The Carnegie-Chicago Hubble Program. VIII. An Independent Determination of the Hubble Constant Based on the Tip of the Red Giant Branch
| Autor: | Christopher R. Burns, In Sung Jang, Taylor J. Hoyt, Rachael L. Beaton, Barry F. Madore, Andrew J. Monson, Jillian R. Neeley, Mark M. Phillips, Jeffrey A. Rich, Dylan Hatt, Myung Gyoon Lee, Wendy L. Freedman, Mark Seibert |
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| Rok vydání: | 2019 |
| Předmět: |
Cosmology and Nongalactic Astrophysics (astro-ph.CO)
010504 meteorology & atmospheric sciences Cepheid variable FOS: Physical sciences Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences Advanced Camera for Surveys symbols.namesake 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics Large Magellanic Cloud 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics 0105 earth and related environmental sciences Physics Astronomy and Astrophysics Astrophysics - Astrophysics of Galaxies Galaxy Red-giant branch Distance modulus Photometry (astronomy) Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) symbols Astrophysics::Earth and Planetary Astrophysics Hubble's law Astrophysics - Cosmology and Nongalactic Astrophysics |
| DOI: | 10.48550/arxiv.1907.05922 |
| Popis: | We present a new and independent determination of the local value of the Hubble constant based on a calibration of the Tip of the Red Giant Branch (TRGB) applied to Type Ia supernovae (SNeIa). We find a value of Ho = 69.8 +/- 0.8 (+/-1.1\% stat) +/- 1.7 (+/-2.4\% sys) km/sec/Mpc. The TRGB method is both precise and accurate, and is parallel to, but independent of the Cepheid distance scale. Our value sits midway in the range defined by the current Hubble tension. It agrees at the 1.2-sigma level with that of the Planck 2018 estimate, and at the 1.7-sigma level with the SHoES measurement of Ho based on the Cepheid distance scale. The TRGB distances have been measured using deep Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) imaging of galaxy halos. The zero point of the TRGB calibration is set with a distance modulus to the Large Magellanic Cloud of 18.477 +/- 0.004 (stat) +/-0.020 (sys) mag, based on measurement of 20 late-type detached eclipsing binary (DEB) stars, combined with an HST parallax calibration of a 3.6 micron Cepheid Leavitt law based on Spitzer observations. We anchor the TRGB distances to galaxies that extend our measurement into the Hubble flow using the recently completed Carnegie Supernova Project I sample containing about 100 well-observed SNeIa. There are several advantages of halo TRGB distance measurements relative to Cepheid variables: these include low halo reddening, minimal effects of crowding or blending of the photometry, only a shallow (calibrated) sensitivity to metallicity in the I-band, and no need for multiple epochs of observations or concerns of different slopes with period. In addition, the host masses of our TRGB host-galaxy sample are higher on average than the Cepheid sample, better matching the range of host-galaxy masses in the CSP distant sample, and reducing potential systematic effects in the SNeIa measurements. Comment: 60 pages, 20 figures, accepted for publication in the Astrophysical Journal |
| Databáze: | OpenAIRE |
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