Search Publications
Statistics on the Magnetosheath Properties Related to Magnetopause Magnetic Reconnection
Zhang, Hui; Liu, Libo; Wan, Weixing +5 more
Magnetosheath properties, particularly those related to magnetopause magnetic reconnection (MR), are investigated in this study. (1) Asymmetries are found to exist in the distributions of plasma and magnetic field parameters in the magnetosheath. These asymmetries are related to the interplanetary magnetic field (IMF) orientation, and they are pro…
A Detailed Study of the Most Relaxed SPT-selected Galaxy Clusters: Properties of the Cool Core and Central Galaxy
Schrabback, T.; Hlavacek-Larrondo, J.; Bayliss, M. +14 more
We present a multi-wavelength analysis of the four most relaxed clusters in the South Pole Telescope 2500 deg2 survey, which lie at 0.55 < z < 0.75. This study, which utilizes new, deep data from the Chandra X-ray Observatory and Hubble Space Telescope, along with ground-based spectroscopy from Gemini and Magellan, improves signif…
Frequency-Distance Structure of Solar Radio Sources Observed by LOFAR
Browning, Philippa; Gordovskyy, Mykola; Kontar, Eduard +1 more
Low-frequency radio observations make it possible to study the solar corona at distances up to 2-3 R ⊙. Frequency of plasma emission is a proxy for electron density of the emitting plasma and, therefore, observations of solar radio bursts can be used to probe the density structure of the outer corona. In this study, positions of solar r…
Radius Inflation at Low Rossby Number in the Hyades Cluster
Stassun, Keivan G.; Somers, Garrett; Jaehnig, Karl
Radius inflation continues to be explored as a peculiar occurrence among magnetically active, low-mass stars. Recently, Somers & Stassun showed that radius inflation among low-mass stars in the young open cluster M45 (Pleiades Cluster) is correlated to the rotation rate: faster rotators are more inflated. Here we extend that work to a sample o…
The Dynamics, Structure, and Fate of a Young Cluster during Gas Dispersal: Hectoschelle, Chandra, Spitzer, and Gaia Observations of Cep OB3b
Jeffries, R. D.; Megeath, S. T.; Gutermuth, R. A. +5 more
We present a study of the kinematics and structure of the Cep OB3b cluster based on new spectra obtained with the Hectoschelle spectrograph on the MMT and data from Spitzer, Chandra, and Gaia. At a distance of 819 ± 16 pc, Cep OB3b is one of the closest examples of a young (∼3-5 Myr), large (∼3000 total members) cluster at the late stages of gas d…
Models of the Mass-ejection Histories of Pre-planetary Nebulae. III. The Shaping of Lobes by Post-AGB Winds
Frank, Adam; Balick, Bruce; Liu, Baowei
We develop a physical framework for interpreting high-resolution images and kinematics of pre-planetary nebulae (“prePNe”). We use hydrodynamical models to infer the historical properties of fast collimated nuclear flows (“jet”) that successfully form hollow, candle-shaped lobes over ≈103 yr, including the density, momenta, and geometry…
The Interplay of the Solar Wind Core and Suprathermal Electrons: A Quasilinear Approach for Firehose Instability
Lazar, M.; Poedts, S.; Yoon, P. H. +1 more
In the solar wind an equipartition of kinetic energy densities can be easily established between thermal and suprathermal electrons and the instability conditions are markedly altered by the interplay of these two populations. The new thresholds derived here for the periodic branch of firehose instability shape the limits of temperature anisotropy…
Transfer of Twists from a Mini-filament to Large-scale Loops by Magnetic Reconnection
Li, Ting; Xue, Zhike; Yan, Xiaoli +4 more
With high spatial and temporal resolution, Hα data from the New Vacuum Solar Telescope, X-ray images from the X-ray telescope on board Hinode and simultaneous observations from the Solar Dynamics Observatory, we present multiwavelength observations of the interaction between a mini-filament (MF) and its overlying large-scale active-region loops (A…
Spectral Evolution and Radial Dust Transport in the Prototype Young Eruptive System EX Lup
Carmona, A.; Ábrahám, P.; Chen, L. +7 more
EX Lup is the prototype of a class of pre-main-sequence eruptive stars defined by their repetitive outbursts lasting several months. In 2008 January-September EX Lup underwent its historically largest outburst, brightening by about 4 mag in visual light. In previous studies we discovered ongoing silicate crystal formation in the inner disk during …
Green Peas in X-Rays
Ehle, M.; Svoboda, J.; Orlitová, I. +1 more
Green Peas represent a population of compact, highly star-forming dwarf galaxies at redshifts z ∼ 0.2-0.3 that have recently been found to show signatures of ultraviolet ionizing radiation leakage. They are being considered as analogs to high-redshift star-forming galaxies, possibly responsible for cosmic reionization. Despite intensive studies of…