Browsing by Author "Kalirai, J."

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    Extended Main Sequence Turnoffs in Intermediate-Age Star Clusters : A Correlation Between Turnoff Width and Early Escape Velocity
    (2014) Goudfrooij, P.; Girardi, L.; Kozhurina-Platais, V.; Kalirai, J.; Platais, I.; Puzia, Thomas H.; Correnti, M.; Bressan, A.; Chandar, R.
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    Mapping Milky Way And Local Volume Structure With LSST
    (2011) Geha, Marla C.; Willman, B.; Bochanski, J.; Bullock, J.; Catelan, Márcio; Debattista, V.; Grillmair, C.; Jordan, A.; Juric, M.; Kalirai, J.; Kallivayalil, N.; McGehee, P.; Minniti, D.; Munoz, R.; Roskar, R.; Sarajedini, A.; Simon, J.; Strader, J.
    The LSST will yield revolutionary, multi-dimensional maps of the Milky Way (MW) galaxy and its neighbors. With its planned 1000 epochs over 6 bands and a final limiting magnitude of r=27.5 (AB mag; 5-sigma), it will provide an excellent resource for mapping the structure and accretion history of the MW and beyond in a way that the present generation of surveys can only hint at. LSST is expected to catalog 10 billion stars, including photometric metallicities for the 200 million F/G stars within 100 kpc and map the tangential velocity field of stars bright than r=24 mag to at least 10 kpc (at 10 km/s precision) and as far as 25 kpc (at 60 km/s precision). Specific related science to be enabled by LSST includes: mapping the 3D distribution of dust in the MW's disk, including variations in RV; understanding the smooth distribution of stars in the MW and other nearby galaxies; understanding large-scale chemical gradients in the MW; discovering lumps and streams in metallicity and phase-space; inferring the mass distribution in the MW; discovering ultra-faint galaxies throughout the Local Volume....
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    Mapping the Stellar Content of the Milky Way with LSST
    (2012) Bochanski, John J.; Thorman, P.; Covey, K.; Olsen, K.; Dhital, S.; Beers, T. C.; Boeshaar, P.; Cargile, P.; Catelan, Márcio; Digel, S.; Guhathakurta, P.; Henry, T.; Ivezic, Z.; Juric, M.; Kalirai, J.; Kirkpatrick, J.; McGehee, P. M.; Minniti, D.; Mukadam, A.; Pepper, J.; Prsa, A.; Roškar, R.; Smith, J.; Stassun, K.; Tyson, A.
    The Large Synoptic Survey Telescope (LSST) will map half of the sky in six filters down to r=27.5 (AB mag; 5-sigma), with typical precision of one percent (0.01 mag). The ten year baseline of the survey will provide about a thousand multi-epoch observations for objects brighter than r=24.5, yielding variability, proper motions and trigonometric parallax measurements for hundreds of millions of stars. The resulting photometric and astrometric catalogs will enable novel and unique investigations, detailing the formation and evolution of the Milky Way's stellar populations, as well as neighboring galaxies. We highlight some of the enabled science studies, including results from the output source catalog derived from simulated LSST images. A few examples of the stellar populations projects will be shown: sampling a census of the MLT population near the solar neighborhood; mapping the structure and stellar metallicity content of the Milky Way's disk and halo; assembling catalogs of eclipsing binaries, subdwarfs and white dwarfs, suitable for measuring fundamental stellar parameters; and measuring the Milky Way's star formation history using stellar ages determined from gyrochronology and rotation periods, as well as the white dwarf luminosity function. We also highlight the studies enabled by the "Deep Drilling" fields, patches within the LSST footprint that will be imaged at a higher cadence over the course of the survey....
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    The Stellar Populations of the Milky Way and Nearby Galaxies with LSST
    (2011) Olsen, Knut A.; Covey, K.; Saha, A.; Beers, T. C.; Bochanski, J.; Boeshaar, P.; Cargile, P.; Catelan, Marcio; Burgasser, A.; Cook, K.; Dhital, S.; Figer, D.; Ivezic, Z.; Kalirai, J.; McGehee, P.; Minniti, D.; Pepper, J.; Prsa, A.; Sarajedini, A.; Silva, D.; Smith, J. A.; Stassun, K.; Thorman, P.; Williams, B.; LSST Stellar Populations Collaboration
    The LSST will produce a multi-color map and photometric object catalog of half the sky to r=27.6 (AB mag; 5-sigma) when observations at the individual epochs of the standard cadence are stacked. Analyzing the ten years of independent measurements in each field will allow variability, proper motion and parallax measurements to be derived for objects brighter than r=24.5. These photometric, astrometric, and variability data will enable the construction of a detailed and robust map of the stellar populations of the Milky Way, its satellites and its nearest extra-galactic neighbors--allowing exploration of their star formation, chemical enrichment, and accretion histories on a grand scale. For example, with geometric parallax accuracy of 1 milli-arc-sec, comparable to HIPPARCOS but reaching more than 10 magnitudes fainter, LSST will allow a complete census of all stars above the hydrogen-burning limit that are closer than 500 pc, including thousands of predicted L and T dwarfs. The LSST time sampling will identify and characterize variable stars of all types, from time scales of 1 hr to several years, a feast for variable star astrophysics; LSST's projected impact on the study of several variable star classes, including eclipsing binaries, are discussed here. We also describe the ongoing efforts of the collaboration to optimize the LSST system for stellar populations science. We are currently investigating the trade-offs associated with the exact wavelength boundaries of the LSST filters, identifying the most scientifically valuable locations for fields that will receive enhanced temporal coverage compared to the standard cadence, and analyzing synthetic LSST outputs to verify that the system's performance will be sufficient to achieve our highest priority science goals....