J/ApJ/869/82 Carnegie-Chicago Hubble Program: RR Lyrae NIR obs. (Rich+, 2018)
The Carnegie-Chicago Hubble Program: calibration of the near-infrared RR Lyrae
period-luminosity relation with HST.
Rich J.A., Madore B.F., Monson A.J., Freedman W.L., Beaton R.L.,
Clementini G., Garofalo A., Hatt D., Hoyt T., Jang I.-S., Kollmeier J.A.,
Gyoon Lee M., Neeley J.R., Scowcroft V., Seibert M.
<Astrophys. J., 869, 82 (2018)>
=2018ApJ...869...82R 2018ApJ...869...82R
ADC_Keywords: Stars, variable; Photometry, HST; Photometry, infrared;
Magnitudes, absolute
Keywords: stars: distances ; stars: variables: RR Lyrae
Abstract:
We present photometry of 30 Galactic RR Lyrae variables taken with HST
WFC3/IR for the Carnegie-Chicago Hubble Program. These measurements
form the base of the distance-ladder measurements that comprise a pure
Population II base to a measurement of Ho at an accuracy of 3%. These
data are taken with the same instrument and filter (F160W) as our
observations of RR Lyrae stars in external galaxies so as to minimize
sources of systematic error in our calibration of the extragalactic
distance scale. We calculate mean magnitudes based on one to three
measurements for each RR Lyrae star using star-by-star templates
generated from densely time-sampled data at optical and midinfrared
wavelengths. We use four RR Lyrae stars from our sample with
well-measured HST parallaxes to determine a zero-point. This
zero-point will soon be improved with the large number of precise
parallaxes to be provided by Gaia. We also provide preliminary
calibration with the TGAS and Gaia DR2 data, and all three zero points
are in agreement, to within their uncertainties.
Description:
Our observations of 30 Galactic RR Lyrae stars were conducted with HST
WFC3/IR and were spread across two HST programs (PID 13472 and PID 13691
PI Freedman) in 2013-2015.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 44 30 Galactic RR Lyrae sample
table2.dat 45 946 PSF photometry of individual exposures;
updated version sent by the author
table3.dat 41 30 Mean magnitudes
table4.dat 39 35 Absolute magnitudes
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/A+AS/125/313 : RR Lyrae radial velocities and [Fe/H] I. (Fernley+ 1997)
J/A+A/330/515 : RR Lyrae parallaxes & proper motions (Fernley+ 1998)
J/AJ/128/2239 : JHKs photometry of 92 LMC Cepheids (Persson+, 2004)
J/MNRAS/386/2115 : Type II Cepheid and RR Lyrae variables (Feast+, 2008)
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/ApJ/808/11 : RR Lyrae stars in M4. II. Spitzer/IRAC phot. (Neeley+, 2015)
J/ApJ/826/56 : HST/WFC3 obs. of Cepheids in SN Ia host gal. (Riess+, 2016)
J/A+A/605/A79 : TGAS Cepheids and RR Lyrae stars (Gaia Collaboration+, 2017)
J/AJ/153/96 : Standard Galactic field RR Lyrae. I. Photom. (Monson+, 2017)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Star name
10- 17 F8.6 d Per [0.26/0.74] Period adopted
from Monson+ (2017, J/AJ/153/96)
19- 25 A7 --- Obs Observation type(s) (1)
27- 30 A4 --- Type RR Lyrae type --"RRab", 21 occurrences ; or
"RRc", 9 occurrences.
32- 32 A1 --- Blazhko [*] * = Blazhko type
34- 38 F5.2 --- [Fe/H] [-2.3/-0.07] Metallicity
40- 44 F5.3 mag AF160W [0.006/0.09] Galactic extinction in the F160W band
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Note (1): Observation types as follows:
a = Direct imaging in SNAP program #13472;
b = Drift-scan imaging in SNAP program #13472;
c = Direct imaging in GO program #13691;
d = Drift-scan imaging in GO program #13691.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Star name
10- 24 F15.9 d MJD [56575.2/57379.3] Modified Julian Date
of Observation, JD-2400000.5
26- 32 F7.5 --- Phase [0.0001/1.15] Phase
34- 39 F6.3 mag F160W [6.4/11] HST WFC3/IR F160W Vega magnitude
41- 45 F5.3 mag e_F160W [0.01/0.04] Uncertainty in F160W
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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- 8 A8 --- Name Star name
10- 15 F6.3 mag F160WS [6.4/10.9] Spitzer-based intensity-averaged
measured mean F160W magnitudes
17- 21 F5.3 mag e_F160WS [0.01/0.06] Error on F160WS
23- 28 F6.3 mag F160WT [6.4/10.9] Template-based intensity-averaged
measured mean F160W magnitudes
30- 34 F5.3 mag e_F160WT [0.01/0.08] Error on F160WT
36- 41 F6.3 mag Hmag [6.5/10.9] Mean apparent H-band magnitude (G1)
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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 --- Source Parallax source (1)
10- 17 A8 --- Name Star name
19- 24 F6.3 mag HMag [-1/0.2] Absolute mean H-band magnitude (2)(G1)
26- 31 F6.3 mag F160WH [-1/0.2] Absolute mean F160W magnitude using
Source Parallax (2)
33- 37 F5.3 mag e_F160WH [0.03/0.8] Uncertainty in F160WH (2)
39 A1 --- Blazhko [*] * = Blazhko type
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Note (1): The parallax sources are as follows:
HST/FGS = Trigonometric parallaxes with HST/FGS
from Benedict+ (2011, J/AJ/142/187);
TGAS = Tycho-Gaia Astrometric Solution (TGAS) parallaxes,
Lindegren et al. (2016A&A...595A...4L 2016A&A...595A...4L),
Gould & Kollmeier (2017JKAS...50....1K 2017JKAS...50....1K),
Gaia Collaboration+ (2017, J/A+A/605/A79);
Gaia DR2 = Gaia data release 2 (DR2) parallaxes
(Gaia Collaboration+ (2018A&A...616A...1G 2018A&A...616A...1G),
Lindegren+ 2018A&A...616A...2L 2018A&A...616A...2L).
Note (2): Absolute magnitudes derived from directly inverted parallaxes used
in our PL analysis and given in the Column Source. The errors for
absolute magnitudes derived with HST /FGS and TGAS parallaxes are
calculated directly from the errors in the parallax as they dominate the
uncertainty. The error in absolute magnitude when derived from Gaia DR2
parallaxes are a combination of the error on the mean magnitude (Table 3)
and the error in parallax.
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Global notes:
Note (G1): Mean absolute H-band magnitudes are on the 2MASS system and sourced
from the work by Monson et al. (2017, J/AJ/153/96) combining archival
data as described in that paper's section 4.2.
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History:
From electronic version of the journal --
Table 2 updated by the author.
Acknowledgments:
Jeff Rich [Carnegie Observatories --http://obs.carnegiescience.edu/]
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 07-Nov-2019