Blue Supergiants as a Tool for Extragalactic Distances - Empirical Diagnostics

Fabio Bresolin

doi:10.1007/978-3-540-39882-0_8

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arXiv · astro-ph/0301179

Blue Supergiants as a Tool for Extragalactic Distances - Empirical Diagnostics

Fabio Bresolin

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Abstract

Blue supergiant stars can be exceptionally bright objects in the optical, making them prime targets for the determination of extragalactic distances. I describe how their photometric and spectroscopic properties can be calibrated to provide a measurement of their luminosity. I first review two well-known techniques, the luminosity of the brightest blue supergiants and, with the aid of recent spectroscopic data, the equivalent width of the Balmer lines. Next I discuss some recent developments concerning the luminosity dependence of the wind momentum and of the flux-weighted gravity, which can provide, if properly calibrated, powerful diagnostics for the determination of the distance to the parent galaxies.

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BibTeX RIS

Fabio Bresolin. 2003-01-10. Blue Supergiants as a Tool for Extragalactic Distances - Empirical Diagnostics. https://doi.org/10.1007/978-3-540-39882-0_8

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