J/ApJ/766/114 Water and methanol masers in G75.78+0.34 (Sanchez-Monge+, 2013)
Deciphering the ionized gas content in the massive star-forming complex
G75.78+0.34.
Sanchez-Monge A., Kurtz S., Palau A., Estalella R., Shepherd D., Lizano S.,
Franco J., Garay G.
<Astrophys. J., 766, 114 (2013)>
=2013ApJ...766..114S 2013ApJ...766..114S
ADC_Keywords: Masers ; Radio continuum ; H II regions ;
Millimetric/submm sources ; Interstellar medium
Keywords: dust, extinction; H II regions; ISM: individual: G75.78+0.34;
radio continuum: ISM; stars: formation
Abstract:
We present subarcsecond observations toward the massive star-forming
region G75.78+0.34. We used the Very Large Array to study the
centimeter continuum and H2O and CH3OH maser emission, and the
Owens Valley Radio Observatory and Submillimeter Array to study the
millimeter continuum and recombination lines (H40α and
H30α). We found radio continuum emission at all wavelengths,
coming from three components: (1) a cometary ultracompact (UC) H II
region with an electron density ∼3.7x104/cm3, excited by a B0 type
star, and with no associated dust emission; (2) an almost unresolved
UCH II region (EAST), located ∼6" to the east of the cometary UCH II
region, with an electron density ∼1.3x105/cm3, and associated with a
compact dust clump detected at millimeter and mid-infrared
wavelengths; and (3) a compact source (CORE), located ∼2" to the
southwest of the cometary arc, with a flux density increasing with
frequency, and embedded in a dust condensation of 30M☉. The CORE
source is resolved into two compact and unresolved sources which can
be well fit by two homogeneous hypercompact H II regions each one
photoionized by a B0.5 zero-age main sequence star, or by free-free
radiation from shock-ionized gas resulting from the interaction of a
jet/outflow system with the surrounding environment. The spatial
distribution and kinematics of water masers close to the CORE-N and S
sources, together with excess emission at 4.5µm and the detected
dust emission, suggest that the CORE source is a massive protostar
driving a jet/outflow.
Description:
G75.78+0.34 was observed with the Very Large Array (VLA) at 6.0, 3.6,
2.0, 1.3, and 0.7cm from 1996 January to 2001 April.
The water maser line at 22.23508GHz (616-523 transition) was
observed with the VLA in the A configuration (project AK490)
simultaneously with the 1.3cm continuum emission. The class I methanol
maser line at 44.06941GHz (70-61 A+ transition) was observed
with the VLA in the B configuration (project AK500) simultaneously
with the 0.7cm continuum emission.
The Owens Valley Radio Observatory (OVRO) observations at 3 and 1mm
were made in the L (Low) and H (High) resolution configurations during
1997 September, October, and December. In 1998 March, additional 3mm
observations were made in the uH (ultra-High) resolution configuration.
G75.78+0.34 was observed with the Submillimeter Array (SMA) in the
1.3mm (230GHz) band using the compact configuration on 2010 June 10.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 58 43 22GHz water and 44GHz methanol masers in G75.78+0.34
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See also:
J/other/IJAA/4.571 : Methanol masers in HII regions (Farmer, 2014)
J/ApJ/763/2 : 95GHz methanol masers in molecular outflows (Gan+, 2013)
J/AJ/136/2391 : GLIMPSE Extended Green Objects catalog (Cyganowski+, 2008)
J/ApJ/685/1005 : Spitzer and high-mass star forming regions (Qiu+, 2008)
J/ApJS/175/277 : Submillimeter-Continuum SCUBA detections (Di Francesco+, 2008)
J/ApJS/155/149 : CH3OH 70-61 A+ maser sources (Kurtz+, 2004)
J/A+AS/133/29 : Molecular line survey towards UC HII (Hatchell+ 1998)
J/A+AS/120/283 : Water maser features in HII regions (Hofner+ 1996)
J/AJ/111/846 : Orion HST survey (O'Dell+ 1996)
J/A+A/291/943 : Protostellar cores (Ossenkopf+, 1994)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Mol Maser component (H2O or CH3OH)
9- 10 I2 h RAh [20] Hour of right ascension (J2000)
12- 13 I2 min RAm [21] Minute of right ascension (J2000)
15- 20 F6.3 s RAs [43.9/45] Second of right ascension (J2000)
22 A1 --- DE- [+] Sign of declination (J2000)
23- 24 I2 deg DEd [37] Degree of declination (J2000)
26- 27 I2 arcmin DEm [26] Arcminute of declination (J2000)
29- 33 F5.2 arcsec DEs [37/56.3] Arcsecond of declination (J2000)
35- 40 F6.2 Jy Spk [0.06/122] Peak flux intensity
42- 46 F5.1 km/s Vpk [-36/14] Peak velocity (LSR)
48- 53 F6.2 Jy.km/s Sdv [0.04/220] Integrated intensity
55- 58 A4 --- Notes [ ,1-4HL] Notes (1)
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Note (1): Labels H and L (for water masers) refer to the VLA observations done
with a spectral resolution of 0.33km/s and 1.3km/s, respectively.
Numbers 1-4 (for methanol masers) refer to the four groups of methanol
masers detected (see Figure 1, panel (a)).
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 07-May-2015