{"id":7,"date":"2011-11-17T21:56:48","date_gmt":"2011-11-17T21:56:48","guid":{"rendered":"http:\/\/as.vanderbilt.edu\/astronomy\/?page_id=7"},"modified":"2011-11-17T21:56:48","modified_gmt":"2011-11-17T21:56:48","slug":"research","status":"publish","type":"page","link":"https:\/\/as.vanderbilt.edu\/astronomy\/research\/","title":{"rendered":"Research"},"content":{"rendered":"

Galaxies & Large Scale Structure<\/h3>\n

\"\"We study the clustering of galaxies on all scales as a probe of\u00a0cosmology and galaxy formation physics. A key part of this research\u00a0program is to understand the detailed relation between the galaxy and\u00a0dark matter spatial and velocity distributions. On the observational
front, we use data from large galaxy surveys such as the Sloan Digital Sky Survey<\/a> (SDSS I, II,\u00a0& III) and we measure galaxy clustering statistics as a function of\u00a0various galaxy properties (luminosity, color, morphology, etc.). On\u00a0the theoretical front, we run and analyze large cosmological N-body\u00a0simulations that that follow the evolution of dark matter in the\u00a0universe. An example of this is our LasDamas<\/a> project.\u00a0Contact Andreas Berlind<\/a> for more details.<\/p>\n

Black Holes<\/h3>\n

\"\"Supermassive black holes (SMBH), more massive than a million suns, are thought\u00a0to be present at the center of most galaxies. It is still a mystery\u00a0how the black holes become so massive – is it primarily via mergers\u00a0that last a fraction of galaxy’s lifetime or via\u00a0accretion during a quiescent phase? We use high resolution numerical\u00a0simulations to study the growth of black holes in an environment similar\u00a0to the Milky Way. Our study will produce the assembly history for\u00a0black holes with masses ranging from a few hundred to a few million\u00a0solar masses while reproducing the properties of the Milky Way SMBH.<\/p>\n

When black holes merge, they emit huge amounts of gravitational\u00a0radiation; and if the merger is not symmetric (say the\u00a0spins are mis-aligned or the masses are different), these\u00a0gravitational waves are emitted in a preferred direction. This sends\u00a0the new black hole careening off with a recoil velocity that can be up\u00a0to 9 million miles per hour! Such rapidly moving black holes will\u00a0easily escape low mass systems like globular clusters. Using N-body simulations, we are studying how well globular clusters can retain Intermediate\u00a0Mass Black Holes against an onslaught of black hole mergers. Contact Kelly\u00a0Holley-Bockelmann<\/a> for more details.<\/p>\n

Orion Nebula Cluster<\/h3>\n

\"\"<\/p>\n

Orion Nebular Cluster (ONC) is a young, and dense star-forming\u00a0cluster. As it is nearby, it can provide us with clues to how stars\u00a0form and evolve into the main sequence. Using data from the Hubble\u00a0Space Telescope and other ground-based telescopes, we have recently\u00a0studied the proplyd-like features, outflows in the Orion-South region,\u00a0and knots in the Helix Nebula. The overarching goals of this recent\u00a0work are to characterize the physical conditions of the environs in\u00a0which these features are found and to explain how they arise. Contact Bob\u00a0O’Dell<\/a> for more details.<\/p>\n

Star & Planet Formation<\/h3>\n

\"\"<\/p>\n

Young stars are shrouded in gas and dust leftover from the collapse of\u00a0the molecular cloud. To study the formation of stars, we\u00a0need to study the molecular cloud in the environments of these young\u00a0stars. Moreover, they will also provide clues about planet\u00a0formation. We use a wide variety of tools to study these young (< 1 Myr),\u00a0including X-ray observations and polarization imaging.\u00a0Contact David Weintraub<\/a> for more information.<\/p>\n

Stellar Structure and Evolution<\/h3>\n

\"\"<\/p>\n

By observing stars in young open clusters and associations we are able\u00a0to get a picture of early stellar evolution, and using these snapshots, we\u00a0can assemble a time-line of how stellar structure and atmosphere\u00a0changes with age. Some individual investigations we are undertaking include:\u00a0using lithium to probe how the stellar internal structure changes,\u00a0using the distribution of rotation periods to study how a stellar angular\u00a0momentum changes with age, looking at the role of circumstellar disks in\u00a0regulating angular momentum evolution, how do young, x-ray active stars\u00a0produce such energetic emission, and ascertain the influence of X-ray\u00a0emission on stellar structure and evolution. Contact Keivan Stassun<\/a> for details.<\/p>\n

Low-mass Binaries<\/h3>\n

\"\"<\/p>\n

Eclipsing Binaries systems allow for direct measurments of the\u00a0mass and radius of the component stars. Mass is the most important property\u00a0of a star, determining the course of its birth, life, and death. Empirical\u00a0mass measurements are fundemental to the calibration of theoretical models\u00a0of stellar formation and evolution. With the\u00a0SMARTS telescopes, we are conducting high cadence observations to identify young, low-mass, and\u00a0brown dwarf eclipsing binaries. Contact Keivan Stassun<\/a> for details.<\/p>\n

\"\"Low-mass M dwarfs account for ~70% of all stars in the Galaxy;\u00a0however, due to their intrinsic faintness and the resulting small\u00a0numbers, their properties are not well studied. With the advent of\u00a0large scale surveys like the SDSS<\/a> and 2MASS<\/a>, large\u00a0homogenous samples of M dwarfs are available. We have identified\u00a02500+ very wide, low-mass pairs from the SDSS photometry and are using\u00a0them to study survivability of the widest binary pairs over time and
to fine\/calibrate the age — rotation — magnetic activity — metallicity\u00a0relations for low-mass dwarfs. See the SLoWPoKES<\/a> website for more information.<\/p>\n

Exoplanets<\/h3>\n

\"\"<\/p>\n

The KELT South<\/a> project\u00a0consists of an automated telescope that has been installed at the SAAO\u00a0observing site in Sutherland, South Africa in 2008. The purpose of the\u00a0project is to discover transiting extrasolar planets around stars in\u00a0the brightness range of 8 < V < 10 mag, although the observations\u00a0should yield a great deal of additional science.<\/p>\n

In order to obtain a homogenous census of planets, the Multi-object\u00a0APO Radial Velocity Exoplanet Large-area Survey (MARVELS<\/a>) will be monitoring\u00a0the radial velocities of 12,000 bright stars, with the precision and\u00a0cadence needed to detect gas giant planets that have orbital periods\u00a0ranging from several hours to two years. Contact Josh Pepper<\/a> for more\u00a0information.<\/p>\n

Astro-Informatics<\/h3>\n

The Vanderbilt Initiative in Data-Intensive Astrophysics<\/a> (VIDA) was established to be unique in the United States by virtue of its dual focus on scientific questions enabled by the informatics-driven revolution in astrophysics and on becoming the national leader in the training of students of color in physics and astronomy.<\/p>\n","protected":false},"excerpt":{"rendered":"

Galaxies & Large Scale Structure We study the clustering of galaxies on all scales as a probe of\u00a0cosmology and galaxy formation physics. A key part of this research\u00a0program is to understand the detailed relation between the galaxy and\u00a0dark matter spatial … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"acf":[],"_links":{"self":[{"href":"https:\/\/as.vanderbilt.edu\/astronomy\/wp-json\/wp\/v2\/pages\/7"}],"collection":[{"href":"https:\/\/as.vanderbilt.edu\/astronomy\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/as.vanderbilt.edu\/astronomy\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/as.vanderbilt.edu\/astronomy\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/as.vanderbilt.edu\/astronomy\/wp-json\/wp\/v2\/comments?post=7"}],"version-history":[{"count":0,"href":"https:\/\/as.vanderbilt.edu\/astronomy\/wp-json\/wp\/v2\/pages\/7\/revisions"}],"wp:attachment":[{"href":"https:\/\/as.vanderbilt.edu\/astronomy\/wp-json\/wp\/v2\/media?parent=7"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}