Dr. Karin Menendez-Delmestre is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to carry out a program of research and education at the Observatories of the Carnegie Institution of Washington. Dr. Menendez-Delmestre will conduct a multi-wavelength study of proto-clusters at high redshift that will use submillimeter galaxies as signposts of these large-scale structures. The aim of the program will be to investigate the relationship between galaxy properties and their proto-cluster environment.
The morphology-density relation, which particularly addresses the distribution of galaxy morphologies within clusters, has been established at z < 1. Dr. Menendez-Delmestre will extend current knowledge of galaxy evolution as a function of environment to incorporate other galaxy properties (morphologies, sizes, star-formation rates, stellar ages, stellar masses, metallicities, outflows and active galactic nuclei activity) and to extend the study out to the higher redshifts traced by submillimeter galaxies, z ~ 1-3. Major components to this research are detailed spectroscopic and photometric observations of individual proto-cluster members using Persson's Auxilliary Nasmyth Infrared Camera (PANIC) and the Inamori Magellan Areal Camera and Spectrograph (IMACS) on the Magellan Telescope.
Dr. Menendez-Delmestre will also extend Carnegie's commitment to outreach and education towards a broader section of the Los Angeles community by strengthening the existing, yet informal ties with the Griffith Observatory, a well recognized leader in the Los Angeles community as a center of public education. With a Hispanic population greater than 50%, Los Angeles is an exceptionally well suited area to develop educational outreach programs that specifically target the Hispanic community. Dr. Menendez-Delmestre will serve as a Curatorial Advisor to the Griffith program team led by Dr. Laura Danly (Curator, Griffith Observatory) by: (1) helping in the implementation of a Griffith school astronomy program directed at elementary-school children; (2) training Observatory guides; (3) reviewing the accuracy of the Observatory's educational materials; and (4) helping to organize public, astronomy-related activities at Griffith.
One the most pressing questions in astronomy is how galaxies form and evolve. During the three years of support by the NSF Astronomy & Astrophysics Postdoctoral Fellowship (NSF-AAPF) at Carnegie Observatories, I led a large number of projects in the realm of galaxy formation and galaxy evolution. In order to build a complete model of galaxy formation and evolution, astronomers need to investigate galaxy properties both near and far. Characterization of the local universe allows us to establish the full range of astrophysical properties present in galaxies. On the other hand, distant galaxies hold the key to understand the early stages of galaxy formation: light from these galaxies travels great distances and, hence, takes a long time to reach us. Therefore, the light that we observe today from very distant galaxies shows us these galaxies as they were a long time ago. Upon the beginning of my NSF-AAPF at Carnegie, I started a large observational program named: "Exploring Galaxy Evolution as a Function of Environment Using Submillimeter Galaxies as Signposts of Protoclusters". To place it into context, we first need to consider that galaxies are not uniformly distributed in the sky, but can be seen to group together into clusters of galaxies. Our own Milky Way has many neighbors and together with more than a thousand other galaxies it forms the Local Supercluster. Studies within the nearby universe show that galaxy properties depend on the galaxy number density of the local environment; for instance, galaxies in very crowded regions tend to be more evolved than galaxies in less dense regions. Galaxy evolution thus appears to be intimately connected to the environment. The physical origin of this relation is still controversial: does this relation arise early in the formation of galaxies? Or, does the environment itself somehow dictate how the galaxies in the region evolve? This is the well-known nature vs. nurture dilemma. To understand the origin of the galaxy-environment relation, one needs to look back at the epoch of galaxy formation in the distant universe, where initial conditions likely set the stage for the establishment of this relation. As an NSF fellow at Carnegie I studied the surroundings of a distant population of extremely luminous galaxies: star-forming monsters in the distant universe easily detected by telescopes that work at submillimeter wavelengths. These submillimeter galaxies are likely good tracers of regions where galaxy clusters are at their infant stage; we refer to these regions as proto-clusters. Using the 6.5m telescope at the Las Campanas Observatory in Chile, collaborators and I have been able to uncover overdensities of galaxies (potential protoclusters!) in these regions and we are now at a stage where we can start investigating the individual properties of these galaxies. By studying different protoclusters at different distances, we can probe how the relation between galaxy and the environment was first established. In addition to my research performance, I continued an active engagement in outreach, teaching, student mentoring and other professional development activities involving Carnegie and other institutes in the Pasadena/Los Angeles area. Some of these activities included: (1) establishing a connection between Carnegie professional astronomers and the museum educators at the historical Griffith Observatory in Los Angeles; (2) mentoring PhD female students on a weekly basis as part of the Women Mentoring Women Program at Caltech (my PhD institution); and (3) designing a short astronomy course for the general public. The latter resulted in the 5-workshop course "Think Like an Astronomer" offered at the Glendale Community College (GCC). The basic structure of each workshop was a brief lecture to introduce the main topics (planets, light, stars, galaxies and telescopes), a series of inquiry-based activities through examples of self-guided and collaborative inquiry of real astronomical data, and short presentations by the students. Some of the comments we received from the participants, collected by means of a final course evaluation, were the following: "The instructors were into what they were doing, which made the class more enjoyable." "The activities were very thought provoking and a great hands-on experience. The lessons were very dynamic and weren't just made up of lectures. It was an experience where you taught yourself half of the time and had the chance to think like an astronomer!" Just at the conclusion of my tenure as an NSF fellow I was offered a faculty position at the Astronomy Department of the Federal University of Rio de Janeiro (UFRJ) in Brazil, my partner’s home country. The UFRJ is one of the best and largest universities in Brazil and the Astronomy Department is speedily growing with a newly established PhD program. The opportunities I had access to as an NSF fellow were critical to my professional development in the last 3 years and I now feel equipped to undertake the many aspects of an academic career.
