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A Joint Chandra and Swift View of the 2015 X-ray Dust-scattering Echo of V404 Cygni
Brandt, W. N.; Smith, R.; Neilsen, J. +4 more
We present a combined analysis of the Chandra and Swift observations of the 2015 X-ray echo of V404 Cygni. Using a stacking analysis, we identify eight separate rings in the echo. We reconstruct the soft X-ray light curve of the 2015 June outburst using the high-resolution Chandra images and cross-correlations of the radial intensity profiles, ind…
Multi-spacecraft Observations and Transport Modeling of Energetic Electrons for a Series of Solar Particle Events in August 2010
Dresing, N.; Dröge, W.; Klassen, A. +1 more
During 2010 August a series of solar particle events was observed by the two STEREO spacecraft as well as near-Earth spacecraft. The events, occurring on August 7, 14, and 18, originated from active regions 11093 and 11099. We combine in situ and remote-sensing observations with predictions from our model of three-dimensional anisotropic particle …
Global Energetics of Solar Flares. IV. Coronal Mass Ejection Energetics
Aschwanden, Markus J.
This study entails the fourth part of a global flare energetics project, in which the mass m cme, kinetic energy E kin, and the gravitational potential energy E grav of coronal mass ejections (CMEs) is measured in 399 M and X-class flare events observed during the first 3.5 years of the Solar Dynamics Observatory (…
On the Active Region Bright Grains Observed in the Transition Region Imaging Channels of IRIS
De Pontieu, B.; Rouppe van der Voort, L.; Skogsrud, H.
The Interface Region Imaging Spectrograph (IRIS) provides spectroscopy and narrow band slit-jaw (SJI) imaging of the solar chromosphere and transition region at unprecedented spatial and temporal resolutions. Combined with high-resolution context spectral imaging of the photosphere and chromosphere as provided by the Swedish 1 m Solar Telescope (S…
Observation of the Evolution of a Current Sheet in a Solar Flare
Liu, Rui; Alexander, David; McAteer, R. T. James +1 more
We report multi-wavelength and multi-viewpoint observations of a solar eruptive event that involves loop-loop interactions. During a C2.0 flare, motions associated with inflowing and outflowing plasma provide evidence for ongoing magnetic reconnection. The flare loop top and a rising “concave-up” feature are connected by a current-sheet-like struc…
Fragmentation Kinematics in Comet 332P/Ikeya-Murakami
Mutchler, Max; Jewitt, David; Weryk, Robert +9 more
We present initial time-resolved observations of the split comet 332P/Ikeya-Murakami taken using the Hubble Space Telescope. Our images reveal a dust-bathed cluster of fragments receding from their parent nucleus at projected speeds in the range 0.06-3.5 m s-1 from which we estimate ejection times from 2015 October to December. The numb…
Pulsation-triggered Mass Loss from AGB Stars: The 60 Day Critical Period
Zijlstra, A. A.; McDonald, I.
Low- and intermediate-mass stars eject much of their mass during the late, red giant branch (RGB) phase of evolution. The physics of their strong stellar winds is still poorly understood. In the standard model, stellar pulsations extend the atmosphere, allowing a wind to be driven through radiation pressure on condensing dust particles. Here, we i…
Observations of Magnetic Flux-rope Oscillation during the Precursor Phase of a Solar Eruption
Zhang, J.; Wang, J. X.; Zhou, G. P.
Based on combined observations from the Interface Region Imaging Spectrograph (IRIS) spectrometer with the coronal emission line of Fe xxi at 1354.08 Å and SDO/AIA images in multiple passbands, we report the finding of the precursor activity manifested as the transverse oscillation of a sigmoid, which is likely a pre-existing magnetic flux rope (M…
IDCS J1426.5+3508: The Most Massive Galaxy Cluster at z > 1.5
Eisenhardt, Peter R.; Gonzalez, Anthony H.; Stanford, S. A. +4 more
We present a deep (100 ks) Chandra observation of IDCS J1426.5+3508, a spectroscopically confirmed, infrared-selected galaxy cluster at z = 1.75. This cluster is the most massive galaxy cluster currently known at z > 1.5, based on existing Sunyaev-Zel’dovich (SZ) and gravitational lensing detections. We confirm this high mass via a variety of X…
A Normal Supermassive Black Hole in NGC 1277
Marconi, Alessandro; Graham, Alister W.; Scott, Nicholas +5 more
The identification of galaxies with “overly massive” black holes requires two measurements: a black hole mass (Mbh) and a host spheroid mass ({M}{{sph,\ast }}). Here we provide our measurements for NGC 1277. Our structural decomposition reveals that NGC 1277 is dominated by a “classical” spheroid with a Sérsic index n = 5.3, …