A 95 GHz CLASS I METHANOL MASER SURVEY TOWARD GLIMPSE EXTENDED GREEN OBJECTS (EGOs)

Journal Article · Thu Sep 01 04:00:00 EDT 2011 · Astrophysical Journal, Supplement Series

DOI:https://doi.org/10.1088/0067-0049/196/1/9· OSTI ID:21560332

Xi, Chen; Zhiqiang, Shen; Conggui, Gan ^[1]; Ellingsen, Simon P; Titmarsh, Anita ^[2]

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1. Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030 (China)
2. School of Mathematics and Physics, University of Tasmania, Hobart, Tasmania (Australia)

We report the results of a systematic survey for 95 GHz class I methanol masers toward a new sample of 192 massive young stellar object candidates associated with ongoing outflows (known as extended green objects or EGOs) identified from the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) survey. The observations were made with the Australia Telescope National Facility (ATNF) Mopra 22 m radio telescope and resulted in the detection of 105 new 95 GHz class I methanol masers. For 92 of the sources our observations provide the first identification of a class I maser transition associated with these objects (i.e., they are new class I methanol maser sources). Our survey proves that there is indeed a high detection rate (55%) of class I methanol masers toward EGOs. Comparison of the GLIMPSE point sources associated with EGOs with and without class I methanol maser detections shows that they have similar mid-IR colors, with the majority meeting the color selection criteria -0.6 < [5.8]-[8.0] < 1.4 and 0.5 < [3.6]-[4.5] < 4.0. Investigations of the Infrared Array Camera and Multiband Imaging Photometer for Spitzer 24 {mu}m colors and the associated millimeter dust clump properties (mass and density) of the EGOs for the sub-samples based on the class of methanol masers they are associated with suggest that the stellar mass range associated with class I methanol masers extends to lower masses than for class II methanol masers, or alternatively class I methanol masers may be associated with more than one evolutionary phase during the formation of a high-mass star.

• OSTI ID: 21560332
• Journal Information: Astrophysical Journal, Supplement Series, Journal Name: Astrophysical Journal, Supplement Series Journal Issue: 1 Vol. 196; ISSN 0067-0049; ISSN APJSA2
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ALCOHOLS
AMPLIFIERS
ANTENNAS
COLOR
DETECTION
ELECTRICAL EQUIPMENT
ELECTRONIC EQUIPMENT
EQUIPMENT
HYDROXY COMPOUNDS
MASERS
MASS
METHANOL
MICROWAVE AMPLIFIERS
MICROWAVE EQUIPMENT
OPTICAL PROPERTIES
ORGANIC COMPOUNDS
ORGANOLEPTIC PROPERTIES
PHYSICAL PROPERTIES
RADIO EQUIPMENT
RADIO TELESCOPES
STARS
TELESCOPES