J/MNRAS/515/4574 Pulsation study of 176 HADS stars with OGLE (Netzel+, 2022)
Modelling of multimode radially pulsating high-amplitude δ Scuti stars
from the OGLE Galactic bulge sample.
Netzel H., Smolec R.
<Mon. Not. R. Astron. Soc. 515, 4574-4586 (2022)>
=2022MNRAS.515.4574N 2022MNRAS.515.4574N (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Galactic center ; Milky Way ; Asteroseismology ;
Photometry ; Optical ; Stars, masses ; Abundances, [Fe/H] ;
Effective temperatures ; Stars, ages
Keywords: asteroseismology - stars: oscillations (including pulsations) -
stars: variables: δ Scuti
Abstract:
Thanks to relatively firm mode identification, possible based only on
period ratios, high-amplitude δ Scuti stars pulsating in at
least three radial modes are promising targets for asteroseismic
inference. In this study, we used the most numerous sample of HADS
from the OGLE inner bulge fields that likely pulsate in either three
or four radial modes simultaneously. We have computed a grid of
pulsation models along evolutionary tracks and determined the physical
parameters of stars by matching their pulsation periods and period
ratios. For 176 HADS, we determined physical parameters, i.e. masses,
luminosities, effective temperatures, metallicities, and ages. We
present the distribution of physical parameters and discuss their
properties. We selected 16 candidates for SX Phoenicis stars.
Description:
Only multimode pulsations are useful for asteroseismic study. Since
the incidence rate of HADS is low, and the incidence rate of multimode
HADS is even lower, the best place to look for these stars are
large-scale photometric surveys as OGLE data to search for δ
Scuti stars in the Galactic bulge region. We aim to perform
asteroseismic modelling of candidates for pulsations in at least three
radial modes in order to obtain basic stellar parameters of these
stars with input data only of information about the periodicities.
Physical parameters are determined solely by matching observed periods
to theoretical periods from the grid of models (i.e see section 2). As
explained in section 2, we apply asteroseismic modelling on a sample
of 428 stars. After in this process we excluding stars for which the
Dmin parameter is too big reducing the sample of stars with fitted
models to 176. For these stars, comparisons of observed and computed
pulsations are available in table1.dat. Physical parameters obtained
from the best fitting model for each star are collected in table2.dat.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 126 176 Observed and calculated periods and ratios for
high-amplitude δ Scuti stars HADS
table2.dat 81 176 Best model results for HADS stars pulsating
in at least three radial modes simultaneously
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See also:
J/MNRAS/490/4040 : δ Scuti and γ Doradus stars in TESS
(Antoci+, 2019)
J/MNRAS/485/2380 : Gaia-derived luminosities of Kepler A/F stars (Murphy+,2019)
J/MNRAS/466/1290 : Metal-rich SX Phe stars in Kepler field (Nemec+, 2017)
J/MNRAS/510/1748 : δ Scuti variable stars with OGLE-IV (Netzel+, 2022)
J/A+AS/144/469 : Delta Scuti stars (Rodriguez+, 2000)
J/AcA/63/379 : OGLE-III variable stars in Galactic disk area
(Pietrukowicz+, 2013)
J/AcA/60/1 : VI light curves of LMC delta Scuti stars (Poleski+, 2010)
I/352 : Distances to 1.47 billion stars in Gaia EDR3
(Bailer-Jones+, 2021)
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- ID Identifier name designation as
OGLE-BLG-DSCT-NNNNN (ID)
21- 26 F6.4 d PLo Longest observed radial period (PLobs)
28- 33 F6.4 --- P1O/PFo ? Observed first overtone to fundamental
period mode ratio (P1O/PFobs)
35- 40 F6.4 --- P2O/PFo ? Observed second overtone to fundamental
period mode ratio (P2O/PFobs)
42- 47 F6.4 --- P3O/PFo ? Observed third overtone to fundamental
period mode ratio (P3O/PFobs)
49- 54 F6.4 --- P2O/P1Oo ? Observed second overtone to first overtone
period mode ratio (P2O/P1Oobs)
56- 61 F6.4 --- P3O/P1Oo ? Observed third overtone to first overtone
period mode ratio (P3O/P1Oobs)
63- 68 F6.4 --- P3O/P2Oo ? Observed third overtone to second overtone
period mode ratio (P3O/P2Oobs)
70- 77 F8.6 --- Dmin Minimum value of D parameter as defined by
the equation 1 of the section 2 data and
analysis (Dmin)
79- 84 F6.4 d PLm Longest model calculated radial period
(PLobs)
86- 91 F6.4 --- P1O/PFm ? Model calculated first overtone to
fundamental period mode ratio (P1O/PFmod)
93- 98 F6.4 --- P2O/PFm ? Model calculated second overtone to
fundamental period mode ratio (P2O/PFmod)
100-105 F6.4 --- P3O/PFm ? Model calculated third overtone to
fundamental period mode ratio (P3O/PFmod)
107-112 F6.4 --- P2O/P1Om ? Model calculated second overtone to first
overtone period mode ratio (P2O/P1Omod)
114-119 F6.4 --- P3O/P1Om ? Model calculated third overtone to first
overtone period mode ratio (P3O/P1Omod)
121-126 F6.4 --- P3O/P2Om ? Model calculated third overtone to second
overtone period mode ratio (P3O/P2Omod)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- ID Identifier name designation as
OGLE-BLG-DSCT-NNNNN (ID)
21- 30 A10 --- Type Type of multimodes radial pulsations as
1O+2O+3O, F+1O+2O, F+1O+2O+3O and
F+1O+3O (Type)
32- 35 F4.2 Msun M* Star mass (M)
37- 42 F6.3 [Sun] [Fe/H] Iron to hydrogen abundance ratio ([Fe/H])
44- 47 F4.2 --- fov The over-shooting parameter (fov)
49- 55 F7.5 [K] log(Teff) Logarithm of the effective temperature
(logTeff)
57- 63 F7.5 [Lsun] log(L) Logarithm of the luminosity (logL)
65- 68 F4.2 Gyr Age Star age (Age)
70- 81 A12 --- Note Remarks regarding evolutionary status
(Remarks) (1)
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Note (1): Evolutionary status was determined based on central hydrogen abundance
in the chosen model as follows:
MS = The model is considered to be on the main sequence if the
central hydrogen abundance is larger that 10-5, 99 sources
in our sample
PostMS = Post main sequence (PostMS) if central hydrogen abundance
is not larger that 10-5, 77 sources in our sample
SXPhe = In this study, we also tried to select a sample of
candidates for SX Phe stars. In this attempt, we selected
stars with higher ages, lower metallicities, and lower
masses. The limit on metallicity was set to -1.5, for age
to 3 Gyr, and for mass to 1.1M☉, 16 sources in our
sample
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History:
From electronic version of the journal
(End) Luc Trabelsi [CDS] 29-Aug-2025