Search Publications
Comparing Dawn, Hubble Space Telescope, and ground-based interpretations of (4) Vesta
Nathues, Andreas; Russell, Christopher T.; Li, Jian-Yang +10 more
Observations of Asteroid (4) Vesta by NASA’s Dawn spacecraft are interesting because its surface has the largest range of albedo, color and composition of any other asteroid visited by spacecraft to date. These hemispherical and rotational variations in surface brightness and composition have been attributed to impact processes since Vesta’s forma…
Current sheet structure and kinetic properties of plasma flows during a near-Earth magnetic reconnection under the presence of a guide field
Malova, H. V.; Zelenyi, L. M.; Sauvaud, J. -A. +8 more
Fortunate positioning of Cluster and TC-1 in the plasma sheet (PS) of the Earth's magnetotail has allowed studies of the current sheet (CS) structure and particle dynamics in mesoscale and microscale in both sides of the near-Earth reconnection, which took place between 03:42 and 03:55 UT on 22 September 2004. The distinctive feature of this event…
High-energy Emission from the Composite Supernova Remnant MSH 15-56
Temim, Tea; Slane, Patrick; Plucinsky, Paul P. +3 more
MSH 15-56 (G326.3-1.8) is a composite supernova remnant (SNR) that consists of an SNR shell and a displaced pulsar wind nebula (PWN) in the radio. We present XMM-Newton and Chandra X-ray observations of the remnant that reveal a compact source at the tip of the radio PWN and complex structures that provide evidence for mixing of the supernova (SN)…
Multi-wavelength Studies of Spectacular Ram-pressure Stripping of a Galaxy. II. Star Formation in the Tail
Makishima, Kazuo; Nakazawa, Kazuhiro; Gu, Liyi +5 more
With multiband photometric data in public archives, we detected four intracluster star-forming regions in the Virgo Cluster. Two of them were at a projected distance of 35 kpc from NGC 4388 and the other two were 66 kpc away. Our new spectroscopic observations revealed that their recessional velocities were comparable to the ram-pressure-stripped …
Preliminary testing of global hybrid-Vlasov simulation: Magnetosheath and cusps under northward interplanetary magnetic field
Palmroth, M.; Pokhotelov, D.; von Alfthan, S. +3 more
Global magnetohydrodynamic (MHD) simulations have been successful in describing systems where the important spatial scales are larger than ion inertial length and the plasma has a well-defined temperature. The weakness of global one-fluid MHD simulations is their inability to model the multi-temperature, multi-component plasmas in the inner magnet…
Hot and cold ion outflow: Observations and implications for numerical models
Nilsson, H.; Slapak, R.; André, M. +2 more
<title type="main">Abstract<p label="1">Cluster observations of oxygen ion outflow and low-frequency waves at high altitude above the polar cap and cold ion outflow in the lobes are used to determine ion heating rates and low-altitude boundary conditions suitable for use in numerical models of ion outflow. Using our results, it is poss…
Multiband Diagnostics of Unidentified 1FGL Sources with Suzaku and Swift X-Ray Observations
Kataoka, J.; Maeda, K.; Nakamori, T. +3 more
We have analyzed all the archival X-ray data of 134 unidentified (unID) gamma-ray sources listed in the first Fermi/LAT (1FGL) catalog and subsequently followed up by the Swift/XRT. We constructed the spectral energy distributions (SEDs) from radio to gamma-rays for each X-ray source detected, and tried to pick up unique objects that display anoma…
Modeling Total Solar Irradiance with San Fernando Observatory Ground-Based Photometry: Comparison with ACRIM, PMOD, and RMIB Composites
Chapman, G. A.; Preminger, D. G.; Cookson, A. M.
We model total solar irradiance (TSI) using photometric irradiance indices from the San Fernando Observatory (SFO), and compare our model with measurements compiled from different space-based radiometers. Space-based measurements of TSI have been obtained recently from ACRIM-3 on board the ACRIMSAT. These data have been combined with other data se…
An Echo of Supernova 2008bk
Van Dyk, Schuyler D.
I have discovered a prominent light echo around the low-luminosity Type II-plateau supernova (SN) 2008bk in NGC 7793, seen in archival images obtained with the Wide Field Channel of the Advanced Camera for Surveys on board the Hubble Space Telescope (HST). The echo is a partial ring, brighter to the north and east than to the south and west. The a…
The Effects of Spatio-temporal Resolution on Deduced Spicule Properties
De Pontieu, Bart; Carlsson, Mats; Pereira, Tiago M. D.
Spicules have been observed on the Sun for more than a century, typically in chromospheric lines such as Hα and Ca II H. Recent work has shown that so-called "type II" spicules may have a role in providing mass to the corona and the solar wind. In chromospheric filtergrams these spicules are not seen to fall back down, and they are shorter lived a…