J/other/PASA/38.58 Rapid ASKAP Continuum Survey. II. RACS cat. (Hale+, 2021)
The Rapid ASKAP Continuum Survey.
Paper II: First Stokes I Source Catalogue Data Release.
Hale C. L., McConnell D., Thomson, A. J. M., Lenc E., Heald G. H.,
Hotan A. W., Leung J. K., Moss V. A., Murphy T., Pritchard J., Sadler E. M.,
Stewart A. J., Whiting M. T.
<Publ. Astron. Soc. Australia, 38, 58 (2021)>
=2021PASA...38...58H 2021PASA...38...58H (SIMBAD/NED BibCode)
ADC_Keywords: Radio continuum; Surveys; Galaxies, radius
Keywords: Catalogues; Radio continuum: galaxies, general; Surveys;
Astrophysics - Astrophysics of Galaxies
Abstract:
The Rapid ASKAP Continuum Survey (RACS) is the first large sky survey
using the Australian Square Kilometre Array Pathfinder (ASKAP),
covering the sky south of +41° declination. With ASKAP's large,
instantaneous field of view, ∼31°2, RACS observed the entire sky
at a central frequency of 887.5MHz using 903 individual pointings with
15 minute observations. This has resulted in the deepest radio survey
of the full Southern sky to date at these frequencies. In this paper,
we present the first Stokes I catalogue derived from the RACS survey.
This catalogue was assembled from 799 tiles that could be convolved to
a common resolution of 25", covering a large contiguous region in the
declination range δ=-80° to +30°. The catalogue provides
an important tool for both the preparation of future ASKAP surveys and
for scientific research. It consists of ∼2.1 million sources and
excludes the |b|<5° region around the Galactic plane. This
provides a first extragalactic catalogue with ASKAP covering the
majority of the sky (δ<+30°). We describe the methods to
obtain this catalogue from the initial RACS observations and discuss
the verification of the data, to highlight its quality. Using
simulations, we find this catalogue detects 95% of point sources at an
integrated flux density of ∼5mJy. Assuming a typical sky source
distribution model, this suggests an overall 95% point source
completeness at an integrated flux density ∼3mJy.
Description:
A detailed description of the Rapid Australian Square Kilometre Array
Pathfinder (ASKAP) Continuum Survey (RACS) tiling and observation
strategy can be found in Paper I (McConnell+ 2020PASA...37...48M 2020PASA...37...48M). The
majority of RACS observations were initially taken over the course of
12 days during April and May 2019. Subsequently, further
re-observations of selected fields were taken in August-November 2019
and between March-June 2020. These observations covered a 288MHz
bandwidth in the frequency range 744.5-1032.5MHz.
The first Stokes I catalogues have now been derived from the RACS
survey. These catalogues were assembled from 799 tiles that are
convolved to a common resolution of 25", covering a large contiguous
region in the declination range δ=-80° to +30°. The
extragalactic catalogue consists of ∼2.1 million sources. The
catalogues are separated into galactic and non-galactic regions.
Source island and component catalogues are provided for both regions.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
galcut.dat 288 2123638 *RACS DR1 source or island catalog: |b|>5deg
(RACSDR1SourcesGalacticCutv2021_08)
galreg.dat 288 173958 *RACS DR1 source or island catalog: |b|<5deg
(RACSDR1SourcesGalacticRegionv2021_08)
gausscut.dat 307 2462693 *Gaussian component catalog: |b|>5deg
(RACSDR1GaussiansGalacticCutv2021_08)
gaussreg.dat 307 203240 *Gaussian component catalog: |b|<5deg
(RACSDR1GaussiansGalacticRegionv2021_08)
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Note on galcut.dat, galreg.dat, gausscut.dat and gaussreg.dat: We make use of
the source extraction software PyBDSF (using version 1.9.1, Mohan &
Rafferty 2015ascl.soft02007M). Details of PyBDSF and the parameters
which users can specify can be found at http://www.astron.nl/citt/pybdsf/
See Section 3.
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Description of file:
Original catalogs, in FITS format, sent by the author, are in ori.tar
See also:
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
VIII/82 : 2nd Epoch Molonglo Galactic Plane Survey (MGPS-2) (Murphy+, 2007)
VIII/81 : Sydney University Molonglo Sky Survey (SUMSS V2.1) (Mauch+ 2008)
VIII/92 : The FIRST Survey Catalog, Version 2014Dec17 (Helfand+ 2015)
VIII/100 : GaLactic and Extragalactic All-sky MWA survey (Hurley-Walker+, 2016)
VIII/102 : GLEAM II. Galactic plane (Hurley-Walker+, 2019)
J/A+AS/118/329 : MOST supernova remnant catalogue (MSC) (Whiteoak+ 1996)
J/ApJ/586/794 : Multiwavelength luminosities of galaxies (Bell, 2003)
J/MNRAS/402/2403 : Australia Telescope 20GHz Survey Catalog (Murphy+, 2010)
J/ApJ/742/49 : Var. & transient radio sources in FIRST (Thyagarajan+, 2011)
J/ApJ/818/105 : CNSS pilot survey (Mooley+, 2016)
J/A+A/598/A78 : The GMRT 150MHz all-sky radio survey (Intema+, 2017)
J/ApJ/836/174 : Extragalactic peaked-sp. radio sources (Callingham+, 2017)
J/A+A/602/A1 : VLA-COSMOS 3 GHz Large Project (Smolcic+, 2017)
J/A+A/602/A2 : VLA-COSMOS 3 GHz Large Project. II. (Smolcic+, 2017)
J/A+A/619/A124 : THOR survey in northern Galactic plane (Wang+, 2018)
J/A+A/622/A1 : LOFAR Two-metre Sky Survey DR1 source cat. (Shimwell+, 2019)
J/MNRAS/490/1202 : ASKAP EMU ESP, Radio Cont. Survey of the SMC (Joseph+ 2019)
J/ApJ/909/193 : The 1.266GHz MeerKAT DEEP2 component catalog (Matthews+, 2021)
J/MNRAS/506/3540 : ASKAP-EMU ESP LMC Radio Continuum Survey (Pennock+, 2021)
http://research.csiro.au/racs/ : Rapid ASKAP Continuum Survey (RACS) home page
Byte-by-byte Description of file: gal*.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- --- [RACS-DR1]
10- 25 A16 --- RACS-DR1 RACS-DR1 name of the source given in the IAU
convention (JHHMMSS.s+DDMMSS) (Source_Name)
27- 45 A19 --- ID ID of the source given by the RACS tile ID
added to the Src_ID generated by PyBDSF
(Source_ID)
47- 59 A13 --- Tile ID of the tile that the source was located in
(Tile_ID)
61- 65 I5 --- SBID [8540/14998] ID of the scheduling block
associated with the observation
67- 77 F11.5 d MJD [58594.5/59021.9] Time that the pointing
observation started (ObsStartTime)
79- 80 I2 --- Ng [1/64] Number of Gaussian components that
were used to fit the source (N_Gaus)
82- 91 F10.6 deg RAdeg Right ascension (J2000) (RA)
93-102 F10.6 deg DEdeg [-84.7/29.2] Declination (J2000) (Dec)
104-108 F5.2 arcsec e_RAdeg [0/90] RAdeg uncertainty (E_RA)
110-115 F6.2 arcsec e_DEdeg [0/102] DEdeg uncertainty (E_Dec)
117-126 F10.3 mJy Ftot [0.006/401950] Total flux density of the
entire source (TotalfluxSource) (G1)
128-135 F8.3 mJy e_Ftot [0.002/6206] Error on the total flux density
from the ETotalFlux column in PyBDSF
(ETotalfluxSourcePyBDSF)
137-145 F9.3 mJy s_Ftot [0.5/28160] Combined error on the total flux
density (ETotalflux_Source) (G2)
147-155 F9.3 mJy/beam Fpk [0.01/60495] Modelled peak flux density for
the source (Peak_flux)
157-163 F7.3 mJy/beam e_Fpk [0.001/233] Fpk uncertainty from PyBDSF
(EPeakflux)
165-170 F6.2 arcsec amaj [14/720] Major axis of the source fit by
PyBDSF (Maj)
172-177 F6.2 arcsec e_amaj [0/259] amaj uncertainty (E_Maj)
179-184 F6.2 arcsec bmin [7/285] Minor axis of the source fit by
PyBDSF (Min)
186-190 F5.2 arcsec e_bmin [0/237] bmin uncertainty (E_Min)
192-197 F6.2 deg PA [0/180] Position angle of the source fit by
PyBDSF
199-204 F6.2 deg e_PA [0/180] PA uncertainty
206-211 F6.2 arcsec amaj0 [1/720]?=0 Deconvolved major axis of the
source (DC_Maj)
213-218 F6.2 arcsec e_amaj0 [0.01/259]?=0 amaj0 uncertainty (EDCMaj)
220-225 F6.2 arcsec bmin0 [0.01/284]?=0 Deconvolved minor axis of the
source (DC_Min)
227-232 F6.2 arcsec e_bmin0 [0.01/49]?=0 bmin0 uncertainty (EDCMin)
234-239 F6.2 deg PA0 [0/180] Deconvolved position angle of the
source (DC_PA)
241-246 F6.2 deg e_PA0 [0/180] PA0 uncertainty (EDCPA)
248 A1 --- Mult [MS] Single, Multiple or Complex source?
(S_Code) (G3)
250-255 F6.4 deg Sep [0.004/5.3] Distance between the source and
the centre of the tile it is located in
(SeparationTileCentre)
257-263 F7.3 mJy/beam Noise [0.002/245] rms noise within the island
boundary, quoted from the Isl_rmscolumn in
PyBDSF
265-274 F10.6 deg GLON Galactic longitude of the source (Gal_lon)
276-285 F10.6 deg GLAT [-90/90] Galactic latitude of the source
(Gal_lat)
287-288 A2 --- Flag [CD- ] Close flag (Flag_Close) (1)
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Note (1): All sources where there was another source within are flagged with
a "C". For 3 pairs of sources, these were so closely located that the
Source_Name was identical. This is only 3 Source name's out of 2 million
and so we have flagged these with "CD" in this column. For
Sources with no match within have "-" in this column.
These close sources that are not specified to be the same source by
PyBDSF likely arise from PyBDSF fitting components during the atrous
mode and not associating these with a co-located source. This affects
∼850 sources.
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Byte-by-byte Description of file: gauss*.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- GID ID corresponding to the Gaussian component
constructed as the RACS tile ID added to a
unique Gaussian ID for the Gaussian
components in the individual tile
(Gaussian_ID)
21- 39 A19 --- ID ID of the source associated with this
Gaussian component given by the RACS tile ID
added to the Src_ID generated by PyBDSF
(Source_ID)
41- 53 A13 --- Tile ID of the tile that the source associated
with this Gaussian component was located in
(Tile_ID)
55- 59 I5 --- SBID [8540/14998] ID of the scheduling block
associated with the observation
61- 71 F11.5 d MJD [58594.5/59021.9] Time that the pointing
observation started (ObsStartTime)
73- 74 I2 --- Ng [1/64] Number of Gaussian components that
were used to fit the source associated with
this Gaussian component (N_Gaus)
76- 85 F10.6 deg RAdeg Right ascension of the Gaussian component
(J2000) (RA)
87- 96 F10.6 deg DEdeg [-84.7/29.2] Declination of the Gaussian
component (J2000) (Dec)
98-102 F5.2 arcsec e_RAdeg [0/90] RAdeg uncertainty (E_RA)
104-108 F5.2 arcsec e_DEdeg [0/102] DEdeg uncertainty (E_Dec)
110-119 F10.3 mJy Fgauss [0/227117] Modelled total flux density of each
individual Gaussian component
(TotalfluxGaussian) (1)
121-128 F8.3 mJy e_Fgauss [0/6206] Error on Fgauss from the
ETotalFlux column
in PyBDSF (ETotalfluxGaussianPyBDSF) (1)
130-138 F9.3 mJy s_Fgauss [0.5/17067] Combined error on Fgauss
(ETotalflux_Gaussian) (1)
140-149 F10.3 mJy Ftot [0.006/401950] Total flux density of the
entire source (TotalfluxSource) (G1)
151-158 F8.3 mJy e_Ftot [0.002/6206] Error on the total flux density
from the ETotalFlux column in PyBDSF
(ETotalfluxSourcePyBDSF)
160-168 F9.3 mJy s_Ftot [0.5/28160] Combined error on the total flux
density (ETotalflux_Source) (G2)
170-178 F9.3 mJy/beam Fpk [0.01/60495] Modelled peak flux density for
the source (Peak_flux)
180-186 F7.3 mJy/beam e_Fpk [0/233] Fpk uncertainty from PyBDSF
(EPeakflux)
188-193 F6.2 arcsec amaj [0.06/720] Major axis of the source (FWHM) of
the Gaussian component used to model the
source (Maj)
195-200 F6.2 arcsec e_amaj [0/259] amaj uncertainty (E_Maj)
202-207 F6.2 arcsec bmin [0/335] Minor axis of the source (FWHM) of
the Gaussian component used to model the
source (Min)
209-213 F5.2 arcsec e_bmin [0/31] bmin uncertainty (E_Min)
215-220 F6.2 deg PA [0/180] Position angle of the Gaussian
component used to model the source
222-227 F6.2 deg e_PA [0/180] PA uncertainty
229-234 F6.2 arcsec amaj0 [0.7/720]?=0 Deconvolved major axis of the
source (DC_Maj)
236-241 F6.2 arcsec e_amaj0 [0.01/157]?=0 amaj0 uncertainty (EDCMaj)
243-248 F6.2 arcsec bmin0 [0.01/334]?=0 Deconvolved minor axis of the
source (DC_Min)
250-254 F5.2 arcsec e_bmin0 [0.01/31]?=0 bmin0 uncertainty (EDCMin)
256-261 F6.2 deg PA0 [0/180] Deconvolved position angle of the
Gaussian component (DC_PA)
263-268 F6.2 deg e_PA0 [0/180] PA0 uncertainty (EDCPA)
270 A1 --- Mult [MS] Single, Multiple or Complex source?
(S_Code) (G3)
272-277 F6.4 deg Sep [0.004/5.3] Distance between the Gaussian
component and the centre of the pointing it
is located in (SeparationTileCentre)
279-285 F7.3 mJy/beam Noise [0.002/245] rms noise within the island
boundary, quoted from the Isl_rmscolumn in
PyBDSF
287-296 F10.6 deg GLON Galactic longitude of the Gaussian component
(Gal_lon)
298-307 F10.6 deg GLAT [-90/90] Galactic latitude of the Gaussian
component (Gal_lat)
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Note (1): The modelled total flux density of each individual Gaussian component
and the associated errors (similar to as described for the source but
now for the component flux density).
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Global notes:
Note (G1): The total flux density of the entire source (i.e. the sum of the
Gaussian components and the Total_Flux column in the PyBDSF source
catalogue).
Note (G2): The combined error on the total flux density derived by summing in
quadrature the error from PyBDSF with the errors of flux density from
Equation 7 of McConnell+ (2020PASA...37...48M 2020PASA...37...48M).
Note (G3): The code from PyBDSF which defines whether a source is as follows:
S = single: a single Gaussian source corresponding to a single island
M = multiple: where a single source is composed of multiple Gaussians
C = complex: where there are multiple Gaussians which form multiple
sources within an island
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Acknowledgements:
Lenc, Emil (S&A, Marsfield) [Emil.Lenc at csiro.au]
References:
McConnell et al. Paper I. 2020PASA...37...48M 2020PASA...37...48M
(End) Emmanuelle Perret [CDS] 20-Mar-2023