J/MNRAS/528/542 SMGPS Local Void HI galaxy catalogue (Kurapati+, 2024)
H I galaxy signatures in the SARAO MeerKAT galactic plane survey.
II. The Local Void and its substructure.
Kurapati S., Kraan-korteweg R.C., Pisano D.J., Chen H., Rajohnson S.H.A.,
Steyn N., Frank B., Serra P., Goedhart S., Camilo F.
<Mon. Not. R. Astron. Soc. 528, 542 (2024)>
=2024MNRAS.528..542K 2024MNRAS.528..542K (SIMBAD/NED BibCode)
ADC_Keywords: Galaxy catalogs ; Surveys ; H I data ; Radial velocities ;
Redshifts ; Positional data ; Milky Way
Keywords: galaxies: evolution - galaxies: ISM - catalogues; surveys -
large-scale structure of Universe - radio lines: galaxies
Abstract:
The Local Void is one of the nearest large voids, located at a
distance of 23Mpc. It lies largely behind the Galactic Bulge and is
therefore extremely difficult to observe. We use HI 21cm emission
observations from the SARAO MeerKAT Galactic Plane Survey (SMGPS) to
study the Local Void and its surroundings over the Galactic longitude
range 329deg<l<55deg, Galactic latitude |b|<1.5deg, and redshift
cz<7500km/s. We have detected 291 galaxies of median rms sensitivity
0.44 mJy per beam per 44 km/s channel. We find 17 galaxies deep inside
the Void, 96 at the border of the Void, while the remaining 178
galaxies are in average density environments. The extent of the Void
is ∼58Mpc. It is severely underdense for the longitude range
350deg<l<35deg up to redshift z<4500km/s. The galaxies in the Void
tend to have HI masses that are lower (by approximately 0.25dex) than
their average density counterparts. We find several potential
candidates for small groups of galaxies, of which two groups (with 3
members and 5 members) in the Void show signs of filamentary
substructure within the Void.
Description:
HI 21-cm emission observations from the SARAO MeerKAT Galactic Plane
Survey (SMGPS) were used to search for galaxies behind the Galactic
Bulge and Zone of Avoidance towards the Local Void, over the Galactic
longitude range 329deg<l<358deg and 2deg<l<55deg (wrapping
through l=0deg), latitude |b|<1.5deg, and heliocentric velocity
range 300<Vhel<7500km/s (440 MeerKAT64 pointings).
Observations were carried out with the full MeerKAT array in L-band
(856-1712MHz) using the SKARAB 4k-correlator, giving a frequency
resolution of ∼209kHz (∼44.1km/s rest-frame velocity resolution at
z=0). Data were reduced with the CARACal pipeline. Individual
primary-beam corrected HI data cubes were stitched into 28 mosaic
cubes (22 overlapping pointings per mosaic, covering 4degx3deg
each), imaged with WSClean using robust=0 weighting and a 15 arcsec
taper, giving a synthesised beam of ∼30x27 arcsec and a median rms
sensitivity of 0.44Jy/beam per 44.1km/s channel.
HI sources were identified with the SoFiA-2 source finding pipeline
(Westmeier et al., 2021MNRAS.506.3962W 2021MNRAS.506.3962W) over the velocity range
300<Vhel<7500km/s.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 86 291 LV-SMGPS HI galaxy catalogue
table3.dat 81 38 HI parameters of galaxies in groups
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Name Name of the galaxy, the format
(SMGPS- HI)JHHMMSS-DDMMSS represents the
rounded values of RA and Declination
16- 18 A3 --- Mosaic Mosaic (Txx or Nxx from Figure 1 in paper)
in which the galaxy is detected
20- 25 F6.2 deg GLON Galactic longitude
27- 31 F5.2 deg GLAT Galactic latitude
33- 37 F5.2 Jy.km/s Fint Integrated flux in L-band (856-1712MHz)
39- 42 F4.2 Jy.km/s e_Fint Error on integrated flux
44- 48 F5.3 Jy Fpeak Peak flux in L-band (856-1712MHz)
50- 53 F4.2 mJy RMS Measured local RMS around the detection in
mJy/beam per 44.1km/s channel
55- 58 I4 km/s HRV Optical heliocentric velocity
60- 62 I3 km/s W20 The measured line width at 20% of the peak
flux
64- 66 I3 km/s W50 The measured line width at 50% of the peak
flux
68- 72 F5.2 [Msun] log(MHI) Logarithm of the HI mass
74 I1 --- Flag [1/2]? Detection flag (1)
76- 86 A11 --- Notes Notes on galaxies (2)
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Note (1): Detection flag as follows: (1=definite; 2=possible)
Note (2): It describes whether a galaxy is interacting, has a companion,
or any other relevant information
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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- 2 A2 --- Group Name of group
4- 9 A6 --- Region Environment in which group was found
11 A1 --- No Group member identifier
13- 26 A14 --- Name Name of galaxy, LV-SMGPS identifier,
JHHMMSS+DDMMSS
28- 33 F6.2 deg GLON Galactic longitude (deg)
35- 39 F5.2 deg GLAT Galactic latitude (deg)
41- 44 I4 km/s HV Optical heliocentric velocity
46- 48 I3 km/s W20 The measured line width at 20% of the peak
flux
50- 52 I3 km/s W50 The measured line width at 50% of the peak
flux
54- 58 F5.2 [Msun] log(MHI) Logarithm of the HI mass
60- 64 F5.2 [Msun] log(Mdyn) Logarithm of the dynamical mass
66- 70 F5.2 [Msun] log(Mhalo) ? Logarithm of the total dynamical mass
of the group
72- 76 F5.3 --- S ? Compactness parameter
78- 81 I4 kpc dproj ? Maximum projected distance between
the members of group
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Acknowledgements:
Sushma Kurapati, sushma(at)ncra.tifr.res.in
License: CC-BY-4.0
References:
Goedhart et al., 2024MNRAS.531..649G 2024MNRAS.531..649G (SMGPS survey overview)
Westmeier et al., 2021MNRAS.506.3962W 2021MNRAS.506.3962W (SoFiA-2)
(End) Patricia Vannier [CDS] 24-Jul-2026