J/ApJ/922/20 CFHT optical & NIR obs. of RR Lyrae in M15 (Bhardwaj+, 2021)
Optical and near-infrared pulsation properties of RR Lyrae and population II
Cepheid variables in the Messier 15 globular cluster.
Bhardwaj A., Rejkuba M., Sloan G.C., Marconi M., Yang S.-C.
<Astrophys. J., 922, 20 (2021)>
=2021ApJ...922...20B 2021ApJ...922...20B
ADC_Keywords: Stars, variable; Photometry, RI; Photometry, infrared;
Clusters, globular
Keywords: RR Lyrae variable stars ; Stellar pulsations ;
Globular star clusters ; Distance indicators
Abstract:
Messier 15 (NGC 7078) is an old and metal-poor post core-collapse
globular cluster that hosts a rich population of variable stars. We
report new optical (gi) and near-infrared (NIR, JKs) multi-epoch
observations for 129 RR Lyrae, 4 Population II Cepheids
(3 BL Herculis, 1 W Virginis), and 1 anomalous Cepheid variable
candidate in M15 obtained using the MegaCam and the WIRCam instruments
on the 3.6m Canada-France-Hawaii Telescope. Multi-band data are used
to improve the periods and classification of variable stars, and
determine accurate mean magnitudes and pulsational amplitudes from the
light curves fitted with optical and NIR templates. We derive optical
and NIR period-luminosity relations for RR Lyrae stars which are best
constrained in the Ks band, mKs=-2.333(0.054)logP+13.948(0.015) with
a scatter of only 0.037mag. Theoretical and empirical calibrations of
RR Lyrae period-luminosity-metallicity relations are used to derive a
true distance modulus to M15: 15.196±0.026 (statistical)
±0.039(systematic) mag. Our precise distance moduli based on RR
Lyrae stars and Population II Cepheid variables are mutually
consistent and agree with recent distance measurements in the
literature based on Gaia parallaxes and other independent methods.
Description:
This work is based on data in the science archive from the
Canada-France-Hawaii Telescope (CFHT). The optical and NIR images of
M15 were taken between 2011 August and 2013 September under the
program focused on pulsations of long-period variables and stellar
deaths in globular clusters (PIs: G. Sloan and D. Devost). Optical
images were obtained using the MegaCam detector. We extracted 112 g-
and 93 i-band dithered images for our analysis which correspond to
16 and 14 epochs in the g and i bands, respectively.
NIR images were taken using WIRCam. We obtained 178 images at J and
119 at Ks for a total of 11 epochs at J and 7 at Ks.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
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21 29 58.32 +12 10 01.1 M15 = NGC 7078
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 31 6017 Time-series photometry of RR Lyrae and
Population II Cepheid variables in M15
table3.dat 148 134 Optical and NIR pulsation properties of RR Lyrae
and Population II Cepheid variables in M15
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See also:
B/cfht : Log of CFHT Exposures (CADC, 1979-)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
V/150 : Updated catalog of variable stars in globular clusters (Clement+ 2017)
J/AJ/110/704 : RR Lyrae Variables in M15 (Silbermann+ 1995)
J/AJ/119/2274 : JK Photometry of globular clusters M15 & M56 (Ivanov+, 2000)
J/MNRAS/351/1204 : IR phot. of 10 Galactic Globular Clusters (Valenti+, 2004)
J/AJ/129/267 : RR Lyrae variables in NGC 5272 (Cacciari+, 2005)
J/AJ/129/2714 : JHK photometry of M92 variable stars (Del Principe+, 2005)
J/AJ/130/2140 : Abund. and velocities in globular clusters (Pritzl+, 2005)
J/other/RMxAA/42.75 : CCD RV LC of M15 RR Lyrae (Arellano Ferro+, 2006)
J/MNRAS/371/1503 : Synthetic photometry of RR Lyr (Marconi+, 2006)
J/MNRAS/370/1979 : JHKs phot. of T2Cs in globular clusters (Matsunaga+, 2006)
J/AJ/135/1459 : Period of M15 variable stars (Corwin+, 2008)
J/ApJ/708/717 : Light curve templates of RR Lyrae stars (Sesar+, 2010)
J/AJ/142/187 : HST obs. of 7 Pop.II variable stars (Benedict+, 2011)
J/MNRAS/439/3765 : RR Lyrae in 15 Galactic globular clusters (Dambis+, 2014)
J/MNRAS/437/2307 : LMC anomalous Cepheid Ks light curves (Ripepi+, 2014)
J/MNRAS/447/3342 : Galactic & LMC Cepheids Fourier parameters (Bhardwaj+, 2015)
J/ApJ/814/71 : Carina project IX: UBVI of Carina variables (Coppola+, 2015)
J/ApJ/807/127 : 70 RR Lyrae stars in the LMC bar (Muraveva+, 2015)
J/AJ/150/129 : Swift UVOT stars survey. II. RRL in M3 & M15 (Siegel+, 2015)
J/AcA/65/233 : OGLE Magellanic Clouds anomalous Cepheids (Soszynski+, 2015)
J/A+A/605/A100 : VVV survey Galactic Bulge Pop. II Cepheids (Bhardwaj+, 2017)
J/A+A/604/A29 : MC Type II & anomalous Cepheids PL & PR (Groenewegen+, 2017)
J/A+A/604/A120 : omega Cen RR Lyrae and SX Phoenicis stars (Navarrete+, 2017)
J/ApJ/841/84 : Theoretical framework for RR Lyrae. II. MIR (Neeley+, 2017)
J/AJ/154/231 : Multi-epoch multi-band photometry of B1-392 (Saha+, 2017)
J/AJ/154/85 : CTIO/DECam photometry of RR Lyrae stars in M5 (Vivas+, 2017)
J/AJ/155/137 : RRLs in globulars. V. ω Cen NIR phot. (Braga+, 2018)
J/A+A/616/A12 : Gaia DR2 sources in GC and dSph (Gaia Collaboration+, 2018)
J/MNRAS/481/1195 : Gaia DR2 RRL stars as standard candles (Muraveva+, 2018)
J/AcA/68/89 : VI light curves of SMC type II Cepheids (Soszynski+, 2018)
J/A+A/625/A1 : RR Lyrae variables NIR light-curve templates (Braga+, 2019)
J/MNRAS/484/4833 : Oosterhoff dichotomy in Galactic bulge (Prudil+, 2019)
J/AJ/160/220 : NIR LC of 234 RR Lyrae in Messier 3 (Bhardwaj+, 2020)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- ID ID (G1)
7- 8 A2 --- Filt Filter (g, i, J or Ks)
10- 18 F9.3 d MJD [55778.4/56544.4] Modified Julian Date
(JD-2400000.5)
20- 25 F6.3 mag omag [10.59/16.55] Observed magnitude in Filter
27- 31 F5.3 mag e_omag [0.001/0.6] Uncertainty in omag
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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- 5 A5 --- ID Identifier (G1)
7- 15 F9.5 deg RAdeg [322.39/322.62] Right Ascension (J2000)
17- 24 F8.5 deg DEdeg [12/12.32] Declination (J2000)
26- 32 F7.4 d PC01 [0/16.9] Period, Clement (see V/150)
34- 41 F8.5 d PTW [0.28/16.85] Period, this work
unless r_PTW is filled
43 I1 --- r_PTW [1/3]? Reference for PTW (1)
45- 48 A4 --- Type Variable type (2)
50- 55 F6.3 mag gmag [13.6/16.1]? CFHT/MegaCam intensity-averaged
mean g-band magnitude
57- 62 F6.3 mag imag [12.7/15.9]? CFHT/MegaCam intensity-averaged
mean i-band magnitude
64- 69 F6.3 mag Jmag [11.5/15.3]? CFHT/WIRCAM intensity-averaged
mean J-band magnitude
71- 76 F6.3 mag Ksmag [11/15]? CFHT/WIRCAM intensity-averaged
mean Ks-band magnitude
78- 82 F5.3 mag e_gmag [0.005/0.06]? Error in gmag
84- 88 F5.3 mag e_imag [0.005/0.05]? Error in imag
90- 94 F5.3 mag e_Jmag [0.02/0.11]? Error in Jmag
96- 100 F5.3 mag e_Ksmag [0.02/0.06]? Error in Ksmag
102- 106 F5.3 mag gAmp [0.16/1.4]? Peak-to-peak amplitude in g-band
108- 112 F5.3 mag iAmp [0.08/0.85]? Peak-to-peak amplitude in i-band
114- 118 F5.3 mag JAmp [0.098/0.81]? Peak-to-peak amplitude in J-band
120- 124 F5.3 mag KsAmp [0.05/0.8]? Peak-to-peak amplitude in Ks-band
126- 130 F5.3 mag e_gAmp [0.007/0.08]? Error in gAmp
132- 136 F5.3 mag e_iAmp [0.006/0.07]? Error in iAmp
138- 142 F5.3 mag e_JAmp [0.03/0.12]? Error in JAmp
144- 148 F5.3 mag e_KsAmp [0.03/0.08]? Error in KsAmp
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Note (1): The period (PTW) is from this work unless specified by r_PTW
as follows:
1 = Clement (2001AJ....122.2587C 2001AJ....122.2587C ; see V/150);
2 = Hoffman et al. (2021MNRAS.502..818H 2021MNRAS.502..818H);
3 = Siegel+ (2015, J/AJ/150/129).
Note (2): Type from the catalog of Clement (2001AJ....122.2587C 2001AJ....122.2587C ; see V/150)
as follows:
RRab = fundamental-mode RR Lyrae (51 occurrences);
RRc = overtone-mode RR Lyrae (58 occurrences);
RRd = mixed-mode RR Lyrae (20 occurrences);
BLH = BL Herculis (3 occurrences);
WVI = W Virginis (1 occurrence);
ACF = fundamental-mode anomalous Cepheid (1 occurrence).
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Global notes:
Note (G1): Var ID in the catalog of Clement (2001AJ....122.2587C 2001AJ....122.2587C ; see V/150).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 17-Mar-2023