J/A+A/616/A82 Physical parameters of classical Cepheids (Proxauf+, 2018)
A new and homogeneous metallicity scale for Galactic classical Cepheids.
I. Physical parameters.
Proxauf B., da Silva R., Kovtyukh V.V., Bono G., Inno L., Lemasle B.,
Pritchard J., Przybilla N., Storm J., Urbaneja M.A., Valenti E.,
Bergemann M., Buonanno R., D'Orazi V., Fabrizio M., Ferraro I.,
Fiorentino G., Francois P., Iannicola G., Laney C.D., Kudritzki R.-P.,
Matsunaga N., Nonino M., Primas F., Romaniello M., Thevenin F.
<Astron. Astrophys. 616, A82 (2018)>
=2018A&A...616A..82P 2018A&A...616A..82P (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Abundances ; Milky Way ; Spectroscopy
Keywords: Galaxy: disk - stars: abundances - stars: fundamental parameters -
stars: variables: Cepheids - stars: oscillations
Abstract:
We gathered more than 1130 high-resolution optical spectra for more
than 250 Galactic classical Cepheids. The spectra were collected with
different optical spectrographs: UVES at VLT, HARPS at 3.6m, FEROS at
2.2m MPG/ESO, and STELLA. To improve the effective temperature
estimates, we present more than 150 new line depth ratio (LDR)
calibrations that together with similar calibrations already available
in the literature allowed us to cover a broad range in wavelength
(between 5348 and 8427 angstrom) and in effective temperatures
(between 3500 and 7700K). This means the unique opportunity to cover
both the hottest and coolest phases along the Cepheid pulsation cycle
and to limit the intrinsic error on individual measurements at the
level of ∼100K. Thanks to the high signal-to-noise ratio of
individual spectra we identified and measured hundreds of neutral and
ionized lines of heavy elements, and in turn, have the opportunity to
trace the variation of both surface gravity and microturbulent
velocity along the pulsation cycle. The accuracy of the physical
parameters and the number of FeI (more than one hundred) and FeII
(more than ten) lines measured allowed us to estimate mean iron
abundances with a precision better than 0.1dex. Here we focus on 14
calibrating Cepheids for which the current spectra cover either the
entire or a significant portion of the pulsation cycle. The current
estimates of the variation of the physical parameters along the
pulsation cycle and of the iron abundances agree quite well with
similar estimates available in the literature. Independent homogeneous
estimates of both physical parameters and metal abundances based on
different approaches that can constrain possible systematics are
highly encouraged.
Description:
A list of 257 LDR calibrations that we used to derive the effective
temperature of our sample of Cepheids is shown in Table 3. This table
shows the pair of lines (wavelength and ion), the effective
temperature range of validity, the coefficients of the analytical
relation, the analytical formula, and the reference of each LDR
calibration. Table 4 lists the atmospheric parameters, Fe abundances,
and radial velocities derived for each spectrum of the 14 calibrating
Cepheids. Finally, in Table 5 we list the spectra for which we have
only radial-velocity measurements.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 51 14 List of studied stars
table3.dat 173 257 New and old Line Depth Ratio (LDR) calibrations
adopted for effective temperature estimates
table4.dat 114 307 Atmospheric parameters, Fe abundances, and
radial velocities for the calibrating Cepheids
table5.dat 44 100 High-resolution spectra only adopted for
radial-velocity measurements
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See also:
J/A+A/404/423 : BVI photometry of Galactic Cepheids (Tammann+, 2003)
J/AcA/61/285 : Galactic Bulge Cepheids VI light curves (Soszynski+, 2011)
J/ApJS/193/12 : JHK photometry of Northern Galactic Cepheids (Monson+, 2011)
J/MNRAS/420/1590 : Abundances of classical Cepheids (Acharova+, 2012)
J/PAZh/39/942 : Galactic classical Cepheids properties (Marsakov+, 2013)
J/A+A/566/A37 : Iron abundances for 42 Galactic Cepheids (Genovali+, 2014)
J/AN/336/70 : Galactic Cepheids velocities & proper motions
(Mel'nik+, 2015)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Cepheid name
13- 14 I2 h RAh Simbad right ascension (J2000)
16- 17 I2 min RAm Simbad right ascension (J2000)
19- 23 F5.2 s RAs Simbad right ascension (J2000)
25 A1 --- DE- Declination sign (J2000)
26- 27 I2 deg DEd Declination (J2000)
29- 30 I2 arcmin DEm Declination (J2000)
32- 35 F4.1 arcsec DEs Declination (J2000)
38- 45 F8.5 d Per Period from Genovali et al.
(2014, Cat. J/A+A/566/A37)
47- 48 A2 --- T4 [T4] Indicates data in table4.dat
50- 51 A2 --- T5 [T5 ] Indicates data in table5.dat
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Byte-by-byte Description of file:table3.dat
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Bytes Format Units Label Explanations
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2- 8 F7.2 0.1nm lambda1 Wavelength of the first line of the pair
11- 14 A4 --- Ion1 Ion of the first line of the pair
17- 23 F7.2 0.1nm lambda2 Wavelength of the second line of the pair
26- 29 A4 --- Ion2 Ion of the second line of the pair
32- 35 I4 K Teff1 Lower value of LDR validity range in
effective temperature
36 A1 --- --- [-]
37- 40 I4 K Teff2 Upper value of LDR validity range in
effective temperature
43- 56 E14.7 --- a Coefficient of the analytical relation
59- 72 E14.7 --- b Coefficient of the analytical relation
75- 88 E14.7 --- c ? Coefficient of the analytical relation
91-104 E14.7 --- d ? Coefficient of the analytical relation
107-120 E14.7 --- e ? Coefficient of the analytical relation
123-136 E14.7 --- f ? Coefficient of the analytical relation
139-170 A32 --- Function Analytical formula
173 I1 --- Ref [1/3] Reference for the LDR calibration (1)
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Note (1): The references for the LDR calibrations are as follows:
1 = Kovtyukh & Gorlova (2000A&A...358..587K 2000A&A...358..587K, KG00)
2 = Kovtyukh (2007MNRAS.378..617K 2007MNRAS.378..617K, K07)
3 = this investigation (K18)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Cepheid name
11- 16 A6 --- Dataset Spectroscopic dataset
19- 31 F13.7 d MJD Modified Julian Date
34- 37 I4 K Teff Effective temperature
40- 42 I3 K e_Teff Error in the effective temperature
45- 47 F3.1 [cm/s2] logg Surface gravity
50- 52 F3.1 km/s vt Microturbulent velocity
55- 59 F5.2 --- FeI Iron abundance from FeI lines [FeI/H]
62- 65 F4.2 --- e_FeI Error in the FeI abundance
68- 70 I3 --- NFeI Number of FeI lines adopted
73- 77 F5.2 --- FeII Iron abundance from FeII lines [FeII/H]
80- 83 F4.2 --- e_FeII Error in the FeII abundance
86- 87 I2 --- NFeII Number of FeII lines adopted
90- 94 F5.2 --- FeH Weighted mean of FeI and FeII abundances
97-100 F4.2 --- e_FeH Error in the weighted Fe abundance
103-108 F6.2 km/s RV Radial velocity
111-114 F4.2 km/s e_RV Error in the radial velocity
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Cepheid name
11- 15 A5 --- Dataset Spectroscopic dataset
18- 30 F13.7 d MJD Modified Julian Date
33- 38 F6.1 km/s RV Radial velocity
41- 44 F4.1 km/s e_RV Error in the radial velocity
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Acknowledgements:
Ronaldo Da Silva, ron.oliveirasilva(at)gmail.com
(End) Patricia Vannier [CDS] 03-May-2018