Jan 19

"On the Formation of Massive Galaxies"
Sukyoung Yi, Yonsei University, South Korea

The mass growth of massive, in particular elliptical, galaxies is a key issue in astrophysics. The apparent simplicity in the observed properties of massive ellipticals may appear as challenges to the widely-discussed hierarchical galaxy formation theory. I will present recent observational results that suggest a much more episodic history of stellar mass growth in massive ellipticals than previously believed. I attempt to improve galaxy evolution models based on the empirical findings.

Feb 9

"Early Star Forming Galaxies and Reionization"
Daniel Stark, Steward Observatory, Arizona

The events of the first billion years of cosmic history are one of the final frontiers in the quest to trace the history of the Universe from its origins to the present day. Exploration of this uncharted era is driven by the desire to locate and understand the nature of the first stars and galaxies and to characterize their contribution to the reionization of hydrogen. The last several years have witnessed major achievements in this pursuit through a series of deep imaging and spectroscopic surveys. I will summarize the latest results of these campaigns, with particular focus on new insight into the mechanical and radiative feedback of the low mass, metal-poor galaxies which dominate the reionization era. I will conclude with a look to the future, discussing how deep surveys with current and upcoming facilities will transform our understanding of the first galaxies.

Feb 23

"Understanding Galaxy Evolution in the Early Universe"
Steven Finkelstein, University of Texas at Austin

Throughout the history of extragalactic astronomy, we are constantly surprised when we push back the veil to uncover a more distant epoch of galaxy evolution. This is true now more than ever, as the advent of the Wide Field Camera 3 on the Hubble Space Telescope allows us to probe galaxies within a few hundred million years of the Big Bang. Initial results have shown us that galaxies in this epoch are vastly different than those we see around us, both in their appearance as well as in their stellar and gas compositions. I will describe my past and current work in this field, summarizing results on what the color evolution of galaxies tells us about the physical conditions in the early universe, with implications on the formation of the first stars and reionization. I will also describe my past work and future plans with the HETDEX survey, which is highly relevant to the z > 7 universe as Lyman alpha emitters at lower redshift exhibit similar properties to the most distant galaxies. Finally, I will present my vision for the future, both in space with HST and JWST, and on the ground, with ALMA, GMT and the McDonald Observatory.

Mar 1

"The Dark Art of Detecting and Characterizing Planets by Direct Imaging"
Thayne Currie, NASA, Goddard Space Flight Center, MD

Direct imaging is a rapidly emerging field that provides a way to detect and characterize planet populations inaccessible by RV and transit methods. In this talk, I describe the state-of-the-art observing/image processing techniques used for direct imaging and my program to characterize imaged planets. In particular, I detail the "locally-optimized combination of images" (LOCI) method essential for extracting the first exoplanet images and an upgrade I'm developing called "adaptive LOCI" (A-LOCI) that yields superior contrast levels. Using the (A)-LOCI approach has led to several major discoveries, including a detection of a 4th planet orbiting HR 8799 (HR 8799e) and the first image of an exoplanet at a sub-Jupiter projected separation (beta Pictoris b). I will also present unpublished results focused on directly imaging planets and planet-forming disks around other young stars.

Imaging planets at multiple wavelengths allows us to characterize their atmospheres. However, my program shows that the atmospheres of young planets differ significantly from the field brown dwarf-like atmospheres we expected them to be like. I discuss how revised planet atmosphere models not only better fit their spectra but lend an important insight into the atmospheric structure and evolution of substellar objects in general.

Over the next 15 years, we will witness a huge increase in planet imaging capabilities that will completely transform our understanding of extrasolar planets. I will close by discussing my involvement with exoplanet imaging programs using the new generation of instruments coming online in the next year and the exciting prospects for the Giant Magellan Telescope to be the leading ground-based facility for exoplanet imaging in the next decade and beyond.

April 26

"Disk Galaxy Assembly as Revealed by the Evolution of the Tully-Fisher Relation"
Sarah Miller, Oxford University, UK & Caltech

I will present new measures of the rotation curves of disk galaxies to z ~ 1.7, using deep exposures from both DEIMOS and LRIS spectrographs on the Keck telescopes, in combination with multi-band HST imaging. Contrary to previous studies, we show that the stellar mass Tully-Fisher relation is tightly in place at z ~ 1 with similar scatter to that found locally. Furthermore, I will discuss evidence that there is little change in this relation beyond z ~ 1 to z ~ 1.7, and explore the implications for galaxy-scale baryonic and dark matter interaction in a universe with a strikingly similar stellar mass Tully-Fisher relation over two-thirds of its age.