Astrophysics Seminars

Abstract: Over 150 years after their discovery, astronomers still lack a complete theory for the origin of the beautiful spiral patterns in disk galaxies. I will review the various ideas that have been proposed and describe some recent...

Observations of the structure and kinematics of different stellar populations in the Milky Way's disk provide a unique perspective on disk formation and evolution. I will discuss how current and future data sets that provide detailed kinematics and...

ABSTRACT: Nearly all astronomers now believe that most or all galaxies contain a supermassive black hole, and that many properties of the galaxy are tightly correlated with the mass of the black hole. It is becoming widely accepted that the energy...

ABSTRACT: In this talk I consider two questions. First, I investigate the formation of molecular clouds from diffuse interstellar gas. It has been argued that the midplane pressure controls the fraction of molecular hydrogen present, and thus the...

Abstract: I introduce a general method for constraining the shape of the inflationary potential from Cosmic Microwave Background (CMB) temperature and polarization power spectra. This approach relates the CMB observables to the shape of the...

Chandra has detected optically thin, thermal X-ray emission with a size of ~1 arcsec and luminosity ~10^33 erg/s from the direction of the Galactic supermassive black hole (SMBH), Sgr A*. We suggest that a significant or even dominant fraction of...