J/other/PASA/26.454 Precise positions of methanol masers (Caswell, 2009) ================================================================================ Precise positions of methanol masers. Caswell J.L. =2009PASA...26..454C ================================================================================ ADC_Keywords: Masers ; Radio sources Keywords: ISM: molecules - masers - methanol - stars: formation Abstract: The Australia Telescope Compact Array (ATCA) has been used to determine positions for many southern methanol maser sites, with accuracy better than 1 arcsec. The results are presented here as a catalogue of more than 350 distinct sites, some of them new discoveries, and many others with positional precision 10-times better than existing published values. Clusters of 2 or 3 sites are occasionally found to account for single previously listed sources. This in turn reveals that the velocity range for each individual site is sometimes smaller than that of the originally tabulated (blended) source. Only a handful of examples then remain with a velocity range of more than 16km/s at a single compact (less than 2 arcsec) site. The precise methanol positions now allow apparent coincidences with OH masers to be confidently accepted or rejected; this has led to the important conclusion that, where a 1665-MHz OH maser lies in a massive star formation region, at more than 80 percent of the OH sites there is a precisely coincident methanol maser. The methanol precision achieved here will also allow clear comparisons with likely associated IR sources when the next generation of far-IR surveys produce precise positions. Description: The methanol maser observations described here were obtained with the ATCA in many sessions since 1993 February, chiefly in any of the four standard '6-km' configurations (instantaneously yielding 15 baselines ranging from 76 to 6000m). File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 83 375 Positions of methanol masers -------------------------------------------------------------------------------- See also: VIII/96 : 6-GHz methanol multibeam maser catalogue (Caswell+, 2010-12) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 14 A14 --- Name Galactic name (LLL.lll+BB.bbbAA) 17- 18 I2 h RAh Right ascension (J2000) 20- 21 I2 min RAm Right ascension (J2000) 23- 27 F5.2 s RAs Right ascension (J2000) 29 A1 --- DE- Declination sign (J2000) 30- 31 I2 deg DEd Declination (J2000) 33- 34 I2 arcmin DEm Declination (J2000) 36- 39 F4.1 arcsec DEs Declination (J2000) 41- 47 F7.2 Jy Fpk Peak intensity of 6668MHz transition 49- 54 F6.1 km/s Vpk [-126/121] Peak velocity of 6668MHz transition 56- 59 I4 km/s Vl [-127/121] Lower value of velocity range 60 A1 --- --- [,] 62- 65 I4 km/s Vu [-118/122] Upper value of velocity range 67- 70 A4 --- OH? Reference to the OH maser data (1) 72- 83 A12 --- Ref References and epoch (abbreviated as year and month) (1) -------------------------------------------------------------------------------- Note (1): References as follows: CVF95 = Caswell, Vaile & Forster (1995MNRAS.277..210C) C96a = Caswell (1996MNRAS.279...79C) C96b = Caswell (1996MNRAS.283..606C) C97 = Caswell (1997MNRAS.289..203C) c98 = Caswell (1998MNRAS.297..215C) c01 = Caswell (2001MNRAS.326..805C) c03 = Caswell (2003MNRAS.341..551C) c04 = Caswell (2004MNRAS.351..279C, 2004MNRAS.349...99C, 2004MNRAS.352..101C) C04 = Caswell (2004MNRAS.351..279C, 2004MNRAS.349...99C, 2004MNRAS.352..101C) text = refers to notes in section 4. of the paper -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Patricia Vannier [CDS] 14-May-2014