CAREER: The Early History of Galaxy Disk Formation

University Of Washington, Seattle WA

Investigators

Abstract

Proposal ID: AST-0238683 Institution: University of Washington PI: Dalcanton, Julianne Dr. Julianne Dalcanton of the University of Washington will use her CAREER award to study the formation of galactic disks. Theoretical models of disk formation have had substantial success in explaining many of the basic features of disk galaxies. The Tully-Fisher relation, the exponential surface brightness profiles, and the rotation curves of disk galaxies all can be reproduced by models of a simple spherical collapse of a rotating gas cloud. However, the recent discovery that all thin disk galaxies are embedded within an additional thick disk component suggests that the existing picture is too simple. Either this pervasive thick disk component captures a distinct phase in the initial collapse of the galaxy, or it tracks the early hierarchical build-up of the galaxy (a phase absent from existing models). With this award, Dr. Dalcanton will provide the critical measurements and the theoretical foundations necessary for incorporating the creation of thick disks into models of disk galaxy formation. By measuring the kinematics, ages, and metallicities of a large sample of thick disks, she will be able to cleanly distinguish among several scenarios for the formation of thick disks and the early evolution of disk galaxies. She will also carry out a systematic program of simulations and analytic calculations to derive the cosmological implications of the previously unexplored thick disk population. In addition to her work in training the next generation of scientists, Dr. Dalcanton will design and execute a novel program to capture and reinforce the scientific interest of middle school girls, before their attrition from scientific, mathematical, and technological fields begins. The program will focus on outreach to the girls and their mothers simultaneously, to help foster a "science positive "culture within the home, and to increase the support that scientifically inclined young women receive from their most influential female role model. This project is an outgrowth of her current work on the Board of Directors of a non-profit organization devoted to fostering the interest of pre-teen girls in science and technology.