J/MNRAS/461/136 MMB Survey ex-OH catalogue (Avison+, 2016)
Excited-state hydroxyl maser catalogue from the methanol multibeam survey.
I. Positions and variability.
Avison A., Quinn L.J., Fuller G.A., Caswell J.L., Green J.A., Breen S.L.,
Ellingsen S.P., Gray M.D., Pestalozzi M., Thompson M.A., Voronkov M.A.
<Mon. Not. R. Astron. Soc., 461, 136-155 (2016)>
=2016MNRAS.461..136A 2016MNRAS.461..136A (SIMBAD/NED BibCode)
ADC_Keywords: Galactic plane ; Masers ; Radio sources
Keywords: masers - surveys - stars: formation - ISM: molecules -
Galaxy: structure
Abstract:
We present the results of the first complete unbiased survey of the
Galactic plane for 6035-MHz excited-state hydroxyl (ex-OH) masers
undertaken as part of the methanol multibeam (MMB) survey. These
observations cover the Galactic longitude ranges 186deg<l<60deg
including the Galactic Centre. We report the detection of 127 ex-OH
masers within the survey region, 47 being new sources. The positions
of new detections were determined from interferometric observations
with the Australia Telescope Compact Array. We discuss the association
of 6035-MHz masers in our survey with the 6668-MHz masers from the MMB
Survey, finding 37 likely CH3OH-ex-OH maser pairs with physical
separations of ≤0.03pc and 55 pairings separated by ≤0.1pc.
Using these we calculate for the first time an ex-OH maser
lifetime of between 3.3x103 and 8.3x103yr. We also discuss
the variability of the 6035-MHz masers and detection rates of
counterpart 6030-MHz ex-OH masers (28 per cent of our sample having
detection at both frequencies).
Description:
The positioning observations of 47 new ex-OH sources were made with
ATCA in 2009 January over three days. Observations were conducted with
the ATCA in the 6C configuration (maximum baseline 6.0km). The
observations were made centred on the ex-OH 6035-MHz transition, with
2048 channels over a bandwidth of 4MHz. The data were flux density
and bandpass calibrated using the ATCA standard sources PKS B1934-638
and PKS B1921-293, respectively. Phase calibration was interleaved
between on source observations of three to four maser sources which
were close in position and velocity, using a calibration source local
(typical offset <10°) to that area of sky.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 127 159 MMB Survey ex-OH catalogue
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- MMBOH Name (LLL.lll+BB.bbbA)
for MMBOH-LLL.lll+BB.bbbA (1)
16- 17 I2 h RAh Right ascension (J2000) (2)
19- 20 I2 min RAm Right ascension (J2000)
22- 27 F6.3 s RAs Right ascension (J2000)
29 A1 --- DE- Declination sign (J2000) (2)
30- 31 I2 deg DEd Declination (J2000)
33- 34 I2 arcmin DEm Declination (J2000)
36- 41 F6.3 arcsec DEs Declination (J2000)
43- 46 I4 MHz Trans [6030 6035] Transition (3)
48- 68 A21 --- r_Pos Position reference (4)
69- 74 F6.2 Jy Speak ?=- MX/(ATCA) or LHPC(Stokes (I))
peak flux density in Trans frequency
76- 82 F7.2 km/s Vpeak ?=- MX/(ATCA) or LHPC(Stokes (I))
peak velocity in Trans frequency
83 A1 --- n_Speak [i] i for Speak and Vpeak of
LHPC(Stokes (I)) (5)
84- 89 F6.1 km/s b_Vpeak ?=- Lower value of Vpeak velocity range (6)
90 A1 --- --- [,]
92- 97 F6.1 km/s B_Vpeak ?=- Upper value of Vpeak velocity range (6)
98 A1 --- n_Vpeak [*] Note on Vpeak (7)
99-104 F6.2 Jy Speak2 ?=- MX RHCP peak flux density in
Trans frequency
106-112 F7.2 km/s Vpeak2 ?=- MX RHCP peak velocity in Trans frequency
114-119 F6.1 km/s b_Vpeak2 ?=- Lower value of Vpeak2 velocity range (6)
120 A1 --- --- [,]
122-127 F6.1 km/s B_Vpeak2 ?=- Upper value of Vpeak2 velocity range (6)
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Note (1): Source name, which is defined as the source position in Galactic
coordinates (rounded at the third decimal point).
Note (2): Source position in right ascension and declination (sources with
positions from MMB observations have three decimal places in RA and two in Dec,
all previously detected masers have two and one decimal accuracy,
respectively).
Note (3): the ex-OH transition for the listed maser, counterpart 6030-MHz masers
are listed directly below their 6035-MHz partner.
Note (4): Reference for the position listed, with the following abbreviations:
ATCA 09 = our ATCA observation results from 2009
ATCA 13 = our ATCA observation results from 2013 October
ATCA 14 = our ATCA observation results from 2014 February
CV95 = Caswell & Vaile (1995MNRAS.273..328C 1995MNRAS.273..328C)
C97 = Caswell (1997MNRAS.289..203C 1997MNRAS.289..203C)
C98 = Caswell (1998MNRAS.297..215C 1998MNRAS.297..215C)
C03 = Caswell (2003MNRAS.341..551C 2003MNRAS.341..551C)
C01 = Caswell (2001MNRAS.326..805C 2001MNRAS.326..805C)
PIGGY = MMB "piggyback" data
Note (5): i for values for Stokes I (total intensity) flux density taken from
the respective ATCA observation as these sources are not present in the nearest
Parkes MX. As such only columns 7-9 are filled in.
Note (6): the ex-OH maser minimum-maximum velocity range over which emission is
seen in the spectrum.
Note (7): Sources 333.136-0.432 and 333.135-0.431 have a blended spectrum
preventing a complete velocity range to be estimated from the MX data.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 04-Nov-2023