Search Publications
Missions
Journals
Publication Years
Whistler anisotropy instability with a cold electron component: Linear theory
Gary, S. Peter; Liu, Kaijun; Denton, Richard E. +1 more
The whistler anisotropy instability is driven by an electron temperature anisotropy T⊥/T∥ > 1 where ⊥ and ∥ denote directions perpendicular and parallel, respectively, to the background magnetic field Bo. Here kinetic linear theory in a magnetized, homogeneous, collisionless plasma model is used to study this in…
Shocked and Scorched: The Tail of a Tadpole in an Interstellar Pond
Sahai, R.; Morris, M. R.; Claussen, M. J.
We report multi-wavelength observations of the far-infrared source IRAS 20324+4057, including high-resolution optical imaging with the Hubble Space Telescope, and ground-based near-infrared, millimeter-wave and radio observations. These data show an extended, limb-brightened, tadpole-shaped nebula with a bright, compact, cometary nebula located in…
Coronal Density Structures and CMEs: Superior Solar Conjunctions of Mars Express, Venus Express, and Rosetta: 2004, 2006, and 2008
Tellmann, Silvia; Tyler, G. Leonard; Tsurutani, Bruce T. +5 more
Coronal radio-sounding experiments were carried out using the S-band (2.3 GHz) and X-band (8.4 GHz) signals of the ESA Mars Express, Venus Express, and Rosetta spacecraft during five superior conjunctions occurring in 2004, 2006 (3×), and 2008/2009. Differential frequency and propagation delay (ranging) observations were recorded during these oppo…
The Central Region of the Barred Spiral Galaxy NGC 1097 Probed by AKARI Near-infrared Spectroscopy
Oyabu, Shinki; Onaka, Takashi; Yamagishi, Mitsuyoshi +6 more
With the Infrared Camera on board AKARI, we carried out near-infrared (2.5-5.0 µm) spectroscopy of the central kiloparsec region of the barred spiral galaxy, NGC 1097, categorized as Seyfert 1 with a circumnuclear starburst ring. Our observations mapped the area of ~50'' × 10'' with the resolution of ~5'', covering about a half of the ring a…
The orientation of Titan's dayside ionosphere and its effects on Titan's plasma interaction
Brecht, Stephen H.; Ledvina, Stephen A.; Cravens, Thomas E.
A hybrid particle code has been used to examine how Titan's interaction with Saturn's magnetosphere is effected by the orientation of the dayside ionosphere with respect to the incident magnetospheric flow. The hybrid code self-consistently includes a version of Titan's ionosphere represented by 7 generic ion species, over 40 ionneutral chemical r…
Spectroscopic parameters for silacyclopropynylidene, SiC2, from extensive astronomical observations toward CW Leo (IRC +10216) with the Herschel satellite
Waters, L. B. F. M.; Cernicharo, José; Teyssier, D. +5 more
A molecular line survey has been carried out toward the carbon-rich asymptotic giant branch star CW Leo employing the HIFI instrument on board of the Herschel satellite. Numerous features from 480 GHz to beyond 1100 GHz could be assigned unambiguously to the fairly floppy SiC2 molecule. However, predictions from laboratory data exhibite…
Multipolar Planetary Nebulae: Not as Geometrically Diversified as Thought
Kwok, Sun; Tafoya, D.; Imai, H. +2 more
Planetary nebulae (PNe) have diverse morphological shapes, including point-symmetric and multipolar structures. Many PNe also have complicated internal structures such as tori, lobes, knots, and ansae. A complete accounting of all the morphological structures through physical models is difficult. A first step toward such an understanding is to der…
Swift/X-ray Telescope monitoring of the candidate supergiant fast X-ray transient IGR J16418-4532
Gehrels, N.; Esposito, P.; Ducci, L. +6 more
We report on the Swift monitoring of the candidate supergiant fast X-ray transient (SFXT) IGR J16418-4532, for which both orbital and spin periods are known (∼3.7 d and ∼1250 s, respectively). Our observations, for a total of ∼43 ks, span over three orbital periods and represent the most intense and complete sampling of the light curve of this sou…
Modeling the Accretion Structure of AU Mon
Peters, Geraldine J.; Miller, Brendan P.; Budaj, Ján +2 more
AU Mon is a long-period (11.113 days) Algol-type binary system with a persistent accretion disk that is apparent as double-peaked Hα emission. We present previously unpublished optical spectra of AU Mon which were obtained over 20 years from 1991-2011 with dense orbital phase coverage. We utilize these data, along with archival UV spectra, to mode…
Coronal Cells
Warren, H. P.; Sheeley, N. R., Jr.
We have recently noticed cellular features in Fe XII 193 Å images of the 1.2 MK corona. They occur in regions bounded by a coronal hole and a filament channel, and are centered on flux elements of the photospheric magnetic network. Like their neighboring coronal holes, these regions have minority-polarity flux that is ~0.1-0.3 times their flux of …