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METHOD:PUBLISH
BEGIN:VEVENT
DTSTART;TZID=Atlantic/Canary:20131113T123000
DTEND;TZID=Atlantic/Canary:20131113T133000
UID:iactalks-551
X-WR-CALNAME: IAC Talks: Open Astronomy Seminars
X-ORIGINAL-URL: /iactalks/Talks/view/551
CREATED:2013-11-13T12:30:00+00:00
X-WR-CALDESC: IAC Talks upcomming talks
SUMMARY:Supergiant Stars as Extragalactic Probes of Cosmic Abundances and D
 istances 
DESCRIPTION:Supergiant Stars as Extragalactic Probes of Cosmic Abundances a
 nd Distances \nProf. Rudolf Kudritzki\n\nThe determination of chemical com
 position and distances of galaxies is crucial for constraining the theory 
 of galaxy formation and evolution in a dark energy and cold dark matter do
 minated universe. However, the standard technique using HII regions to det
 ermine the metallicity of star forming galaxies, nearby and at high redshi
 ft, is subject to large systematic uncertainties that are poorly understoo
 d and the  determinination of accurate distances using Cepheids suffers fr
 om  uncertainties caused by the metallicity dependence of the period  lumi
 nosity relationship and extinction and crowding corrections.  Multi-object
  spectroscopy of blue and red supergiant stars - the  brightest stars in t
 he universe at visual and NIR wavelengths - provides  an attractive altern
 ative. I will present results accumulated over  recent years for galaxies 
 in the Local Group and beyond out to a  distance of 8 Mpc and will discuss
  the potential of future work with TMT  and E-ELT. Combining the photon co
 llecting power of these next  generation telescopes with Adaptive Optics w
 e will be able to study  individual supergiant stars in galaxies as distan
 t as the Coma cluster. With spectroscopy of the integrated light of young 
 very massive Star  Super Clusters and simple population synthesis techniqu
 es we can reach  out ten times further.
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