J/A+A/702/A264 Nearby galaxies opt. attenuation, dust, gas (Paspaliaris+, 2025)
Relating spatially resolved optical attenuation, dust and gas in nearby
galaxies.
Paspaliaris E.D., Bianchi S., Corbelli E., Concas A.
<Astron. Astrophys. 702, A264 (2025)>
=2025A&A...702A.264P 2025A&A...702A.264P (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Extinction ; Optical
Keywords: ISM: abundances - ISM: atoms - dust, extinction - ISM: molecules -
galaxies: ISM - galaxies: spiral
Abstract:
The purpose of the present study is to relate the optical attenuation
inferred by the Balmer decrement, AVBD, and by the spectral energy
distribution (SED)-fitting, AVSED, to the dust distribution and gas
surface density throughout the disc of galaxies, down to scales
smaller than 0.5kpc
We investigate five nearby Herschel-detected star-forming spiral
galaxies with available far-ultraviolet to sub-millimetre
observations, along with atomic and molecular gas surface density maps
and optical integral-field spectroscopic data. We use the CIGALE
SED-fitting code to map the dust mass surface density SigmaDUST and
AVSED of different stellar populations. For each pixel, we
independently estimate the attenuation from the Balmer decrement.
We find that both SigmaDUST and AVBD trace better the molecular and
total gas mass surface density, rather than the atomic gas. Since
regions sampled in this study have high molecular fractions, atomic
gas surface densities, indicative of molecular gas shielding layers,
decrease as the mean dust-to-gas ratio increases from galaxy to
galaxy. The fitted attenuation towards the young stellar population,
AVSEDyoung, is in good agreement with AVBD and it can then be used to
trace the attenuation in star-forming galaxies where integral-field
observations are not available. We estimate the ratio of AVBD over the
total stellar AVSED and find it slightly larger than what has been
found in previous studies. Finally, we investigate which dust
distribution reproduces better the estimated AVBD and AVSED. We find
that the attenuation towards old stars is consistent with the
expectations for a standard galactic disc, where the stellar and dust
distributions are mixed, while AVBD and the AVSEDyoung are between the
values expected for a foreground dust screen and the mixed
configuration.
Description:
table1.dat contains the physical properties derived in this work,
including SigmaDUST, AVBD, AVSED, AVSEDold and AVSEDyoung.
table2.dat contains general integrated properties of each galaxy.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 100 5 Integrated properties
tablea1.dat 122 162800 *Derived physical properties per pixel
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Note on tablea1.dat: All properties are provided in the line-of-site. No
inclination correction is applied.
Pixels that do not have at least eleven bands above 3σ, mandatorily
including SPIRE-250um and at least one more Herschel band, are omitted.
Only pixels with CIGALE reliable estimates (i.e. 1/5≤best/bayes≤5) are
included.
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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- 7 A7 --- Id Galaxy identifier
9- 10 I2 h RAh Right ascension (J2000)
12- 13 I2 min RAm Right ascension (J2000)
15- 20 F6.3 s RAs Right ascension (J2000)
22 A1 --- DE- Declination sign (J2000)
23- 24 I2 deg DEd Declination (J2000)
26- 27 I2 arcmin DEm Declination (J2000)
29- 33 F5.2 arcsec DEs Declination (J2000)
35- 38 A4 --- Type Hubble Type (1)
40- 44 F5.2 arcmin D25 Major axis of the optical 25mag/arcsec2
isophote (1)
46- 50 F5.2 Mpc D Distance (Anand et al., 2021MNRAS.501.3621A 2021MNRAS.501.3621A)
52- 55 F4.2 kpc pw Pixel width in physical scale
57- 60 F4.1 deg i Inclination
62- 64 I3 deg PA Position angle (Walter et al.,
2008AJ....136.2563W 2008AJ....136.2563W, Cat. J/AJ/136/2563;
Chung et al. 2009AJ....138.1741C 2009AJ....138.1741C)
66- 69 F4.2 10+9Msun MHI HI mass
71- 74 F4.1 10+9Msun MH2 H2 mass
76- 78 F3.1 Msun/yr SFR Star formation rate
80- 82 F3.1 Msun/yr e_SFR Star formation rate error
84- 87 F4.1 10+9Msun Mstar Stellar mass
89- 92 F4.1 10+9Msun e_Mstar Stellar mass error
94- 96 F3.1 10+9Msun Mdust Dust mass
98-100 F3.1 10+9Msun e_Mdust Dust mass error
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Note (1): Properties with no reference are taken from DustPedia archive
(see Clark et al., 2018A&A...609A..37C 2018A&A...609A..37C, Cat. J/A+A/609/A37;
Davies et al., 2019A&A...626A..63D 2019A&A...626A..63D; http://dustpedia.astro.noa.gr/).
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 10 F10.4 --- pixid Unique ID of each pixel with fractional
part indicating NGC galaxy ID
12- 16 I5 --- px x-axis pixel serial number (1)
18- 22 I5 --- py y-axis pixel serial number (1)
24- 32 E9.4 Msun/pc2 SigmaDUST ?=-999.999 dust mass surface density
34- 42 E9.4 Msun/pc2 e_SigmaDUST ?=-999.999 Error on dust mass surface
density
44- 52 F9.3 mag AVBD ?=-999.999 V-band attenuation inferred
by BD
54- 62 F9.3 mag e_AVBD ?=-999.999 Error on V-band attenuation
inferred by BD
64- 72 F9.3 mag AVSED ?=-999.999 V-band attenuation inferred
by SED
74- 82 F9.3 mag e_AVSED ?=-999.999 Error on V-band attenuation
inferred by SED
84- 92 F9.3 mag AVSEDold ?=-999.999 V-band attenuation towards old
stars inferred by SED
94-102 F9.3 mag e_AVSEDold ?=-999.999 Error on V-band attenuation
towards old stars inferred by SED
104-112 F9.3 mag AVSEDyoung ?=-999.999 V-band attenuation towards
young stars inferred by SED
114-122 F9.3 mag e_AVSEDyoung ?=-999.999 Error on V-band attenuation
towards young stars inferred by SED
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Note (1): The pixel size is 6", equal to the pixel size of SPIRE-250um band.
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Acknowledgements:
Evangelos D. Paspaliaris, evangelos.paspaliaris(at)inaf.it
INAF-Arcetri Astrophysical Observatory
(End) Evangelos Paspaliaris [INAF], Patricia Vannier [CDS] 02-Sep-2025