Determining the Hubble constant using giant extragalactic H ii regions and H ii galaxies
Article first published online: 4 JUL 2012
© 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS
Monthly Notices of the Royal Astronomical Society: Letters
Volume 425, Issue 1, pages L56–L60, September 2012
How to Cite
Chávez, R., Terlevich, E., Terlevich, R., Plionis, M., Bresolin, F., Basilakos, S. and Melnick, J. (2012), Determining the Hubble constant using giant extragalactic H ii regions and H ii galaxies. Monthly Notices of the Royal Astronomical Society: Letters, 425: L56–L60. doi: 10.1111/j.1745-3933.2012.01299.x
- Issue published online: 20 AUG 2012
- Article first published online: 4 JUL 2012
- Accepted 2012 June 8. Received 2012 June 8; in original form 2012 March 28
- H ii regions;
- cosmological parameters;
- distance scale
We report the first results of a long-term programme aiming to provide accurate independent estimates of the Hubble constant (H0) using the L(Hβ)–σ distance estimator for giant extragalactic H ii regions (GEHR) and H ii galaxies.
We have used Very Large Telescope and Subaru high-dispersion spectroscopic observations of a local sample of H ii galaxies, identified in the Sloan Digital Sky Survey Data Release 7 (SDSS DR7) catalogue in order to redefine and improve the L(Hβ)–σ 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 H ii galaxies and 23 GEHR in nine galaxies, we obtain H0= 74.3 ± 3.1 (statistical) ± 2.9 (systematic) km s−1 Mpc−1, in excellent agreement with, and independently confirming, the most recent Type Ia supernovae based results.