Search Publications
Formation of Dust in the Ejecta of Type Ia Supernovae
Nomoto, Ken'ichi; Maeda, Keiichi; Tanaka, Masaomi +3 more
We investigate the formation of dust grains in the ejecta of Type Ia supernovae (SNe Ia), adopting the carbon-deflagration W7 model. In the calculations of dust formation, we apply the nucleation and grain growth theory and consider the two extreme cases of the formation of CO and SiO molecules: complete formation and no formation. The results of …
Near-ultraviolet Excess in Slowly Accreting T Tauri Stars: Limits Imposed by Chromospheric Emission
Edwards, Suzan; Brown, Alexander; France, Kevin +20 more
Young stars surrounded by disks with very low mass accretion rates are likely in the final stages of inner disk evolution and therefore particularly interesting to study. We present ultraviolet (UV) observations of the ~5-9 Myr old stars RECX-1 and RECX-11, obtained with the Cosmic Origins Spectrograph and Space Telescope Imaging Spectrograph on t…
Quasi-stellar Object Selection Algorithm Using Time Variability and Machine Learning: Selection of 1620 Quasi-stellar Object Candidates from MACHO Large Magellanic Cloud Database
Trichas, Markos; Alcock, Charles; Kim, Dae-Won +3 more
We present a new quasi-stellar object (QSO) selection algorithm using a Support Vector Machine, a supervised classification method, on a set of extracted time series features including period, amplitude, color, and autocorrelation value. We train a model that separates QSOs from variable stars, non-variable stars, and microlensing events using 58 …
Solar Source and Heliospheric Consequences of the 2010 April 3 Coronal Mass Ejection: A Comprehensive View
Bale, Stuart D.; Liu, Ying; Luhmann, Janet G. +1 more
We study the solar source and heliospheric consequences of the 2010 April 3 coronal mass ejection (CME) in the frame of the Sun-Earth connection using observations from a fleet of spacecraft. The CME is accompanied by a B7.4 long-duration flare, dramatic coronal dimming, and EUV waves. It causes significant heliospheric consequences and space weat…
Detailed Fit of "Critical Balance" Theory to Solar Wind Turbulence Measurements
Wicks, Robert T.; Horbury, Timothy S.; Forman, Miriam A.
We derive the reduced spectrum of turbulent magnetic fluctuations at different frequencies f which would be observed by a single spacecraft in the solar wind when the magnetic field was at an angle θ B to the solar wind flow, if the wavevector spectrum in the solar wind frame were in anisotropic "critical balance" (CB) as proposed by Go…
GALEX Far-ultraviolet Color Selection of UV-bright High-redshift Quasars
Worseck, Gábor; Prochaska, J. Xavier
We study the small population of high-redshift (z em>2.7) quasars detected by the Galaxy Evolution Explorer(GALEX), whose far-UV emission is not extinguished by intervening H I Lyman limit systems. These quasars are of particular importance to detect intergalactic He II absorption along their sight lines. We correlate almost all veri…
Discovery of Two Millisecond Pulsars in Fermi Sources with the Nançay Radio Telescope
Abdo, A. A.; Ballet, J.; Camilo, F. +29 more
We report the discovery of two millisecond pulsars in a search for radio pulsations at the positions of Fermi-Large Area Telescope sources with no previously known counterparts, using the Nançay Radio Telescope. The two millisecond pulsars, PSRs J2017+0603 and J2302+4442, have rotational periods of 2.896 and 5.192 ms and are both in binary systems…
Multiphase Gas in Galaxy Halos: The O VI Lyman-limit System toward J1009+0713
Sembach, K. R.; Prochaska, J. X.; Tripp, T. M. +6 more
We have serendipitously detected a strong O VI-bearing Lyman-limit system (LLS) at z abs = 0.3558 toward the quasi-stellar object (QSO) J1009+0713 (z em = 0.456) in our survey of low-redshift galaxy halos with the Hubble Space Telescope's (HST) Cosmic Origins Spectrograph. Its total rest-frame equivalent width of Wr
A Low Escape Fraction of Ionizing Photons of L > L* Lyman Break Galaxies at z = 3.3
Fiore, F.; Castellano, M.; Pentericci, L. +12 more
We present an upper limit for the relative escape fraction (f rel esc) of ionizing radiation at z ~ 3.3 using a sample of 11 Lyman break galaxies (LBGs) with deep imaging in the U band obtained with the Large Binocular Camera, mounted on the prime focus of the Large Binocular Telescope. We selected 11 LBGs with secure redshif…
Chromospheric Jet and Growing "Loop" Observed by Hinode: New Evidence of Fan-spine Magnetic Topology Resulting from Flux Emergence
Liu, Wei; Berger, Thomas E.; Tarbell, Theodore D. +2 more
We present observations of a chromospheric jet and growing "loop" system that show new evidence of a fan-spine topology resulting from magnetic flux emergence. This event, occurring in an equatorial coronal hole on 2007 February 9, was observed by the Hinode Solar Optical Telescope in the Ca II H line in unprecedented detail. The predecessor of th…