Search Publications
Is the Asymmetric Cone Model for Halo Coronal Mass Ejections Correct?
Michalek, G.
A set of 106 limb CMEs which are wide and could be possible halo events, when directed towards Earth, are used to check the accuracy of the asymmetric cone model. For this purpose characteristics of CMEs (widths and radial speeds) measured for the possible halo CMEs are compared with these obtained for halo CMEs using the asymmetric cone model (Mi…
A new technique for determining orientation and motion of a 2-D, non-planar magnetopause
Marghitu, O.; Klecker, B.; Scholer, M. +3 more
For a four-point mission like Cluster, the differences in position and time when the satellites detect the magnetopause or any other discontinuity, can be used to infer the discontinuity local orientation, thickness and motion. This timing technique, commonly assuming a planar geometry, offers an independent check for various single-spacecraft tec…
Characteristics and Evolution of the Magnetic Field and Chromospheric Emission in an Active Region Core Observed by Hinode
Winebarger, Amy R.; Warren, Harry P.; Brooks, David H.
We describe the characteristics and evolution of the magnetic field and chromospheric emission in an active region core observed by the Solar Optical Telescope (SOT) on Hinode. Consistent with previous studies, we find that the moss is unipolar, the spatial distribution of magnetic flux evolves slowly, and that the magnetic field is only moderatel…
Lower-hybrid (LH) oscillitons evolved from ion-acoustic (IA)/ion-cyclotron (IC) solitary waves: effect of electron inertia
Ma, J. Z. G.; Hirose, A.
Lower-hybrid (LH) oscillitons reveal one aspect of geocomplexities. They have been observed by rockets and satellites in various regions in geospace. They are extraordinary solitary waves the envelop of which has a relatively longer period, while the amplitude is modulated violently by embedded oscillations of much shorter periods. We employ a two…
Cosmic Origins Spectrograph Observations of Translucent Clouds: Cyg OB2 8A
Danforth, Charles W.; Snow, Theodore P.; Destree, Joshua D. +3 more
Data from the Cosmic Origins Spectrograph (COS) are presented for the first highly reddened target (Cyg OB2 8A) under the COS Science Team's guaranteed time allocation. Column densities of ionic, atomic, and molecular species are reported and implications are discussed. Data from Cyg OB2 8A demonstrate the ability to analyze highly reddened inters…
A microflare with hard X-ray-correlated gyroresonance line emission at 314 MHz
Veronig, A.; Aurass, H.; Rausche, G. +1 more
Context. Small energy release events in the solar corona can give insights into the flare process which are regularly hidden in the complex morphology of larger events. For one case we find a narrowband radio signal well correlated with the hard X-ray flare. We investigate wether these signals are probes for the flare current sheet.
Aims: We …
What Bandwidth Do I Need for My Image?
Hogg, David W.; Price-Whelan, Adrian M.
Computer representations of real numbers are necessarily discrete, with some finite resolution, discreteness, quantization, or minimum representable difference. We perform astrometric and photometric measurements on stars and co-add multiple observations of faint sources to demonstrate that essentially all of the scientific information in an optic…
Very High Energy Observations of Gamma-ray Bursts with STACEE
Fortin, P.; Aune, T.; Mukherjee, R. +14 more
Gamma-ray bursts (GRBs) are the most powerful explosions known in the universe. Sensitive measurements of the high-energy spectra of GRBs can place important constraints on the burst environments and radiation processes. Until recently, there were no observations during the first few minutes of GRB afterglows in the energy range between 30 GeV and…
Suzaku and INTEGRAL Observations of IGR J16318-4848
Pottschmidt, Katja; Wilms, Jörn; Kreykenbohm, Ingo +3 more
IGR J16318-4848 is the first example, and probably the most extreme case, of a new class of highly absorbed X-ray binaries that has been discovered by the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) in the last years. We report on the analysis of the first joint Suzaku/INTEGRAL observation of this source, and also on the detection o…
New Results from the Magellan IMACS Spectroscopic Lyα Survey: NICMOS Observations of Lyα Emitters at z = 5.7
Martin, Crystal L.; Sawicki, Marcin; Dressler, Alan +2 more
We present NICMOS J 110 (rest-frame 1200-2100 Å) observations of the three z = 5.7 Lyα emitters discovered in the blind multislit spectroscopic survey by Martin et al. These images confirm the presence of the two sources that were previously only seen in spectroscopic observations. The third source, which is undetected in our J 110…