J/ApJ/920/33 Fe/H estimation of 104 RR Lyrae from I- light curve (Dekany+, 2021)
Metallicity Estimation of RR Lyrae Stars From Their I-band light curves.
Dekany I.,Grebel E.K.,Pojmanski G.
<Astrophys. J., 920, 33 (2021)>
=2021ApJ...920...33D 2021ApJ...920...33D
ADC_Keywords: Stars, variable; Photometry, RI; Abundances, [Fe/H]
Keywords: RR Lyrae variable stars ; Metallicity ; Light curves
Abstract:
We have revisited the problem of metallicity prediction of RR-Lyrae
stars from their near-infrared light curves in the Cousins I wave
band. Our study is based on high-quality time series photometry and
state-of-the-art high-resolution spectroscopic abundance measurements
of 80 fundamental-mode (RRab) and 24 first-overtone (RRc) stars,
spanning ~[-2.7;+0.18]dex and ~[-3;-0.5]dex ranges, respectively.
Employing machine-learning methods, we investigated various
light-curve representations and regression models to identify their
optimal form for our objective. Accurate new empirical relations
between the [Fe/H] iron abundance and the light-curve parameters have
been obtained using Bayesian regression for both RRab and RRc stars
with mean absolute prediction errors of 0.16dex and 0.18dex,
respectively. We found that earlier I-band [Fe/H] estimates had a
systematic positive bias of up to ∼0.4dex in the metal-poor regime.
Our new predictive models were deployed on large ensembles of RR Lyrae
stars to obtain photometric metallicity distribution functions (MDFs)
for various old stellar populations in and around the Milky Way. We
find that the mode of the old bulge component's MDF is approximately
-1.4dex, in remarkable agreement with the latest spectroscopic result.
Furthermore, we derive MDF modes of -1.83, -2.13, and -1.77dex for the
Large and Small Magellanic Clouds and the Sagittarius dwarf galaxy,
respectively.
Description:
We surveyed the literature for RR-Lyrae stars with both
high-resolution spectroscopic metallicity determinations and well
sampled, accurate light curves in the Cousins I photometric passband.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 165 104 Names and photometric parameters of the RR Lyrae
stars in the calibration data set
table3.dat 134 104 Light-curve parameters in the principal component
space of the RR Lyrae stars in the calibration
data set
table4.dat 52 528 Spectroscopic metallicities of RR Lyrae stars
compiled from the literature
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See also:
J/AJ/108/1016 : Kinematics of local RR lyrae stars. I. (Layden, 1994)
J/AJ/110/2319 : Abundances in RR Lyr variables (Clementini+ 1995)
J/A+A/312/111 : [Fe/H] from RR Lyrae light curves (Jurcsik+, 1996)
J/A+A/430/1049 : RR Gem BV(RI)c differential photometry (Jurcsik+, 2005)
J/A+A/476/307 : Period variations in galactic RRab stars (Le Borgne+, 2007)
J/AcA/59/137 : ASAS Galactic fundamental mode RRLyrae star (Szczygiel+, 2009)
J/AJ/137/4377 : List of SEGUE plate pairs (Yanny+, 2009)
J/ApJS/197/29 : Chemical compositions of 11 RR Lyrae (For+, 2011)
J/ApJ/782/59 : Abundances 8 RR Lyrae subclass C variable stars (Govea+, 2014)
J/MNRAS/447/2404 : Equivalent width of 21 RR Lyrae stars (Pancino+, 2015)
J/ApJ/821/L25 : Bulge RRLyrae Radial Velocity Assay (BRAVA-RR) (Kunder+, 2016)
J/AJ/153/96 : Standard Galactic field RR Lyrae I. Photometry (Monson+, 2017)
J/ApJ/848/68 : Abundances & RVs of stable & Blazhko RRc stars (Sneden+, 2017)
J/ApJ/857/54 : JHKs photometry of VVV RR Lyrae stars (Dekany+, 2018)
J/MNRAS/481/1195 : Gaia DR2 RRLyrae stars as standard candles (Muraveva+, 2018)
J/A+A/622/A60 : Gaia DR2 misclassified RR Lyrae list (Clementini+, 2019)
J/ApJ/883/58 : Cepheids from VVV southern Galactic midplane (Dekany+, 2019)
J/ApJ/898/46 : NIR LCs of RRab stars from the VVV survey (Dekany+, 2020)
J/ApJ/908/20 : On use field RR Lyrae as galactic probes II. (Crestani+, 2021)
J/ApJ/912/144 : Metallicity Gal. RR Lyrae from opt. & IR LCs (Mullen+, 2021)
J/ApJ/911/109 : RR Lyrae variable stars in DES Y6 (Stringer+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 20 A20 --- Name Common name
22- 40 I19 --- Gaia Gaia DR2 identifier
42- 54 A13 --- ASAS ASAS identifier
56- 59 A4 --- Type RR Lyrae type
61- 61 I1 --- Blazhko [0/1] Blazhko modulation
63- 66 A4 --- Ref Photometric reference (1)
68- 71 I4 --- Nep [102/3000] Number of observation epochs
73- 80 F8.6 d Per [0.21/0.81] Pulsation period
82- 87 F6.3 mag Imag [1.07/13.2] Mean I band magnitude
89- 93 F5.3 --- At [0.16/0.94] Peak-to-valley amplitude of the
light-curve model
95- 99 F5.3 --- A1 [0.07/0.3] First order Fourier term in amplitude
101-105 F5.3 --- e_A1 [0.001/0.02] Uncertainty in A1
107-111 F5.3 --- A2 [0.004/0.17] Second order Fourier term in
amplitude
113-117 F5.3 --- e_A2 [0.001/0.02] Uncertainty in A2
119-123 F5.3 --- A3 [0.001/0.12] Third order Fourier term in
amplitude
125-129 F5.3 --- e_A3 [0.001/0.02] Uncertainty in A3
131-137 F7.4 --- phi21 [8.71/12.4] Second order Fourier term in phase
139-144 F6.4 --- e_phi21 [0.006/0.3] Uncertainty in phi21
146-150 F5.3 --- phi31 [4.21/7.78] Third order Fourier term in phase
152-156 F5.3 --- e_phi31 [0.01/0.9] Uncertainty in phi31
158-165 F8.3 --- S/N [77.5/2597] Signal to Noise value
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Note (1): References as follows:
ASAS = The All Sky Automated Survey Pojmanski, 1997AcA....47..467P 1997AcA....47..467P
J05 = Jurcsik+, 2005, J/A+A/430/1049
M17 = Monson+, 2017, 2017AJ....153...96M 2017AJ....153...96M
OGLE = Optical Gravitational Lensing Experiment Udalski+, 2015AcA....65....1U 2015AcA....65....1U
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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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1- 20 A20 --- Name Common name
22- 30 F9.6 --- u1 [-3.99/5.75] First linearly uncorrelated u parameter
32- 39 F8.6 --- e_u1 [0.03/2] Uncertainty in u1
41- 49 F9.6 --- u2 [-2.04/3.28] Second linearly uncorrelated u parameter
51- 58 F8.6 --- e_u2 [0.02/3] Uncertainty in u2
60- 68 F9.6 --- u3 [-8.61/2.12] Third linearly uncorrelated u parameter
70- 77 F8.6 --- e_u3 [0.03/4] Uncertainty in u3
79- 87 F9.6 --- u4 [-2.4/2.12] Fourth linearly uncorrelated u parameter
89- 96 F8.6 --- e_u4 [0.02/2] Uncertainty in u4
98-106 F9.6 --- u5 [-1.52/1.61] Fifth linearly uncorrelated u parameter
108-115 F8.6 --- e_u5 [0.02/2] Uncertainty in u5
117-125 F9.6 --- u6 [-0.83/1.52] Sixth linearly uncorrelated u parameter
127-134 F8.6 --- e_u6 [0.02/0.8] Uncertainty in u6
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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- 20 A20 --- Name Common name
22- 27 F6.3 [Sun] [Fe/H] [-2.99/0.2] Metallicity
29- 32 F4.3 [Sun] e_[Fe/H] [0.04/0.3] Uncertainty in [Fe/H]
34- 39 F6.3 --- Delta [-0.26/0.16] Computed shift with respect to
CFCS data
41- 43 A3 --- Ref Reference code (1)
45- 52 A8 --- Inst Instrument used
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Note (1): References as follows
A18 = Andrievsky+, 2018PASP..130b4201A 2018PASP..130b4201A
C17 = Chadid+, 2017ApJ...835..187C 2017ApJ...835..187C
C21 = Crestani+, 2021, J/ApJ/908/20
C95 = Clementini+, 1995, J/AJ/110/2319
F11 = For+, 2011, J/ApJS/197/29
F96 = Fernley & Barnes, 1996A&A...312..957F 1996A&A...312..957F
G14 = Govea+, 2014, J/ApJ/782/59
L13 = Liu+, 2013RAA....13.1307L 2013RAA....13.1307L
L96 = Lambert+, 1996ApJS..103..183L 1996ApJS..103..183L
N13 = Nemec+, 2013ApJ...773..181N 2013ApJ...773..181N
P15 = Pancino+, 2015, 2015MNRAS.447.2404P 2015MNRAS.447.2404P
S17 = Sneden+, 2017, 2017ApJ...848...68S 2017ApJ...848...68S
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 06-Feb-2023