J/other/Ser/189.15 Point source catalogue of M31. DR2 (Galvin+, 2014)
20cm VLA radio-continuum study of M31. Images and point source catalogues DR2:
Extraction of a supernova remnant sample.
Galvin T.J., Filipovic M.D.
<Serbian Astron. J., 189, 15 (2014)>
=2014SerAJ.189...15G 2014SerAJ.189...15G
ADC_Keywords: Galaxies, nearby ; Supernovae ; Radio sources
Keywords: catalogs - ISM: supernova remnants - radio continuum: galaxies -
techniques: image processing
Abstract:
We present Data Release 2 of the Point Source Catalogue created from a
series of previously constructed radio-continuum images of M31 at
lambda=20cm (nu=1.4GHz) from archived VLA observations. In total, we
identify a collection of 916 unique discrete radio sources across the
field of M31. Comparing these detected sources to those listed by
Gelfand et al. (2004ApJS..155...89G 2004ApJS..155...89G, Cat. J/ApJS/155/89) at
lambda=92cm, the spectral index of 98 sources has been derived. The
majority (73%) of these sources exhibit a spectral index of
α←0.6, indicating that their emission is predominantly
non-thermal in nature, which is typical for background objects and
Supernova Remnants (SNRs).
Description:
We list the integrated flux densities for 916 unique sources detected
across 28 VLA observations. Of these 916 unique sources, 109 we
detected in at least two separate images. For such sources, we list a
group identifier, a group count, an average flux and error. Sources
were cross referenced with Gelfand et al. (2004ApJS..155...89G 2004ApJS..155...89G, Cat.
J/ApJS/155/89) at lambda=92cm. For matched sources, we list the
Gelfand et al. (2004, Cat. J/ApJS/155/89) flux density and derived
spectral index.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
m31radio.dat 101 1131 *Integrated flux densities for sources at 20cm
(table1 of the paper)
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Note on m31radio.dat: For sources also detected by Gelfand et al. (2004,
Cat. J/ApJS/155/89) we list their measurements and the spectral index.
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See also:
J/ApJS/155/89 : 325MHz radio survey in M31 (Gelfand+, 2004)
Byte-by-byte Description of file: m31radio.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- Name ATCA name (JHHMMSS+DDMMSS)
17- 18 I2 h RAh Right ascension (J2000.0)
20- 21 I2 min RAm Right ascension (J2000.0)
23- 27 F5.2 s RAs Right ascension (J2000.0)
29 A1 --- DE- Declination sign (J2000.0)
30- 31 I2 deg DEd Declination (J2000.0)
33- 34 I2 arcmin DEm Declination (J2000.0)
36- 40 F5.2 arcsec DEs Declination (J2000.0)
42- 49 F8.2 mJy Flux [0.22/15270] Integrated flux density at 20cm
51- 60 A10 --- Proj VLA project and segment code (1)
61- 63 I3 --- Grp [1/109]? Group identifier for common sources (2)
65- 66 I2 --- Ns [2/11]? The number of sources in group (2)
68- 73 F6.2 mJy Favg [0.36/340]? The average flux for group (2)
75- 80 F6.2 % e_Favg [0.27/234]? The error of average for a group (2)
82- 88 F7.2 mJy GFlux ? Gelfand et al. (2004, Cat. J/ApJS/155/89)
integrated flux density at 92cm, if available
90- 95 F6.2 mJy e_GFlux [0.4/105]? GFlux error, if available
97-101 F5.2 --- alpha [-2.5/0.4]? Derived spectral index α,
Sν∝να (3)
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Note (1): VLA Project AC0308 was conducted as part of the NVSS. Its segment
is listed as a number instead of a normal letter segment code.
Note (2): Fields only contained values if a source was found in two or more
VLA projects.
Note (3): Was calculated between flux densities at 20cm (the average flux if
available) of this study and the 92cm flux of Gelfand et al. (2004,
Cat. J/ApJS/155/89) (if available)
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Acknowledgements:
Timothy Galvin, t.galvin(at)bigpond.com
(End) Timothy Galvin [UWS, Australia], Patricia Vannier [CDS] 22-Dec-2014