J/MNRAS/526/3386 4 A-type stars abundances and spectra (Romanovskaya+, 2023)
Non-LTE abundance analysis of A-B stars with low rotational velocities.
II. Are there normal A-type stars?
Romanovskaya A.M., Ryabchikova T.A., Pakhomov Yu.V., Korotin S.A.,
Sitnova T.M.
<Mon. Not. R. Astron. Soc. 526, 3386-3399 (2023)>
=2023MNRAS.526.3386R 2023MNRAS.526.3386R (SIMBAD/NED BibCode)
ADC_Keywords: Stars, A-type ; Abundances ; Spectra, optical ; Spectra, infrared
Keywords: stars: abundances - stars: atmospheres -
(stars:) binaries: spectroscopic - stars: chemically peculiar -
stars: fundamental parameters
Abstract:
We present chemical composition and fundamental parameters (the
effective temperature, surface gravity and radius) for four
sharp-lined A-type stars gamma Gem (HD 41705), omicron Peg
(HD 214994), theta Vir (HD 114330) and nu Cap (HD193432). Our analysis
is based on a self-consistent model fitting of high-resolution spectra
and spectrophotometric observations over a wide wavelength range. We
refined the fundamental parameters of the stars with the SME package
and verified their accuracy by comparing with the spectral energy
distribution and hydrogen line profiles. We found
Teff/logg=9190±130K/3.56±0.08, 9600±50K/3.81±0.04,
9600±140K/3.61±0.12, and 10200±220K/3.88±0.08 for gamma Gem,
omicron Peg, theta Vir and nu Cap, respectively. Our detailed
abundance analysis employs a hybrid technique for spectrum synthesis
based on classical model atmospheres calculated in local thermodynamic
equilibrium (LTE) assumption together with the non-LTE (NLTE) line
formation for 18 of 26 investigated species. Comparison of the
abundance patterns observed in A stars of different types (normal A,
Am, Ap) with similar fundamental parameters reveals significant
abundance diversity that cannot be explained by the current mechanisms
of abundance peculiarity formation in stellar atmospheres. We found a
rise of the heavy element (Zn, Sr, Y, Zr, Ba) abundance excess up to
+1dex with Teff increasing from 7200 to 10000K, with a further
decrease down to solar value at Teff=13000K, indicating that stars
with solar element abundances can be found among late B-type stars.
Description:
Online materials contains linelist with LTE and non-LTE abundances and
normalised spectra of HD 41705, HD 214994, HD 114330 and HD 193432.
Spectroscopic observations were extracted from the FEROS, ESPaDOnS,
HARPS, UVES archives.
Objects:
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RA (2000) DE Designation(s)
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06 37 42.71 +16 23 57.4 gamma Gem = HD 47105
22 41 45.40 +29 18 27.6 omicron Peg = HD 214994
13 09 56.98 -05 32 20.4 theta Vir = HD 114330
20 20 39.81 -12 45 32.6 nu Cap = HD 193432
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File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
linelist.dat 120 555 Linelist with 491 LTE and NLTE abundances from
individual lines in gamma Gem, omicron Peg,
theta Vir and nu Cap together with the line
atomic parameters and the references to them
refs.dat 175 98 References of loggf, hfs and iso
gg-sp.dat 26 239493 Spectrum of HD 41705 (gamma Gem) (FEROS)
op-sp.dat 26 238101 Spectrum of HD 214994 (omicron Peg) (ESPaDOnS)
tv-spa.dat 25 77947 Spectrum of HD 114330 (theta Vir) (ESPaDOnS)
tv-sp1.dat 19 151782 Spectrum of HD 114330 (theta Vir) (HARPS)
tv-sp2.dat 19 133200 Spectrum of HD 114330 (theta Vir) (HARPS)
nc-sp1.dat 21 31995 Spectrum of HD 193432 (nu Cap) 3800-4760Å
(UVES, R=37000)
nc-sp2.dat 21 32031 Spectrum of HD 193432 (nu Cap) 4779-5750Å
(UVES, R=37000)
nc-sp3.dat 21 47996 Spectrum of HD 193432 (nu Cap) 5840-6800Å
(UVES, R=37000)
nc-sp4.dat 19 29352 Spectrum of HD 193432 (nu Cap) 7000-7520Å
(UVES, R=107000)
nc-sp5.dat 19 23598 Spectrum of HD 193432 (nu Cap) 7660-8200Å
(UVES, R=107000)
nc-sp6.dat 19 26221 Spectrum of HD 193432 (nu Cap) 8200-8800Å
(UVES, R=107000)
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Byte-by-byte Description of file: linelist.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- El Element with ion number
6- 15 F10.5 0.1nm lambda Wavelength in angstrom
17- 23 F7.4 eV Ei Excitation energy
25- 30 F6.3 --- loggf Logarithm of oscillator strength
32- 39 A8 --- r_loggf References of loggf, in refs.dat file
41- 53 A13 --- r_hfs References of hyperfine splitting,
in refs.dat file
55- 58 A4 --- r_iso References of isotope splitting,
in refs.dat file
62- 66 F5.2 --- GG-LTE ?=- LTE abundances of gamma Gem (1)
70- 74 F5.2 --- GG-NLTE ?=- Non-LTE abundances of gamma Gem (1)
78- 82 F5.2 --- OP-LTE ?=- LTE abundances of omicron Peg (1)
86- 90 F5.2 --- OP-NLTE ?=- Non-LTE abundances of omicron Peg (1)
94- 98 F5.2 --- TV-LTE ?=- LTE abundances of theta Vir (1)
102-106 F5.2 --- TV-NLTE ?=- Non-LTE abundances of theta Vir (1)
109-113 F5.2 --- NC-LTE ?=- LTE abundances of nu Cap (1)
116-120 F5.2 --- NC-NLTE ?=- Non-LTE abundances of nu Cap (1)
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Note (1): All abundances are given in log(epsilon) = log(Nel/NH)+12.04 units.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Ref Reference code
9- 27 A19 --- BibCode ADS bibcode
31- 63 A33 --- DOI DOI
65-175 A111 --- Com Comments
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Byte-by-byte Description of file: gg-sp.dat op-sp.dat tv-spa.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 F10.5 0.1nm lambda Wavelength
11- 26 E16.8 --- Flux Normalized flux
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Byte-by-byte Description of file: tv-sp[12].dat tv-sp2.dat nc-sp?.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 F10.5 0.1nm lambda Wavelength
12- 21 F10.8 --- Flux Normalized flux
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Acknowledgements:
Anna Romanovskaya, annarom(at)inasan.ru
(End) Patricia Vannier [CDS] 15-Dec-2023