J/AJ/153/154 LMC NIR survey. IV. Type II Cepheid variables (Bhardwaj+, 2017)
Large Magellanic Cloud near-infrared synoptic survey.
IV. Leavitt laws for Type II Cepheid variables.
Bhardwaj A., Macri L.M., Rejkuba M., Kanbur S.M., Ngeow C.-C., Singh H.P.
<Astron. J., 153, 154 (2017)>
=2017AJ....153..154B 2017AJ....153..154B (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Magellanic Clouds ; Milky Way ; Stars, variable ;
Photometry, VRI ; Photometry, infrared ; Clusters, globular ;
Stars, distances
Keywords: distance scale - Magellanic Clouds - stars: variables: Cepheids
Abstract:
We present time-series observations of Population II Cepheids in the
Large Magellanic Cloud at near-infrared (JHKs) wavelengths. Our
sample consists of 81 variables with accurate periods and optical (VI)
magnitudes from the OGLE survey, covering various subtypes of
pulsators (BL Herculis, W Virginis, and RV Tauri). We generate
light-curve templates using high-quality I-band data in the LMC from
OGLE and Ks-band data in the Galactic bulge from VISTA Variables in
Via Lactea survey (2010NewA...15..433M 2010NewA...15..433M) and use them to obtain robust
mean magnitudes. We derive period-luminosity (P-L) relations in the
near-infrared and Period-Wesenheit (P-W) relations by combining
optical and near-infrared data. Our P-L and P-W relations are
consistent with published work when excluding long-period RV Tauris.
We find that Pop II Cepheids and RR Lyraes follow the same P-L relations
in the LMC. Therefore, we use trigonometric parallax from the Gaia DR1
(Cat. I/337) for VY Pyx and the Hubble Space Telescope parallaxes for
κ Pav and 5 RR Lyrae variables to obtain an absolute calibration of
the Galactic Ks-band P-L relation, resulting in a distance modulus to
the LMC of µLMC=18.54±0.08 mag. We update the mean magnitudes
of Pop II Cepheids in Galactic globular clusters using our light-curve
templates and obtain distance estimates to those systems, anchored to
a precise late-type eclipsing binary distance to the LMC. We find that
the distances to these globular clusters based on Pop II Cepheids are
consistent (within 2σ) with estimates based on the MV-[Fe/H]
relation for horizontal branch stars.
Description:
This paper is the fourth in a series of articles based on observations
obtained by the Large Magellanic Cloud Near-infrared Synoptic Survey
(LMCNISS; Macri et al. 2015, J/AJ/149/117, hereafter Paper I).
In Paper I we carried out a time-series survey of 18 deg2 in the
central region of the LMC at JHKs wavelengths using the 1.5 m telescope
at the Cerro Tololo Inter-American Observatory and the CPAPIR camera.
Observations were carried out in queue mode by the SMARTS consortium
during 32 nights from 2006 November to 2007 November. The survey products
include measurements for more than 3.5x106 sources, including ∼1500
Classical Cepheids.
We cross-matched the LMCNISS catalog (Paper I) against OGLE-III
(Soszynski et al. 2008, J/AcA/58/293) and identified 81 T2Cs with periods
ranging from 1 to 68 days; 70 of these have JHKs measurements, while
the remaining 11 only have data in J and/or H band. The sample consists of
16 BLH, 31 WVI, 12 PWV, and 22 RVT stars.
Objects:
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RA (ICRS) DE Designation(s)
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05 23 34.6 -69 45 22 Large Magellanic Cloud = NAME LMC
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File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table4.dat 79 81 Properties of Type II Cepheids in the LMC
table1.dat 39 9153 Time-series photometry for Type II Cepheids
table11.dat 47 26 Type II Cepheid-based Distance Estimates for
Galactic Globular Clusters
table10.dat 70 46 Template-fit mean magnitudes for Type II
Cepheids in Galactic globular clusters
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See also:
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
J/AcA/49/223 : BVI photometry of OGLE LMC Cepheids (Udalski+, 1999)
J/ApJS/142/71 : BVRI observations of LMC Cepheids (Sebo+, 2002)
J/AJ/128/2239 : JHKs photometry of 92 LMC Cepheids (Persson+, 2004)
J/MNRAS/370/1979 : JHKs photometry of T2Cs in globular clusters
(Matsunaga+, 2006)
J/AcA/58/293 : Type-II and anomalous Cepheids in LMC (Soszynski+, 2008)
J/MNRAS/397/933 : LMC type II Cepheids JHKs magnitudes (Matsunaga+, 2009)
J/AcA/61/285 : VI light curves of Galactic Bulge Cepheids
(Soszynski+, 2011)
J/ApJ/743/76 : Spitzer photometry of LMC Cepheids (Scowcroft+, 2011)
J/MNRAS/424/1807 : VISTA Magellanic Cloud Survey. V. Cepheids (Ripepi+, 2012)
J/A+A/550/A70 : Galactic and Magellanic Cloud Cepheids distance
(Groenewegen, 2013)
J/AJ/149/117 : LMC infrared survey. I. Photometry of Cepheids
(Macri+, 2015)
J/MNRAS/446/3034 : LMC Type II Cepheids J and Ks light curves (Ripepi+, 2015)
J/AJ/151/88 : LMC NIR Synoptic Survey. II. Wesenheit relations
(Bhardwaj+, 2016)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name Cepheid identifier (T2CEP-NNN,
OGLE LMC-T2CEP-NNN in Simbad) (1)
11- 16 F6.3 d Per [1.152/67.965] Period (1)
18- 20 A3 --- Type Subtype of Cepheids (1) (2)
22- 27 F6.3 mag Vmagmean [13.806/20.149] T2C mean V magnitude (1) (3)
29- 34 F6.3 mag Imagmean [13.658/18.416] T2C mean I magnitude (1) (3)
36- 41 F6.3 mag Jmagmean [13.193/17.787]?=99.999 T2C mean J magnitude
(3)
43- 48 F6.3 mag Hmagmean [12.696/16.942]?=99.999 T2C mean H magnitude
(3)
50- 55 F6.3 mag Ksmagmean [12.03/16.235]?=99.999 T2C mean Ks magnitude
(3)
57- 61 F5.3 mag e_Jmagmean [0.02/0.146]?=9.999 Uncertainty in Jmagmean
(3)
63- 67 F5.3 mag e_Hmagmean [0.024/0.193]?=9.999 Uncertainty in Hmagmean
(3)
69- 73 F5.3 mag e_Ksmagmean [0.018/0.184]?=9.999 Uncertainty in Ksmagmean
(3)
75- 79 F5.3 mag E(V-I) [0.02/0.22] The (V-I) color excess (4)
--------------------------------------------------------------------------------
Note (1): Name, Per, Type and mean V & I magnitudes are taken from OGLE-III
from Soszynski et al. (2008, J/AcA/58/293).
Note (2): Subtype of LMC Cepheids, from Soszynski et al. (2008, J/AcA/58/293),
are defined as follows:
BLH = BLHer Type II Cepheid;
PWV = pWVir Type II Cepheid;
RVT = RVTau Type II Cepheid;
WVI = WVir Type II Cepheid.
Note (3): Mean magnitudes are estimated via intensity-weighted integration of
the best-fit I and Ks-band based templates. The JHKs mean
magnitudes were corrected for extinction using the reddening law of
Cardelli et al. (1989ApJ...345..245C 1989ApJ...345..245C) and the given E(V-I) values.
Note (4): Individual reddening values from the map of Haschke et al.
(2011AJ....141..158H 2011AJ....141..158H). The total-to-selective absorption ratios per
unit of E(V-I) are RJ=0.69, RH=0.43 and RK=0.28 (Bhardwaj et al.
2016AJ....151...88B 2016AJ....151...88B).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name Cepheid identifier (T2CEP-NNN,
OGLE LMC-T2CEP-NNN in Simbad) (1)
11- 12 A2 --- Filt [J H Ks] Filter in which the magnitude
was obtained
14- 20 F7.3 d MJD [42.605/437.856] Modified Julian Date of
observation (JD-2450000)
22- 26 F5.3 --- Phase [0/1] Light curve phase (2)
28- 33 F6.3 mag mag [11.923/18.356] Near-infrared magnitude in Filt
35- 39 F5.3 mag e_mag [0.005/0.399] Uncertainty in mag
--------------------------------------------------------------------------------
Note (1): Cepheid ID from OGLE-III catalog of LMC Type II Cepheids,
Soszynski et al. (2008, J/AcA/58/293).
Note (2): Phase is determined using the period and time of maximum brightness
in I-band from OGLE-III (2008, J/AcA/58/293).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table11.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Cluster Galactic globular cluster name
10- 14 F5.2 mag mu(J) [13.54/15.66] Distance modulus in J band
µ(J)
16- 19 F4.2 mag e_mu(J) [0.06/0.13] Uncertainty in mu(J)
21- 25 F5.2 mag mu(H) [13.58/15.85] Distance modulus in H band
µ(H)
27- 30 F4.2 mag e_mu(H) [0.06/0.12] Uncertainty in mu(H)
32- 36 F5.2 mag mu(Ks) [13.53/15.71] Distance modulus in Ks band
µ(Ks)
38- 41 F4.2 mag e_mu(Ks) [0.06/0.13] Uncertainty in mu(Ks)
43- 47 F5.2 mag mu(M06) [13.23/15.93] Distance modulus µM06 (1)
--------------------------------------------------------------------------------
Note (1): µM06: derived by Matsunaga et al. (2006, J/MNRAS/370/1979) based
on magnitudes of horizontal branch stars.
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Byte-by-byte Description of file: table10.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Cluster Galactic globular cluster name
10- 13 A4 --- Star Star name
15- 20 F6.3 d Per [1.182/87.5] Period
22- 27 F6.3 mag Jmagmean [9.083/14.227] T2C mean J magnitude
29- 34 F6.3 mag Hmagmean [8.43/13.788] T2C mean H magnitude
36- 41 F6.3 mag Ksmagmean [8.251/13.648] T2C mean Ks magnitude
43- 47 F5.3 mag e_Jmagmean [0.014/0.107] Uncertainty in Jmagmean
49- 53 F5.3 mag e_Hmagmean [0.009/0.103] Uncertainty in Hmagmean
55- 59 F5.3 mag e_Ksmagmean [0.013/0.093] Uncertainty in Ksmagmean
61- 64 F4.2 mag E(B-V) [0.01/2.28] The (B-V) color excess
66- 70 F5.2 [-] [Fe/H] [-2.26/-0.53] Metallicity
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History:
From electronic version of the journal
References:
Macri et al. Paper I. 2015AJ....149..117M 2015AJ....149..117M, Cat. J/AJ/149/117
Bhardwaj et al. Paper II. 2016AJ....151...88B 2016AJ....151...88B, Cat. J/AJ/151/88
Bhardwaj et al. Paper III. 2016MNRAS.457.1644B 2016MNRAS.457.1644B
Yuan et al. Paper V. 2017AJ....154..149Y 2017AJ....154..149Y
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 25-May-2018