J/ApJ/929/116 Distances to Local Group galaxies. II. Fornax dSph (Oakes+, 2022)
Distances to Local Group galaxies via Population II, stellar distance
indicators.
II. The Fornax dwarf spheroidal.
Oakes E.K., Hoyt T.J., Freedman W.L., Madore B.F., Tran Q.H., Cerny W.,
Beaton R.L., Seibert M.
<Astrophys. J., 929, 116 (2022)>
=2022ApJ...929..116O 2022ApJ...929..116O
ADC_Keywords: Galaxies, dwarf; Stars, population II; Photometry, VRI;
Local group
Keywords: Fornax dwarf spheroidal galaxy ; Population II stars ;
Distance measure ; RR Lyrae variable stars ; Red giant tip ;
Horizontal branch ; Local Group
Abstract:
We determine three independent Population II distance moduli to the
Fornax dwarf spheroidal (dSph) galaxy, using wide-field, ground-based
VI imaging acquired with the Magellan-Baade telescope at Las Campanas
Observatory. After subtracting foreground stars using Gaia EDR3 proper
motions, we measure an I-band tip of the red giant branch (TRGB)
magnitude of I0TRGB=16.753±0.03stat±0.037sysmag, with a
calibration based in the LMC giving a distance modulus of
µ0TRGB=20.80±0.037stat±0.057sysmag. We determine an RR
Lyrae (RRL) distance from template mean magnitudes, with periods
adopted from the literature. Adopting a Gaia DR2 calibration of first
overtone RRL period-luminosity and period-Wesenheit relations, we find
µ0PLZ=20.74±0.01stat±0.12sysmag and
µ0PWZ=20.68±0.02stat±0.07sysmag. Finally, we determine
a distance from Fornax's horizontal branch (HB) and two galactic
globular cluster calibrators, giving
µ0HB=20.83±0.03stat±0.09sysmag. These distances are
each derived from homogeneous IMACS photometry, are anchored to
independent geometric zero-points, and utilize different classes of
stars. We therefore average over independent uncertainties and report
the combined distance modulus
<µ0≥20.770±0.042stat±0.024sysmag (corresponding to a
distance of 143±3kpc).
Description:
Ground-based observations of Fornax were acquired with the
Inamori-Magellan Areal Camera and Spectrograph (IMACS) mounted on the
6.5m Magellan-Baade telescope at the Carnegie Institution's Las
Campanas Observatory in Chile. On the nights of 2014 July 24-25 and
September 20-21, 19 epochs over 9 pointings were obtained in the
Johnsons-Cousins V and I filters.
During approximately the same time period, overlapping HST imaging in
F606W and F814W was obtained with the ACS/WFC instrument on
2014 September 13-14 (PID: GO-13691, PI: Freedman) and retrieved from
the Mikulski Archive for Space Telescopes (MAST).
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
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02 39 59.29 -34 26 56.9 Fornax = NAME Fornax dSph
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 52 180471 IMACS photometry
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See also:
B/hst : HST Archived Exposures Catalog (STScI, 2007)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
VII/195 : Globular Clusters in the Milky Way (Harris, 1996)
VII/202 : Globular Clusters in the Milky Way (Harris, 1997)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
J/AJ/115/193 : RR Lyrae V light curves (Layden, 1998)
J/PASP/110/533 : BR photometry of Fornax bright stars (Stetson+ 1998)
J/AJ/118/1671 : Fornax cluster 4 VI photometry (Buonanno+, 1999)
J/AJ/123/840 : VI photometry of variable stars in Fornax (Bersier+, 2002)
J/MNRAS/345/747 : RR Lyrae in 4 Fornax globular clusters (Mackey+, 2003)
J/AJ/128/2239 : JHKs photometry of 92 LMC Cepheids (Persson+, 2004)
J/AJ/127/840 : VRI photometry of Fornax red giants (Pont+, 2004)
J/A+A/459/423 : VI and [Fe/H] of Fornax dSph RGB stars (Battaglia+, 2006)
J/A+A/467/1025 : JHK phot. of Fornax red giant branch (Gullieuszik+, 2007)
J/MNRAS/389/1924 : Old stellar syst. (globulars to ellipticals) (Forbes+, 2008)
J/ApJ/685/947 : SX Phe stars in Fornax. II. (Poretti+, 2008)
J/MNRAS/384/1583 : JHK light curves of RR Lyr (Sollima+, 2008)
J/ApJ/701/1323 : Variable stars in Fornax dSph. III. (Greco+, 2009)
J/MNRAS/394/795 : AGB stars in Fornax dwarf spheroidal gal. (Whitelock+, 2009)
J/A+A/544/A73 : BVI photometry of Fornax dSph galaxy (de Boer+, 2012)
J/A+A/544/A155 : HST photometry of M31 globular clusters (Federici+, 2012)
J/A+A/572/A82 : Abundances in outer parts of Fornax dSph (Hendricks+, 2014)
J/ApJ/789/147 : Star formation histories of LG dwarf galaxies (Weisz+, 2014)
J/MNRAS/453/2653 : Carbon stars in the Galaxy and its satellites (Huxor+, 2015)
J/A+A/585/A86 : Fornax dSph H4 globular cluster stars (Hendricks+, 2016)
J/ApJ/826/56 : HST/WFC3 obs. of Cepheids in SN Ia host gal. (Riess+, 2016)
J/ApJ/845/146 : Carnegie-Chicago Hubble Program. II. IC 1613 (Hatt+, 2017)
J/AJ/154/263 : NIR photometry of 77 RR Lyrae stars (Karczmarek+, 2017)
J/AJ/153/96 : Standard Gal. field RR Lyrae. I. Photometry (Monson+, 2017)
J/ApJ/869/82 : Carnegie-Chicago Hubble Program: RRL NIR obs. (Rich+, 2018)
J/ApJ/876/85 : HST observations for LMC Cepheids (Riess+, 2019)
J/MNRAS/485/3042 : UBVRI photometry in 48 globular clusters (Stetson+, 2019)
J/AJ/158/16 : RR Lyrae stars from the DES (Stringer+, 2019)
J/ApJ/906/125 : Carnegie-Chicago Hubble Program IX. TRGB (Jang+, 2021)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 10 F10.7 deg RAdeg [39.5/40.5] Right Ascension (J2000)
12- 22 F11.7 deg DEdeg [-35/-34] Declination (J2000)
24- 29 F6.3 mag Vmag [16/26.3]? Averaged apparent V band Vega magnitude
31- 36 F6.4 mag e_Vmag [0.01/0.6]? Uncertainty in Vmag (1)
38- 43 F6.3 mag Imag [15/25.6]? Averaged apparent I band Vega magnitude
45- 50 F6.4 mag e_Imag [0.01/0.6]? Uncertainty in Imag (1)
52 I1 --- Cut [0/1] Gaia EDR3 cut flag (2)
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Note (1): Magnitude errors were estimated as a sum of squares with DAOPHOT
magnitude errors and the standard deviation of the calibrating
image, and should not be interpreted as rigorous estimates of the
photometric error.
Note (2): Sources excluded by Gaia EDR3 proper motions are flagged with "1".
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History:
From electronic version of the journal
References:
Tran et al. Paper I. 2022ApJ...935...34T 2022ApJ...935...34T
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 07-Mar-2024