J/MNRAS/497/672 Abundance determination in HII regions (Arellano-Cordova+, 2020)
The Te[N II]-Te[O III] temperature relation in H II regions and the
reliability of strong-line methods.
Arellano-Cordova K.Z., Rodriguez M.
<Mon. Not. R. Astron. Soc., 497, 672-686 (2020)>
=2020MNRAS.497..672A 2020MNRAS.497..672A (SIMBAD/NED BibCode)
ADC_Keywords: Abundances, peculiar ; H II regions ; Galaxies ; Spectra, optical
Keywords: ISM: abundances - HII regions - galaxies: abundances
Abstract:
We use a sample of 154 observations of 124 HII regions that have
measurements of both Te[OIII] and Te[NII], compiled from the
literature, to explore the behaviour of the Te[OIII]-Te[NII]
temperature relation. We confirm that the relation depends on the
degree of ionization and present a new set of relations for two
different ranges of this parameter. We study the effects introduced by
our temperature relations and four other available relations in the
calculation of oxygen and nitrogen abundances. We find that our
relations improve slightly on the results obtained with the previous
ones. We also use a sample of 26 deep, high-resolution spectra to
estimate the contribution of blending to the intensity of the
temperature-sensitive line [OIII]λ4363, and we derive a
relation to correct Te[OIII] for this effect. With our sample of 154
spectra, we analyse the reliability of the R, S, O3N2, N2, ONS, and C
strong-line methods by comparing the metallicity obtained with these
methods with the one implied by the direct method. We find that the
strong-line methods introduce differences that reach ∼0.2dex or more,
and that these differences depend on O/H, N/O, and the degree of
ionization.
Description:
Our initial sample contains 168 spectra of 133 H II regions compiled
from the literature. The spectral resolutions are in the range
0.1-10Å, but most observations have spectral resolutions larger
than 5Å. The 168 observed spectra have measurements of both
[OIII]λ4363 and [NII]λ5755, which makes it possible to
compute the electron temperatures Te[NII] and Te[OIII].
The initial sample was filtered following the criteria defined in
Section 4.1. The final sample contains 154 spectra of 124 H II
regions. Table A1 lists the sample H II regions and the references
for their spectra, along with the galaxy to which they belong and the
identifications used in the original references.
Table A2 shows the oxygen abundances calculated using strong-line
methods for the regions in our final sample. We have excluded the
Galactic H II regions from these calculations because their spectra
are generally obtained in a small area that cannot be considered as
representative of the whole object.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 136 154 Our calculated values for electron densities,
temperatures, oxygen abundances and
nitrogen-to-oxygen abundance ratios for a sample
of 154 observations of 124 HII regions compiled
from the literature
tablea2.dat 107 126 Our calculated values for the oxygen abundances
using Te and the R, S, ONS, C, O3N2, and N2
strong-line methods for the sample of
extragalactic HII regions
refs.dat 71 33 References for Table A1
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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- 3 I3 --- ID [1/154] Observation identifier
5- 17 A13 --- Galaxy Galaxy name
19 I1 --- f_Galaxy [1/5]? Flag on Galaxy (1)
21- 32 A12 --- Name Name of the HII region
34- 35 A2 --- f_Name [*67 ] Flag on Name (2)
37 A1 --- l_ne[SII] Limit flag on ne[SII]
39- 42 I4 cm-3 ne[SII] ? Electron density from the [SII] line
44- 47 I4 cm-3 E_ne[SII] ? Upper error on ne[SII]
49- 52 I4 cm-3 e_ne[SII] ? Lower error on ne[SII]
54 A1 --- f_ne[SII] [*] Flag on ne[SII] (3)
56 A1 --- l_ne[OII] Limit flag on ne[OII]
58- 61 I4 cm-3 ne[OII] ? Electron density from the [OII] line
63- 66 I4 cm-3 E_ne[OII] ? Upper error on ne[OII]
68- 70 I3 cm-3 e_ne[OII] ? Lower error on ne[OII]
72- 76 I5 K Te[OIII] Electron temperature from the [OIII] line (4)
78- 81 I4 K E_Te[OIII] Upper error on Te[OIII]
83- 86 I4 K e_Te[OIII] Lower error on Te[OIII]
88- 92 I5 K Te[NII] Electron temperature from the [NII] line
94- 97 I4 K E_Te[NII] Upper error on Te[NII]
99- 102 I4 K e_Te[NII] Lower error on Te[NII]
104- 107 F4.2 [-] 12+logO/H Oxygen abundance 12+log (O/H)
109- 112 F4.2 [-] E_12+logO/H Upper error on 12+logO/H
114- 117 F4.2 [-] e_12+logO/H Lower error on 12+logO/H
119- 123 F5.2 [-] logN/O Logarithm of the nitrogen-to-oxygen
abundance ratio
125- 128 F4.2 [-] E_logN/O Upper error on logN/O
130- 133 F4.2 [-] e_logN/O Lower error on logN/O
135- 136 I2 --- Ref [1/33] Reference for the line intensities
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Note (1): Flag as follows:
1 = Large Magellanic Cloud
2 = The Milky Way
3 = SDSS J002101.03+005248.1 is the object ID used in the original study
4 = SDSS J172906.56+565319.4 is the object ID used in the original study
5 = Small Magellanic Cloud
Note (2): Flag as follows:
* = HII region with Wolf-Rayet features
6 = Spectrum from the Sloan Digital Sky Survey (SDSS)
7 = Spectrum from the William Herschel Telescope
Note (3): Flag as follows:
* = In the original table, the value of ne[SII] was 10060
Note (4): The objects with Te[OIII]<10000K and low-resolution spectra have
been corrected using Equation 2 of Section 3.2
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ID [1/154] Observation identifier
5- 17 A13 --- Galaxy Galaxy name
19- 30 A12 --- Name Name of the HII region
32 A1 --- f_Name [*] Flag on Name (1)
34- 37 F4.2 [-] (O/H)Te Oxygen abundance 12+log(O/H) calculated
using Te
39- 42 F4.2 [-] E_(O/H)Te Upper error on (O/H)Te
44- 47 F4.2 [-] e_(O/H)Te Lower error on (O/H)Te
49- 52 F4.2 [-] (O/H)R Oxygen abundance 12+log(O/H) calculated
using the R method of Pilyugin & Grebel
(2016MNRAS.457.3678P 2016MNRAS.457.3678P)
54- 57 F4.2 [-] e_(O/H)R Error on (O/H)R
59- 62 F4.2 [-] (O/H)S Oxygen abundance 12+log(O/H) calculated
using the S method of Pilyugin & Grebel
(2016MNRAS.457.3678P 2016MNRAS.457.3678P)
64- 67 F4.2 [-] e_(O/H)S Error on (O/H)S
69- 72 F4.2 [-] (O/H)ONS Oxygen abundance 12+log(O/H) calculated
using the ONS method of Pilyugin et al.
(2010ApJ...720.1738P 2010ApJ...720.1738P)
74- 77 F4.2 [-] e_(O/H)ONS Error on (O/H)ONS
79- 82 F4.2 [-] (O/H)C Oxygen abundance 12+log(O/H) calculated
using the C method of Pilyugin et al.
(2012MNRAS.424.2316P 2012MNRAS.424.2316P, Cat. J/MNRAS/424/2316)
84- 87 F4.2 [-] e_(O/H)C Error on (O/H)C
89- 92 F4.2 [-] (O/H)O3N2 ? Oxygen abundance 12+log(O/H) calculated
using the O3N2 method of Marino et al.
(2013A&A...559A.114M 2013A&A...559A.114M, Cat. J/A+A/559/A114)
94- 97 F4.2 [-] e_(O/H)O3N2 ? Error on (O/H)O3N2
99- 102 F4.2 [-] (O/H)N2 ? Oxygen abundance 12+log(O/H) calculated
using the N2 method of Marino et al.
(2013A&A...559A.114M 2013A&A...559A.114M, Cat. J/A+A/559/A114)
104- 107 F4.2 [-] e_(O/H)N2 ? Error on (O/H)N2
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Note (1): Flag as follows:
* = HII region with Wolf-Rayet features
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref [1/33] Reference number
4- 22 A19 --- BibCode BibCode
24- 50 A27 --- Aut Author's name
52- 71 A20 --- Com Comments
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 24-Jul-2023