J/AJ/167/247 Variable stars in the NIR in nearby galaxies. I. (Bhardwaj+, 2024)
Stellar Variability and Distance Indicators in the Near-infrared in Nearby
Galaxies.
I. RR Lyrae and Anomalous Cepheids in Draco Dwarf Spheroidal.
Bhardwaj A., Rejkuba M., Ngeow C.-C., Marconi M., Ripepi V.,
Samantaray A.S., Singh H.P.
<Astron. J., 167, 247 (2024)>
=2024AJ....167..247B 2024AJ....167..247B
ADC_Keywords: Galaxies, dwarf; Photometry, infrared; Stars, variable
Keywords: Dwarf spheroidal galaxies ; RR Lyrae variable stars ;
Anomalous Cepheid variable stars
Abstract:
The Draco Dwarf spheroidal (dSph) galaxy is one of the nearest and the
most dark-matter-dominated satellites of the Milky Way. We obtained
multiepoch near-infrared (NIR, JHKs) observations of the central
region of Draco dSph covering a sky area of ∼21x21' using the WIRCam
instrument at the 3.6m Canada-France-Hawaii Telescope. Homogeneous
JHKs time-series photometry for 212 RR Lyrae (173 fundamental-mode, 24
first-overtone, and 15 mixed-mode variables) and five Anomalous
Cepheids in Draco dSph are presented and used to derive their
period-luminosity relations at NIR wavelengths for the first- time.
The small scatter of ∼0.05mag in these empirical relations for RR
Lyrae stars is consistent with those in globular clusters and suggests
a very small metallicity spread, up to ∼0.2dex, among these centrally
located variables. Based on empirically calibrated NIR
period-luminosity-metallicity relations for RR Lyrae in globular
clusters, we determined a distance modulus to Draco dSph of
µRRL=19.557±0.026mag. The calibrated Ks-band period-luminosity
relations for Anomalous Cepheids in the Draco dSph and the Large
Magellanic Cloud exhibit statistically consistent slopes but
systematically different zero points, hinting at possible metallicity
dependence of ~-0.3mag/dex. Finally, the apparent magnitudes of the
tip of the red-giant branch in I and J bands also agree well with
their absolute calibrations with the adopted RR Lyrae distance to
Draco. Our recommended ∼1.5% precise RR Lyrae distance,
DDraco=81.55±0.98(statistical)±1.17(systematic)kpc, is the
most accurate and precise distance to Draco dSph galaxy.
Description:
Multiepoch NIR observations of Draco dSph were obtained using the
WIRCam instrument mounted on the 3.6m Canada-France-Hawaii Telescope
(CFHT). The NIR camera, WIRCam, is an array of four 2048x2048 HgCdTe
HAWAII-RG2 detectors that are arranged in a 2x2 grid with gaps of 45"
between adjacent detectors.
Objects:
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RA (2000) DE Designation(s)
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17 20 14.33 +57 55 16.3 Draco dSph = NAME Dra dSph
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 92 217 NIR pulsation properties of variable stars
in Draco dSph
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See also:
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
J/AJ/124/3222 : VI photometry of Draco and UMi galaxies (Bellazzini+, 2002)
J/AJ/127/861 : RR Lyrae in Draco dSph (Bonanos+, 2004)
J/A+A/421/937 : Metal abundances of LMC RR Lyrae (Gratton+, 2004)
J/A+A/442/165 : IJKs photom of late-type stars in Draco dSph (Cioni+, 2005)
J/MNRAS/375/831 : Draco MegaCam, INT and HST photometry (Segall+, 2007)
J/AJ/136/1921 : Variable stars of Draco dSph (Kinemuchi+, 2008)
J/A+A/502/505 : Ks photometry of LMC RR Lyrae (Borissova+, 2009)
J/AJ/144/4 : Prop of dwarf galaxies in Local Group (McConnachie+, 2012)
J/ApJ/779/102 : Metallicities of RGB stars in dwarf galaxies (Kirby+, 2013)
J/MNRAS/437/2307 : LMC anomalous Cepheid Ks light curves (Ripepi+, 2014)
J/MNRAS/448/2717 : Bayesian analysis resolved stellar spectra (Walker+, 2015)
J/AJ/153/204 : RR Lyrae stars from the PS1 3π survey (Sesar+, 2017)
J/A+A/625/A1 : RR Lyrae variables NIR light-curve templates (Braga+, 2019)
J/AJ/160/220 : NIR light curve 234 RR Lyrae in Messier 3 (Bhardwaj+, 2020)
J/A+A/633/A36 : 3D kinematics in the Draco dwarf spheroidal (Massari+, 2020)
J/MNRAS/499/4040 : RR Lyrae population in Draco dwarf galaxy (Muraveva+, 2020)
J/ApJ/922/20 : CFHT optical & NIR obs. of RR Lyrae in M15 (Bhardwaj+, 2021)
J/ApJS/253/42 : The Araucaria Project; deep NIR phot. I. (Karczmarek+, 2021)
J/A+A/664/A109 : Gaia EDR3 and Johnson-Kron-Cousins stds (Pancino+, 2022)
J/A+A/681/A65 : Cepheids PL relation metallicity dependence (Trentin+, 2024)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- ID Gaia DR3 source ID
21- 30 F10.6 deg RAdeg [259/261] Right Ascension (J2000)
32- 40 F9.6 deg DEdeg [57/59] Declination (J2000)
42- 48 F7.5 d Per [0.3/1.6] Pulsation period
50- 53 A4 --- Type Variable type (1)
55- 60 F6.3 mag Jmag [17.1/19.8] Mean apparent J magnitude
62- 67 F6.3 mag Hmag [16.8/19.5] Mean apparent H magnitude
69- 74 F6.3 mag Ksmag [16.8/19.5] Mean apparent Ks magnitude
76- 80 F5.3 mag e_Jmag [0.01/0.08] Uncertainty in Jmag
82- 86 F5.3 mag e_Hmag [0.01/0.2] Uncertainty in Hmag
88- 92 F5.3 mag e_Ksmag [0.01/0.08] Uncertainty in Ksmag
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Note (1): Types of variable stars as follows:
RRc = first-overtone RR Lyrae (24 occurrences)
RRd = mixed-mode RR Lyrae (15 occurrences)
RRab = fundamental mode RR Lyrae (173 occurrences)
Acep = Anomalous Cepheid (5 occurrences)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 14-Jun-2024