J/MNRAS/452/4070 Chemical abundances in the PN Wray16-423 (Otsuka, 2015)
Chemical abundances in the PN Wray16-423 in the Sagittarius dwarf spheroidal
galaxy: constraining the dust composition.
Otsuka M.
<Mon. Not. R. Astron. Soc., 452, 4070-4093 (2015)>
=2015MNRAS.452.4070O 2015MNRAS.452.4070O (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Planetary nebulae ; Spectroscopy ; Abundances
Keywords: ISM: abundances - dust, extinction -
planetary nebulae: individual: Wray16-423
Abstract:
We performed a detailed analysis of elemental abundances, dust features,
and polycyclic aromatic hydrocarbons (PAHs) in the C-rich planetary nebula
(PN) Wray16-423 in the Sagittarius dwarf spheroidal galaxy, based on
a unique data set taken from the Subaru/HDS, MPG/ESO FEROS, HST/WFPC2, and
Spitzer/IRS. We performed the first measurements of Kr, Fe, and
recombination O abundance in this PN. The extremely small [Fe/H] implies
that most Fe atoms are in the solid phase, considering into account the
abundance of [Ar/H]. The Spitzer/IRS spectrum displays broad 16-24 µm
and 30 µm features, as well as PAH bands at 6-9 and 10-14 µm.
The unidentified broad 16-24 µm feature may not be related to iron
sulphide (FeS), amorphous silicate, or PAHs. Using the spectral energy
distribution model, we derived the luminosity and effective temperature
of the central star, and the gas and dust masses. The observed elemental
abundances and derived gas mass are in good agreement with asymptotic giant
branch nucleosynthesis models for an initial mass of 1.90 M☉ and
a metallicity of Z=0.004. We infer that respectively about 80, 50, and
90 per cent of the Mg, S, and Fe atoms are in the solid phase. We also
assessed the maximum possible magnesium sulphide (MgS) and iron-rich
sulphide (Fe50S) masses and tested whether these species can produce the
band flux of the observed 30 µm feature. Depending on what fraction
of the sulphur is in sulphide molecules such as CS, we conclude that MgS
and Fe50S could be possible carriers of the 30 µm feature in this PN.
Description:
Optical high-dispersion spectra were taken using the High-Dispersion
Spectrograph (HDS; Noguchi et al. 2002PASJ...54..855N 2002PASJ...54..855N) attached to the
Nasmyth focus of the 8.2 m Subaru Telescope on 2012 July 4 (Prop.ID:
S12A-126S, PI: M. Otsuka) and 2014 July 9 (Prop.ID: S14A-174, the same PI).
Optical high-dispersion spectra (3500-9200 Å) were obtained using
the Fiber-fed Extended Range Optical Spectrograph (FEROS; Kaufer et al.
1999Msngr..95....8K 1999Msngr..95....8K) attached to the MPG/ESO 2.2 m Telescope, La Silla,
Chile on 2013 June 18 (Prop.ID: 91.D-0055A, PI: M. Otsuka), as a follow-up
to HDS observations; auroral [O II] lines, nebular [S III], [Cl IV], and
[Ar III] lines, and the Paschen discontinuity were measured, and line
identifications and flux measurements were cross-checked for both HDS
and FEROS spectra.
Objects:
----------------------------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------------------------
18 55 03.1 -30 28 42 Sagittarius dwarf spheroidal galaxy = NAME SDG
19 22 10.63 -31 30 38.7 WRAY16-423 = 2MASS J19221062-3130387
----------------------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea1.dat 51 298 Detected lines and identifications in
the HDS/FEROS spectra
tableb1.dat 83 46 Ionic abundances from collisionally excited
lines (CELs)
tableb2.dat 67 21 Ionic abundances from recombination lines (RLs)
--------------------------------------------------------------------------------
See also:
J/A+A/465/815 : Abundances of Sgr dSph stars (Sbordone+, 2007)
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 F7.2 0.1nm lambda(obs) [3688.46/9073.07] Observed wavelength
λobs (Å)
9- 16 A8 --- Ion Ion designation
18- 24 F7.2 0.1nm lambda(lab) [3686.83/9068.6]? Laboratory wavelength
λlab (Å)
26- 27 A2 --- n_lambda(lab) [BC ] Flag on lambda(lab) (1)
29 A1 --- ID Identification number (2)
31- 36 F6.3 --- f(lambda) [-0.59/0.33] Interstellar extinction
function at λ (3)
38- 45 F8.3 --- I(lambda) [0.009/1062.111] De-reddened line flux (3)
(G1)
47- 51 F5.3 --- dI(lambda) [0/8.96] Line flux difference
δI(λ)
--------------------------------------------------------------------------------
Note (1): Flag as follows:
BC = BC in component 2 of C IV λ5801/11 Å means the broad component
shown in Fig. 6.
Note (2): For lines composed of multiple components, we list the de-reddened
relative fluxes of each component, as well as the sum of these components
(indicated by "T").
Note (3): The measured line fluxes in the obtained spectra were de-reddened
using the following formula:
I(λ)=F(λ)x10c(Hβ)(1+f(λ)), where I(λ) is
the de-reddened line flux, F(λ) is the observed line flux, f(λ)
is the interstellar extinction function at λ computed by the reddening
law of Cardelli, Clayton & Mathis (1989ApJ...345..245C 1989ApJ...345..245C) with RV=3.1, and
c(Hβ) is the reddening coefficient at Hβ.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tableb1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- Ion Ion designation
8- 16 F9.2 0.1nm b_lambda(lab) [3726.03/360000] Laboratory wavelength,
lower value (Å)
18- 21 I4 0.1nm B_lambda(lab) [7330]? Laboratory wavelength, upper value
(Å)
23- 29 E7.3 --- I(llab) [0.0109/1060] De-reddened line flux (G1)
31- 37 E7.3 --- e_I(llab) [0.00207/8.96] Uncertainty in I(llab)
39- 43 I5 K Te [10000/12800] Electron temperature
45- 49 I5 cm-3 ne [1010/11320] Electron density
51- 57 E7.3 [-] [X/H] [1.71e-09/0.000191] Ionic abundance relative
to the H+
59- 66 E8.3 [-] e_[X/H] [8.18e-11/7.3e-06] 1σ uncertainty
in [X/H]
68- 74 E7.3 [-] [X/H]a [1.71e-09/0.00019] Adopted ionic abundance
76- 83 E8.3 [-] e_[X/H]a [8.18e-11/4.02e-06] Uncertainty in [X/H]a
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tableb2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- Ion Ion designation
8- 14 F7.2 0.1nm lambda(lab) [4072.15/6678.15] Laboratory wavelength
16- 19 A4 --- Mult Multiplet
21- 27 E7.3 --- I(llab) [0.0115/15.2] De-reddened line flux (G1)
29- 35 E7.3 --- e_I(llab) [0.00169/0.331] Uncertainty in I(llab)
37- 43 E7.3 [-] [X/H] [2.45e-05/0.0989] Ionic abundance
relative to the H+
45- 51 E7.3 [-] e_[X/H] [6.75e-06/0.0212] Uncertainty in [X/H]
53- 59 E7.3 [-] [X/H]a [2.45e-05/0.0963] Adopted ionic abundance
61- 67 E7.3 [-] e_[X/H]a [6.75e-06/0.0094] Uncertainty in [X/H]a
--------------------------------------------------------------------------------
Global notes:
Note (G1): Relative to [I(Hβ)=100].
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 19-Dec-2019