Search Publications
Unbiased Differential Size Evolution and the Inside-out Growth of Galaxies in the Deep CANDELS GOODS Fields at 1 ≤ z ≤ 7
Conselice, C. J.; Duncan, K.; Bhatawdekar, R. +1 more
We present a size analysis of a sample of ∼49,000 galaxies from the Cosmic Assembly Near-infrared Deep Extragalactic Survey GOODS North and South fields, using redshift-independent relative surface-brightness metrics to determine an unbiased measure of the differential size evolution of galaxies at 1 ≤ z ≤ 7. We introduce a novel method of removin…
NuSTAR Detection of X-Rays Concurrent with Gamma-Rays in the Nova V5855 Sgr
Sokoloski, J. L.; Chomiuk, Laura; Mukai, Koji +7 more
We report the first detection of hard (>10 keV) X-ray emission simultaneous with gamma-rays in a nova eruption. Observations of the nova V5855 Sgr carried out with the NuSTAR satellite on Day 12 of the eruption revealed faint, highly absorbed thermal X-rays. The extreme equivalent hydrogen column density toward the X-ray emitting region (∼3 × 1…
Exploring Plasma Heating in the Current Sheet Region in a Three-dimensional Coronal Mass Ejection Simulation
Reeves, Katharine K.; Mikić, Zoran; Török, Tibor +2 more
We simulate a coronal mass ejection using a three-dimensional magnetohydrodynamic code that includes coronal heating, thermal conduction, and radiative cooling in the energy equation. The magnetic flux distribution at 1 R s is produced by a localized subsurface dipole superimposed on a global dipole field, mimicking the presence of an…
Observation of a Reversal of Breakout Reconnection Preceding a Jet: Evidence of Oscillatory Magnetic Reconnection?
Yang, Bo; Yang, Jiayan; Bi, Yi +3 more
Recent studies have revealed that solar jets involving minifilament eruptions may be initiated under the well-known magnetic-breakout mechanism. Before or just at the onset of those jets, there should be a current sheet, where breakout magnetic reconnection takes place, between open fields and the outside of the jet-base arcade carrying a minifila…
The JCMT Transient Survey: An Extraordinary Submillimeter Flare in the T Tauri Binary System JW 566
Herczeg, Gregory J.; Johnstone, Doug; Lee, Jeong-Eun +7 more
The binary T Tauri system JW 566 in the Orion Molecular Cloud underwent an energetic, short-lived flare observed at submillimeter wavelengths by the SCUBA-2 instrument on 2016 November 26 (UT). The emission faded by nearly 50% during the 31 minute integration. The simultaneous source fluxes averaged over the observation are 500+/- 107 {mJy} {beam}…
Two Types of Confined Solar Flares
Hou, Yijun; Li, Ting; Zhang, Jun +1 more
With the aim of understanding the physical mechanisms of confined flares, we selected 18 confined flares during 2011-2017, and first classified them into two types based on their different dynamic properties and magnetic configurations. “Type I” confined flares are characterized by slipping reconnection, strong shear, and a stable filament. “Type …
Active Galactic Nuclei with Ultrafast Outflows Monitoring Project: The Broad-line Region of Mrk 79 as a Disk Wind
Ho, Luis C.; Bian, Wei-Hao; Kim, Minjin +23 more
We developed a spectroscopic monitoring project to investigate the kinematics of the broad-line region (BLR) in active galactic nuclei (AGNs) with ultrafast outflows (UFOs). Mrk 79 is a radio-quiet AGN with UFOs and warm absorbers and has been monitored by three reverberation mapping (RM) campaigns, but its BLR kinematics are not yet understood. I…
Observations of a Footpoint Drift of an Erupting Flux Rope
Aulanier, Guillaume; Dudík, Jaroslav; Gömöry, Peter +2 more
We analyze the imaging observations of an M-class eruptive flare of 2015 November 4. The pre-eruptive Hα filament was modeled by the nonlinear force-free field model, which showed that it consisted of two helical systems. Tether-cutting reconnection involving these two systems led to the formation of a hot sigmoidal loop structure rooted in a smal…
Albedos, Equilibrium Temperatures, and Surface Temperatures of Habitable Planets
Del Genio, Anthony D.; Guzewich, Scott D.; Way, Michael J. +8 more
The potential habitability of known exoplanets is often categorized by a nominal equilibrium temperature assuming a Bond albedo of either ∼0.3, similar to Earth, or 0. As an indicator of habitability, this leaves much to be desired, because albedos of other planets can be very different, and because surface temperature exceeds equilibrium temperat…
Spacecraft Radio Frequency Fluctuations in the Solar Corona: A MESSENGER-HELIOS Composite Study
Wexler, David B.; Hollweg, Joseph V.; Jensen, Elizabeth A. +4 more
Fluctuations in plasma electron density may play a role in solar coronal energy transport and the dissipation of wave energy. Transcoronal spacecraft radio sounding observations reveal frequency fluctuations (FFs) that encode the electron number density disturbances, allowing an exploration of the coronal compressive wave and advected inhomogeneit…