J/A+A/691/A173 HII in galaxies abundances (Brazzini+, 2024)
Metallicity calibrations based on auroral lines from PHANGS-MUSE data.
Brazzini M., Belfiore F., Ginolfi M., Groves B., Kreckel K., Vaught J.R.R.,
Baron D., Bigiel F., Blanc A.G., Dale A.D., Grasha K., Habjan E.,
Klessen S.R., Mendez-Delgado J.E., Sandstrom K., Williams G.T.
<Astron. Astrophys. 691, A173 (2024)>
=2024A&A...691A.173B 2024A&A...691A.173B (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; H II regions ; Abundances
Keywords: ISM: abundances - HII regions - galaxies: abundances - galaxies: ISM
Abstract:
We present a chemical analysis of selected HII regions from the
PHANGS-MUSE nebular catalogue. Our intent is to empirically
re-calibrate strong-line diagnostics of gas-phase metallicity,
applicable across a wide range of metallicities within nearby
star-forming galaxies. To ensure reliable measurements of auroral line
fluxes, we carried out a new spectral fitting procedure whereby only
restricted wavelength regions around the emission lines of interest
are taken into account: this assures a better fit for the stellar
continuum. No prior cuts to nebulae luminosity were applied to limit
biases in auroral line detections. Ionic abundances of O+, O2+,
N+, S+, and S2+ were estimated by applying the direct method. We
integrated the selected PHANGS-MUSE sample with other existing auroral
line catalogues, appropriately re-analysed to obtain a homogeneous
dataset. This was used to derive strong-line diagnostic calibrations
that span from 12+log(O/H)=7.5 to 8.8. We investigate their dependence
on the ionisation parameter and conclude that it is likely the primary
cause of the significant scatter observed in these diagnostics. We
apply our newly calibrated strong-line diagnostics to the total sample
of HII regions from the PHANGS-MUSE nebular catalogue, and we
exploit these indirect metallicity estimates to study the radial
metallicity gradient within each of the 19 galaxies of the sample. We
compare our results with the literature and find good agreement,
validating our procedure and findings. With this paper, we release the
full catalogue of auroral and nebular line fluxes for the selected HII
regions from the PHANGS-MUSE nebular catalogue. This is the first
catalogue of direct chemical abundance measurements carried out with
PHANGS-MUSE data.
Description:
In this work, we provide a chemical analysis of HII regions from
the PHANGS-MUSE nebular catalogue compiled in Groves et al.
(2023MNRAS.520.4902G 2023MNRAS.520.4902G). We fitted all the spectra from the catalogue
following an innovative procedure based on single-region spectral
fitting, with the intent of better constraining the stellar continuum.
We carried out a selection procedure that aimed to select without any
prior bias the brightest sources of the catalogue, then we exploited
the measured line fluxes to estimate the electron temperatures and
densities, and hence the ionic abundances. We complemented the
PHANGS-MUSE emission line catalogue with other emission line
compilations from the literature, which have been carefully
re-analysed in order to obtain a homogeneous and comprehensive sample
of direct metallicity estimates covering a wide range in metallicity
(7.4≤12+log(O/H)≤8.8). We then exploited the total dataset to
empirically re-calibrate some of the most widely used strong-line
diagnostics for the determination of the oxygen abundance, and we
investigated their dependence on the ionisation parameter. Lastly, we
used our newly calibrated diagnostics to infer the metallicity of all
HII regions within the PHANGS-MUSE sample, and for each galaxy of
the sample we evaluated the radial metallicity gradients.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 557 95 Selected regions abundances
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Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Galaxy Galaxy name
9- 12 I4 --- ID HII region ID
14- 32 F19.15 deg RAdeg Right ascension (J2000)
34- 54 F21.17 deg DEdeg Declination (J2000)
56- 59 F4.2 mag Av Absorption
61- 69 F9.3 10-20W/m2 FHb Hβ flux
(in 10-17erg/s/cm2 unit)
71- 76 F6.3 10-20W/m2 e_FHb Hβ flux error
(in 10-17erg/s/cm2 unit)
78- 86 F9.3 10-20W/m2 FHa Hα flux
(in 10-17erg/s/cm2 unit)
88- 93 F6.3 10-20W/m2 e_FHa Hα flux error
(in 10-17erg/s/cm2 unit)
95-103 F9.3 10-20W/m2 FOIII5007 OIII5007 flux
(in 10-17erg/s/cm2 unit)
105-110 F6.3 10-20W/m2 e_FOIII5007 OIII5007 flux error
(in 10-17erg/s/cm2 unit)
112-118 F7.3 10-20W/m2 FNII5756 NII5756 flux
(in 10-17erg/s/cm2 unit)
120-124 F5.3 10-20W/m2 e_FNII5756 NII5756 flux error
(in 10-17erg/s/cm2 unit)
126-143 F18.16 10-20W/m2 FNIIcorfact NII flux error correction factor
145-152 F8.3 10-20W/m2 FSII6717 SII6717 flux
(in 10-17erg/s/cm2 unit)
154-158 F5.3 10-20W/m2 e_FSII6717 SII6717 flux error
(in 10-17erg/s/cm2 unit)
160-167 F8.3 10-20W/m2 FSII6731 SII6731 flux
(in 10-17erg/s/cm2 unit)
169-173 F5.3 10-20W/m2 e_FSII6731 SII6731 flux error
(in 10-17erg/s/cm2 unit)
175-181 F7.3 10-20W/m2 FOII7320 OII7320 flux
(in 10-17erg/s/cm2 unit)
183-187 F5.3 10-20W/m2 e_FOII7320 OII7320 flux error
(in 10-17erg/s/cm2 unit)
189-195 F7.3 10-20W/m2 FOII7330 OII7330 flux
(in 10-17erg/s/cm2 unit)
197-201 F5.3 10-20W/m2 e_FOII7330 OII7330 flux error
(in 10-17erg/s/cm2 unit)
203-221 F19.16 --- FOIIcorfact OII flux error correction factor
223-231 F9.3 10-20W/m2 FOIII4959 OIII4959 flux
(in 10-17erg/s/cm2 unit)
233-238 F6.3 10-20W/m2 e_FOIII4959 OIII4959 flux error
(in 10-17erg/s/cm2 unit)
240-246 F7.3 10-20W/m2 FSIII6312 SIII6312 flux
(in 10-17erg/s/cm2 unit)
248-252 F5.3 10-20W/m2 e_FSIII6312 SIII6312 flux error
(in 10-17erg/s/cm2 unit)
254-272 F19.16 --- FSIIIcorfact SIII flux error correction factor
274-281 F8.3 10-20W/m2 FSIII9069 SIII9069 flux
(in 10-17erg/s/cm2 unit)
283-287 F5.3 10-20W/m2 e_FSIII9069 SIII9069 flux error
(in 10-17erg/s/cm2 unit)
289-297 F9.3 10-20W/m2 FNII6584 NII6584 flux
(in 10-17erg/s/cm2 unit)
299-304 F6.3 10-20W/m2 e_FNII6584 NII6584 flux error
(in 10-17erg/s/cm2 unit)
306-314 F9.3 10-20W/m2 FNII6548 NII6548 flux
(in 10-17erg/s/cm2 unit)
316-320 F5.3 10-20W/m2 e_FNII6548 NII6548 flux error
(in 10-17erg/s/cm2 unit)
322-338 F17.11 K temNII Temperature from NII
340-358 F19.15 K e_temNII Error on temNII
360-376 F17.11 K temSIII Temperature from SIII
378-396 F19.15 K e_temSIII Error on temSIII
398-416 F19.15 cm-3 Ne Electron number density
418-437 F20.17 cm-3 e_Ne Error on electron number density
439-455 F17.15 [-] A(O) Oxygen abundance
457-476 F20.18 [-] e_A(O) Error on oxygen abundance
478-495 F18.16 [-] A(S) Sulphur abundance
497-517 F21.19 [-] e_A(S) Error on sulphur abundance
519-536 F18.16 [-] A(N) Nitrogen abundance
538-557 F20.18 [-] e_A(N) Error on nitrogen abundance
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Acknowledgements:
Matilde Brazzini, matilde.brazzini(at)inaf.it
(End) Patricia Vannier [CDS] 19-Sep-2024