Search Publications
The impact of a weak south pole on thermal convection in Enceladus’ ice shell
Showman, Adam P.; Tobie, Gabriel; Han, Lijie
Enceladus exhibits a strong hemispheric dichotomy of tectonism and heat flux, with geologically young, heavily tectonized terrains and a high heat flux in the South Polar Terrain (SPT) and relatively ancient terrains with presumably lower heat fluxes over the rest of the satellite. To understand the convective pattern and its relationship with sur…
A New Microlensing Event in the Doubly Imaged Quasar Q 0957+561
Kochanek, C. S.; Harris, Hugh C.; Fadely, Ross +6 more
We present evidence for ultraviolet/optical microlensing in the gravitationally lensed quasar Q 0957+561. We combine new measurements from our optical monitoring campaign at the United States Naval Observatory, Flagstaff, with measurements from the literature and find that the time-delay-corrected r-band flux ratio mA - mB ha…
The abundance of C18O and HDO in the envelope and hot core of the intermediate mass protostar NGC 7129 FIRS 2
Cernicharo, J.; Johnstone, D.; Fuente, A. +11 more
Context. NGC 7129 FIRS 2 is a young intermediate-mass (IM) protostar, which is associated with two energetic bipolar outflows and displays clear signs of the presence of a hot core. It has been extensively observed with ground based telescopes and within the WISH guaranteed time Herschel key program.
Aims: This paper is dedicated to the model…
Numerical Simulation of Three-dimensional Asymmetric Reconnection and Application to a Physical Mechanism of Penumbral Microjets
Shibata, Kazunari; Isobe, Hiroaki; Nakamura, Naoki
Three-dimensional (3D) component reconnection, where reconnecting field lines are not perfectly anti-parallel, is studied with a 3D magnetohydrodynamic simulation. In particular, we consider the asymmetry of the field strength of the reconnecting field lines. As the asymmetry increases, the generated reconnection jet tends to be parallel to strong…
An Over-and-out Halo Coronal Mass Ejection Driven by the Full Eruption of a Kinked Filament
Yang, Bo; Yang, Jiayan; Bi, Yi +5 more
Over-and-out coronal mass ejections (CMEs) represent a broad class of CMEs that come from flare-producing magnetic explosions of various sizes but are laterally far offset from the flare, and their productions can be depicted by the magnetic-arch-blowout scenario. In this paper, we present observations of an over-and-out halo CME from the full eru…
Modeling and Interpreting the Effects of Spatial Resolution on Solar Magnetic Field Maps
Leka, K. D.; Barnes, G.
Different methods for simulating the effects of spatial resolution on magnetic field maps are compared, including those commonly used for inter-instrument comparisons. The investigation first uses synthetic data, and the results are confirmed with Hinode/SpectroPolarimeter data. Four methods are examined, one which manipulates the Stokes spectra t…
The Ultraviolet Spectral Energy Distributions of Quiescent Black Holes and Neutron Stars
Robinson, E. L.; Hynes, R. I.
We present Hubble Space Telescope/Advanced Camera for Surveys ultraviolet photometry of three quiescent black hole X-ray transients, X-ray Nova Muscae 1991 (GU Mus), GRO J0422+32 (V518 Per), and X-ray Nova Vel 1993 (MM Vel), and one neutron star system, Aql X-1. These are the first quiescent UV detections of these objects. All are detected at a mu…
First ever VLF monitoring of the lunar occultation of a solar flare during the 2010 annular solar eclipse and its effects on the D-region electron density profile
Chakrabarti, Sandip K.; Pal, Sujay; Maji, Surya K.
A ground based Very Low Frequency (VLF) radio receiver of Indian Centre for Space Physics located at Khukurdaha (22°27‧N, 87°45‧E) monitored the VLF signal at 19.8 kHz from the NWC station during a partial solar eclipse (maximum obscuration 75%) which took place on January 15, 2010. The receiver and the transmitter were on two opposite sides of th…
In-plane electric fields in magnetic islands during collisionless magnetic reconnection
Chen, Li-Jen; Roytershteyn, Vadim; Daughton, William +3 more
Magnetic islands are a common feature in both the onset and nonlinear evolution of magnetic reconnection. In collisionless regimes, the onset typically occurs within ion-scale current layers leading to the formation of magnetic islands when multiple X lines are involved. The nonlinear evolution of reconnection often gives rise to extended electron…
Identifying the Radio Bubble Nature of the Microwave Haze
Dobler, Gregory
Using seven-year data from the Wilkinson Microwave Anisotropy Probe, I identify a sharp "edge" in the microwave haze at high southern Galactic latitude (-55° < b < -35°) that is spatially coincident with the southern edge of the "Fermi haze/bubbles." This finding proves conclusively that the edge in the gamma rays is real (and not a processi…