J/ApJS/218/25 Abundances in PNe. III: Se and Kr (Sterling+, 2015)
The abundances of light neutron-capture elements in planetary nebulae.
III. The impact of new atomic data on nebular selenium and krypton abundance
determinations.
Sterling N.C., Porter R.L., Dinerstein H.L.
<Astrophys. J. Suppl. Ser., 218, 25 (2015)>
=2015ApJS..218...25S 2015ApJS..218...25S
ADC_Keywords: Abundances ; Atomic physics ; Planetary nebulae
Keywords: atomic data; infrared: general;
nuclear reactions, nucleosynthesis, abundances;
planetary nebulae: general; stars: AGB and post-AGB
Abstract:
The detection of neutron(n)-capture elements in several planetary
nebulae (PNe) has provided a new means of investigating s-process
nucleosynthesis in low-mass stars. However, a lack of atomic data has
inhibited accurate trans-iron element abundance determinations in
astrophysical nebulae. Recently, photoionization (PI) and
recombination data were determined for Se and Kr, the two most widely
detected n-capture elements in nebular spectra. We have incorporated
these new data into the photoionization code Cloudy (Ferland et al.
2013RMxAA..49..137F 2013RMxAA..49..137F). To test the atomic data, numerical models were
computed for 15 PNe that exhibit emission lines from multiple Kr ions.
We found systematic discrepancies between the predicted and observed
emission lines that are most likely caused by inaccurate PI and
recombination data. These discrepancies were removed by adjusting the
Kr+-Kr3+ PI cross sections within their cited uncertainties and
the dielectronic recombination rate coefficients by slightly larger
amounts. From grids of models spanning the physical conditions
encountered in PNe, we derive new, broadly applicable ionization
correction factor (ICF) formulae for calculating Se and Kr elemental
abundances. The ICFs were applied to our previous survey of
near-infrared [KrIII] and [SeIV] emission lines in 120 PNe. The
revised Se and Kr abundances are 0.1-0.3dex lower than former
estimates, with average values of [Se/(O,Ar)]=0.12±0.27 and
[Kr/(O,Ar)]=0.82±0.29, but correlations previously found between
their abundances and other nebular and stellar properties are
unaffected. We also find a tendency for high-velocity PNe that can be
associated with the Galactic thick disk to exhibit larger s-process
enrichments than low-velocity PNe belonging to the thin-disk
population.
Description:
We have selected 15 PNe that exhibit emission lines from multiple Kr
ions in their optical and near-infrared spectra (Table 1). Ten of
these objects were modeled in Paper I (Sterling et al.,
2007ApJS..169...37S 2007ApJS..169...37S). We draw the other objects from optical spectra
published since Paper I (Sharpee et al. 2007, J/ApJ/659/1265;
Garcia-Rojas et al. 2012, J/A+A/538/A54), with the exception of NGC
5315 (Peimbert et al. 2004ApJS..150..431P 2004ApJS..150..431P). Intensities for the K-band
emission lines from Paper II (Sterling+, 2008ApJS..174..158S 2008ApJS..174..158S) were
determined using the extinction coefficients listed in Table 1 and the
extinction law adopted by the optical data reference. See section 3
for the complete explanation.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 155 15 Observational data references
input.dat 113 16 *Model input parameters (tables 2 and 3)
table4.dat 49 1155 Predicted vs. observed diagnostics and
line intensities
table7.dat 53 15 Comparison of modeled Se and Kr abundances
table14.dat 120 151 Se and Kr abundances relative to H, O, and Ar
refs.dat 89 54 References
--------------------------------------------------------------------------------
Note on input.dat: Input parameters for Cloudy models. All models were run
with Cloudy version C13, modified as described in the text.
--------------------------------------------------------------------------------
See also:
VI/64 : Recombination line intensities for hydrogenic ions (Storey+ 1995)
J/A+A/562/A71 : Abundances of solar neighbourhood dwarfs (Bensby+, 2014)
J/ApJ/778/149 : Abundances for 3 stars in Sgr dSph (McWilliam+, 2013)
J/ApJ/771/67 : Abundances for 97 metal-poor stars. II. (Ishigaki+, 2013)
J/A+A/552/A128 : Abundances of neutron-capture elements (Mishenina+, 2013)
J/MNRAS/428/3443 : PNe and HII regions plasma diagnostics (McNabb+, 2013)
J/A+A/538/A54 : Spectroscopy of 12 planetary nebulae (Garcia-Rojas+, 2012)
J/A+A/535/A117 : Low-charge ions charge transfer rate coeff. (Sterling+, 2011)
J/A+A/535/A107 : Spectrosc. survey of 479 thick disc stars (Kordopatis+, 2011)
J/A+A/533/A62 : Atomic Data for Neutron-Capture Elements. II (Sterling, 2011)
J/MNRAS/415/181 : Deep spectroscopy of NGC 7009 (Fang+, 2011)
J/A+A/530/A138 : Geneva-Copenhagen survey re-analysis (Casagrande+, 2011)
J/A+A/529/A147 : Photoionization cross sections of Selenium (Sterling+, 2011)
J/ApJ/724/975 : Heavy elements abundance of metal-poor stars (Roederer+, 2010)
J/ApJ/724/748 : Galactic anticenter PNe and oxygen abundance (Henry+, 2010)
J/ApJ/723/658 : Abundances of the halo PN BoBn 1 (Otsuka+, 2010)
J/ApJ/714/1096 : Galactic planetary nebulae (Stanghellini+, 2010)
J/A+A/500/1089 : Abundances in planetary nebulae (Gorny+, 2009)
J/ApJ/696/797 : Evolution and yields of low-mass AGB stars (Cristallo+, 2009)
J/ApJ/659/1265 : Emission lines in 4 planetary nebulae (Sharpee+, 2007)
J/A+A/465/271 : Oxygen abundances in nearby stars (Ramirez+, 2007)
J/A+A/463/265 : Chemical compositions of WR planetary nebulae (Girard+, 2007)
J/MNRAS/367/1329 : Elemental abundances for 176 stars (Reddy+, 2006)
J/A+A/442/249 : Integrated spectrum of NGC 7027 (Zhang+, 2005)
J/A+A/427/231 : Abundances in planetary nebulae (Gorny+, 2004)
J/A+A/423/199 : Chemical abundances of planetary nebulae (Costa+, 2004)
J/MNRAS/349/793 : Galactic PNe abundances (Perinotto+, 2004)
J/A+A/415/155 : Oxygen abundances in the Galactic disk (Bensby+, 2004)
J/A+A/410/527 : Abundances in the Galactic disk (Bensby+, 2003)
J/A+AS/147/111 : Iron Project. XLIV. Fe VI. (Chen+, 2000)
J/ApJS/124/195 : PN medium-resolution spectra (Hora+, 1999)
J/A+A/332/721 : Planetary nebulae abundances (Perinotto+ 1998)
J/A+AS/126/297 : PN abundances (Ratag+ 1997)
J/A+A/318/256 : Planetary nebulae properties (Gorny+ 1997)
J/A+A/307/215 : Spectrophotomety of planetary nebulae (Cuisinier+, 1996)
J/A+A/303/893 : Planetary nebulae with WR-type nuclei (Gorny+, 1995)
J/PASP/105/1279 : The Spectrum of NGC 6567 (Hyung+ 1993)
http://fruity.oa-teramo.inaf.it/ : Full-Network Repository of Updated
Isotopic Tables and Yields (FRUITY)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- ID Planetary nebula identifier (NGC/IC number)
10- 28 A19 --- Auth Optical data author's name(s)
30- 48 A19 --- Bib1 Optical data bibcode
50- 68 A19 --- Bib2 Second optical bibcode
70- 73 F4.2 --- c(Hb) [0.06/1.93] Extinction coefficient c(Hβ)
75- 98 A24 --- Auth3 Other reference author's name(s)
100-118 A19 --- Bib3 Other bibcode
120 A1 --- f_Bib3 Flag on Bib (1)
122-135 A14 --- Auth4 Other reference author's name
137-155 A19 --- Bib4 Second other bibcode
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Note (1): Flag as follows:
a = Reference for abundances, UV, and mid-IR data if not from optical data
reference.
b = [KrIV]5867.7 is taken from this reference and scaled to [KrIV]5346.0 of
Liu et al. (2004MNRAS.353.1251L 2004MNRAS.353.1251L, 2004MNRAS.353.1231L 2004MNRAS.353.1231L). All other abundance,
optical, and IR data (except the K band) are from Liu et al.
(2004MNRAS.353.1251L 2004MNRAS.353.1251L, 2004MNRAS.353.1231L 2004MNRAS.353.1231L).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: input.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- ID Planetary nebula identifier (or "Solar")
10 A1 --- f_ID a: From Asplund et al. (2009ARA&A..47..481A 2009ARA&A..47..481A)
12- 16 F5.1 kK Teff [38/189]? Stellar effective temperature
18- 21 F4.1 kK e_Teff [3/30]? Teff uncertainty
23- 26 F4.2 [cm/s2] logg [3.4/8]? Log of surface gravity
28- 32 I5 Lsun Lum [520/12400]? Luminosity (L/L☉)
34- 38 F5.2 10+3/cm3 nH [1.6/59]? Nebular hydrogen density
40- 45 F6.3 [pc] logRin [-3/-1.6]? Log of nebular inner radiu(Rin)
47- 52 F6.3 [pc] logRout [-1.9/-0.8]? Log of outer radius (Rout)
54- 58 F5.3 --- He/H [0.08/0.2] He/H abundance (linear scale)
60- 63 F4.2 [-] C/H [8.2/9.1] 12+log(C/H) abundance
65- 68 F4.2 [-] N/H [7.5/8.7] 12+log(N/H) abundance
70- 73 F4.2 [-] O/H [8.3/9.1] 12+log(O/H) abundance
75- 78 F4.2 [-] Ne/H [7.7/8.4] 12+log(Ne/H) abundance
80- 83 F4.2 [-] S/H [6.3/7.3] 12+log(S/H) abundance
85- 88 F4.2 [-] Cl/H [4.2/5.5] 12+log(Cl/H) abundance
90- 93 F4.2 [-] Ar/H [5.7/6.6] 12+log(Ar/H) abundance
95- 98 F4.2 [-] Se/H [2.9/3.7]? 12+log(Se/H) abundance
100-103 F4.2 [-] e_Se/H [0.03/0.2]? Se/H uncertainty
105-108 F4.2 [-] Kr/H [3.1/4.2] 12+log(Kr/H) abundance
110-113 F4.2 [-] e_Kr/H [0.1/0.3]? Kr/H uncertainty
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- ID Planetary nebula identifier
10- 17 A8 --- Ion Ion or diagnostic identifier (1)
19- 22 I4 0.1nm lam_aa [1240/9532]? Wavelength in Angstroms
24- 29 F6.3 um lam_um [2.1/57]? Wavelength in microns
31- 38 E8.3 --- Pred [0/2180]? Predicted line intensity (2)
40 A1 --- f_Pred [ab] peculiar line ratio (3)
42- 49 E8.3 --- Obs [0.003/1720]? Observed line intensity (2)
--------------------------------------------------------------------------------
Note (1): The diagnostic ratios are defined as follows:
Ar IIIna = [Ar III] (7135+7751)/5192;
Ar IVnn = [Ar IV] 4740/4711;
Cl IIInn = [Cl III] 5518/5538;
N IIna = [N II] (6548+6584)/5755;
O IIna = [O II] (3726+3729)/(7320+7330);
O IInn = [O II] 3726/3729;
O IIIna = [O III] (4959+5007)/4363; and
S IInn = [S II] 6716/6731.
The notation "na" indicates a nebular to auroral line ratio, and "nn"
indicates nebular to nebular. Nebular lines arise from the first excited
term of the ground configuration whereas auroral lines come from the
second excited term.
Note (2): Line intensities on the scale I(Hβ)=100, except for
the diagnostic ratios mentioned in Note (1) above.
Note (3): Flag as follows:
a = Ar IIIna = [Ar III] 7135/5192 (7751 line not taken into account)
b = O IIIna = [O III] 4959/4363 (5007 line not taken into account)
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Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- ID Planetary nebula identifier
10- 13 F4.2 [-] Se [2.9/3.7]? This work 12+log(Se/H) abundance
15- 18 F4.2 [-] e_Se [0.03/0.2]? Se uncertainty
20- 23 F4.2 [-] Se1 [2.8/3.8]? 12+log(Se/H) abundance from
Paper I (Sterling et al. 2007ApJS..169...37S 2007ApJS..169...37S)
25- 28 F4.2 [-] e_Se1 [0.05/0.2]? Se1 uncertainty
30- 33 F4.2 [-] Kr [3.1/4.2] Adopted 12+log(Kr/H) abundance
35- 38 F4.2 [-] e_Kr [0.1/0.3] Kr uncertainty
40- 43 F4.2 [-] Kr0 [3.1/4.3] Kr abundance without adjustment
45- 48 F4.2 [-] Kr1 [3.2/4.3]? 12+log(Kr/H) abundance from
Paper I (Sterling et al. 2007ApJS..169...37S 2007ApJS..169...37S)
50- 53 F4.2 [-] e_Kr1 [0.1/0.3]? Kr1 uncertainty
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table14.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- ID Object name
12 A1 --- f_ID [f] Abundances may be not reliable (1)
14 A1 --- l_[Kr/H] Limit flag on [Kr/H]
16- 20 F5.2 [Sun] [Kr/H] [-0.4/2.1]? Kr abundance relative to H
22- 25 F4.2 [Sun] e_[Kr/H] [0.1/0.5]? [Kr/H] uncertainty
27- 29 A3 --- f_[Kr/H] [de, ] [Kr/H] may be not reliable (1)
31 A1 --- l_[Kr/O] Limit flag on [Kr/O]
33- 37 F5.2 [Sun] [Kr/O] [-0.7/2.1]? Kr abundance relative to O (2)
39- 42 F4.2 [Sun] e_[Kr/O] [0.1/0.8]? [Kr/O] uncertainty
44- 46 A3 --- f_[Kr/O] [cdeo, ] [Kr/O] may be not reliable (1)
48 A1 --- l_[Kr/Ar] Limit flag on [Kr/Ar]
50- 54 F5.2 [Sun] [Kr/Ar] [-0.4/2.1]? Kr abundance relative to Ar (2)
56- 59 F4.2 [Sun] e_[Kr/Ar] [0.1/0.8]? [Kr/Ar] uncertainty
61- 63 A3 --- f_[Kr/Ar] [cde, ] [Kr/Ar] may be not reliable (1)
65 A1 --- l_[Se/H] Limit flag on [Se/H]
67- 71 F5.2 [Sun] [Se/H] [-1/1.5]? Se abundance relative to H
73- 76 F4.2 [Sun] e_[Se/H] [0.08/0.7]? [Se/H] uncertainty
78 A1 --- f_[Se/H] [d] Flag on [Se/H] may be not reliable (1)
80 A1 --- l_[Se/O] Limit flag on [Se/O]
82- 87 A6 [Sun] [Se/O] Se abundance relative to O (2)
89- 92 F4.2 [Sun] e_[Se/O] [0.08/1]? [Se/O] uncertainty
94- 96 A3 --- f_[Se/O] [cdeo, ] [Se/O] may be not reliable (1)
98 A1 --- l_[Se/Ar] Limit flag on [Se/Ar]
100-104 F5.2 [Sun] [Se/Ar] [-1.1/1.7]? Se abundance relative to Ar (2)
106-109 F4.2 [Sun] e_[Se/Ar] [0.1/1]? [Se/Ar] uncertainty
111-113 A3 --- f_[Se/Ar] [cde, ] [Se/Ar] may be not reliable (1)
115-120 A6 --- Ref Near-infrared reference starting by "IR" and
optical/UV/MIR reference (see refs.dat file)
--------------------------------------------------------------------------------
Note (1): Flag as follows:
c = Ar is used as a reference element. This object exhibits N enrichments
that fall just below the value for Type I classification, and hence its
O abundance may not be reliable.
d = Based on a weak or uncertain detection.
e = Ionization correction factor ICF(Kr) from Equation (1).
f = IC 4997 has an uncertain O abundance, and Ar is used as the reference
element for this object.
o = The [Kr/O] and [Se/O] values of Type I PNe are flagged to indicate that
O may not be a reliable metallicity indicator in these objects (see text).
Note (2): Abundances are relative to the Asplund et al. (2005ASPC..336...25A 2005ASPC..336...25A)
solar composition for ease of comparison with Paper II (Sterling et al.
2008ApJS..174..158S 2008ApJS..174..158S). Using the Asplund et al. (2009ARA&A..47..481A 2009ARA&A..47..481A)
solar composition, the listed [Kr/O] and [Se/O] values would increase
by 0.05 and 0.02dex, respectively, while [Kr/Ar] and [Se/Ar] would
increase by 0.24 and 0.21dex.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- Ref Code reference
5- 23 A19 --- BibCode Bibcode
25- 48 A24 --- Aut First author's name(s)
50- 89 A40 --- Comm Comment
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History:
From electronic version of the journal
References:
Sterling et al. Paper I. 2007ApJS..169...37S 2007ApJS..169...37S
Sterling & Dinerstein Paper II. 2008ApJS..174..158S 2008ApJS..174..158S
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 07-Aug-2015