J/A+A/700/A33 VVV NIRGC III (Alonso+, 2025)
The VVV near-IR galaxy catalogue of the southern Galactic disc.
Alonso M.V., Baravalle L.D., Nilo-Castellon J.L., Villalon C., Soto M.,
Sgro M.A., Daza-Perilla I.V., Valotto C., Lares M., Minniti D.,
Marchant Cortes P., Milla Castro F., Hempel M., Alonso-Garcia J., Macri L.,
Pichel A., Masetti N., Saito R.K., Gomez M.
<Astron. Astrophys. 700, A33 (2025)>
=2025A&A...700A..33A 2025A&A...700A..33A (SIMBAD/NED BibCode)
ADC_Keywords: Galactic plane ; Galaxies, IR ; Galaxy catalogs ;
Photometry, infrared
Keywords: galaxies: fundamental parameters - galaxies: general -
galaxies: photometry
Abstract:
The distribution of galaxies in the Zone of Avoidance (ZoA) is
incomplete due to the presence of our own Galaxy.
Our research focused on the identification and characterisation of
galaxies in the ZoA, using the new near-infrared (NIR) data from the
VVVX survey in the regions that cover the southern Galactic disc
(230°<l<350°).
We used our previously-established procedure based on photometric and
morphological criteria to identify galaxies. The large data volume
collected by the VVVX required alternatives to visual inspection,
including artificial intelligence techniques, such as classifiers
based on neural networks.
The VVV NIR galaxy catalogue (VVV NIRGC III) is presented, covering
the southern Galactic disc, significantly extending the vision down to
Ks0=16mag throughout the ZoA. This catalogue provides positions,
photometric and morphological parameters for a total of 167559
galaxies with their probabilities determined by the CNN and XGBoost
algorithms based on image and photometric data, respectively. The
construction of the catalogue involves the employment of optimal
probability criteria. 14% of these galaxies were confirmed by visual
inspection or by matching with previous catalogues. The peculiarities
exhibited by distinct regions across the Galactic disc, along with the
characteristics of the galaxies, are thoroughly examined. The
catalogue serves as a valuable resource for extragalactic studies
within the ZoA, providing a crucial complement to the forthcoming
radio catalogues and future surveys utilizing the Vera C. Rubin
Observatory and the Nancy Grace Roman Space Telescope.
We present a deep galaxy map, covering a 1080 sq. deg. region
(230°<l<350° and |b|<4.5°), which reveals that the
apparent galaxy density is predominantly influenced by foreground
extinction from the Milky Way. However, the presence of intrinsic
inhomogeneities, potentially associated with candidate galaxy groups
or clusters and filaments, is also discernible.
Description:
We present the VVV NIRGC III catalogue using the VVVX survey of the
southern Galactic disc (230°<l<350°), which comprises the
photometric and morphological properties of 167559 galaxies having
joint IS-CNN and PS-XGBoost probabilities >0.6, or
0.5< IS-CNN probabilities <0.6 and PS-XGBoost probabilities >0.8.
Our catalogue has a contamination rate due to misclassification of
about 10% and a completeness of 78%.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
nirgc3.dat 167 167559 VVV NIRGC III
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See also:
J/MNRAS/502/601 : The VVV near-IR galaxy catalogue (Baravalle+, 2021)
Byte-by-byte Description of file: nirgc3.dat
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Bytes Format Units Label Explanations
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1- 24 A24 --- ID Identifier (VVVX-JHHMMSS.ss+DDMMSS.s)
26- 27 I2 h RAh Right Ascension (J2000)
29- 30 I2 min RAm Right Ascension (J2000)
32- 36 F5.2 s RAs Right Ascension (J2000)
38 A1 --- DE- Declination sign (J2000)
39- 40 I2 deg DEd Declination (J2000)
42- 43 I2 arcmin DEm Declination (J2000)
45- 48 F4.1 arcsec DEs Declination (J2000)
50- 67 F18.14 deg GLON Galactic longitude
69- 85 E17.15 deg GLAT Galactic latitude
87- 90 F4.2 mag AKs Interstellar extinction (Ks band)
92- 96 F5.2 mag Jmag Total extinction-corrected J magnitude
98-102 F5.2 mag Hmag Total extinction-corrected H magnitude
104-108 F5.2 mag Ksmag Total extinction-corrected Ks magnitude
110-114 F5.2 mag JmagAp Extinction-corrected J aperture magnitude
within a fixed aperture of 2 arcsec diameter
116-120 F5.2 mag HmagAp Extinction-corrected H aperture magnitude
within a fixed aperture of 2 arcsec diameter
122-126 F5.2 mag KsmagAp Extinction-corrected Ks aperture magnitude
within a fixed aperture of 2 arcsec diameter
128-132 F5.2 arcsec Rhl Half-light radius
134-137 F4.2 --- C Concentration index
139-142 F4.2 --- Ellip Ellipticity
144-148 F5.2 --- n Spheroid Sersic index
150-155 F6.4 --- probIS IS-CNN probability
157-162 F6.4 --- probPS PS-XGBoost probability
164-165 I2 --- Gxflag Galaxy flag (1)
167 A1 --- zflag Redshift availability flag (2)
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Note (1): Galaxy flag as follows:
1 = Visually confirmed galaxy
2 = 2MASX galaxy
99 = Galaxies without visual inspection
Note (2): Redshift flag as follows:
0 = No redshift estimation available
1 = Spectroscopic redshift available
2 = Photometric redshift available
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Acknowledgements:
Carolina Villalon, cvillalon(at)unc.edu.ar
References:
Baravalle et al., VVV NIRGC I, 2021MNRAS.502..601B 2021MNRAS.502..601B, Cat. J/MNRAS/502/601
Daza-Perilla et al., VVV NIRGC II, 2023MNRAS.524..678D 2023MNRAS.524..678D
(End) Patricia Vannier [CDS] 01-Jul-2025