J/MNRAS/540/2685 SARAO MeerKAT Galactic Plane Survey stellar pop. (Egbo+, 2025)
The stellar population in the SARAO MeerKAT Galactic Plane Survey.
Egbo O.D., Buckley D.A.H., Groot P.J., Cavallaro F., Woudt P.A.,
Thompson M.A., Mutale M., Bietenholz M.
<Mon. Not. R. Astron. Soc. 540, 2685 (2025)>
=2025MNRAS.540.2685E 2025MNRAS.540.2685E (SIMBAD/NED BibCode)
ADC_Keywords: Galactic plane ; Stars, radio ; Optical ; Cross identifications
Keywords: methods: statistical - surveys - (stars:) binaries: general -
stars: variables: general - stars: Wolf-Rayet - radio continuum: stars
Abstract:
We report on optically selected stellar candidates of SARAO MeerKAT
1.3 GHz radio continuum survey sources of the Galactic plane. Stellar
counterparts to radio sources are selected by cross-matching the
MeerKAT source positions with Gaia DR3, using two approaches. The
first approach evaluated the probability of chance alignments between
the radio survey and Gaia sources and used AllWISE infrared
colour-colour information to select potential stellar candidates. The
second approach utilized a Monte Carlo method to evaluate the
cross-matching reliability probability, based on populations of known
radio-emitting stars. From the combined approaches, we found 629
potential stellar counterparts, of which 169 have existing SIMBAD
classifications, making it the largest Galactic plane radio-optical
crossmatch sample to date. A colour-magnitude analysis of the sample
revealed a diverse population of stellar objects, ranging from massive
OB stars, main-sequence stars, giants, young stellar objects, emission
line stars, red dwarfs and white dwarfs. Some of the proposed optical
counterparts include chromospherically/coronally active stars, for
example RS CVn binaries, BY Dra systems, YSOs and flare stars, which
typically exhibit radio emission. Based on Gaia's low-resolution
spectroscopy, some of the stars show strong Hα emission,
indicating they are magnetically active, consistent with them being
radio emitters. While MeerKAT's sensitivity and survey speed make it
ideal for detecting faint radio sources, its angular resolution limits
accurate counterpart identification for crowded fields such as the
Galactic Plane. Higher frequency, and, thereby, better spatial
resolution, radio observations plus circular polarization would be
required to strengthen the associations.
Description:
This catalog contains radio sources observed with SARAO MeerKAT
Galactic Plane Survey (SMGPS) compact source catalog and cross-matched
with Gaia DR3. It includes radio and optical properties, astrometric
parameters, fluxes, and cross-identifications.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 880 629 Cross-matched MeerKAT SMGPS-Gaia catalog
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- SMGPS SMGPS identifier (GLLL/ll+B.bbbb)
18- 30 A13 --- FileName SMGPS image file name
32- 51 F20.16 deg GLON Galactic Longitude
53- 73 E21.17 deg e_GLON Source-finding fitting error on longitude
75- 93 F19.16 deg GLAT Galactic Latitude
95-115 E21.17 deg e_GLAT Source-finding fitting error on latitude
117-136 F20.16 mJy/beam Fpeak MeerKAT 1.3.GHz peak flux density (1)
138-155 F18.16 mJy/beam e_Fpeak Error on MeerKAT 1.3.GHz peak flux density
157-176 F20.16 mJy Fint MeerKAT 1.3.GHz integrated flux density (1)
178-195 F18.16 mJy e_Fint Error on MeerKAT 1.3.GHz integrated
flux density
197-215 F19.16 arcsec a Fitted semi-major axis
217-237 E21.17 arcsec e_a ?=-1 Error on semi-major axis
239-257 F19.16 arcsec b Fitted semi-minor axis
259-278 E20.16 arcsec e_b ?=-1 Error on semi-minor axis
280-297 F18.14 deg RAdeg SMGPS right ascension (ICRS) at Ep=2019.4
299-318 F20.16 deg DEdeg SMGPS declination (ICRS) at Ep=2019.4
320-337 F18.16 arcsec e_RAdeg Error in right ascension
339-356 F18.16 arcsec e_DEdeg Error in declination
358-375 F18.16 arcsec ePos Combined RA and Dec error
377-395 I19 --- GaiaDR3 The Gaia DR3 source identifier
397-411 F15.11 deg RAGdeg Gaia right ascension (ICRS) at Ep=2016.0
413-427 F15.11 deg DEGdeg Gaia Declinayion (ICRS) at Ep=2016.0
429-434 F6.4 mas e_RAGdeg Error in RAGdeg
436-441 F6.4 mas e_DEGdeg Error in DEGdeg
443-461 I19 --- SolID Gaia DR3 solution identifier
463-469 F7.4 mas Plx Gaia DR3 parallax
471-477 F7.3 mas/yr PM Gaia DR3 total proper motion
479-487 F9.6 mag Gmag Gaia G-band mean magnitude
489-497 F9.6 mag BPmag Gaia BP-band mean magnitude
499-507 F9.6 mag RPmag Gaia RP-band mean magnitude
509-523 F15.11 deg RA2deg Right ascension (J2000)
525-539 F15.11 deg DE2deg Declination (J2000)
541-549 F9.6 mas e_RA2deg Error in RA2deg
551-559 F9.6 mas e_DE2deg Error in DE2deg
561-578 F18.14 deg RA1deg Gaia right ascension (ICRS) at Ep=J2019.4
580-599 F20.16 deg DE1deg Gaia declination (ICRS) at Ep=J2019.4
601-618 F18.16 mas dRA1deg Correction for right ascension (ICRS)
at Ep=J2019.4
620-637 F18.16 mas dDE1deg Correction declination (ICRS)
at Ep=J2019.4
639-648 I10 --- TIC ? TESS Input Catalog identifier
650-668 A19 --- AllWISE AllWISE identifier (JHHMMSS.ss+DDMMSS.s)
670-685 A16 --- 2MASS 2MASS identifier (HHMMSSss+DDMMSss)
687-698 F12.7 pc rpgeo Photogeometric distance
700-718 F19.16 --- fo1sig ? Normalised positional offset (1σ)
720-726 E7.5 --- so1sig ? Match confidence level (1σ)
728-732 F5.3 mag E(B-V) Extinction value E(B-V)
734-752 F19.16 mag G0mag Dereddened G-band magnitude
754-772 F19.16 mag GMAG G-band absolute magnitude
774-796 F23.16 mJy Fopt Optical flux derived from G0mag
798-816 F19.16 mag Gmagab G-band AB magnitude
818-838 E21.18 10-7W LumOpt Optical luminosity
840-861 E22.18 10-7W/Hz LumRad Radio luminosity
863-880 F18.16 arcsec SepSG SMGPS-Gaia angular separation
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Note (1): Fluxes are measured at 1.3GHz from MeerKAT continuum imaging.
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Acknowledgements:
Okwudili Daniel Egbo, egbo(at)saao.ac.za
(End) Patricia Vannier [CDS] 21-May-2025