J/A+A/667/A39 APERTIF DR1 continuum source catalog (Kutkin+, 2022)
Continuum source catalog for the first APERTIF data release.
Kutkin A.M., Oosterloo T.A., Morganti R., Adams E.A.K., Mancini M.,
Adebahr B., de Blok W.J.G., Denes H., Hess K.M., van der Hulst J.M.,
Lucero D.M., Moss V.A., Berger A., van den Brink R., van Cappellen W.A.,
Connor L., Damstra S., Loose G.M., van Leeuwen J., Maan Y., Mika A.,
Norden M.J., Offringa A.R., Oostrum L.C., van der Schuur D., Vohl D.,
Wijnholds S.J., Ziemke J.
<Astron. Astrophys. 667, A39 (2022)>
=2022A&A...667A..39K 2022A&A...667A..39K (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Radio sources ; Morphology
Keywords: astronomical databases:miscellaneous - catalogs - surveys -
radio continuum: general
Abstract:
The first data release of Apertif survey contains 3074 radio continuum
images covering a thousand square degrees of the sky. The observations
were performed during August 2019 to July 2020. The continuum images
were produced at a central frequency 1355MHz with the bandwidth of
∼150MHz and angular resolution reaching 10''. In this work we
introduce and apply a new method to obtain a primary beam model using
a machine learning approach, Gaussian process regression. The primary
beam models obtained with this method are published along with the
data products for the first Apertif data release. We apply the method
to the continuum images, mosaic them and extract the source catalog.
The catalog contains 249672 radio sources many of which are detected
for the first time at these frequencies. We cross-match the
coordinates with the NVSS, LOFAR/DR1/value-added and LOFAR/DR2
catalogs resulting in 44523, 22825 and 152824 common sources
respectively. The first sample provides a unique opportunity to detect
long term transient sources which have significantly changed their
flux density for the last 25 years. The second and the third ones
combined together provide information about spectral properties of the
sources as well as the redshift estimates.
Description:
First scientific verification imaging observations with Apertif
started in April 2019 followed by the launch of the full survey
program on 1 July 2019. Apertif is undertaking a two-tiered imaging
survey: a wide field single-pointing survey and a deeper survey with
multiple pointings over a smaller area (Hess et al., in prep).
The first-year Apertif data release (ADR1) occurred in November 2020
(A22). This time period includes a total of 221 observations of 160
independent fields, covering about a thousand square degrees of sky.
The released data products include continuum images, polarization
images and cubes, and spectral line cubes, obtained with an automatic
processing pipeline separately for every compound beam.
The ADR1 data products are available through a virtual observatory
interface
(https://vo.astron.nl/apertif_dr1/q/apertif_dr1_continuum_images/form)
The catalog contains 249672 radio sources, many of which are detected
for the first time at L-band (1400MHz). The full catalog has a
completeness of about 95% at the 1mJy level.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 334 249672 Continuum source catalog
table3.dat 208 152824 Common Apertif and LOFAR sources
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See also:
J/A+A/659/A1 : LOFAR Two-metre Sky Survey (LoTSS) DR2 (Shimwell+, 2022)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- Apertif Apertif source name (APTF_JHHMMSS+DDMMSS)
21- 39 F19.15 deg RAdeg [20.46/358.82] Right ascension (ICRS, J2000)
41- 60 F20.17 arcsec e_RAdeg [0.32/12.58] Right ascension error
62- 79 F18.15 deg DEdeg [27.46/62.34] Declination (ICRS, J2000)
81-100 F20.17 arcsec e_DEdeg [0.21/29.55] Declination error
102-123 F22.17 mJy Sint [0.09/2555.64] 1355MHz Total flux density
125-146 F22.18 mJy e_Sint [0.03/129.58] 1355MHz Total flux density
error
148-169 F22.17 mJy/beam Speak [0.08/2101.62] 1355MHz Peak flux density
171-192 F22.18 mJy/beam e_Speak [0.01/105.17] 1355MHz Peak flux density
error
194-215 E22.17 arcsec DCmaj Deconvolved major source size (1)
217-238 F22.18 arcsec e_DCmaj [0.0/122.63] Deconvolved major source size
error or DCmaj upper limit if DCmaj=0
240-250 E11.6 arcsec DCmin Deconvolved minor source size (1)
252-272 F21.18 arcsec e_DCmin [0.0/28.07] Deconvolved minor source size
error or DCmin upper limit if DCmin=0
274-288 E15.9 deg DCPA [-90/90] Deconvolved position angle of the
source (measured relative to the north
celestial pole, turning positive into the
direction of the right ascension) (1)
290-311 F22.18 deg e_DCPA [0.03/90.0]? Deconvolved position angle
error or CDPA upper limit if DCPA=0
313-332 F20.18 uJy/beam Islrms [0.01/6.91] local background noise RMS
334 A1 --- SCode [SCM] Source type as classified by
PyBDSF (2)
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Note (1): A source size value 0.0 means that the PSF can not be deconvolved
from the fitted source along the given axis, and the corresponding
uncertainty, represents an upper size limit estimate.
When both major and minor size are 0.0 the position angle is omitted
Note (2): Source type as follows:
S = an isolated source fitted with a single Gaussian
C = sources that were fit by a single Gaussian but are within an
island of emission that also contains other sources
M = sources fitted with multiple Gaussians
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- Apertif Apertif source name (APTF_JHHMMSS+DDMMSS)
21- 42 A22 --- LOFAR LOFAR source name (ILTJHHMMSS.ss+DDMMSS.s)
44- 65 F22.17 mJy/beam SpeakA [0.09/2101.62] Apertif 1335MHz peak flux
density
67- 89 F23.18 mJy/beam SpeakL [0.04/7017.09] Lofar 150MHz peak flux density
91-112 F22.17 mJy SintA [0.1/2555.64] Apertif 1335MHz total flux
density
114-136 F23.17 mJy SintL [0.21/15694.12] Lofar 150MHz total flux
density
138-161 E24.17 --- SI [-2.85/2.41] Spectral index
163-183 F21.19 arcsec Sep [0.0/10.0] Angular separation
185-208 E24.17 --- zbest [-0.01/6.61]? Redshift estimate from Lofar
value-added catalog
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Acknowledgements:
Alexander Kutkin, kutkin(at)astron.nl
(End) Patricia Vannier [CDS] 11-Aug-2022