J/MNRAS/460/1739 Giant HII regions BOND abundances (Vale Asari+, 2016)
BOND: Bayesian Oxygen and Nitrogen abundance Determinations in giant H II
regions using strong and semistrong lines.
Vale Asari N., Stasinska G., Morisset C., Cid Fernandes R.
<Mon. Not. R. Astron. Soc., 460, 1739-1757 (2016)>
=2016MNRAS.460.1739V 2016MNRAS.460.1739V (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; H II regions ; Abundances
Keywords: methods: data analysis - ISM: abundances - H II regions -
galaxies: abundances
Abstract:
We present the Bayesian oxygen and nitrogen abundance determinations
(bond) method. bond is a Bayesian code (available at:
http://bond.ufsc.br) to simultaneously derive oxygen and nitrogen
abundances in giant HII regions. It compares observed emission lines
to a grid of photoionization models without assuming any relation
between O/H and N/O. Our grid spans a wide range in O/H, N/O and
ionization parameter U, and covers different starburst ages and
nebular geometries. Varying starburst ages accounts for variations in
the ionizing radiation field hardness, which arise due to the ageing
of HII regions or the stochastic sampling of the initial mass
function. All previous approaches assume a strict relation between the
ionizing field and metallicity. The other novelty is extracting
information on the nebular physics from semistrong emission lines.
While strong lines ratios alone ([OIII]/Hβ, [OII]/Hβ and
[NII]/Hβ) lead to multiple O/H solutions, the simultaneous use
of [ArIII]/[NeIII] allows one to decide whether an HII region is of
high or low metallicity. Adding HeI/Hβ pins down the hardness of
the radiation field. We apply our method to HII regions and blue
compact dwarf galaxies, and find that the resulting N/O versus O/H
relation is as scattered as the one obtained from the
temperature-based method. As in previous strong-line methods
calibrated on photoionization models, the bond O/H values are
generally higher than temperature-based ones, which might indicate the
presence of temperature fluctuations or kappa distributions in real
nebulae, or a too soft ionizing radiation field in the models.
Description:
BOND determines nitrogen and oxygen gas-phase abundances by using
strong and semistrong lines and comparing them to a grid of
photoionization models in a Bayesian framework. The code is written in
python and its source is publicly available at http://bond.ufsc.br.
The grid of models presented here is included in the 3MdB data base
(Morisset, Delgado-Inglada & Flores-Fajardo 2015RMxAA..51..103M 2015RMxAA..51..103M, see
https://sites.google.com/site/mexicanmillionmodels/) under the
reference 'BOND'. The Bayesian posterior probability calculated by
bond stands on two pillars: our grid of models and our choice of
observational constraints (from which we calculate our likelihoods).
We discuss each of these in turn.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 221 708 Giant HII regions and blue compact dwarves
emission lines
table2.dat 168 156 BOND results for sample B of Giant HII regions
and blue compact dwarves
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Id [1/708] Sequnetial number
5 A1 --- r_Id Reference for Id (1)
7- 23 A17 --- Name HII region name (NGCNNNNNNNN)
25- 34 E10.5 --- F3727 Line flux of [OII] 3737Å
relative to Hβ
36- 45 E10.5 --- e_F3727 rms uncertainty on F3727
47- 56 E10.5 --- F3869 ?=0 Line flux of [NeII] 3869Å
relative to Hβ
58- 67 E10.5 --- e_F3869 ?=0 rms uncertainty on F3869
69- 78 E10.5 --- F4363 ?=0 Line flux of [OIII] 4363Å
relative to Hβ
80- 89 E10.5 --- e_F4363 ?=0 rms uncertainty on F4363
91-100 E10.5 --- F5007 Line flux of [OIII] 5007Å
relative to Hβ
102-111 E10.5 --- e_F5007 rms uncertainty on F5007
113-122 E10.5 --- F5755 ?=0 Line flux of [NII] 5755Å
relative to Hβ
124-133 E10.5 --- e_F5755 ?=0 rms uncertainty on F5755
135-144 E10.5 --- F5876 ?=0 Line flux of [HeI] 5876Å
relative to Hβ
146-155 E10.5 --- e_F5876 ?=0 rms uncertainty on F5876
157-166 E10.5 --- F6584 Line flux of [NII] 6584Å
relative to Hβ
168-177 E10.5 --- e_F6584 rms uncertainty on F6584
179-188 E10.5 --- F7135 ?=0 Line flux of [ArIII] 7153Å
relative to Hβ
190-199 E10.5 --- e_F7135 ?=0 rms uncertainty on F7135
201-210 E10.5 --- limF4363 ?=0 Upper limit of [OIII] 4363Å line flux
relative to Hβ
212-221 E10.5 --- limF5755 ?=0 Upper limit of [NII] 5755Å line flux
relative to Hβ
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Note (1): References as follows:
a = Bolin et al. (2005, Cat. J/A+A/441/981)
b = Bresolin et al. (2004ApJ...615..228B 2004ApJ...615..228B)
c = Kennicutt et al. (2003ApJ...591..801K 2003ApJ...591..801K)
d = van Zee et al. (1998, Cat. J/AJ/116/2805)
g = Bresolin et al. (2009ApJ...700..309B 2009ApJ...700..309B)
i = Bresolin (2007ApJ...656..186B 2007ApJ...656..186B)
j = Bresolin et al. (2010MNRAS.404.1679B 2010MNRAS.404.1679B)
k = Li et al. (2013ApJ...766...17L 2013ApJ...766...17L)
l = Zurita & Bresolin (2012MNRAS.427.1463Z 2012MNRAS.427.1463Z)
m = Bresolin et al. (2012ApJ...750..122B 2012ApJ...750..122B)
n = Goddard et al. (2011MNRAS.412.1246G 2011MNRAS.412.1246G)
p = Bresolin et al. (2009, Cat. J/ApJ/695/580)
z = Izotov et al. (2007, Cat. J/ApJ/662/15)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Id [1/708] Sequnetial number
5- 15 E11.5 [-] logO/H(jmod) Maximun a posteriori logO/H
17- 27 E11.5 [-] logN/O(jmod) Maximun a posteriori logN/O
29- 39 E11.5 [-] logO/H(jc68cen) Centre term for logO/H
41- 50 E10.5 [-] logO/H(jc68sig) 68% credibility ellipse error for logO/H
52- 62 E11.5 [-] logN/O(jc68cen) Centre term for logN/O
64- 73 E10.5 [-] logN/O(jc68sig) 68% credibility ellipse error for logN/O
75- 85 E11.5 [-] jc68(cov) Covariance term used to construct the
68 per cent credibility ellipse
87- 96 E10.5 [-] jc68(scale) Scaling used to construct the
68 per cent credibility ellipse
98-108 E11.5 [-] logO/H(mmed) Marginalized median value of logO/H
110-120 E11.5 [-] logN/O(mmed) Marginalized median value of logN/O
122-132 E11.5 [-] logO/H(mp68l) Lower value of 68% equal-tailed interval
for logO/H
134-144 E11.5 [-] logO/H(mp68u) Upper value of 68% equal-tailed interval
for logO/H
146-156 E11.5 [-] logN/O(mp68l) Lower value of 68% equal-tailed interval
for logN/O
158-168 E11.5 [-] logN/O(mp68u) Upper value of 68% equal-tailed interval
for logN/O
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History:
Copied at http://bond.ufsc.br/
(End) Patricia Vannier [CDS] 06-Oct-2017