Search Publications
On slowly evolving Grad-Shafranov equilibria
Hasegawa, Hiroshi; Sonnerup, Bengt U. Ã. -.
A method is developed for analyzing the slow, purely kinematic evolution of magnetohydrostatic Grad-Shafranov equilibria, recovered by reconstruction from data taken by a single spacecraft as it traverses a quasi-static, two-dimensional, magnetic field/plasma structure in space, such as a flux transfer event at the magnetopause. The evolution is c…
Evidence of grain growth in the disk of the bipolar proto-planetary nebula M 1-92
Meixner, M.; Murakawa, K.; Ueta, T.
Aims: We investigate the dust grain size and dust shell structure of the bipolar proto-planetary nebula M 1-92.
Methods: We performed radiative transfer modeling of the dust shells of M 1-92. Our models consists of a disk and bipolar lobes that are surrounded by an AGB shell, each component having different dust characteristics. The mode…
Spitzer Observations of A1763. II. Constraining the Nature of Activity in the Cluster-feeding Filament with VLA and XMM-Newton Data
Fadda, Dario; Frayer, David T.; Durret, Florence +2 more
The A1763 superstructure at z = 0.23 contains the first galaxy filament to be directly detected using mid-infrared observations. Our previous work has shown that the frequency of starbursting galaxies, as characterized by 24 µm emission is much higher within the filament than at either the center of the rich galaxy cluster, or the field surr…
A FUSE View of Winds from the Central Stars of Planetary Nebulae
Guerrero, Martín A.; Ramos-Larios, Gerardo; Massa, Derck
Since the IUE satellite produced a vast collection of high-resolution UV spectra of the central stars of planetary nebulae (CSPNe), there has not been any further systematic study of the stellar winds of these stars. The high spectral resolution, sensitivity and large number of archival observations in the FUSE archive allow the study of the stell…
High-sensitivity Array Observations of the z = 1.87 Submillimeter Galaxy GOODS 850-3
Wang, Wei-Hao; Momjian, Emmanuel; Knudsen, Kirsten K. +3 more
We present sensitive phase-referenced Very Long Baseline Interferometry (VLBI) results on the radio continuum emission from the z = 1.87 luminous submillimeter galaxy (SMG) GOODS 850-3. The observations were carried out at 1.4 GHz using the High-Sensitivity Array (HSA). Our sensitive tapered VLBI image of GOODS 850-3 at 0farcs47 × 0farcs34 (3.9 × …
Observations of solar scattering polarization at high spatial resolution
Lites, B. W.; Ichimoto, K.; Snik, F. +3 more
Context. The weak, turbulent magnetic fields that supposedly permeate most of the solar photosphere are difficult to observe, because the Zeeman effect is virtually blind to them. The Hanle effect, acting on the scattering polarization in suitable lines, can in principle be used as a diagnostic for these fields. However, the prediction that the ma…
Interstellar absorptions towards the LMC:. small-scale density variations in Milky Way disc gas
Wakker, B. P.; Nasoudi-Shoar, S.; de Boer, K. S. +1 more
Observations show that the interstellar medium (ISM) contains sub-structure on scales less than 1 pc, detected in the form of spatial and temporal variations in column densities or optical depth. Despite the number of detections, the nature and ubiquity of the small-scale structure in the ISM is not yet fully understood. We use UV absorption data …
Investigation of the force balance in the Titan ionosphere: Cassini T5 flyby model/data comparisons
Luhmann, J. G.; Wahlund, J. -E.; Waite, J. H. +5 more
Cassini's Titan flyby on 16 April, 2005 (T5) is the only encounter when the two main ionizing sources of the moon's atmosphere, solar radiation and corotating plasma, align almost anti-parallel. In this paper a single-fluid multi-species 3D MHD model of the magnetospheric plasma interaction for T5 conditions is analyzed. Model results are compared…
Hybrid simulations of the plasma environment around Enceladus
Russell, C. T.; Tokar, R. L.; Leisner, J. S. +1 more
The plasma environment around Enceladus is governed by the interaction between the corotating plasma with the body of the moon and the neutral gas associated with Saturn's extended cloud and plumes ejected from its southern polar region. To understand the nature of this interaction, we use 3-D electromagnetic hybrid simulations that treat ions kin…
The Herschel-SPIRE submillimetre spectrum of Mars
Thomas, N.; Hartogh, P.; Blommaert, J. +44 more
We have obtained the first continuous disk averaged spectrum of Mars from 450 to 1550 Ghz using the Herschel-SPIRE Fourier-transform spectrometer. The spectrum was obtained at a constant resolution of 1.4 GHz across the whole band. The flux from the planet is such that the instrument was operated in “bright source” mode to prevent saturation of th…