J/ApJS/281/33 1.28GHz filaments in the central molecular zone (Arendt+, 2025)
A catalog of filaments in the central molecular zone.
Arendt R.G., Yusef-Zadeh F., Heywood I.
<Astrophys. J. Suppl. Ser., 281, 33 (2025)>
=2025ApJS..281...33A 2025ApJS..281...33A
ADC_Keywords: Galactic center; Interstellar medium; Radio sources
Keywords: Galactic center ; Interstellar filaments ; Galactic radio sources ;
Interstellar synchrotron emission
Abstract:
We present a catalog of 1.28GHz radio filaments observed by MeerKAT
over the innermost 200pc of the Galaxy (roughly ±1:5), which
includes the central molecular zone. The catalog is generated by
repurposing software developed for the automated detection of
filaments in solar coronal loops. There are two parts to the catalog.
The first part, the main catalog, provides a point-by-point listing
of locations and basic observational properties along each detected
filament. The second part is a summary catalog that provides a listing
of mean, median, or total values of various properties for each
filament. Tabulated quantities include position, length, curvature,
brightness, and spectral index. The catalogs contain a heterogeneous
mix of filamentary structures, including nonthermal radio filaments,
and parts of supernova remnants and thermally emitting regions (e.g.,
HII regions). We discuss criteria for selecting useful subsamples of
filaments from the catalogs, and some of the details encountered in
examining filaments or selections of filaments from the catalogs.
Description:
Here we summarize key aspects of the MeerKAT data, which are discussed
in more detail in Yusef-Zadeh+ (2022ApJ...925L..18Y 2022ApJ...925L..18Y) and
Heywood+ (2022ApJ...925..165H 2022ApJ...925..165H). The L-band (1.28GHz) MeerKAT mosaic
spans ∼3°x2° (in Galactic orientation) across the central
molecular zone (CMZ). The image itself is in equatorial coordinates
with 1.1" pixels (4" beam FWHM).
To enhance the visibility of filaments, this image is filtered using a
difference of Gaussians to smooth noise and remove large-scale
backgrounds.
We also used a spectral index image constructed from the MeerKAT
observations to characterize the 856-1712MHz spectral index of the
identified filaments.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 130 464505 Main catalog
table3.dat 158 9887 Summary catalog
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See also:
J/AJ/128/1646 : The Galactic Center region at 330MHz (Nord+, 2004)
J/ApJS/155/421 : Survey of Galactic Center region at 20cm (Yusef-Zadeh+, 2004)
J/ApJS/177/515 : 6cm and 20cm survey of Galactic Center (Law+, 2008)
J/ApJS/213/22 : NIR polarimetry in Central Molecular Zone (Yoshikawa+, 2014)
J/PASJ/67/90 : Central Molecular Zone in H13CO+ (Tsuboi+, 2015)
J/A+A/586/A50 : Central Molecular Zone H2CO temperature maps (Ginsburg+, 2016)
J/ApJS/244/35 : VLA observations of the Central Molecular Zone (Lu+, 2019)
J/ApJ/894/L14 : ALMA obs. of massive clouds in the CMZ (Lu+, 2020)
J/A+A/668/A183 : CMZ cloud complexes datacubes (Busch+, 2022)
J/ApJS/261/13 : High-vel. dispersion compact clouds in the CMZ (Oka+, 2022)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- ID [0/9999] ID number
6- 13 F8.2 pix x [14.6/10088.6] x position
15- 22 F8.2 pix y [10.6/10477.3] y position
24- 32 F9.6 deg GLON [-2.1/1.5] Galactic longitude
34- 42 F9.6 deg GLAT [-1.5/1.2] Galactic latitude
44- 55 E12.5 Jy/beam Flux [-0.0002/0.0092]?=-9999.99 Flux density,
Iν
57- 65 F9.4 pix Length [0/1161] Cumulative length
67- 78 E12.5 Jy/beam fg [-5.5e+10/9.3e+11] Cross-sectional
gaussian fit amplitude, fg
80- 91 E12.5 arcsec delg [-6.6e+13/1.4e+13] Cross-sectional gaussian
fit offset, δg
93- 104 E12.5 arcsec sigg [0/4.8e+13]?=-9999.99 Cross-sectional
gaussian fit sigma, σg
106- 117 E12.5 --- alpha [-5.2/3.7]?=-9999.99 Spectral index
119- 130 E12.5 arcsec r0 [30/883315]?=-9999.99 Local radius of curvature
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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- 4 I4 --- ID [0/9999] ID number
6- 13 F8.2 pix x [17.4/10086.4] Midpoint x position
15- 22 F8.2 pix y [27/10463] Midpoint y position
24- 33 F10.7 deg GLON [-2.1/1.5] Midpoint Galactic longitude
35- 44 F10.7 deg GLAT [-1.5/1.2] Midpoint Galactic latitude
46- 55 E10.3 Jy/beam Flux [-1.1e-05/0.05] Median flux density, Iν
57- 63 F7.2 arcsec Length [33/1278.2] Total length
65- 70 F6.2 deg PAeq [0/180] Position angle, θe
(equatorial)
72- 77 F6.2 deg PAgal [0/180] Position angle, θg (Galactic)
79- 85 F7.2 arcsec Rad1 [32/3000] Radius of curvature (3-point fit)
87- 96 F10.2 arcsec Rad2 [33/1119467] Radius of curvature (full fit)
98- 104 F7.2 arcsec Rad3 [32.7/5522] Median local radius of curvature
106- 115 E10.3 Jy/beam fg [-0.05/0.08] Median cross-sectional gaussian
fit amplitude
117- 120 F4.2 arcsec sigg [0/9.1] Median cross-sectional gaussian fit
sigma
122- 131 E10.3 --- alpha [-2.7/2.7]?=-9999 Median spectral index
133- 142 E10.3 --- e_alpha [0.003/2.3]?=-9999 Standard deviation of
spectral index
144- 147 I4 --- o_alpha [0/1021] Number of point for spectral index
149- 158 E10.3 arcsec-1 da/dL [-0.9/0.5] Linear gradient of spectral index
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History:
From electronic version of the journal
License: CC-BY-4.0
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 24-Jun-2026