Search Publications
New Evidence for a Coronal Mass Ejection-driven High Frequency Type II Burst near the Sun
Kumari, Anshu; Ramesh, R.; Kathiravan, C. +1 more
We report observations of the high frequency type II radio burst (≈430-30 MHz) that occurred in the solar corona on 2015 November 4. The drift rate of the burst, estimated close to the start frequency of its fundamental component (≈215 MHz), is unusually high (≈2 MHz s-1). Our analysis shows that the estimated speed of the magnetohydrod…
Turbulent Transport in a Three-dimensional Solar Wind
Bruno, R.; Zank, G. P.; Shiota, D. +3 more
Turbulence in the solar wind can play essential roles in the heating of coronal and solar wind plasma and the acceleration of the solar wind and energetic particles. Turbulence sources are not well understood and thought to be partly enhanced by interaction with the large-scale inhomogeneity of the solar wind and the interplanetary magnetic field …
A High Space Density of Luminous Lyman Alpha Emitters at z ∼ 6.5
Bagley, Micaela B.; Martin, Crystal L.; Garel, Thibault +16 more
We present the results of a systematic search for Lyα emitters (LAEs) at 6≲ z≲ 7.6 using the HST WFC3 Infrared Spectroscopic Parallel (WISP) Survey. Our total volume over this redshift range is ∼ 8× {10}5 Mpc3, comparable to many of the narrowband surveys despite their larger area coverage. We find two LAEs at z = 6.38 and 6.…
Carbon Chain Anions and the Growth of Complex Organic Molecules in Titan’s Ionosphere
Lewis, G. R.; Coates, A. J.; Kataria, D. O. +13 more
Cassini discovered a plethora of neutral and ionized molecules in Titan’s ionosphere including, surprisingly, anions and negatively charged molecules extending up to 13,800 u q-1. In this Letter, we forward model the Cassini electron spectrometer response function to this unexpected ionospheric component to achieve an increased mass res…
Investigating the Wave Nature of the Outer Envelope of Halo Coronal Mass Ejections
Vourlidas, Angelos; Kwon, Ryun-Young
We investigate the nature of the outer envelope of halo coronal mass ejections (H-CMEs) using multi-viewpoint observations from the Solar Terrestrial Relations Observatory-A, -B, and SOlar and Heliospheric Observatory coronagraphs. The 3D structure and kinematics of the halo envelopes and the driving CMEs are derived separately using a forward mod…
Various Local Heating Events in the Earliest Phase of Flux Emergence
Toriumi, Shin; Cheung, Mark C. M.; Katsukawa, Yukio
Emerging flux regions (EFRs) are known to exhibit various sporadic local heating events in the lower atmosphere. To investigate the characteristics of these events, especially to link the photospheric magnetic fields and atmospheric dynamics, we analyze Hinode, Interface Region Imaging Spectrograph (IRIS), and Solar Dynamics Observatory data of a …
ALMA Observations of Circumnuclear Disks in Early-type Galaxies: 12CO(2-1) and Continuum Properties
Ho, Luis C.; Barth, Aaron J.; Buote, David A. +4 more
We present results from an Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 2 program to map CO(2-1) emission in nearby early-type galaxies (ETGs) that host circumnuclear gas disks. We obtained ∼0.″3 resolution Band 6 observations of seven ETGs selected on the basis of dust disks in Hubble Space Telescope images. We detect CO emission in …
DUSTiNGS. III. Distribution of Intermediate-age and Old Stellar Populations in Disks and Outer Extremities of Dwarf Galaxies
McQuinn, Kristen B. W.; Skillman, Evan D.; Boyer, Martha L. +8 more
We have traced the spatial distributions of intermediate-age and old stars in nine dwarf galaxies in the distant parts of the Local Group, using multi-epoch 3.6 and 4.5 µm data from the DUST in Nearby Galaxies with Spitzer (DUSTiNGS) survey. Using complementary optical imaging from the Hubble Space Telescope, we identify the tip of the red g…
Radio Pulse Search and X-Ray Monitoring of SAX J1808.4-3658: What Causes Its Orbital Evolution?
Hessels, Jason W. T.; Wijnands, Rudy; van der Klis, Michiel +6 more
The accreting millisecond X-ray pulsar SAX J1808.4-3658 shows a peculiar orbital evolution that proceeds at a very fast pace. It is important to identify the underlying mechanism responsible for this behavior because it can help to understand how this system evolves and which physical processes (such as mass loss or spin-orbit coupling) are occurr…
Observational Evidence of Magnetic Reconnection for Brightenings and Transition Region Arcades in IRIS Observations
Feng, Li; Zhu, Xiaoshuai; Li, Hui +4 more
By using a new method of forced-field extrapolation, we study the emerging flux region AR11850 observed by the Interface Region Imaging Spectrograph and Solar Dynamical Observatory. Our results suggest that the bright points (BPs) in this emerging region exhibit responses in lines formed from the upper photosphere to the transition region, which h…