J/AJ/132/1322 Water maser survey (Gomez+, 2006)
A sensitive survey for water maser emission toward Bok globules using the
Robledo 70 m antenna.
Gomez J.F., De Gregorio-Monsalvo I., Suarez O., Kuiper T.B.H.
<Astron. J., 132, 1322-1332 (2006)>
=2006AJ....132.1322G 2006AJ....132.1322G
ADC_Keywords: Surveys ; Masers ; Radio lines ; Infrared sources
Keywords: ISM: globules - masers - radio lines: ISM - stars: formation -
stars: pre-main sequence
Abstract:
We report on the most sensitive water maser survey toward Bok globules
to date, performed using NASA's 70m antenna at Robledo de Chavela
(Spain). We observed 207 positions within the Clemens and Barvainis
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), geometric centers of
molecular outflows, peaks in maps of high-density gas tracers (NH3 or
CS), and IRAS point sources. We have obtained seven maser detections,
six 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 (30km/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 to 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 (0.6pc) known to be associated with water maser
emission, although it would be superseded by the cases of CB 65
(0.3pc) and CB 199 (0.5pc) if their association with YSOs is
confirmed. All our selection criteria have statistically compatible
detection rates, except for IRAS sources, which tend to be somewhat
worse predictors for the presence of maser emission.
Description:
We observed the 616-->523 transition of the water molecule (rest
frequency 22235.080MHz), using the NASA 70m antenna (DSS-63) at
Robledo de Chavela (Spain). Water maser observations were carried out
using three different back ends depending on the observing dates: From
2002 March 13 to April 10 we used a 4096 channel spectrometer covering
a bandwidth of 400MHz (5398km/s), which provided a velocity
resolution of 1.3km/s. From 2002 April 14 to 2003 July 18 we used a
256 channel spectrometer covering a bandwidth of 10MHz, which provided
a velocity resolution of 0.5km/s. From 2004 July 6 to 2005 October
16 we used a 384 channel spectrometer covering a bandwidth of 16MHz
(216km/s with 0.6km/s resolution).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 130 207 Sources searched for water maser emission
refs.dat 46 24 References
table3.dat 60 244 Non detections
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See also:
J/A+AS/120/283 : Water maser in ultracompact HII regions (Hofner+ 1996)
J/PASJ/53/517 : Water maser survey of late-type stars (Takaba+, 2001)
J/ApJ/581/325 : NGC 2071 water masers (Seth+, 2002)
J/ApJ/615/702 : IC 133 water vapor maser (Argon+, 2004)
J/A+A/434/613 : Water maser survey of methanol maser sources (Szymczak+, 2005)
J/ApJ/628/789 : IRAS03301+3057 water masers (De Gregorio-Monsalvo+, 2005)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- GName Globule identification (G1)
8- 29 A22 --- SName Source name (G2)
31 A1 --- n_SName Note on SName (3)
33- 34 I2 h RAh Hour of Right Ascension (J2000)
36- 37 I2 min RAm Minute of Right Ascension (J2000)
39- 42 F4.1 s RAs Second of Right Ascension (J2000)
44 A1 --- DE- Sign of the Declination (J2000)
45- 46 I2 deg DEd Degree of Declination (J2000)
48- 49 I2 arcmin DEm Arcminute of Declination (J2000)
51- 52 I2 arcsec DEs Arcsecond of Declination (J2000)
54-114 A61 --- Include Included source(s) (4)
116-130 A15 --- Refs Reference(s) (5)
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Note (3): Flag as follows:
e = Maser detected by Scappini et al. (1991MNRAS.249..763S 1991MNRAS.249..763S)
f = Maser detected by Schwartz & Buhl (1975ApJ...201L..27S 1975ApJ...201L..27S)
g = Coordinates used for IRAS 16544-1604 are those in the IRAS Point
Source Catalog. SIMBAD reports for this source the coordinates
of F16544-1604 in the IRAS Faint Source Catalog, which is also
within the Robledo beam from our pointing position;
h = Maser detected by Neckel et al. (1985A&A...153..253N 1985A&A...153..253N).
Note (4): Other sources included within the telescope beam, complying any
of the selection criteria mentioned in Sec. 3. Where available, SIMBAD
names are given between parentheses. Abbreviations are as follows:
Cm = centimeter source
mm = millimeter source
smm = submillimeter source
outf = center of molecular outflow
nh3 = peak of NH3 map
cs = peak of CS map
Note (5): For the sources complying the selection criteria (except for IRAS
sources), detailed in refs.dat file.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference number
4- 22 A19 --- BibCode BibCode
24- 46 A23 --- Aut Author's name
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- GName Globule identification (G1)
8- 29 A22 --- SName Source name (G2)
31- 37 F7.1 km/s Vmin Minimum velocity covered by bandwidth
39- 44 F6.1 km/s Vmax Maximum velocity covered by bandwidth
46- 49 F4.2 Jy RMS The 1σ noise level
51- 60 A10 "YYYY/MM/DD" Obs.Date Date of the observation
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Global notes:
Note (G1): CB NNN identified as [CB88] NNN in Simbad
Note (G2): SIMBAD names were used, where available. Labels [YMT96], [MYT99],
[ARC92], and [ARC2001] indicate cm sources.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 25-Apr-2008