Characterizing Star Formation in the Tidal Debris of Minor Galaxy Mergers

Knierman Karen A, Tucson AZ

Investigators

Abstract

Karen Knierman is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to carry out a program of research and education at Arizona State University. Mergers between galaxies of different mass are very common in the universe and may affect the majority of galaxies including our own Milky Way galaxy. The debris produced in these minor mergers is a unique place to study the factors that influence star formation since it is away from the dense centers of the mergers. Due to the lower pressures and densities in the tidal debris, this study probes the lower bounds of where star formation is possible. To attract a diverse workforce in science and engineering, a new astronomy outreach initiative, Multicultural Milky Way, will engage under-served populations in Arizona in learning about our Milky Way and other galaxies. Arizona is home to many diverse populations with rich cultural histories such as Mayan, Navajo, and Apache. Linking astronomy practiced by one's indigenous culture to that of Western astronomy may increase the interest in science. Through multicultural planetarium shows and associated hands-on activities, under-served families will learn how the Milky Way is represented in different cultures and about the science of galaxies. This project will characterize how star formation occurs in tidal debris and the origin of the debris. Narrowband infrared images of molecular hydrogen will provide a picture of the hot molecular gas component and how the interstellar medium of the tail has been molded by in-situ star formation. This project will provide the first survey of molecular hydrogen in minor mergers. With optical, H-alpha, and submillimeter observations, these data will give a more complete picture of star formation in tidal debris of minor mergers. Using the metallicity calculated from spectra of tidal clumps in minor mergers compared to regions in the parent spiral and dwarf galaxy, the origin of the tidal debris of minor mergers can be determined: the cannibalized dwarf, the outer regions of the spiral, or the center. In addition, a new astronomy outreach initiative, Multicultural Milky Way, will engage under-served populations in Arizona in learning about stars and galaxies. New shows featuring how different cultures view the Milky Way will be created for the Digistar static and STARLAB portable planetariums. STARLAB shows and associated new hands-on activities will feature at Community Astronomy Nights around Arizona. For authentic assessment, evaluation techniques and procedures will be developed with education mentors.