Extragalactic Stellar Astronomy in the Local Universe Quantitative Spectroscopy of Blue Supergiants
Blue supergiants are the intrinsically brightest normal stars at visual light with absolute visual magnitudes up to -9. They are ideal to study young stellar populations in galaxies beyond the Local Group to determine chemical composition and evolution, interstellar extinction, reddening laws and distances. We discuss most recent results on the quantitative spectral analysis of such objects in galaxies be yond the Local Group based on medium and low resolution spectra obtained with the ESO VLT and Keck. We describe the analysis method including the determination of metallicity and metallicity gradients. A new method to measure accurate extragalac tic distances based on the stellar gravities and effective temperatures is presented, the flux weighted gravity - luminosity relationship (FGLR). The FGLR is a purely spectroscopic method, which overcomes the untertainties introduced by interstellar extinction and variations of metallicity, which plague all photometric stellar distance determination methods. We discuss the perspectives of the extension of this work us ing the next generation of giant ground-based telescopes with aperture sizes of 30m or larger.
galaxies distances galaxies abundances galaxies stellar content galax-ies individual (NGC300) stars early-type stars abundances stars distances
Rolf Kudritzkj Miguel A. Urbaneja Fabio Bresolin Norbert Przybilla
Institute for Astronomy,University of Hawaii,Honolulu,Hawaii Dr.Remeis-Sternvarte Bamberg,Erlangen university,Bamberg,Germany
国际会议
The 10th Asian-Pacific Regional International Astronomical Union Meeting(第十届亚洲及太平洋地区天文学大会 APRIM)
昆明
英文
15-20
2008-08-03（万方平台首次上网日期，不代表论文的发表时间）