Steward Observatory/NOAO Joint Colloquium Series- Searching for the Stellar and Substellar members of Star-forming Regions
Dr. Taran Esplin, University of Arizona
Abstract: Complete or nearly-complete samples of the stellar and substellar members of nearby starforming regions are necessary for accurate measurements of the shape of the initial mass function, the disk fraction, and the structure and kinematics of those regions. To determine how these parameters are effected by the star-formation environment, measurements are need for variety of regions. In addition, finding the least massive planetary-mass brown dwarfs (<10 MJup) in these regions can constrain star-formation theories by testing the low-mass cutoff of the initial mass function as well as provide analogs for directly imaged planets. To discover these objects, I have conducted a survey of four nearby star-forming regions, Taurus, Ophiuchus, Chamaeleon I, and Corona Australis, using Magellan, UKIRT, Spitzer, MMT, and Gemini and the large scale surveys of 2MASS, UKIDSS, and Gaia. By combining all available data, I am able to identify candidate members of these regions will a high yield of bona fide members. Among the many new members I have spectroscopically confirmed, I have discovered the faintest known members of these regions with estimated masses as low as 3 MJup, according to evolutionary models.