J/other/ChJAA/3.49 Velocity and distance of methanol maser sources (Xu+, 2003)
Statistical properties of 6.7GHz methanol maser sources.
Xu Y., Zheng X.-W., Jiang D.-R.
<Chinese J. Astron. Astrophys., 3, 49-68 (2003)>
=2003ChJAA...3...49X 2003ChJAA...3...49X
ADC_Keywords: Masers ; Radial velocities ; Stars, distances
Keywords: masers - ISM: molecules - stars: circumstellar matter -
stars: formation - ISM: HII regions
Abstract:
We present a statistical analysis of 482 6.7GHz methanol maser
sources from the available literature, on their maser emission and
the characteristics of their associated infrared sources. On the
color-color diagram, more than 70% of the objects fall within a very
small region (0.57≤[25-12]≤1.30 and 1.30≤[60-12]≤2.50). This
suggests that 6.7GHz methanol maser emission occurs only within a
very short evolutionary phase during the earliest stage of star
formation. The velocity ranges of the masers belong to two main
groups: one from 1 to 10km/s, and one from about 11 to 20km/s.
These velocity ranges indicate that the masers are probably associated
with both disks and outflows. The correlations between the maser
and infrared flux densities, and between the maser and infrared
luminosities, suggest that far-infrared radiation is a possible
pumping mechanism for the masers which most probably originate
from some outer molecular envelopes or disks.
Description:
We have searched the literature for all known 6.7GHz methanol maser
sources and found a total of 482 objects. Among these, 361 have IRAS
identifications.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 96 652 Parameters of CH3OH Spectra Source
refs.dat 68 20 References
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See also:
J/A+AS/110/81 : Methanol masers towards IRAS sources (van der Walt+ 1995)
J/AZh/72/22 : A 95 GHz Survey of Methanol Masers (Valtts+, 1995)
J/MNRAS/291/261 : Methanol maser of IRAS-selected sources (Walsh+ 1997)
J/A+AS/134/115 : Medicina 6.7GHz methanol masers survey (Slysh+ 1999)
J/A+AS/143/269 : 6.7GHz methanol maser emission survey (Szymczak+, 2000)
J/A+A/403/1095 : 6.7GHz methanol masers survey of low-mass YSO (Minier+ 2003)
J/A+A/410/597 : Warm dust near methanol masers (Walsh+, 2003)
J/A+A/413/233 : 12.2 GHz methanol survey (Blaszkiewicz+, 2004)
J/A+A/428/1019 : Rest frequencies of methanol maser lines (Mueller+, 2004)
J/A+A/434/613 : Water maser survey of methanol masers (Szymczak+ 2005)
J/MNRAS/359/1498 : Class I and class II methanol masers (Ellingsen+, 2005)
J/A+A/432/737 : 6.7GHz Methanol Masers General Catalogue (Pestalozzi+, 2005)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Source name, GGG.gg+LL.ll
14- 24 A11 --- IRAS IRAS Name
26- 27 I2 h RAh Right ascension (B1950)
29- 30 I2 min RAm Right ascension (B1950)
32- 35 F4.1 s RAs Right ascension (B1950)
37 A1 --- DE- Declination sign (B1950)
38- 39 I2 deg DEd Declination (B1950)
41- 42 I2 arcmin DEm Declination (B1950)
44- 45 I2 arcsec DEs Declination (B1950)
47- 52 F6.1 km/s Vpeak ? Peak velocity
54- 59 F6.1 km/s Vmin ? Lower limit of velocity range
60 A1 --- --- [,]
61- 65 I5 km/s Vmax ? Upper limit of velocity range
67- 73 F7.2 Jy Speak ? Peak flux density at 6.7GHz
75- 78 F4.1 kpc Dist ? Distance
79 A1 --- --- [/]
80- 84 F5.2 kpc Dist2 ? Second value for distance
85- 86 I2 --- r_Dist ? Distance reference (1)
88- 96 A9 --- r_Name Source references
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Note (1): Distances that have no reference are heliocentric kinematic distances,
computed from the peak velocities of the 6.7GHz methanol spectrum
using the galactic rotation curve of Wouterloot & Brand (1989, Cat.
J/A+AS/80/149), and assuming R0=8.5kpc and {THETA}0=220km/s.
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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- 42 A19 --- Aut Author's name
47- 68 A22 --- Com Comments
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 04-Nov-2005