J/ApJ/908/L5 Color-magnitude diagram for ω Centauri (Soltis+, 2021)
The Parallax of ω Centauri measured from Gaia EDR3 and a direct, geometric
calibration of the tip of the red giant branch and the Hubble constant
Soltis J., Casertano S., Riess A.G.
<Astrophys. J., 908, L5 (2021)>
=2021ApJ...908L...5S 2021ApJ...908L...5S
ADC_Keywords: Optical; Clusters, open; Milky Way; Parallaxes, trigonometric;
Photometry
Keywords: Red giant tip ; Hubble constant ; Distance measure ; Globular
star clusters ; Distance indicators
Abstract:
We use data from the ESA Gaia mission Early Data Release 3 (EDR3) to
measure the trigonometric parallax of ωCen, the first
high-precision parallax measurement for the most massive globular
cluster in the Milky Way. We use a combination of positional and
high-quality proper motion data from EDR3 to identify over 100000
cluster members, of which 67000 are in the magnitude and color range
where EDR3 parallaxes are best calibrated. We find the estimated
parallax to be robust, demonstrating good control of systematics
within the color-magnitude diagram of the cluster. We find a parallax
for the cluster of
0.191±0.001(statistical)±0.004(systematic)mas (2.2% total
uncertainty) corresponding to a distance of 5.24±0.11kpc. The
parallax of ωCen provides a unique opportunity to directly and
geometrically calibrate the luminosity of the tip of the red giant
branch (TRGB) because it is the only cluster with sufficient mass to
provide enough red giant stars, more than 100 one magnitude below the
tip, for a precise, model-free measurement of the tip. Combined with
the preexisting and most widely used measurements of the tip and
foreground Milky Way extinction, we find MI,TRGB=-3.97±0.06mag for
the I-band luminosity of the blue edge. Using the TRGB luminosity
calibrated from the Gaia EDR3 parallax of ωCen to calibrate the
luminosity of Type Ia supernovae results in a value for the Hubble
constant of H0=72.1±2.0km/s/Mpc. We make the data for the stars in
ωCen available electronically and encourage independent analyses
of the results presented here.
Objects:
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RA (2000) DE Designation(s)
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11 55 01.32 -59 15 13.5 omega Century = v* w Cen
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . this file
fig5.dat 150 67347 Color-magnitude diagram for ω Centauri
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See also:
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
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)
J/A+AS/120/139 : Variables in Omega Cen Fields 5139A-C (Kaluzny+ 1996)
J/ApJ/652/1133 : BVI photometry of NGC 4258 Cepheids (Macri+, 2006)
J/AJ/140/631 : HST WFC3/UVIS photometry of omega Cen core (Bellini+, 2010)
J/AJ/142/187 : HST observations of 7 PopII variable stars (Benedict+, 2011)
J/A+A/583/A76 : OmegaCen candidates RAVEselected (Fernandez-Trincado+, 2015)
J/ApJ/812/149 : HSTPROMO. III. Dynamical distances (Watkins+, 2015)
J/ApJ/829/108 : Kinematic data of Galactic globular clusters (Eadie+, 2016)
J/ApJ/844/164 : HST astro-photometric of NGC5139. III. (Bellini+, 2017)
J/MNRAS/478/1520 : Milky Way globular clusters data (Baumgardt+, 2018)
J/ApJ/853/86 : HST large programme on ωCentauri. II. (Bellini+, 2018)
J/A+A/616/A12 : Gaia DR2 sources in GC and dSph (Gaia Collaboration+, 2018)
J/MNRAS/482/5138 : Galactic GC mean pm & velocities (Baumgardt+, 2019)
J/ApJ/870/115 : Reddening, dist modulus & Fe/H of RRLs in wCen (Bono+, 2019)
J/ApJ/874/150 : The first 3yrs of DES-SN (DES-SN3YR) (Brout+, 2019)
J/MNRAS/489/3093 : Gaia DR2 parallax of globular clusters (Shao+, 2019)
J/ApJ/886/61 : OGLE-III, MCPS and HST VI obs. of LMC & SMC (Yuan+, 2019)
J/ApJ/889/5 : HST obs Mira variables in SNIa host NGC1559 (Huang+, 2020)
J/ApJ/906/125 : Carnegie-Chicago Hubble Program IX. TRGB M106 (Jang+, 2021)
Byte-by-byte Description of file: fig5.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- Gaia Gaia mission Early Data Release 3 index
identifier
21- 38 F18.14 deg RAdeg [200/203] Right Ascension,
(ICRS at epoch 2016.0)
40- 58 F19.15 deg DEdeg [-49/-46] Declination, (ICRS at epoch 2016.0)
60- 69 F10.7 mag Gmag [11.8/19.5] G-band magnitude
71- 82 F12.10 mag BpRp [0.0009/1.5] Gaia Bp-Rp color
84-106 A23 mas plx Gaia DR3 parallax
108-119 F12.10 mas e_plx [0.01/2] Uncertainty in plx
121-129 F9.6 mas plx0 [-0.05/0.009] Gaia parallax zeropoint
correction (subtract this from parallax)
131-144 A14 --- GOF Gaia mission Early Data Release 3
goodness of fit
146-150 A5 --- cut Passes color-magnitude diagram cut; True or
False
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 26-Feb-2024