J/ApJS/270/33 MeerKAT Absorption Line Survey (MALS). I. DR1 (Deka+, 2024)
The MeerKAT Absorption Line Survey (MALS) Data Release.
I. Stokes I image catalogs at 1-1.4GHz.
Deka P.P., Gupta N., Jagannathan P., Sekhar S., Momjian E., Bhatnagar S.,
Wagenveld J., Klockner H.-R., Jose J., Balashev S.A., Combes F.,
Hilton M., Borgaonkar D., Chatterjee A., Emig K.L., Gaunekar A.N.,
Jozsa G.I.G., Klutse D.Y., Knowles K., Krogager J.-K., Mohapatra A.,
Moodley K., Muller S., Noterdaeme P., Petitjean P., Salas P.,
Sikhosana S.
<Astrophys. J. Suppl. Ser., 270, 33 (2024)>
=2024ApJS..270...33D 2024ApJS..270...33D
ADC_Keywords: Radio continuum; Redshifts; Surveys; Active gal. nuclei
Keywords: Active galaxies ; Radio interferometry ; Surveys ;
Radio source catalogs
Abstract:
The MeerKAT Absorption Line Survey (MALS) has observed 391 telescope
pointings at the L band (900-1670MHz) at δ≲+20°. We present
radio continuum images and a catalog of 495325 (240321) radio sources
detected at a signal-to-noise ratio (S/N)>5 over an area of 2289deg2
(1132deg2) at 1006MHz (1381MHz). Every MALS pointing contains a
central bright radio source (S1GHz≳0.2Jy). The median spatial
resolution is 12" (8"). The median rms noise away from the pointing
center is 25µJy/beam (22µJy/beam) and is within ∼15% of the
achievable theoretical sensitivity. The flux density scale ratio and
astrometric accuracy deduced from multiply observed sources in MALS
are <1% (8% scatter) and 1", respectively. Through comparisons with
NVSS and FIRST at 1.4GHz, we establish the catalog's accuracy in the
flux density scale and astrometry to be better than 6% (15% scatter)
and 0.8", respectively. The median flux density offset is higher (9%)
for an alternate beam model based on holographic measurements. The
MALS radio source counts at 1.4GHz are in agreement with literature.
We estimate spectral indices (α) of a subset of 125621 sources
(S/N>8), confirm the flattening of spectral indices with decreasing
flux density, and identify 140 ultra-steep-spectrum (α<-1.3)
sources as prospective high-z radio galaxies (z>2). We have identified
1308 variable and 122 transient radio sources comprising primarily
active galactic nuclei that demonstrate long-term (26yr) variability
in their observed flux densities.
Description:
Each MeerKAT Absorption Line Survey (MALS) pointing is centered at a
radio source brighter than 200mJy at ∼1GHz in NVSS or SUMSS. We have
carried out a large spectroscopic campaign using the Nordic Optical
Telescope (NOT) and the Southern African Large Telescope (SALT) to
measure the redshifts and confirm the nature of 303 AGN candidates
identified on the basis of mid-infrared colors.
The sky coverage of 391 pointings observed at the L band during the
first phase of the survey from 2020 April 1 to 2021 January 18, is
shown in Figure 1 (see Appendix A). For these observations, the 856MHz
bandwidth of the L band centered at 1283.9869MHz was split into
32,768 frequency channels.
For spectral line or cube imaging, we split the continuous band of
30,720 frequency channels into 15 spectral windows (SPWs) labeled SPW0
to SPW14. In this paper, we focus on continuum images at 1006.0 and
1380.9MHz from the spectral line processing of SPW2 (976.4-1036.5MHz
frequency range) and SPW9 (1350.9-1411.0MHz frequency range).
See Section 2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 1367 735646 The complete MeerKAT Absorption Line Survey (MALS)
DR1 (v2) radio source catalog
tablea1.dat 95 395 *All L-band (900-1670MHz) MeerKAT Absorption Line
Survey pointings
tablee1.dat 71 182 List of ultra-steep sources flagged as candidate
high-redshift radio galaxies
tablef1.dat 36 1371 List of variable radio sources
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Note on tablea1.dat: SPW2 and SPW9 are the L-band spectral ranges,
[976.4-1036.5MHz] and [1350.9-1411.0MHz], respectively. Further there
are 395 observations for 391 pointings in this Table. The pointings
J233913.22-552350.4, J113320.08+004052.5, J114226.58-263313.7,
J114450.43-145502.7 were each repeated twice; the RMS/Flux
measurements for the combined pointing is provided only for the
earlier epoch observation row. The row values for the 2nd epoch
observation are listed as nulls.
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See also:
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
VIII/81 : Sydney University Molonglo Sky Survey (SUMSS V2.1) (Mauch+ 2008)
VIII/90 : The FIRST Survey Catalog, Version 12Feb16 (Becker+ 2012)
II/328 : AllWISE Data Release (Cutri+ 2013)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
VIII/100 : GaLactic and Extragalactic All-sky MWA survey (Hurley-Walker+, 2016)
J/ApJS/80/137 : Southern Extragalactic Radio Sources (Jones+, 1992)
J/A+AS/110/19 : Kinematical obs. of pairs of galaxies (Davoust+ 1995)
J/A+AS/124/259 : Westerbork Northern Sky Survey I. (Rengelink+ 1997)
J/A+A/457/517 : ATESP 5 GHz radio survey. I. (Prandoni+, 2006)
J/MNRAS/372/741 : SXDF 100µJy catalogue (Simpson+, 2006)
J/MNRAS/383/75 : Deep 610MHz survey of ELAIS-N1 sources (Garn+, 2008)
J/MNRAS/397/281 : Radio imaging in Lockman Hole (Ibar+, 2009)
J/AN/330/223 : High frequency peakers. Faint sample (Stanghellini+, 2009)
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/ApJS/230/7 : Spectral flux densities from 50MHz to 50GHz (Perley+, 2017)
J/A+A/598/A104 : LOFAR Two-metre Sky Survey (Shimwell+, 2017)
J/A+A/602/A2 : VLA-COSMOS 3 GHz Large Project. II. (Smolcic+, 2017)
J/A+A/602/A1 : VLA-COSMOS 3 GHz Large Project (Smolcic+, 2017)
J/ApJ/836/185 : SEDs of the radio cont. from KINGFISHER (Tabatabaei+, 2017)
J/MNRAS/474/5008 : Radio spectral index 147-1400MHz (de Gasperin+, 2018)
J/ApJS/235/34 : Deep JVLA imaging of GOODS-N at 20cm (Owen, 2018)
J/MNRAS/481/4548 : New constraints on the 1.4GHz counts (Prandoni+, 2018)
J/A+A/628/A56 : Extragalactic MHz Peaked Sources at mas scales (Keim+, 2019)
J/A+A/621/A19 : ATESP 5 GHz radio survey. IV. (Ricci+, 2019)
J/A+A/622/A1 : LOFAR Two-metre Sky Survey DR1 source cat. (Shimwell+, 2019)
J/ApJ/903/139 : COSMOS-XS. II. Ultra-faint radio population (Algera+, 2020)
J/MNRAS/491/92 : Young radio AGNs study based on SDSS sp. (Liao+, 2020)
J/ApJS/248/25 : SFRS: 3-33GHz VLA observations (Linden+, 2020)
J/MNRAS/500/3821 : Square Km Array Science Data Challenge 1 (Bonaldi+ 2021)
J/A+A/648/A116 : PKS 1830-211 OH and HI spectra (Combes+, 2021)
J/ApJS/255/30 : VLASS QL Ep.1 Catalog, CIRADA version (Gordon+, 2021)
J/other/PASA/38.58 : Rapid ASKAP Continuum Survey. II. RACS cat. (Hale+, 2021)
J/ApJ/909/193 : 1.266GHz MeerKAT DEEP2 component catalog (Matthews+, 2021)
J/A+A/659/A1 : LOFAR Two-metre Sky Survey (LoTSS) DR2 (Shimwell+, 2022)
J/A+A/670/A158 : CHANG-ES. XXVI. radio images of 5 galaxies (Stein+, 2023)
J/A+A/673/A113 : MALS ten pointings continuum catalogue (Wagenveld+ 2023)
http://mals.iucaa.in/ : MeerKAT Absorption Line Survey (MALS) homepage
Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- IDPtg [1/782] Pointing sequence number (id_x)
5- 23 A19 --- Pointing MALS pointing ID (JHHMMSS.ss+DDMMSS.s)
based on the position (J2000) of the
central source in NVSS or SUMSS
(pointing_name)
25- 26 A2 --- StUHF Always "[]" (obsdateu)
28- 43 A16 "date" Date1 The date and time (UTC) of the start of
L-band observing block (s) (ISO)
(obsdatel)
45- 60 A16 "date" Date2 Second date and time (UTC) of the start
of L-band observing block (s) (ISO) if
any (obsdatel_2) 62 A1 --- Band
Observing band (always "L") (obs_band)
64- 73 A10 --- FluxCal1 Calibrator used for flux density and
bandpass calibration of the data set
(fluxcal)
75- 84 A10 --- FluxCal2 Second calibrator used for flux density
and bandpass calibration of the data
set if any (fluxcal)
86- 128 A43 --- FluxSc Flux density scales used for the flux
density calibrators (fluxscale) (1)
130- 135 A6 --- SPW/WB Whether the continuum image is made
using an SPW or the entire wideband (WB)
(spw_id) (2)
137- 143 F7.2 MHz Freq [1005.8/1381.2] Reference frequency of
the continuum image (ref_freq)
145- 161 F17.14 arcsec Majaxis [7.6/22.2] Major axis of the restoring
beam (majrestoringbeam)
163- 179 F17.14 arcsec Minaxis [6/11.7] Minor axis of the restoring
beam (minrestoringbeam)
181- 200 F20.16 deg PA [-86.5/89] Position angle of the
restoring beam (parestoringbeam)
202- 219 F18.13 uJy/beam sigma1 [15/1312] RMS noise measured from
primary beam-uncorrected rms image in
an annular ring at primary beam FWHM
(sigma_1)
221- 237 F17.13 uJy/beam sigma2 [13/645] RMS noise measured from
primary beam-uncorrected rms image in
an annular ring at 2 times the primary
beam FWHM (sigma_2)
239- 249 F11.6 uJy/beam sigma20 [26/2530] RMS noise at a cumulative
fraction of 0.2 of the rms noise
distribution of the primary
beam-corrected rms image
(see Wagenveld+ 2023 for details)
(sigma_20)
251- 257 I7 --- ID [735647/1471292] Identifier (source_id)
259- 261 I3 --- Set [1/782] Metadata ID (same as IDPtg)
(metadata_id)
263- 281 A19 --- Name MALS name of the source
(JHHMMSS.ss+DDMMSS.s) (source_name)
283- 305 F23.20 arcmin SepPtg [0.0003/86] Distance of the source from
the pointing center (distance_pointing)
307- 326 F20.17 arcmin SepNN [0.1/25] Distance of the source from
the nearest neighbor in the field
(distance_nn)
328 A1 --- Scode [MS] The PyBDSF code defining the
source structure (s_code) (3)
330- 331 I2 --- Ngauss [1/96] Number of Gaussian components
fitted to the source (n_gauss)
333- 353 F21.17 arcsec GaussMax [0.08/450]?=-1 Maximum separation
between the Gaussian components
(NULL for "S"-type sources)
(maxsep_gauss)
355- 374 F20.16 arcsec MajFWHM [5/366] FWHM of the major axis of the
source (maj)
376- 397 F22.19 arcsec e_MajFWHM [0.001/81] 1σ error on MajFWHM
(maj_e)
399- 418 F20.16 arcsec MinFWHM [2/144] FWHM of the minor axis of the
source (min)
420- 441 F22.19 arcsec e_MinFWHM [0.0005/29.3] 1σ error on MinFWHM
(min_e)
443- 466 F24.20 deg MajPA [3.6e-5/180] Position angle of the
major axis of the source measured east
of north (PA)
468- 492 F25.21 deg e_MajPA [2.2e-5/180] 1σ error on MajPA
(pa_e)
494- 521 F28.24 arcsec Maj0FWHM [0/366] FWHM of the deconvolved major
axis of the source (dc_maj)
523- 544 F22.19 arcsec e_Maj0FWHM [0.001/81] 1σ error on Maj0FWHM
(dcmaje)
546- 573 F28.24 arcsec Min0FWHM [0/143] FWHM of the deconvolved minor
axis of the source (dc_min)
575- 596 F22.19 arcsec e_Min0FWHM [0.0005/29.3] 1σ error on
Min0FWHM (dcmine)
598- 620 F23.19 deg Maj0PA [0/180] Position angle of the
deconvolved major axis of the source
measured east of north (dc_pa)
622- 646 F25.21 deg e_Maj0PA [2.2e-5/180] 1σ error on Maj0PA
(dcpae)
648- 670 F23.19 deg RAdeg Right ascension (J2000) of the mean
intensity-weighted position of all
pixels above the island threshold
measured if source is fitted with
multiple Gaussians (ra_mean)
672- 694 F23.21 deg e_RAdeg [5.5e-05/0.007] 1σ error on RAdeg
using Equation 1 (rameane)
696- 719 F24.20 deg DEdeg [-79/32.2] Declination (J2000) of the
mean intensity-weighted position of all
pixels above the island threshold
measured if source is fitted with
multiple Gaussians (dec_mean)
721- 742 F22.20 deg e_DEdeg [8.3e-5/0.01] 1σ error on DEdeg
using Equation 1 (decmeane)
744- 766 F23.19 deg RAMdeg The R.A. (J2000) of the pixel
corresponding to maximum flux density
(ra_max)
768- 790 F23.21 deg e_RAMdeg [5.5e-5/0.007] 1σ error on RAMdeg
using Equation 1 (ramaxe)
792- 815 F24.20 deg DEMdeg [-79/32.2] The decl. (J2000) of the
pixel corresponding to maximum flux
density (dec_max)
817- 838 F22.20 deg e_DEMdeg [8.3e-5/0.01] 1σ error on DEMdeg
using Equation 1 (decmaxe)
840- 863 F24.18 mJy Flux [0.015/17901] Total integrated flux
density of the source based on Gaussian
component fits, i.e., corrected for
primary beam and wideband effects
(total_flux)
865- 886 F22.18 mJy e_Flux [0.009/968] 1σ error on Flux
estimated using Equation 2
(totalfluxe)
888- 909 F22.18 --- ErrFlux [0.007/549] The fitting error on total
flux density to be taken into account
to obtain e_Flux
(see Section 4.2 and Equation 2)
(totalfluxe_fit)
911- 933 F23.19 --- sErrFlux [0.006/797] The systematic error to be
taken into account to obtain e_Flux
(see Section 4.2 and Equation 2)
(totalfluxe_sys)
935- 958 F24.18 mJy FluxAlt [0.01/17473] Total integrated flux
density of the source based on
alternate primary beam model, i.e.,
plumber (Section 4.3) obtained by
multiplying Flux and FluxCorr
(totalfluxmeasured)
960- 981 F22.18 mJy e_FluxAlt [0.009/957] 1σ error on FluxAlt
(totalfluxmeasured_e)
983- 1006 F24.18 mJy/beam FluxPk [0.03/11876] Peak flux density of the
source (peak_flux)
1008- 1028 F21.18 mJy/beam e_FluxPk [0.006/46] 1σ error on FluxPk
(peakfluxe)
1030- 1053 F24.18 mJy FluxIsl [-0.03/17981] Total integrated flux
density of the island in which the
source is located (isltotalflux)
1055- 1076 F22.18 mJy e_FluxIsl [0.009/236] 1σ error on FluxIsl
(isltotalflux_e)
1078- 1098 F21.18 mJy/beam rmsIsl [0.009/46] Average background rms noise
of the island in which the source is
located (isl_rms)
1100- 1128 F29.25 mJy/beam Isl [-22/23] Average background mean value
of the island in which the source is
located (isl_mean)
1130- 1157 F28.25 mJy/beam ResrmsIsl [0/51] Average residual background rms
noise of the island in which the source
is located (residislrms)
1159- 1186 F28.24 mJy/beam ResIsl [-25/35] Average residual background
mean value of the island in which the
source is located (residislmean)
1188- 1205 F18.16 --- FluxCorr [0.9/1.1] The factor to be multiplied
to flux density measurements and errors
to obtain the values corresponding to
the plumber beam model
(see Section 4.3 and Appendix C)
(flux_correction)
1207- 1210 A4 --- Real Whether a source is a real
astrophysical source or an artifact
(Always "True") (real_source)
1212- 1216 A5 --- Res Whether a source is resolved based on
the reliability envelope method
(see Figure 10) (resolved)
1218- 1219 A2 --- Link Always "[]" (source_linked)
1221- 1227 I7 --- IDy [735647/1471292] Same as ID (id_y)
1229- 1236 A8 --- SpInd Spectral index and curvature of the
source determined from the wideband
MTMFS image (always """[]""")
(spectral_index) (4)
1238- 1245 A8 --- e_SpInd 1σ error on SpInd
(always """[]""") (spectralindexe)
1247- 1261 A15 --- SpWind Spectral windows used for determining
spectral index and curvature using the
narrowband multifrequency synthesis
(MFS) images (spectralindexspwused)
(5)
1263- 1285 E23.6 --- Spwfit [-50/45]? Spectral index and curvature
of the source based on Flux from
narrowband (i.e., SPW-based) images
(spectralindexspwfit)
1287- 1306 E20.7 --- e_Spwfit [0.006/7]? 1σ error on Spwfit
(spectralindexspwfit_e)
1308- 1329 E22.6 --- SpMALS [-2.6/2]? Spectral index and curvature
based on Flux from narrowband images
from MALS and measurements from the
literature (spectralindexmals_lit)
1331- 1350 E20.7 --- e_SpMALS [0.04/0.5]? 1σ error on SpMALS
(spectralindexmalslite)
1352- 1367 A16 --- SpIndLit List of external surveys ("TGSS-ADR1",
"L:9" or "L:2") used
(spectralindexlit)
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Note (1): We used models based on Perley-Butler 2017
(Perley & Butler 2017, J/ApJS/230/7), the model based on
Stevens-Reynolds 2016 (Partridge+ 2016ApJ...821...61P 2016ApJ...821...61P) or the VLA
Calibrator Manual (http://science.nrao.edu/facilities/vla/observing/callist).
See Section 2.
Note (2): The possible values are LWB-WP, LWB-AWP, UWB-WP, UWB-AWP, LSPW_i, and
USPW_i; here i goes from 0-14. For example, LWB and UWB imply L- and
UHF-band wideband image, respectively. LSPW_2 and LSPW_9 correspond to
SPW2 and SPW9 of the L band included in DR1 presented here. WP and AWP
identify the imaging algorithm used for wideband imaging. WP:
W-Projection algorithm is used to correct for the wide-field effect of
noncoplanar baselines (Cornwell+ 1992A&A...258..583C 1992A&A...258..583C), and the primary
beam correction is applied after the imaging. AWP: A-term is also
included, and the wideband effects of the primary beam are corrected
prior to integration in time and frequency for the continuum imaging
(Bhatnagar+ 2013ApJ...770...91B 2013ApJ...770...91B).
Note (3): The PyBDSF code defining the source structure as follows:
S = a single source in the island, fitted with a single-Gaussian component.
C = a source with other neighbors within the island, fitted with a
single-Gaussian component.
M = a source fitted with multiple Gaussian components.
Note (4): For an extended source, a mean value for the pixels above some
threshold in the island is reported (see Section 5.2).
Note (5): For example, [''L:1∼4;7,'' 'U:3∼8;12''] implies Total_flux from
spectral windows 1-4 and 7 for the L band, and 3-8 and 12 for the
UHF band are used. Always """['L:2;9']""" or """[]""".
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- ID Pointing ID (JHHMMSS.ss+DDMMSS.s) (G1)
21 A1 --- flag Pointing flag (2)
23- 38 A16 --- DateTime UTC Date and Start time, ISO8601 format
40- 44 F5.1 uJy/beam sigma1-SPW9 [15.3/380]? RMS at primary beam, for
SPW9
46- 50 F5.1 uJy/beam sigma2-SPW9 [14/265]? RMS at twice of the primary
beam, for SPW9
52- 58 F7.1 mJy SSPW9 [32.7/11902]? Flux density of the
central radio source, for SPW9
(1350.9-1411.0MHz)
60- 64 A5 --- Class Class (3)
66- 71 F6.1 uJy/beam sigma1-v [16/1311.4]? RMS at primary beam, for
SPW2
73- 77 F5.1 uJy/beam sigma2-v [13.8/645]? RMS at twice of the primary
beam, for SPW2
79- 85 F7.1 mJy SSPW2 [87.6/11287]? Flux density of the
central radio source, for SPW2
(976.4-1036.5MHz)
87- 90 I4 --- NsrcSPW9 [186/1292]? Total number of sources
detected in the primary beam-corrected
field, SPW9
92- 95 I4 --- NsrcSPW2 [34/3428]? Total number of sources
detected in the primary beam-corrected
field, SPW2
--------------------------------------------------------------------------------
Note (2): Flags on pointings as follows:
* = field removed from spectral index analysis (Section 5.2)
owing to problematic SPW2 images;
d = one of the two pointings with extreme median flux density
offset (Section 4.2) and Fig. 17.
Note (3): Class; see also Section 3.1. With the format: "[A.#,B]_R",
where # is the subclass of A, "_R" marks one of the 50
representative images and A.#,B refer to --
A.1 = radio source at the pointing center is the brightest source
in the SPW9 image and the peak flux density range is
0.08-0.23Jy.beam-1;
A.2 = radio source at the pointing center is the brightest source
in the SPW9 image and the peak flux density range is
0.23-0.32Jy.beam-1;
A.3 = radio source at the pointing center is the brightest source
in the SPW9 image and the peak flux density range is
0.32-0.49Jy.beam-1;
A.4 = radio source at the pointing center is the brightest source
in the SPW9 image and the peak flux density range is
0.49-11.87Jy.beam-1;
B = an off-axis source in image is serendipitously brighter than
the central source.
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Byte-by-byte Description of file: tablee1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- ID Pointing ID (JHHMMSS.ss+DDMMSS.s) (G1)
21- 21 A1 --- SCode S_Code from PyBDSF catalog, Table 3 (2)
23- 27 F5.2 mJy SSPW2 [0.9/32] Total integrated flux density in SPW2
29- 33 F5.2 --- alpha [-2/-1.3] Spectral index (3)
35- 38 F4.2 --- e_alpha [0.05/0.2] Uncertainty in alpha
40- 44 A5 --- PS1 Boolean flag for PS1 match
("True": 42 occurrences)
46- 50 A5 --- WISE Boolean flag for WISE match
("True": 55 occurrences)
52- 52 I1 --- Flag [1/4] PS1+WISE match flag (4)
54- 58 F5.3 --- zNED [0.098/0.91]? NED redshift measurement
60- 71 A12 --- r_zNED Reference for NED redshift (5)
--------------------------------------------------------------------------------
Note (2): PyBDSF code defining the source structure as follows:
S = a single source in the island, fitted with a single Gaussian component;
M = a source fitted with multiple Gaussian components (5 occurrences).
Note (3): Spectral index based on TGSS ADR1 (147MHz) and SPW2 measurements.
Note (4): Match flag as follows:
1 = detected in WISE but not in PS1;
2 = not detected in both;
3 = detected in PS1 but not in WISE;
4 = detected in both.
Note (5): References for zNED as follows:
Bornancini07 = Bornancini et al. 2007MNRAS.378..551B 2007MNRAS.378..551B
SDSS12 = Alam+ 2015ApJS..219...12A 2015ApJS..219...12A (Cat. V/147)
SDSS13 = Albareti+ 2017ApJS..233...25A 2017ApJS..233...25A
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Byte-by-byte Description of file: tablef1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- ID Pointing IDs (JHHMMSS.ss+DDMMSS.s) (G1)
21- 26 F6.2 --- Vs [-17.2/43.4] Variability strength (Equation 9:
Vs=ΔS/(σ12+σ12)0.5;
Section 5.3)
28- 31 F4.2 --- m [0.1/2.6] Modulation index (see Equation 8
in Section 5.3)
33- 36 F4.2 --- fvar [0.3/4] Fractional variability
--------------------------------------------------------------------------------
Global notes:
Note (G1): Pointing ID based on R.A. and declination (J2000) of the
bright radio source at the center of the pointing.
--------------------------------------------------------------------------------
History:
Tables A1, E1 and F1 from electronic version of the journal
Catalogue (cataloguemalsdr1v2all.csv) downloaded at:
http://mals.iucaa.in/release/latest-release/search
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 01-Mar-2024