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arXiv · 1203.6222

Determining the Hubble constant using Giant extragalactic HII regions and HII galaxies

Ricardo Chavez·Elena Terlevich·Roberto Terlevich·Manolis Plionis·Fabio Bresolin·Spyros Basilakos·Jorge Melnick
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Abstract

We report the first results of a long term program aiming to provide accurate independent estimates of the Hubble constant (H0) using the L-sigma distance estimator for Giant extragalactic HII regions (GEHR) and HII galaxies. We have used VLT and Subaru high dispersion spectroscopic observations of a local sample of HII galaxies, identified in the SDSS DR7 catalogue in order to re-define and improve the L(Hbeta)-sigma distance indicator and to determine the Hubble constant. To this end we utilized as local calibration or `anchor' of this correlation, GEHR in nearby galaxies which have accurate distance measurements determined via primary indicators. Using our best sample of 69 nearby HII galaxies and 23 GEHR in 9 galaxies we obtain H0=74.3 +- 3.1 (statistical) +- 2.9 (systematic) km /s Mpc, in excellent agreement with, and independently confirming, the most recent SNe Ia based results.

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Ricardo Chavez, Elena Terlevich, Roberto Terlevich, Manolis Plionis, Fabio Bresolin, Spyros Basilakos, Jorge Melnick. 2012-06-14. Determining the Hubble constant using Giant extragalactic HII regions and HII galaxies. https://doi.org/10.1111/j.1745-3933.2012.01299.x

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