Search Publications
Evidence of Thermal Conduction Suppression in a Solar Flaring Loop by Coronal Seismology of Slow-mode Waves
Sun, Xudong; Ofman, Leon; Davila, Joseph M. +2 more
Analysis of a longitudinal wave event observed by the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory is presented. A time sequence of 131 Å images reveals that a C-class flare occurred at one footpoint of a large loop and triggered an intensity disturbance (enhancement) propagating along it. The spatial features and temp…
The Lyα Line Profiles of Ultraluminous Infrared Galaxies: Fast Winds and Lyman Continuum Leakage
Martin, Crystal L.; Henry, Alaina; Danforth, Charles W. +3 more
We present new Hubble Space Telescope Cosmic Origins Spectrograph far-ultraviolet (far-UV) spectroscopy and Keck Echellete optical spectroscopy of 11 ultraluminous infrared galaxies (ULIRGs), a rare population of local galaxies experiencing massive gas inflows, extreme starbursts, and prominent outflows. We detect Lyα emission from eight ULIRGs an…
Metal Deficiency in Cluster Star-Forming Galaxies At Z = 2
Daddi, E.; Bournaud, F.; Juneau, S. +8 more
We investigate the environmental effect on the metal enrichment of star-forming galaxies (SFGs) in the farthest spectroscopically confirmed and X-ray-detected cluster, CL J1449+0856 at z = 1.99. We combined Hubble Space Telescope/WFC3 G141 slitless spectroscopic data, our thirteen-band photometry, and a recent Subaru/Multi-object InfraRed Camera a…
Structure and Formation of cD Galaxies: NGC 6166 in ABELL 2199
Kormendy, John; Bender, Ralf; Fisher, David B. +1 more
Hobby-Eberly Telescope (HET) spectroscopy is used to measure the velocity dispersion profile of the nearest prototypical cD galaxy, NGC 6166 in the cluster Abell 2199. We also present composite surface photometry from many telescopes. We confirm the defining feature of a cD galaxy; i.e., (we suggest), a halo of stars that fills the cluster center …
Quasi-periodic Pulsations in Solar and Stellar Flares: Re-evaluating their Nature in the Context of Power-law Flare Fourier Spectra
Dominique, M.; Ireland, J.; Inglis, A. R.
The nature of quasi-periodic pulsations (QPPs) in solar and stellar flares remains debated. Recent work has shown that power-law-like Fourier power spectra are an intrinsic property of solar and stellar flare signals, a property that many previous studies of this phenomenon have not accounted for. Hence a re-evaluation of the existing interpretati…
On the 2012 October 23 Circular Ribbon Flare: Emission Features and Magnetic Topology
Ding, M. D.; Yang, Kai; Guo, Yang
Circular ribbon flares are usually related to spine-fan type magnetic topology containing null points. In this paper, we investigate an X-class circular ribbon flare on 2012 October 23, using the multiwavelength data from the Solar Dynamics Observatory, Hinode, and RHESSI. In Ca ii H emission, the flare showed three ribbons with two highly elongat…
A NuSTAR Survey of Nearby Ultraluminous Infrared Galaxies
Hailey, Charles J.; Alexander, D. M.; Koss, Michael +17 more
We present a Nuclear Spectroscopic Telescope Array (NuSTAR), Chandra, and XMM-Newton survey of nine of the nearest ultraluminous infrared galaxies (ULIRGs). The unprecedented sensitivity of NuSTAR at energies above 10 keV enables spectral modeling with far better precision than was previously possible. Six of the nine sources observed were detecte…
The Interaction of Venus-like, M-dwarf Planets with the Stellar Wind of Their Host Star
Gombosi, T. I.; Drake, J. J.; Glocer, A. +4 more
We study the interaction between the atmospheres of Venus-like, non-magnetized exoplanets orbiting an M-dwarf star, and the stellar wind using a multi-species MHD model. We focus our investigation on the effect of enhanced stellar wind and enhanced EUV flux as the planetary distance from the star decreases. Our simulations reveal different topolog…
A Coordinated X-Ray and Optical Campaign of the Nearest Massive Eclipsing Binary, δ Orionis Aa. IV. A Multiwavelength, Non-LTE Spectroscopic Analysis
Corcoran, M. F.; Hamann, W. -R.; Nazé, Y. +13 more
Eclipsing systems of massive stars allow one to explore the properties of their components in great detail. We perform a multi-wavelength, non-LTE analysis of the three components of the massive multiple system δ Ori A, focusing on the fundamental stellar properties, stellar winds, and X-ray characteristics of the system. The primary’s distance-in…
The Optically Unbiased GRB Host (TOUGH) Survey. VII. The Host Galaxy Luminosity Function: Probing the Relationship between GRBs and Star Formation to Redshift ∼ 6
Milvang-Jensen, B.; Fynbo, J. P. U.; Krühler, T. +12 more
Gamma-ray bursts (GRBs) offer a route to characterizing star-forming galaxies and quantifying high-z star formation that is distinct from the approach of traditional galaxy surveys: GRB selection is independent of dust and probes even the faintest galaxies which can evade detection in flux-limited surveys. However, the exact relation between the G…