Tuesday. Farewell party for Phillip Bett and Karina last night. I'm putting in my best effort to find a great apartment, and I feel like I've more or less "caught up" with the web postings. Got a bank account, cell phone, making appointments for viewing.
Bonn Astronomisches Kolloquium
Stellar Spectroscopy unleashed -- ELTs and Red Supergiants in the Coma Cluster
Prof. Dr. Rolf Kudritzki
Chemical composition and distances to star forming galaxies are subject to large systematic uncertainties that are poorly understood. New method: use low resolution J-band spectroscopy of individual red supergiant stars (RSGs) in distance galaxies (Mauna Kea IRTF SpeX low resolution spectra of MW RSGs and MARCS model atmospheres). Individual metallicities and alpha/Fe ratio can be determined with an accuracy of about 0.1 dex. Extendable to MOSFIRE/Keck and KMOS/VLT. Can reach individual RSGs in galaxies as distant as the Coma Cluster in the next generation of ELTs and AO supported MOS instruments. Potential of observing integrated light of super star clusters (SSCs). The J-band light of these objects is entirely dominated by RSGs as soon as the cluster age is >8Myr. This allows for the determination of accurate detailed chemical composition by simple Pop Synth techniques. Since SSCs are bright in J, a large volume in the local universe can be studied this way.
* super star cluster: a very large region that is thought to be the precursor of a globular cluster. Typically contain very large number of young, massive stars that ionize a surrounding H II region, similar to the MW's Ultra dense H II regions (UDHIIs). SSC's H II regions is in trun surrounded by a cocoon of dust. The youngest SSCs are best observed in radio and infrared. n_e = 1e3 to 1e6 cm^-3.
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