Microtuble [i.e. Microtubule] dynamics in interphase and mitotic cells

ZoologyDoctor of Philosophy (PhD

Very Low Mass Stellar and Substellar Companions to Solar-Like Stars From MARVELS V: A Low Eccentricity Brown Dwarf from the Driest Part of the Desert, MARVELS-6b

We describe the discovery of a likely brown dwarf (BD) companion with a minimum mass of 31.7 +/- 2.0 M_Jup to GSC 03546-01452 from the MARVELS radial velocity survey, which we designate as MARVELS-6b. For reasonable priors, our analysis gives a probability of 72% that MARVELS-6b has a mass below the hydrogen-burning limit of 0.072 M_Sun, and thus it is a high-confidence BD companion. It has a moderately long orbital period of 47.8929 +0.0063/-0.0062 days with a low eccentricty of 0.1442 +0.0078/-0.0073, and a semi-amplitude of 1644 +12/-13 m/s. Moderate resolution spectroscopy of the host star has determined the following parameters: T_eff = 5598 +/- 63, log g = 4.44 +/- 0.17, and [Fe/H] = +0.40 +/- 0.09. Based upon these measurements, GSC 03546-01452 has a probable mass and radius of M_star = 1.11 +/- 0.11 M_Sun and R_star = 1.06 +/- 0.23 R_Sun with an age consistent with less than ~6 Gyr at a distance of 219 +/- 21 pc from the Sun. Although MARVELS-6b is not observed to transit, we cannot definitively rule out a transiting configuration based on our observations. There is a visual companion detected with Lucky Imaging at 7.7 arcsec from the host star, but our analysis shows that it is not bound to this system. The minimum mass of MARVELS-6b exists at the minimum of the mass functions for both stars and planets, making this a rare object even compared to other BDs.Comment: 15 pages, 15 figures, 5 tables. Accepted for publication in The Astronomical Journa

Very Low-Mass Stellar and Substellar Companions to Solar-Like Stars from MARVELS I: A Low Mass Ratio Stellar Companion to TYC 4110-01037-1 in a 79-day Orbit

TYC 4110-01037-1 has a low-mass stellar companion, whose small mass ratio and short orbital period are atypical amongst solar-like (Teff ~< 6000 K) binary systems. Our analysis of TYC 4110-01037-1 reveals it to be a moderately aged (~<5 Gyr) solar-like star having a mass of 1.07 +/- 0.08 MSun and radius of 0.99 +/- 0.18 RSun. We analyze 32 radial velocity measurements from the SDSS-III MARVELS survey as well as 6 supporting radial velocity measurements from the SARG spectrograph on the 3.6m TNG telescope obtained over a period of ~2 years. The best Keplerian orbital fit parameters were found to have a period of 78.994 +/- 0.012 days, an eccentricity of 0.1095 +/- 0.0023, and a semi-amplitude of 4199 +/- 11 m/s. We determine the minimum companion mass (if sin i = 1) to be 97.7 +/- 5.8 MJup. The system's companion to host star mass ratio, >0.087 +/- 0.003, places it at the lowest end of observed values for short period stellar companions to solar-like (Teff ~< 6000 K) stars. One possible way to create such a system would be if a triple-component stellar multiple broke up into a short period, low q binary during the cluster dispersal phase of its lifetime. A candidate tertiary body has been identified in the system via single-epoch, high contrast imagery. If this object is confirmed to be co-moving, we estimate it would be a dM4 star. We present these results in the context of our larger-scale effort to constrain the statistics of low mass stellar and brown dwarf companions to FGK-type stars via the MARVELS survey.Comment: 22 pages; accepted in A

The Eleventh and Twelfth data releases of the Sloan Digital Sky Survey: Final data from SDSS-III

The third generation of the Sloan Digital Sky Survey (SDSS-III) tookdata from 2008 to 2014 using the original SDSS wide-field imager, theoriginal and an upgraded multi-object fiber-fed optical spectrograph, anew near-infrared high-resolution spectrograph, and a novel opticalinterferometer. All of the data from SDSS-III are now made public. Inparticular, this paper describes Data Release 11 (DR11) including alldata acquired through 2013 July, and Data Release 12 (DR12) adding dataacquired through 2014 July (including all data included in previous datareleases), marking the end of SDSS-III observing. Relative to ourprevious public release (DR10), DR12 adds one million new spectra ofgalaxies and quasars from the Baryon Oscillation Spectroscopic Survey(BOSS) over an additional 3000 deg2 of sky, more than triplesthe number of H-band spectra of stars as part of the Apache PointObservatory (APO) Galactic Evolution Experiment (APOGEE), and includesrepeated accurate radial velocity measurements of 5500 stars from theMulti-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS).The APOGEE outputs now include the measured abundances of 15 differentelements for each star. In total, SDSS-III added 5200 deg2 ofugriz imaging; 155,520 spectra of 138,099 stars as part of the SloanExploration of Galactic Understanding and Evolution 2 (SEGUE-2) survey;2,497,484 BOSS spectra of 1,372,737 galaxies, 294,512 quasars, and247,216 stars over 9376 deg2; 618,080 APOGEE spectra of156,593 stars; and 197,040 MARVELS spectra of 5513 stars. Since itsfirst light in 1998, SDSS has imaged over 1/3 of the Celestial sphere infive bands and obtained over five million astronomical spectra.Fil: Alam, Shadab. University of Carnegie Mellon; Estados UnidosFil: Albareti, Franco D.. Universidad Autónoma de Madrid; EspañaFil: Prieto, Carlos Allende. Universidad de La Laguna; EspañaFil: Anders, F.. Leibniz Institute For Astrophysics Potsdam; AlemaniaFil: Anderson, Scott F.. University of Utah; Estados UnidosFil: Anderton, Timothy. University of Utah; Estados UnidosFil: Andrews, Brett H.. Ohio State University; Estados Unidos. University of Pittsburgh; Estados UnidosFil: Armengaud, Eric. Service de Physique Des Particules; FranciaFil: Aubourg, Éric. Université Paris Diderot - Paris 7; FranciaFil: Bailey, Stephen. Lawrence Berkeley National Laboratory; Estados UnidosFil: Basu, Sarbani. University of Yale; Estados UnidosFil: Bautista, Julian E.. Université Paris Diderot - Paris 7; FranciaFil: Beaton, Rachael L.. University of Virginia; Estados UnidosFil: Beers, Timothy C.. University of Notre Dame; Estados UnidosFil: Bender, Chad F.. Pennsylvania State University; Estados UnidosFil: Berlind, Andreas A.. Vanderbilt University; Estados UnidosFil: Beutler, Florian. Lawrence Berkeley National Laboratory; Estados UnidosFil: Bhardwaj, Vaishali. Lawrence Berkeley National Laboratory; Estados UnidosFil: Bird, Jonathan C.. Vanderbilt University; Estados UnidosFil: Bizyaev, Dmitry. Apache Point Observatory; Estados UnidosFil: Blake, Cullen H.. University of Pennsylvania; Estados UnidosFil: Blanton, Michael R.. New York University; Estados UnidosFil: Blomqvist, Michael. University of California at Irvine; Estados UnidosFil: Bochanski, John J.. University of Washington; Estados UnidosFil: Bolton, Adam S.. University of Utah; Estados UnidosFil: Bovy, Jo. Institute For Advanced Studies; Estados UnidosFil: Shelden, Bradley, A.. Apache Point Observatory; Estados UnidosFil: Brandt, W. N.. Pennsylvania State University; Estados UnidosFil: Brauer, D. E.. Leibniz Institute For Astrophysics Potsdam; AlemaniaFil: Nuza, Sebastian Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina. Institut Max Planck Fuer Gesellschaft. Max Planck Institute For Extraterrestrial Physics; AlemaniaFil: Scoccola, Claudia Graciela. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentin

Very Low-mass Stellar and Substellar Companions to Solar-like Stars from MARVELS II: A Short-period Companion Orbiting an F Star with Evidence of a Stellar Tertiary And Significant Mutual Inclination

We report the discovery via radial velocity of a short-period (P = 2.430420 \pm 0.000006 days) companion to the F-type main sequence star TYC 2930-00872-1. A long-term trend in the radial velocities indicates the presence of a tertiary stellar companion with $P > 2000$ days. High-resolution spectroscopy of the host star yields T_eff = 6427 +/- 33 K, log(g) = 4.52 +/- 0.14, and [Fe/H]=-0.04 +/- 0.05. These parameters, combined with the broad-band spectral energy distribution and parallax, allow us to infer a mass and radius of the host star of M_1=1.21 +/- 0.08 M_\odot and R_1=1.09_{-0.13}^{+0.15} R_\odot. We are able to exclude transits of the inner companion with high confidence. The host star's spectrum exhibits clear Ca H and K core emission indicating stellar activity, but a lack of photometric variability and small v*sin(I) suggest the primary's spin axis is oriented in a pole-on configuration. The rotational period of the primary from an activity-rotation relation matches the orbital period of the inner companion to within 1.5 \sigma, suggesting they are tidally locked. If the inner companion's orbital angular momentum vector is aligned with the stellar spin axis, as expected through tidal evolution, then it has a stellar mass of M_2 ~ 0.3-0.4 M_\odot. Direct imaging limits the existence of stellar companions to projected separations < 30 AU. No set of spectral lines and no significant flux contribution to the spectral energy distribution from either companion are detected, which places individual upper mass limits of M < 1.0 M_\odot, provided they are not stellar remnants. If the tertiary is not a stellar remnant, then it likely has a mass of ~0.5-0.6 M_\odot, and its orbit is likely significantly inclined from that of the secondary, suggesting that the Kozai-Lidov mechanism may have driven the dynamical evolution of this system.Comment: 37 pages, 7 tables, 21 figures, Accepted in A

The Eleventh and Twelfth Data Releases of the Sloan Digital Sky Survey: Final Data from SDSS-III

The third generation of the Sloan Digital Sky Survey (SDSS-III) took data from 2008 to 2014 using the original SDSS wide-field imager, the original and an upgraded multi-object fiber-fed optical spectrograph, a new near-infrared high-resolution spectrograph, and a novel optical interferometer. All of the data from SDSS-III are now made public. In particular, this paper describes Data Release 11 (DR11) including all data acquired through 2013 July, and Data Release 12 (DR12) adding data acquired through 2014 July (including all data included in previous data releases), marking the end of SDSS-III observing. Relative to our previous public release (DR10), DR12 adds one million new spectra of galaxies and quasars from the Baryon Oscillation Spectroscopic Survey (BOSS) over an additional 3000 deg2 of sky, more than triples the number of H-band spectra of stars as part of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE), and includes repeated accurate radial velocity measurements of 5500 stars from the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS). The APOGEE outputs now include the measured abundances of 15 different elements for each star. In total, SDSS-III added 5200 deg2 of ugriz imaging; 155,520 spectra of 138,099 stars as part of the Sloan Exploration of Galactic Understanding and Evolution 2 (SEGUE-2) survey; 2,497,484 BOSS spectra of 1,372,737 galaxies, 294,512 quasars, and 247,216 stars over 9376 deg2; 618,080 APOGEE spectra of 156,593 stars; and 197,040 MARVELS spectra of 5513 stars. Since its first light in 1998, SDSS has imaged over 1/3 of the Celestial sphere in five bands and obtained over five million astronomical spectra. \ua9 2015. The American Astronomical Society

SDSS-III: Massive Spectroscopic Surveys of the Distant Universe, the Milky Way Galaxy, and Extra-Solar Planetary Systems

Building on the legacy of the Sloan Digital Sky Survey (SDSS-I and II), SDSS-III is a program of four spectroscopic surveys on three scientific themes: dark energy and cosmological parameters, the history and structure of the Milky Way, and the population of giant planets around other stars. In keeping with SDSS tradition, SDSS-III will provide regular public releases of all its data, beginning with SDSS DR8 (which occurred in Jan 2011). This paper presents an overview of the four SDSS-III surveys. BOSS will measure redshifts of 1.5 million massive galaxies and Lya forest spectra of 150,000 quasars, using the BAO feature of large scale structure to obtain percent-level determinations of the distance scale and Hubble expansion rate at z<0.7 and at z~2.5. SEGUE-2, which is now completed, measured medium-resolution (R=1800) optical spectra of 118,000 stars in a variety of target categories, probing chemical evolution, stellar kinematics and substructure, and the mass profile of the dark matter halo from the solar neighborhood to distances of 100 kpc. APOGEE will obtain high-resolution (R~30,000), high signal-to-noise (S/N>100 per resolution element), H-band (1.51-1.70 micron) spectra of 10^5 evolved, late-type stars, measuring separate abundances for ~15 elements per star and creating the first high-precision spectroscopic survey of all Galactic stellar populations (bulge, bar, disks, halo) with a uniform set of stellar tracers and spectral diagnostics. MARVELS will monitor radial velocities of more than 8000 FGK stars with the sensitivity and cadence (10-40 m/s, ~24 visits per star) needed to detect giant planets with periods up to two years, providing an unprecedented data set for understanding the formation and dynamical evolution of giant planet systems. (Abridged)Comment: Revised to version published in The Astronomical Journa