J/A+AS/143/269 6.7GHz methanol maser emission survey (Szymczak+, 2000)
A survey of the 6.7 GHz methanol maser emission from IRAS sources. I. Data.
Szymczak M., Hrynek G., Kus A.J.
<Astron. Astrophys. Suppl. Ser. 143, 269 (2000)>
=2000A&AS..143..269S 2000A&AS..143..269S
ADC_Keywords: Masers ; Surveys ; Radio sources ; Infrared sources
Keywords: masers - surveys - stars: formation - ISM: molecules -
radio lines: ISM - HII regions
Abstract:
We report the first results of a search for 6.7GHz methanol masers in
the direction of 1399 IRAS objects north of declination -20° with
the flux densities greater than 100 Jy at 60 µm and the flux
density ratio F60/F25>1. Observations were made with the
sensitivity of 1.7 Jy and the velocity resolution of 0.04km/s using
the 32-m Torun radio telescope. Maser emission was found in 182
sources, including 70 new detections. 32 new sources were identified
with objects of radio emission associated with star-forming regions.
Comparison of the present data set with other observations suggests
that about 65% of methanol masers exhibit moderate or strong
variations on time-scales of about 4 and 8 years.
Description:
File table1 contains 182 methanol maser sources detected at 6.7GHz.
The IRAS name, the start and end velocities of emission, the velocity
of peak emission, the peak flux density, the integrated flux density,
the epoch of observation and the discovery reference are given.
The data were taken during 1999 using the 32m Torun radio telescope.
The average sensitivity limit (3σ) was 1.7Jy and the velocity
resolution was 0.044km/s.
File table2 contains the sources not detected with the 32m
Torun radio telescope at 6.7GHz. The IRAS name, the 1σ level,
the epoch of observation and the IRAS name of possible contamination
sources are given. The number of non-detections is 1217.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 47 182 List of detections
table2.dat 35 1239 List of non-detections
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See also:
J/A+AS/110/81 : Methanol masers towards IRAS sources (van der Walt+ 1995)
J/A+AS/134/115 : Medicina 6.7GHz methanol masers survey (Slysh+ 1999)
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)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 ---- IRAS IRAS name
12- 14 I3 km/s Vstart Start LSR velocity of emission
16- 18 I3 km/s Vend End LSR velocity of emission
20- 24 F5.1 km/s Vpeak LSR velocity of peak emission
26- 31 F6.1 Jy Speak Peak flux density
33- 38 F6.1 Jy.km/s Sint Integrated flux density
40- 44 A5 "MM/YY" Epoch Epoch of observation (Month/Year)
46- 47 I2 ---- Ref [1-11] Discovery reference (1)
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Note (1): Discovery reference:
1: this paper
2: Menten (1991ApJ...380L..75M 1991ApJ...380L..75M)
3: MacLeod & Gaylard (1992MNRAS.256..519M 1992MNRAS.256..519M)
4: Gaylard & MacLeod (1993MNRAS.262...43G 1993MNRAS.262...43G)
5: Schutte et al. (1993MNRAS.261..783S 1993MNRAS.261..783S)
6: Caswell et al. (1995MNRAS.272...96C 1995MNRAS.272...96C)
7: van der Walt et al. (1995, Cat. J/A+AS/110/81)
8: Lyder & Galt (1997AJ....113.1310L 1997AJ....113.1310L)
9: Walsh et al. (1997, Cat. J/MNRAS/291/261)
10: MacLeod et al. (1998AJ....116.2936M 1998AJ....116.2936M)
11: Slysh et al. (1999, Cat. J/A+AS/134/115)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 ---- IRAS IRAS name
12- 15 F4.2 Jy 1σ 1 σ level at 6.7GHz
17- 24 A8 "DD/MM/YY" Epoch Month of observation
26- 35 A10 ---- Cont Contamination source
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Acknowledgements: Marian Szymczak msz(at)astro.uni.torun.pl
(End) Patricia Bauer [CDS] 23-Mar-2000