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Properties and origin of subproton-scale magnetic holes in the terrestrial plasma sheet
Burgess, D.; Sundberg, T.; Haynes, C. T.
Electron-scale magnetic depressions in the terrestrial plasma sheet are studied using Cluster multispacecraft data. The structures, which have an observed duration of ~5-10 s, are approximately 200-300 km wide in the direction of propagation, and they show an average reduction in the background magnetic field of 10-20%. A majority of the events ar…
Quasi-periodic Fluctuations and Chromospheric Evaporation in a Solar Flare Ribbon Observed by IRIS
Brosius, Jeffrey W.; Daw, Adrian N.
The Interface Region Imaging Spectrograph (IRIS) satellite obtained rapid cadence (9.4 s) stare spectra of an M7 flare ribbon in AR 12036 on 2014 April 18. Chromospheric and transition region line emission exhibited quasi-periodic intensity and velocity fluctuations in the ribbon prior to the appearance of Fe xxi emission. Seven intensity peaks we…
Structural mapping of Enceladus and implications for formation of tectonized regions
Crow-Willard, Emma N.; Pappalardo, Robert T.
Global structural mapping of high-resolution Cassini images of Enceladus reveals a richly varied surface. Most notable are three main regions of deformation each containing multiple structural units. In addition to the well known "South Polar Terrain" (SPT), there are two other large regions of deformation that we term "Leading Hemisphere Terrain"…
Properties of solar plage from a spatially coupled inversion of Hinode SP data
Solanki, S. K.; Lagg, A.; van Noort, M. +1 more
Aims: The properties of magnetic fields forming an extended plage region in AR 10953 were investigated.
Methods: Stokes spectra of the Fe I line pair at 6302 Å recorded by the spectropolarimeter aboard the Hinode satellite were inverted using the SPINOR code. The code performed a 2D spatially coupled inversion on the Stokes spectra, allo…
The Grism Lens-amplified Survey from Space (GLASS). IV. Mass Reconstruction of the Lensing Cluster Abell 2744 from Frontier Field Imaging and GLASS Spectroscopy
Vulcani, B.; Hoag, A.; Bradač, M. +12 more
We present a strong and weak lensing reconstruction of the massive cluster Abell 2744, the first cluster for which deep Hubble Frontier Fields (HFF) images and spectroscopy from the Grism Lens-Amplified Survey from Space (GLASS) are available. By performing a targeted search for emission lines in multiply imaged sources using the GLASS spectra, we…
An extended star formation history in an ultra-compact dwarf
van den Bosch, Remco C. E.; Forte, Juan Carlos; Faifer, Favio R. +3 more
There has been significant controversy over the mechanisms responsible for forming compact stellar systems like ultra-compact dwarfs (UCDs), with suggestions that UCDs are simply the high-mass extension of the globular cluster population, or alternatively, the liberated nuclei of galaxies tidally stripped by larger companions. Definitive examples …
Revised Lens Model for the Multiply Imaged Lensed Supernova, “SN Refsdal” in MACS J1149+2223
Sharon, Keren; Johnson, Traci L.
We present a revised lens model of MACS J1149+2223, in which the first resolved multiply imaged lensed supernova (SN) was discovered. The lens model is based on the model of Johnson et al. with some modifications. We include more lensing constraints from the host galaxy of the newly discovered SN, and increase the flexibility of the model in order…
Observation of a new type of low-frequency waves at comet 67P/Churyumov-Gerasimenko
Altwegg, K.; Tsurutani, B. T.; Glassmeier, K. -H. +23 more
We report on magnetic field measurements made in the innermost coma of 67P/Churyumov-Gerasimenko in its low-activity state. Quasi-coherent, large-amplitude (δ B/B ~ 1), compressional magnetic field oscillations at ~ 40 mHz dominate the immediate plasma environment of the nucleus. This differs from previously studied cometary interaction regions wh…
Electrostatic solitary waves with distinct speeds associated with asymmetric reconnection
André, M.; Vaivads, A.; Khotyaintsev, Yu. V. +1 more
Electrostatic solitary waves (ESWs) are observed at the magnetopause with distinct time scales. These ESWs are associated with asymmetric reconnection of the cold dense magnetosheath plasma with the hot tenuous magnetospheric plasma. The distinct time scales are shown to be due to ESWs moving at distinct speeds and having distinct length scales. T…
A Consistent Picture Emerges: A Compact X-Ray Continuum Emission Region in the Gravitationally Lensed Quasar SDSS J0924+0219
Kochanek, C. S.; Dai, X.; Chartas, G. +7 more
We analyze the optical, UV, and X-ray microlensing variability of the lensed quasar SDSS J0924+0219 using six epochs of Chandra data in two energy bands (spanning 0.4-8.0 keV, or 1-20 keV in the quasar rest frame), 10 epochs of F275W (rest-frame 1089 Å) Hubble Space Telescope data, and high-cadence R-band (rest-frame 2770 Å) monitoring spanning 11…