A sensitive survey for water maser emission towards Bok globules using the Robledo 70m antenna

• Main Authors: Gomez, Jose F, de Gregorio-Monsalvo, Itziar, Suarez, Olga, Kuiper, Thomas B. H
• Format: Journal Article
• Language: English
• Published: 05-06-2006
• Subjects: Physics - Astrophysics of Galaxies; Physics - Cosmology and Nongalactic Astrophysics; Physics - Earth and Planetary Astrophysics; Physics - High Energy Astrophysical Phenomena; Physics - Instrumentation and Methods for Astrophysics; Physics - Solar and Stellar Astrophysics
• DOI: 10.48550/arxiv.astro-ph/0606087

Astron.J.132:1322-1332,2006 We report the most sensitive water maser survey towards Bok globules to date,
using NASA's 70m antenna in Robledo de Chavela (Spain). We observed 207
positions within the CB catalog with a higher probability of harboring a young
star, using as selection criteria the presence of radio continuum emission
(from submillimeter to centimeter wavelengths), geometrical centers of
molecular outflows, peaks in maps of high-density gas tracers (NH3 or CS), and
IRAS point sources. We have obtained 7 maser detections, 6 of which (in CB 34,
CB 54, CB 65, CB 101, CB 199, and CB 232) are reported for the first time here.
Most of the water masers we detected are likely to be associated with young
stellar objects (YSOs), except for CB 101 (probably an evolved object) and CB
65 (uncertain nature). The water maser in CB 199 shows a relatively high shift
(~30 km/s) of its velocity centroid with respect to the cloud velocity, which
is unusual for low-mass YSOs. We speculate that high-velocity masers in this
kind of object could be related with episodes of energetic mass-loss in close
binaries. Alternatively, the maser in CB 199 could be pumped by a
protoplanetary or a young planetary nebula. CB 232 is the smallest Bok globule
(~0.6 pc) known to be associated with water maser emission, although it would
be superseded by the cases of CB 65 (~0.3 pc) and CB 199 (~0.5 pc) if their
association with YSOs is confirmed. All our selection criteria have
statistically compatible detection rates, except for IRAS sources, which tend
to be a somewhat worse predictor for the presence of maser emission.