0.05 pc resolution. We find three areas of thermal NH{sub 3} emission, two within the EGO (designated as the NE and SW cores) and one toward an adjacent IRDC. The NE core contains a UC H II region (CM1) and a candidate hyper-compact H II region (CM2). A region of non-thermal, likely masing NH{sub 3} (3,3) and (6,6) emission is coincident with an arc of 44 GHz CH{sub 3}OH masers. We also detect two new 25 GHz Class-I CH{sub 3}OH masers. A complementary Submillimeter Array 1.3 mm continuum image shows that the distribution of dust emission is similar to the lower-lying NH{sub 3} lines, all peaking to the NW of CM2, indicating the likely presence of an additional MYSO in this protocluster. By modeling the NH{sub 3} and 1.3 mm continuum data, we obtain gas temperatures of 20-220 K and masses of 20-130 M{sub sun}. The diversity of continuum emission properties and gas temperatures suggests that objects in a range of evolutionary states exist concurrently in this protocluster.

• OSTI ID: 21565449
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 739; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ALCOHOLS
AMMONIA
AMPLIFIERS
DISTRIBUTION
DUSTS
ELECTRONIC EQUIPMENT
EMISSION
EQUIPMENT
EVOLUTION
HYDRIDES
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
IMAGES
MASERS
METHANOL
MICROWAVE AMPLIFIERS
MICROWAVE EQUIPMENT
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
ORGANIC COMPOUNDS
STAR EVOLUTION
STARS