Search Publications

Hubble Space Telescope and Optical Data on SDSSJ0804+5103 (EZ Lyn) One Year after Outburst

Szkody, Paula; Sion, Edward M.; Gänsicke, Boris T. +3 more

We present an ultraviolet (UV) spectrum and light curve of the short orbital period cataclysmic variable EZ Lyn obtained with the Cosmic Origins Spectrograph on the Hubble Space Telescope 14 months after its dwarf nova outburst, along with ground-based optical photometry. The UV spectrum can be fit with a 13,100 K, log g = 8 white dwarf using 0.5 …

Collisionless Plasmas in Astrophysics

Belmont, G.; Pantellini, F.; Pelletier, G. +2 more

Antisunward structure of thin current sheets in the Earth's magnetotail: Implications of quasi-adiabatic theory

Malova, H. V.; Popov, V. Yu.; Delcourt, D. C. +2 more

developed a self-consistent kinetic model of thin current sheets (TCS), taking into account the inhomogeneity of TCS parameters in the antisunward direction. We show that the charged particle dynamics depending on the magnetic field distribution in the downtail direction completely determines the magnetotail equilibrium structure. We demonstrate t…

Self-assembly of tholins in environments simulating Titan liquidospheres: implications for formation of primitive coacervates on Titan

Kawai, Jun; Jagota, Seema; Kaneko, Takeo +6 more

Titan, the largest satellite of Saturn, has a thick atmosphere containing nitrogen and methane. A variety of organic compounds have been detected in the atmosphere, most likely produced when atmospheric gases are exposed to ultraviolet light, electrons captured by the magnetosphere of Saturn and cosmic rays. The Cassini/Huygens probe showed that t…

The runaway binary LP 400-22 is leaving the Galaxy

Gianninas, A.; Kenyon, S. J.; Heinke, Craig O. +7 more

We present optical spectroscopy, astrometry, radio and X-ray observations of the runaway binary LP 400-22. We refine the orbital parameters of the system based on our new radial velocity observations. Our parallax data indicate that LP 400-22 is significantly more distant (3σ lower limit of 840 pc) than initially predicted. LP 400-22 has a tangent…

The Relationship between the Dense Neutral and Diffuse Ionized Gas in the Thick Disks of Two Edge-on Spiral Galaxies

Hirschauer, Alec S.; Savage, Blair D.; Fox, Andrew J. +3 more

We present high-resolution, optical images (BVI + Hα) of the multiphase interstellar medium (ISM) in the thick disks of the edge-on spiral galaxies NGC 4013 and NGC 4302. Our images from the Hubble Space Telescope (HST), Large Binocular Telescope, and WIYN 3.5 m telescope reveal an extensive population of filamentary dust absorption seen to z ~2-2…

Chemistry of the Atmospheres of Mars, Venus, and Titan

Lefèvre, F.; Krasnopolsky, V. A.

The X-ray under-luminosity of the O-type supergiants HD 16691 and HD 14947 revealed by XMM-Newton

De Becker, M.

The members of the scarce category of Of⁺ supergiants present properties that are intermediate between regular O-stars and Wolf-Rayet (WR) stars. Significant similarities between these transitional stars and WN-type objects are now clearly established, at least in the visible and near-infrared domains, pointing to common stellar wind pr…

Correlations between variations in solar EUV and soft X-ray irradiance and photoelectron energy spectra observed on Mars and Earth

Brain, D. A.; Peterson, W. K.; Mitchell, D. L. +2 more

extreme ultraviolet (EUV; 10-120 nm) and soft X-ray (XUV; 0-10 nm) radiation are major heat sources for the Mars thermosphere as well as the primary source of ionization that creates the ionosphere. In investigations of Mars thermospheric chemistry and dynamics, solar irradiance models are used to account for variations in this radiation. Because …

Dual periodicities in the flapping of Saturn's magnetodisk

Szego, K.; Cowley, S. W. H.; Provan, G. +2 more

In this report, we modify the model of Arridge et al. (2011) which was proposed to describe the shape of the magnetodisk of Saturn and its north-south oscillations near the planetary rotation period. The modification is based on the recent results of Provan et al. (2011, 2012) and Andrews et al. (2012), who have shown that the magnetic modulations…