VIII/104 SPECFIND V3.0 Catalog of radio continuum spectra (Stein+, 2021)
The SPECFIND V3.0 catalog of radio continuum cross-identifications and spectra:
Reaching lower frequencies.
Stein Y., Vollmer B., Boch T., Landais G., Vannier P., Brouty M.,
Allen M.G., Derriere S., Ocvirk P.
<Astron. Astrophys., 655, A17 (2021)>
=2021A&A...655A..17S 2021A&A...655A..17S
=2020yCat.8104....0S 2020yCat.8104....0S
ADC_Keywords: Radio sources ; Galaxies, radio ; Radio continuum
Keywords: catalogs - radio continuum: general -
astronomical data bases: miscellaneous
Abstract:
Many radio continuum catalogs with different sensitivity limits and
spatial resolutions are published via the VizieR database. Because of
the diversity of spatial resolution, the cross-identification of
individual sources is complex. By assuming a power-law spectrum, the
SPECFIND tool is able to handle radio surveys at different frequencies
from different instruments and different resolutions.
Since the former version of the SPECFIND catalog was released ten
years ago, hundreds of new radio continuum catalogs have been
published. We upgraded the SPECFIND tool to reach a wider frequency
range, especially the lower-frequency radio regime, as well as to have
better spatial sky coverage.
We adapted special selection criteria to all radio tables listed in
VizieR to define a final sample of new catalogs. We implemented the
new catalogs into the SPECFIND tool by unifying them and then compare
the results to the last version. Furthermore we present and
investigate sources with spectral breaks around 1.4GHz and around
325MHz.
By increasing the number of implemented SPECFIND catalogs from 115 to
204, we improve the number of resulting spectra from 107500 to 340000
and increase the number of cross-identified sources from 600000 to 1.6
million. Furthermore, we present two samples of spectral break
sources. The first sample includes 3104 spectral break sources with
turnover frequencies around 1.4GHz, the second sample includes 18075
spectral break sources with turnover frequencies around 325MHz. Both
samples include concave sources and Gigaherz-Peaked Spectrum (GPS) or
Megaherz-Peaked Spectrum (MPS) sources.
The SPECFIND V3.0 catalog is a very useful resource and a powerful
open access tool, reachable via VizieR. By tripling the resulting
spectra and including many radio continuum surveys from the last 50
years, we provide a significantly extended catalog of cross-identified
radio continuum sources. Furthermore, the SIMBAD database will be
updated using the SPECFIND V3.0 catalog and will contain more radio
continuum data, serving the needs of future projects.
Description:
We present a new version of SPECFIND. The SPECFIND tool was
successfully upgraded from 115 catalogs in version 2.0 to version 3.0
with a final number of 204 processed catalogs. 89 new catalogs were
ingested and two catalogs were updated. The final number of resulting
spectra was increased more than a factor of three from 107500 in
version 2.0 to 340000 in version 3.0. The number of objects with
cross-identified sources was more than doubled from 600000 in version
2.0 to 1.6 million in version 3.0.
The main result is presented in table "spectra" with every radio
continuum source having one entry row. The different objects/spectra
are named by different sequence numbers (column "Seq"). All radio
continuum sources with the same sequence number belong to the same
object/spectrum. In the second column, the name of the source is given
followed by the number of sources within the spectrum ("N"). The
columns "a" and "b" are the spectral index and the abscissa of the
spectral fit, respectively. The sixth column contains the frequency of
the catalog, followed by the flux density, its error and the position
of the source (Right Ascension and Declination). The column "SED" is a
link to the spectral fit, i.e. the spectrum containing this source.
The next column "Aladin" shows an Aladin Lite6 view of the source. The
last column gives the beam size of the observation.
The "beam" table contains all 204 tables from the VizieR catalogs
which were used in SPECFIND V3.0.
The "waste" table has the same general structure as "spectra", but
contains measurements which were cross-identified by position but did
not match the power-law spectrum. These points are added to the VizieR
SED plot.
The spectral break sources are provided in two different tables. The
first table contains all 5515 spectral break sources including the 210
concave sources with turnover frequencies around 1.4GHz. The second
table lists the 19691 spectral break sources including the 900 concave
sources with turnover frequencies around 325MHz. The structure of the
tables is similar to the spectra table. The first column gives the
running number "Seq". The sources belonging to the same spectrum have
the same sequence number. The second column provides the source name;
the third column the type (spectral break (sb), concave (conc),
GPS/MPS (gps/mps), GGPS/GMPS (ggps/gmps)), followed by the spectral
slope and the abscissa associated with the source. In the next column,
the mean spectral slope of the part of the spectrum (lower or higher
frequency part) is given. Then the frequency, the flux density and its
error are listed. Lastly, the position (Right Ascension and
Declination) and the beam/resolution are specified.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
spectra.dat 131 1658207 The parameters of the radio spectra
waste.dat 116 3570814 Source parameters based on positional cross-id
beam.dat 142 220 Characterisation of catalogues in SPECFIND
ghzbreak_cand.dat 142 31179 Spectral break source candidates at 1.4 GHz
(table A2)
mhzbreak_cand.dat 142 173703 Spectral break source candidates at 325 MHz
(table A3)
figa2.dat 410 2 List of pdf files of Fig. A2
figa2/* . 2 Fig. A2 pdf individual files
simbadz.dat 137 339547 Redshifts from Simbad database (April 2024)
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See also:
VIII/13 : A new catalog of 53522 4.85GHz sources (BWE) (Becker+ 1991)
VIII/14 : 87GB Catalog of radio sources (Gregory et al., 1991)
VIII/15 : Parkes Radio Sources Catalogue (PKS) (Wright+ 1990)
VIII/16 : Molonglo Reference Catalogue of Radio Sources (MRC) (Large+ 1991)
VIII/17 : The North 20cm Survey (WB) (White+ 1992)
VIII/36 : The Second Bologna Survey (B2) (Colla+ 1970-1974)
VIII/37 : The Third Bologna Survey (B3) (Ficarra+ 1985)
VIII/38 : The Parkes-MIT-NRAO 4.85GHz (PMN) Surveys (Griffith+ 1993-1996)
VIII/40 : GB6 catalog of radio sources (Gregory+ 1996)
VIII/42 : Texas Survey of radio sources at 365MHz (TXS) (Douglas+ 1996)
VIII/44 : Miyun 232MHz survey (MIYUN) (Zhang+ 1997)
VIII/52 : The MIT-Green Bank 5GHz Survey (Bennett+, 1986-91)
VIII/60 : Interferometer phase calibration sources (JVAS) (Patnaik+ 1998)
VIII/62 : The Westerbork Northern Sky Survey (WENSS) (Leiden, 1998)
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
VIII/69 : The WISH catalogue at 352 MHz (de Breuck+ 2002)
VIII/70 : Sydney University Molonglo Sky Survey (SUMSS) (Mauch+ 2003)
VIII/71 : The FIRST Survey Catalog, Version 03Apr11 (Becker+ 2003)
J/A+AS/85/805 : 11cm radio continuum survey. IV. (F3R) (Fuerst+ 1990)
Byte-by-byte Description of file: spectra.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- Seq [1/339592] Sequential number of the spectrum (1)
8- 42 A35 --- Name Main name of the radio source (G1)
44- 45 I2 --- N [2/34] Number of points in spectrum
47- 52 F6.2 --- a Slope of spectrum (3)
54- 60 F7.2 [mJy] b Abscissa of spectrum (3)
62- 66 I5 MHz nu [16/31000] Frequency
68- 76 E9.3 mJy S(nu) Flux density at frequency nu
78- 85 E8.2 mJy e_S(nu) Mean error on S(nu)
87- 94 F8.4 deg RAdeg Right ascension (J2000) of source
96-103 F8.4 deg DEdeg Declination (J2000) of source
105-115 F11.2 mJy dFlux Difference with flux expected from NVSS
117-123 F7.1 arcsec dRA ?=9999 Offset in RA from NVSS source
125-131 F7.1 arcsec dDE ?=9999 Offset in DE from NVSS source
--------------------------------------------------------------------------------
Note (1): This number relates the sources that contribute to a single
spectrum, i.e. there are N radio sources sharing the same Seq number.
The number of independent spectra is 339592.
Note (3): The coefficients of a and b of the flux density parametrization
log(S(ν)) = a.log(ν) + b
where the log is decimal (log10), S expressed in mJy and ν in
MHz. Thus b represents log(S(1MHz)/1mJy).
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Byte-by-byte Description of file: waste.dat
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Bytes Format Units Label Explanations
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1- 31 A31 --- Assoc Main name of the radio association (G1)
32- 39 I8 --- Seq [-3326064/339592] Spectrum Sequential number (1)
41- 46 I6 MHz nu [16/31000] Frequency
48- 56 E9.3 mJy S(nu) Flux density at frequency nu
58- 65 E8.2 mJy e_S(nu) Mean error on S(nu)
67- 74 F8.4 deg RAdeg Right ascension (J2000) of source
76- 83 F8.4 deg DEdeg Declination (J2000) of source
85-116 A32 --- Name Name of the associated radio source (G1)
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Note (1): when positive, the radio flux matches a spectrum and is therefore
also included in the "spectra.dat" file; when negative, the flux does
not match a spectrum.
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Byte-by-byte Description of file: beam.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Name Catalog abbreviation used in SPECFIND (G1)
15- 31 A17 --- Abrev Other abbreviation
33- 35 A3 --- I [I&S? -] Interferometer or Single dish
37- 44 F8.2 MHz nu [16,31000] Frequency
46- 54 F9.6 arcmin beam Beam size
56- 63 F8.3 mJy Smin ? Sensitivity limit
65- 71 I7 --- N Number of sources in catalog
73- 77 I5 deg+2 Cov Coverage
79- 82 F4.1 % sp ? Percentage of sources having a spectrum
84-102 A19 --- BibCode Reference's bibcode
104-142 A39 --- Cat Catalog acronyms in VizieR
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Byte-by-byte Description of file: ghzbreak_cand.dat mhzbreak_cand.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- Seq [1/18075] The sources belonging to the same
spectrum have the same sequence number (1)
7- 46 A40 --- Name Source name
48- 51 A4 --- cat Spectral break code (2)
53 I1 --- Resolved [0/1] Resolved (1) flag (3)
55- 59 F5.2 --- a Spectral slope associated with the source
61- 65 F5.2 --- b ? Abscissa associated with the source
67- 71 F5.2 --- alow Spectral slope at low frequencies
74- 77 F4.2 --- e_alow rms uncertainty on spectral slope at
low frequencies
79- 83 F5.2 --- ahigh Spectral slope at high frequencies
86- 89 F4.2 --- e_ahigh rms uncertainty on spectral slope at high
frequencies
91- 95 I5 MHz Freq Frequency
98-106 E9.4 mJy S Flux density at Freq
109-116 E8.3 mJy e_S rms uncertainty on S
118-125 F8.4 deg RAdeg Right ascension (J2000)
127-134 F8.4 deg DEdeg Declination (J2000)
136-142 F7.4 --- Beam beam/resolution
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Note (1): Sequential number within the table:
No = 1/31179 for gps_cand.dat
No = 1/186895 for mps_cand.dat
Note (2): Spectral break code as follows:
sb = spectral break
conc = concave
gps = GPS, Gigaherz-Peaked Spectrum
Note (3): The source is considered to be resolved if
FIRST14 - column fMaj≤6", CRATES - column Morph=P; CLASS - column b/a=0;
TXS - column Struct=P
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Byte-by-byte Description of file: figa2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- FileName Name of the pdf file in figa2 subdirectory
11-410 A400 --- Title Title of the file
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Byte-by-byte Description of file: simbadz.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- Seq [1/339592] Sequential number of the spectrum
11- 44 A34 --- Name Main name of the radio source (G1)
48- 50 A3 --- SType Simbad object type
53- 74 E22.17 --- z ? Simbad redshift
76- 88 E13.9 --- e_z ? rms uncertainty on z
91- 93 A3 --- n_z Simbad nature redshift (1)
96-137 A42 --- SName Simbad name
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Note (1): Simbad nature redshift as follows:
p = photometric redshfit
s = spectroscopic redshfit
sa = absorption spectroscopic redshfit
se = emission spectroscopic redshfit
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Global Notes:
Note (G1): a summary of the acronyms used, with indication of interferometric
or single dish instrumentation, frequency, resolution, sensitivity
limit (mJy), number of sources, percentage of sources with identified
spectrum, and the identification of the catalog in the CDS collection
is given as file "beam.dat". To distinguish sources of the same survey
observed at different frequencies, we added a lowercase letter to the
source acronym (e.g. FORa, FORb).
Acknowledgements:
Yelena Stein, yelena.stein(at)astro.unistra.fr
History:
* 22-Jan-2020: on-line version
* 19-Jun-2024: File simbadz.dat added
(End) Y. Stein, B. Vollmer, F. Ochsenbein, P. Vannier [CDS] 22-Jan-2020