Search Publications
Wavenumber spectrum of whistler turbulence: Particle-in-cell simulation
Narita, Y.; Gary, S. Peter; Saito, S.
The forward cascade of decaying whistler turbulence is studied in low beta plasma to understand essential properties of the energy spectrum at electron scales, by using a two-dimensional electromagnetic particle-in-cell (PIC) simulation. This simulation demonstrates turbulence in which the energy cascade rate is greater than the dissipation rate a…
Late-time Observations of GRB 080319B: Jet Break, Host Galaxy, and Accompanying Supernova
Kouveliotou, C.; Fruchter, A. S.; Rol, E. +15 more
The Swift-discovered GRB 080319B was by far the most distant source ever observed at naked-eye brightness, reaching a peak apparent magnitude of 5.3 at a redshift of z = 0.937. We present our late-time optical (Hubble Space Telescope, Gemini, and Very Large Telescope) and X-ray (Chandra) observations, which confirm that an achromatic break occurre…
Particle pressure, inertial force, and ring current density profiles in the magnetosphere of Saturn, based on Cassini measurements
Coates, A. J.; Krupp, N.; Dougherty, M. K. +9 more
We report initial results on the particle pressure distribution and its contribution to ring current density in the equatorial magnetosphere of Saturn, as measured by the Magnetospheric Imaging Instrument (MIMI) and the Cassini Plasma Spectrometer (CAPS) onboard the Cassini spacecraft. Data were obtained from September 2005 to May 2006, within ±0.…
Kilometer-thick ice accumulation and glaciation in the northern mid-latitudes of Mars: Evidence for crater-filling events in the Late Amazonian at the Phlegra Montes
Head, James W.; Marchant, David R.; Dickson, James L.
Amazonian non-polar ice deposits on Mars record periods and events when the climate differed substantially from that of today. Particularly evident are examples of ice-rich deposits in the martian mid-latitudes (lobate debris aprons, lineated valley fill, and concentric crater fill). Uncertain, however, is the amount of ice remaining in these depo…
The 1.6 µm Near-infrared Nuclei of 3C Radio Galaxies: Jets, Thermal Emission, or Scattered Light?
Baum, Stefi A.; O'Dea, Christopher P.; Axon, David J. +6 more
Using HST NICMOS 2 observations we have measured 1.6 µm near-infrared nuclear luminosities of 100 3CR radio galaxies with z < 0.3, by modeling and subtracting the extended emission from the host galaxy. We performed a multiwavelength statistical analysis (including optical and radio data) of the properties of the nuclei following classifi…
Bursting SN 1996cr's bubble: hydrodynamic and X-ray modelling of its circumstellar medium
Dwarkadas, V. V.; Dewey, D.; Bauer, F.
SN1996cr is one of the five closest supernovae (SNe) to explode in the past 30 yr. Due to its fortuitous location in the Circinus galaxy at ~3.7 Mpc, there is a wealth of recently acquired and serendipitous archival data available to piece together its evolution over the past decade, including a recent 485-ks Chandra high-energy transmission grati…
Intermittent outflows at the edge of an active region - a possible source of the solar wind?
Tu, C. -Y.; Marsch, E.; Tian, H. +2 more
Context. It has already been established that the solar wind may originate at the edges of active regions (ARs), but the key questions of how frequently these outflows occur, and at which height the nascent solar wind originates have not yet been addressed.
Aims: We study the occurrence rate of these intermittent outflows, the related plasma …
The X-ray Spectra of the Luminous LMXBs in NGC 3379: Field and Globular Cluster Sources
Zezas, A.; Gallagher, J.; King, A. R. +10 more
From a deep multi-epoch Chandra observation of the elliptical galaxy NGC 3379 we report the spectral properties of eight luminous LMXBs (L X >1.2 × 1038 erg s-1). We also present a set of spectral simulations, produced to aid the interpretation of low-count single-component spectral modeling. These simulations d…
Observation and modelling of main-sequence star chromospheres - XIV. Rotation of dM1 stars
Houdebine, E. R.
We have measured v sin i for a selected sample of dM1-type stars. We give 114 measurements of v sin i for 88 different stars, and six upper detection limits. These are the first measurements of v sin i for most of the stars studied here. This represents the largest sample of v sin i measurements for M dwarfs at a given spectral type. For these mea…
The Mass of HD 38529c from Hubble Space Telescope Astrometry and High-precision Radial Velocities
Nelan, Edmund P.; Harrison, Thomas E.; Bean, Jacob L. +5 more
Hubble Space Telescope Fine Guidance Sensor astrometric observations of the G4 IV star HD 38529 are combined with the results of the analysis of extensive ground-based radial velocity (RV) data to determine the mass of the outermost of two previously known companions. Our new RVs obtained with the Hobby-Eberly Telescope and velocities from the Car…