J/ApJ/845/146 The Carnegie-Chicago Hubble Program. II. IC 1613 (Hatt+, 2017)
The Carnegie-Chicago Hubble Program.
II. The distance to IC 1613: the tip of the red giant branch and RR Lyrae
period-luminosity relations.
Hatt D., Beaton R.L., Freedman W.L., Madore B.F., Jang I.-S., Hoyt T.J.,
Lee M.G., Monson A.J., Rich J.A., Scowcroft V., Seibert M.
<Astrophys. J., 845, 146 (2017)>
=2017ApJ...845..146H 2017ApJ...845..146H
ADC_Keywords: Galaxies, nearby ; Stars, distances ; Stars, variable ;
Stars, population II ; Photometry, HST
Keywords: distance scale; galaxies: individual (IC 1613); stars: Population II;
stars: variables: RR Lyrae
Abstract:
IC 1613 is an isolated dwarf galaxy within the Local Group. Low
foreground and internal extinction, low metallicity, and low crowding
make it an invaluable testbed for the calibration of the local
distance ladder. We present new, high-fidelity distance estimates to
IC 1613 via its Tip of the Red Giant Branch (TRGB) and its RR Lyrae
(RRL) variables as part of the Carnegie-Chicago Hubble Program, which
seeks an alternate local route to H0 using Population II stars. We
have measured a TRGB magnitude
IACSTRGB=20.35±0.01stat±0.01sysmag using wide-field
observations obtained from the IMACS camera on the Magellan-Baade
telescope. We have further constructed optical and near-infrared RRL
light curves using archival BI- and new H-band observations from the
ACS/WFC and WFC3/IR instruments on board the Hubble Space Telescope
(HST). In advance of future Gaia data releases, we set provisional
values for the TRGB luminosity via the Large Magellanic Cloud and
Galactic RRL zero-points via HST parallaxes. We find corresponding
true distance moduli µ0TRGB=24.30±0.03stat±0.05sysmag
and <µ0RRL≥24.28±0.04stat+sysmag. We compare our results
to a body of recent publications on IC 1613 and find no statistically
significant difference between the distances derived from Population I
and II stars.
Description:
Observations of IC 1613 were obtained on 2015 June 12 using the
Inamori-Magellan Areal Camera and Spectrograph (IMACS) on the 6.5m
Magellan-Baade telescope at Las Campanas Observatory. We obtain a
15.46'x15.46' field of view with resolution of 0.2"/pixel and observed
in the BVI filters. See section 2.1.1.
We have made use of archival imaging of IC 1613 taken from the Local
Cosmology from Isolated Dwarfs program (PID:GO10505, PI: Gallart;
Gallart 2005, LCID). A single field was imaged over 24 orbits between
2006 August 28 and 30 approximately 5' west of the center of IC 1613
using the HST ACS/WFC instrument, which provides a 202"x202" field of
view with 0.05"/pixel resolution. Each orbit was divided between two
∼1200s exposures in the F475W and F814W passbands, resulting in 48
epochs per filter. See section 2.1.2.
We obtained near-infrared imaging over 24 orbits between 2014 December
17 and 18 using the HST WFC3/IR instrument (PID:GO13691, PI: Freedman;
Freedman W. 2014 HST Proposal). The orbits were divided between two
overlapping 136"x123" WFC3/IR pointings with a native resolution of
0.135"/pixel. See section 2.1.3.
In parallel with the observations described in the previous section
were 24 orbits with the HST ACS/WFC instrument (PID:GO13691, PI:
Freedman; Freedman 2014 W. HST Proposal). Each exposure in F606W and
F814W spanned ∼500s. See section 2.1.4.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table5.dat 64 85 IC 1613 RR Lyrae (RRL) ACS/WFC WCS Circa 2017 &
photometry notes
table6.dat 42 4860 Variable star photometry
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See also:
J/A+A/363/29 : Variable stars in IC 1613 (Antonello+, 2000)
J/A+A/367/759 : Variable stars in IC 1613 (Mantegazza+, 2001)
J/AcA/51/221 : OGLE-II. Cepheids in IC 1613 (Udalski+, 2001)
J/AJ/128/2239 : JHKs photometry of 92 LMC Cepheids (Persson+, 2004)
J/A+A/445/901 : BV(RI)c bands of Cepheids in IC 1613 (Antonello+, 2006)
J/ApJ/712/1259 : LCID project. II. Variables in IC1613 (Bernard+, 2010)
J/AJ/142/187 : HST obs. of 7 Pop.II variable stars (Benedict+, 2011)
J/ApJ/743/76 : Spitzer photometry of LMC Cepheids (Scowcroft+, 2011)
J/ApJ/758/11 : Bayesian distances to M31 satellites (Conn+, 2012)
J/AJ/144/4 : Dwarf galaxies in the Local Group (McConnachie+, 2012)
J/MNRAS/435/3206 : Properties of field RR Lyrae variables (Dambis+, 2013)
J/ApJ/779/102 : Metallicities of RGB stars in dwarf galaxies (Kirby+, 2013)
J/ApJ/807/127 : 70 RR Lyrae stars data in the LMC bar (Muraveva+, 2015)
J/ApJ/826/56 : HST/WFC3 obs. of Cepheids in SN Ia host gal. (Riess+, 2016)
J/AJ/153/96 : Standard Galactic field RR Lyrae. I. Phot. (Monson+, 2017)
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- [BMG2010] Object identification (VNNN) (G1)
6- 6 I1 h RAh [1] Hour of Right Ascension (J2000)
8- 9 I2 min RAm [4] Minute of Right Ascension (J2000)
11- 14 F4.1 s RAs Second of Right Ascension (J2000)
16 A1 --- DE- [+] Sign of Declination (J2000)
17- 17 I1 deg DEd [2] Degree of Declination (J2000)
19- 20 I2 arcmin DEm [7/11] Arcminute of Declination (J2000)
22- 25 F4.1 arcsec DEs Arcsecond of Declination (J2000)
27- 40 A14 --- Notes Notes ("Blend": 12 occurrences;
"Possible-blend": 4 occurrences) (G1)
42- 58 A17 --- Filt Filter notes (G1)
60- 64 F5.2 mag <F160W> [22.3/24.4]? Average HST WFC3/IR F160W
magnitude, Vega mag
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Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- [BMG2010] Object identification (VNNN) (G1)
6- 10 A5 --- Filt Filter used (F475W, F814W or F160W)
12- 23 F12.6 d MJD Observation time, mid-exposure, JD-2400000.5
25- 29 F5.3 --- Phase Phase
31- 36 F6.3 mag omag [21.9/65.2] Observed magnitude in Filt
38- 42 F5.3 mag e_omag [0.02/7.1] Uncertainty in omag
--------------------------------------------------------------------------------
Global notes:
Note (G1): Object ids and photometry notes taken from
Bernard+, 2010, J/ApJ/712/1259
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History:
From electronic version of the journal
References:
Scowcroft et al. 2016MNRAS.459.1170S 2016MNRAS.459.1170S
Beaton et al. Paper I. 2016ApJ...832..210B 2016ApJ...832..210B
Lee et al. 2017ApJ...835L..27L 2017ApJ...835L..27L
Hatt et al. Paper II. 2017ApJ...845..146H 2017ApJ...845..146H This catalog
Jang et al. Paper III. 2018ApJ...852...60J 2018ApJ...852...60J
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 05-Apr-2018