J/other/PASA/42.38 RACS VI. RACS-high 1655.5MHz catalogue (Duchesne+, 2025)
The Rapid ASKAP Continuum Survey (RACS) VI:
The RACS-high 1655.5 MHz images and catalogue.
Duchesne S., Ross K., Thomson A.J.M., Lenc E., Murphy T., Galvin T.J.,
Hotan A.W., Moss V.A., Whiting M.T.
<Publ. Astron. Soc. Australia, 42, 38 (2025)>
=2025PASA...42...38D 2025PASA...42...38D (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Radio sources ; Radio continuum ; Morphology
Keywords: catalogues - surveys - radio continuum: general -
radio continuum: galaxies
Abstract:
We have conducted a widefield, wideband, snapshot survey using the
Australian SKA Pathfinder (ASKAP) referred to as the Rapid ASKAP
Continuum Survey (RACS). RACS covers ∼90% of the sky, with multiple
observing epochs in three frequency bands sampling the ASKAP frequency
range of 700-1800MHz. This work contains the catalogues from the
third major epoch at 1655.5MHz, RACS-high. From the 1493 images
covering the sky up to declination +48 degrees, we present a catalogue
of 2677509 radio sources and 3526674 Gaussian components. The
catalogue is constructed from images with a median root-mean-square
noise of 195uJy/beam and a median angular resolution of 11.8" by
8.1". The overall reliability of the catalogue is estimated to be
99.18%, and we find a decrease in reliability as angular resolution
improves. We estimate the brightness scale to be accurate to 10%, and
the astrometric accuracy to be within ∼0.6" in right ascension and
∼0.7" in declination after correction of a systematic
declination-dependent offset. All data products from RACS-high,
including calibrated visibility datasets, images from individual
observations, full- sensitivity mosaics, and the all-sky catalogue are
available at the CSIRO ASKAP Science Data Archive:
https://doi.org/10.25919/g3jd-av02.
Description:
Stokes I catalogues from the Rapid ASKAP Continuum Survey (RACS) at
1655.5MHz (RACS-high). This work took the images of the tiles
associated with the RACS-high survey at 1655.5MHz, convolved them to
a common resolution, and mosaicked them with neighbouring images to
obtain near-uniform sensitivity images covering the sky up to
declination +49 degrees. Catalogues were made by running PyBDSF (see
Mohan and Rafferty: 2015ascl.soft02007M) over each mosaicked tile
image. These tile catalogues were combined together and duplicates
removed.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
sourcesh.dat 359 2677509 RACS-high source or island catalogue
(RACS-high_sources, table B1)
gcompsh.dat 350 3526674 RACS-high Gaussian component catalogue
(RACS-high_components, table B2)
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See also:
J/other/PASA/38.58 : Rapid ASKAP Continuum Survey. II. RACS cat. (Hale+, 2021)
J/other/PASA/41.3 : Rapid ASKAP Continuum Survey. V. 1367.5MHz
(Duchesne+, 2024)
https://research.csiro.au/racs : RACS project website
https://doi.org/10.25919/g3jd-av02 : RACS-high collection on CASDA
Byte-by-byte Description of file: sourcesh.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 23 A23 --- Name Source name following IAU source name
convention: RACS-MID1 JHHMMSS.s+DDMMSS
(Name)
25- 41 A17 --- SourceID Unique identifier based on the field the
source is located in and the index
assigned by PyBDSF, RACSHHMM+DDNNNN
(Source_ID)
43- 54 A12 --- FieldID Field name, RACS_HHMM+DD (Field_ID)
56- 68 F13.9 deg RAdeg Right ascension (J2000) of the source (RA)
70- 82 F13.9 deg DEdeg Declination (J2000) of the source (Dec)
84- 94 F11.7 deg DEdegc Declination (J2000) of the source after
declination-dependent offsets applied
(Dec_corr)
96-106 F11.9 deg e_RAdeg Uncertainty on right ascension from
fitting the source position (E_RA)
108-116 F9.7 deg e_DEdeg Uncertainty on declination from fitting
the source position (E_Dec)
118-126 F9.7 deg e_DEdegc Uncertainty on corrected declination from
fitting (EDeccorr)
128-138 F11.3 mJy Ftot Total flux density at 1655.5MHz of the
source (Total_flux)
140-149 F10.5 mJy e_FtotPy Uncertainty in the total flux density at
1655.5MHz from PyBDSF fitting
(ETotalflux_PyBDSF)
151-160 F10.3 mJy e_Ftot Quadrature sum of the brightness scale and
PyBDSF uncertainties for total flux
density at 1655.5MHz (ETotalflux)
162-171 F10.3 mJy/beam Fpeak Peak flux density at 1655.5MHz of the
source (Peak_flux)
173-181 F9.5 mJy/beam e_FpeakPy Uncertainty in the peak flux density at
1655.5MHz from PyBDSF fitting
(EPeakflux_PyBD)
183-191 F9.3 mJy/beam e_Fpeak Quadrature sum of the brightness scale and
PyBDSF uncertainties for peak flux
density at 1655.5MHz (EPeakflux)
193-200 F8.4 arcsec Maj Size of the major axis of the source
(Maj_axis)
202-211 F10.6 arcsec Min Size of the minor axis of the source
(Min_axis)
213-222 F10.6 deg PA Position angle of the source,
east of north (PA)
224-231 F8.4 arcsec e_Maj Uncertainty in the source major axis
(EMajaxis)
233-239 E7.2 arcsec e_Min Uncertainty in the source minor axis
(EMinaxis)
241-247 E7.2 deg e_PA Uncertainty in the source PA (E_PA)
249-256 F8.4 arcsec DCMaj Deconvolved source major axis (DCMajaxis)
258-265 F8.4 arcsec DCMin Deconvolved source minor axis (DCMinaxis)
267-276 F10.6 deg DCPA Deconvolved source PA (DC_PA)
278-285 F8.4 arcsec e_DCMaj Uncertainty in the deconvolved source major
axis (EDCMaj_axis)
287-293 E7.2 arcsec e_DCMin Uncertainty in the deconvolved source minor
axis (EDCMin_axis)
295-301 E7.2 deg e_DCPA Uncertainty in the deconvolved source PA
(EDCPA)
303-309 F7.3 mJy/beam Noise Local estimate of the root-mean-square
noise (Noise)
311-318 F8.5 deg Tilel Direction cosine l of the source with
respect to the field centre (Tile_l)
320-327 F8.5 deg Tilem Direction cosine m of the source with
respect to the field centre (Tile_m)
329-335 F7.5 deg Tilesep Angular separation from the field centre
(Tile_sep)
337-340 F4.1 arcsec PSFMaj Major axis FWHM of the PSF for the field
(PSF_Maj)
342-345 F4.1 arcsec PSFMin Minor axis FWHM of the PSF for the field
(PSF_Min)
347-352 F6.2 deg PSFPA PA of the PSF for the field (PSF_PA)
354 A1 --- SCode [MS] Source structure classification by
PyBDSF, S = single, M = multiple
(S_Code)
356-357 I2 --- NGauss [1/77] Number of Gaussian components
comprising the source (N_Gaussians)
359 I1 --- Flag [0/1] Source type flag,
0 = unresolved, 1 = resolved (Flag)
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Byte-by-byte Description of file: gcompsh.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- GaussID Unique identifier based on the field the
component is located in and the index
assigned by PyBDSF (Gaussian_ID)
19- 35 A17 --- SourceID Unique identifier based on the field the
source is located in and the index
assigned by PyBDSF (Source_ID)
37- 48 A12 --- FieldID Field name: RACS_HHMM+DD (Field_ID)
50- 62 F13.9 deg RAdeg Right ascension (J2000) of the source (RA)
64- 76 F13.9 deg DEdeg Declination (J2000) of the source (Dec)
78- 88 F11.7 deg DEdegc Declination (J2000) of the source after
declination-dependent offsets applied
(Dec_corr)
90-100 F11.9 deg e_RAdeg Uncertainty on right ascension from fitting
the source position (E_RA)
102-110 F9.7 deg e_DEdeg Uncertainty on declination from fitting
the source position (E_Dec)
112-120 F9.7 deg e_DEdegc Uncertainty on corrected declination from
fitting (EDeccorr)
122-129 E8.3 mJy Ftot Total flux density of the source
(Total_flux)
131-138 E8.3 mJy e_FtotPy Uncertainty in the total flux density from
PyBDSF fitting (ETotalflux_PyBDSF)
140-146 E7.2 mJy e_Ftot Quadrature sum of the brightness scale and
PyBDSF uncertainties for total flux
density (ETotalflux)
148-158 F11.4 mJy/beam Fpeak Peak flux density of the source (Peak_flux)
160-167 E8.3 mJy/beam e_FpeakPy Uncertainty in the peak flux density from
PyBDSF fitting (EPeakflux_PyBDSF)
169-178 F10.4 mJy/beam e_Fpeak Quadrature sum of the brightness scale and
PyBDSF uncertainties for peak flux density
(EPeakflux)
180-191 F12.8 arcsec Maj Size of the major axis of the source
(Maj_axis)
193-207 F15.11 arcsec Min Size of the minor axis of the source
(Min_axis)
209-218 F10.6 deg PA Position angle of the source,
east of north (PA)
220-226 E7.2 arcsec e_Maj Uncertainty in the source major axis
(EMajaxis)
228-234 E7.2 arcsec e_Min Uncertainty in the source minor axis
(EMinaxis)
236-242 E7.2 deg e_PA Uncertainty in the source PA (E_PA)
244-251 F8.4 arcsec DCMaj Deconvolved source major axis (DCMajaxis)
253-260 F8.4 arcsec DCMin Deconvolved source minor axis (DCMinaxis)
262-271 F10.6 deg2 DCPA Deconvolved source PA (DC_PA)
273-279 E7.2 arcsec e_DCMaj Uncertainty in the deconvolved source
major axis (EDCMaj_axis)
281-287 E7.2 arcsec e_DCMin Uncertainty in the deconvolved source
minor axis (EDCMin_axis)
289-295 E7.2 deg2 e_DCPA Uncertainty in the deconvolved source
PA (EDCPA)
297-303 F7.3 mJy/beam Noise Local estimate of the root-mean-square
noise (Noise)
305-312 F8.5 deg Tilel Direction cosine l of the source with
respect to the field centre (Tile_l)
314-321 F8.5 deg Tilem Direction cosine m of the source with
respect to the field centre (Tile_m)
323-329 F7.5 deg2 Tilesep Angular separation from the field centre
(Tile_sep)
331-334 F4.1 arcsec PSFMaj Major axis FWHM of the PSF for the field
(PSF_Maj)
336-339 F4.1 arcsec PSFMin Minor axis FWHM of the PSF for the field
(PSF_Min)
341-346 F6.2 deg PSFPA PA of the PSF for the field (PSF_PA)
348 A1 --- SCode [MS] Source structure classification by
PyBDSF, S = single, M = multiple
(S_Code)
350 I1 --- Flag [0/2] Source type flag,
0 = unresolved, 1 = resolved (Flag)
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Acknowledgements:
Stefan Duchesne, Stefan.Duchesne(at)csiro.au
References:
McConnell et al., Paper I 2020PASA...37...48M 2020PASA...37...48M
Hale et al., Paper II 2021PASA...38...58H 2021PASA...38...58H, Cat. J/other/PASA/38.58
Thomson et al., Paper III 2023PASA...40...40T 2023PASA...40...40T
Duchesne et al., Paper IV 2023PASA...40...34D 2023PASA...40...34D
Duchesne et al., Paper V 2024PASA...41....3D 2024PASA...41....3D, Cat. J/other/PASA/41.3
(End) Patricia Vannier [CDS] 17-Feb-2025