Search Publications
Extended Magnetic Reconnection across the Dayside Magnetopause
Berchem, J.; Lavraud, B.; Wild, J. A. +18 more
The extent of where magnetic reconnection (MR), the dominant process responsible for energy and plasma transport into the magnetosphere, operates across Earth’s dayside magnetopause has previously been only indirectly shown by observations. We report the first direct evidence of X-line structure resulting from the operation of MR at each of two wi…
Finding the trigger to Iapetus' odd global albedo pattern: Dynamics of dust from Saturn's irregular satellites
Hamilton, Douglas P.; Hedman, Matthew M.; Burns, Joseph A. +1 more
The leading face of Saturn's moon Iapetus, Cassini Regio, has an albedo only one tenth that on its trailing side. The origin of this enigmatic dichotomy has been debated for over 40 years, but with new data, a clearer picture is emerging. Motivated by Cassini radar and imaging observations, we investigate Soter's model of dark exogenous dust strik…
Observations of thermal tides in the middle atmosphere of Mars by the SPICAM instrument
Montmessin, F.; Bertaux, J. -L.; Withers, Paul +1 more
We use vertical profiles of Martian atmospheric density, pressure, and temperature from the Mars Express SPICAM UV spectrometer to study thermal tides in the poorly studied middle atmosphere region at 70-120 km. Here we show that nonmigrating tides cause zonal pressure variations of tens of percent and zonal temperature variations on the order of …
Spectra of globular clusters in the Sombrero galaxy: evidence for spectroscopic metallicity bimodality
Spitler, Lee R.; Forbes, Duncan A.; Brodie, Jean P. +4 more
We present a large sample of over 200 integrated-light spectra of confirmed globular clusters (GCs) associated with the Sombrero (M104) galaxy taken with the Deep Imaging Multi-Object Spectrograph (DEIMOS) instrument on the Keck telescope. A significant fraction of the spectra have signal-to-noise ratio levels high enough to allow measurements of …
Linking Remote-Sensing and In Situ Observations of Coronal Mass Ejections Using STEREO
Mierla, M.; Zhukov, A. N.; Rodriguez, L. +2 more
The twin STEREO spacecraft have been observing the Sun since 2006. Even though STEREO has only been active during solar minimum conditions so far, an important number of coronal mass ejections (CMEs) and their interplanetary counterparts (ICMEs) have been observed. Many of the ICMEs can be linked back to the corresponding CMEs on the Sun through t…
PTF 10bzf (SN 2010ah): A Broad-line Ic Supernova Discovered by the Palomar Transient Factory
Cenko, S. B.; Mitrofanov, I.; Bloom, J. S. +26 more
We present the discovery and follow-up observations of a broad-line Type Ic supernova (SN), PTF 10bzf (SN 2010ah), detected by the Palomar Transient Factory (PTF) on 2010 February 23. The SN distance is cong218 Mpc, greater than GRB 980425/SN 1998bw and GRB 060218/SN 2006aj, but smaller than the other SNe firmly associated with gamma-ray bursts (G…
New Ion-Wave Path in the Energy Cascade
Perrone, Denise; Califano, Francesco; Valentini, Francesco +2 more
We present the results of kinetic numerical simulations that demonstrate the existence of a novel branch of electrostatic nonlinear waves driven by particle trapping processes. These waves have an acoustic-type dispersion with phase speed comparable to the ion thermal speed and would thus be heavily Landau damped in the linear regime. At variance …
The Extremely Red Host Galaxy of GRB 080207
Cresci, Giovanni; Savaglio, Sandra; Pian, Elena +5 more
We present optical, near-infrared, and Spitzer IRAC and MIPS observations of the host galaxy of the dark Swift gamma-ray burst GRB 080207. The host is faint, with extremely red optical-infrared colors (R - K = 6.3, 24 µm/R-band flux ~1000) making it an extremely red object (ERO) and a dust-obscured galaxy (DOG). The spectral energy distribut…
The Young Binary DQ Tau: A Hunt for X-ray Emission from Colliding Magnetospheres
Garmire, Gordon P.; Broos, Patrick S.; Getman, Konstantin V. +2 more
The young high-eccentricity binary DQ Tau exhibits powerful recurring millimeter-band (mm) flaring attributed to collisions between the two stellar magnetospheres near periastron, when the stars are separated by only ~8 R sstarf. These magnetospheric interactions are expected to have scales and magnetic field strengths comparable to tho…
Spectral Properties of Regions and Structures in the Interstellar Boundary Explorer (IBEX) Sky Maps
Reisenfeld, D. B.; McComas, D. J.; Schwadron, N. A. +5 more
We study the spectral properties of different regions and structures in the energetic neutral atom (ENA) maps at energies from ~0.5 keV to ~6 keV from the Interstellar Boundary Explorer (IBEX) mission. We find that (1) an ankle-shaped break (spectrum hardens) between ~1 keV and ~2 keV characterizes the polar spectra and the right flank, while a kn…