Search Publications
Numerical Simulations of the Magnetic Rayleigh-Taylor Instability in the Kippenhahn-Schlüter Prominence Model
Shibata, Kazunari; Isobe, Hiroaki; Hillier, Andrew +1 more
The launch of the Hinode satellite has allowed unprecedented high-resolution, stable images of solar quiescent prominences to be taken over extended periods of time. These new images led to the discovery of dark upflows that propagated from the base of prominences, developing highly turbulent profiles. As yet, how these flows are driven is not ful…
Solar X-ray Jets, Type-II Spicules, Granule-size Emerging Bipoles, and the Genesis of the Heliosphere
Cirtain, Jonathan W.; Moore, Ronald L.; Sterling, Alphonse C. +1 more
From Hinode observations of solar X-ray jets, Type-II spicules, and granule-size emerging bipolar magnetic fields in quiet regions and coronal holes, we advocate a scenario for powering coronal heating and the solar wind. In this scenario, Type-II spicules and Alfvén waves are generated by the granule-size emerging bipoles (EBs) in the manner of t…
A Study of Cepheids in M81 with the Large Binocular Telescope (Efficiently Calibrated with Hubble Space Telescope)
Kochanek, C. S.; Stanek, K. Z.; Prieto, J. L. +2 more
We identify and phase a sample of 107 Cepheids with 10 days < P < 100 days in M81 using the Large Binocular Telescope and calibrate their B, V, and I mean magnitudes with archival Hubble Space Telescope (HST) data. The use of a ground-based telescope to identify and phase the Cepheids and HST only for the final calibration reduces the demand…
Adaptive Optics Imaging of Quasi-stellar Objects with Double-peaked Narrow Lines: Are They Dual Active Galactic Nuclei?
Shields, G. A.; Rosario, D. J.; McGurk, R. C. +3 more
Active galaxies hosting two accreting and merging supermassive black holes (SMBHs)—dual active galactic nuclei (AGNs)—are predicted by many current and popular models of black-hole-galaxy co-evolution. We present here the results of a program that has identified a set of probable dual AGN candidates based on near-infrared laser guide star adaptive…
Electron Acceleration Associated with Solar Jets
Krucker, Säm; Lin, R. P.; Kontar, E. P. +2 more
This paper investigates the solar source region of supra-thermal (few keV up to the MeV range) electron beams observed near Earth by combining in situ measurements of the three-dimensional Plasma and Energetic Particles experiment on the WIND spacecraft with remote-sensing hard X-ray observations by the Reuven Ramaty High Energy Solar Spectroscopi…
Modeling the Dispersal of an Active Region: Quantifying Energy Input into the Corona
Green, L. M.; Mackay, Duncan H.; van Ballegooijen, Aad
In this paper, a new technique for modeling nonlinear force-free fields directly from line-of-sight magnetogram observations is presented. The technique uses sequences of magnetograms directly as lower boundary conditions to drive the evolution of coronal magnetic fields between successive force-free equilibria over long periods of time. It is ill…
The Supernova Impostor Impostor SN 1961V: Spitzer Shows That Zwicky Was Right (Again)
Kochanek, C. S.; Stanek, K. Z.; Szczygiel, D. M.
SN 1961V, one of Zwicky's defining Type V supernovae (SNe), was a peculiar transient in NGC 1058 that has variously been categorized as either a true core-collapse SN leaving a black hole (BH) or neutron star (NS) remnant, or an eruption of a luminous blue variable star. The former case is suggested by its possible association with a decaying non-…
The Effect of Environment on Shear in Strong Gravitational Lenses
Zabludoff, Ann I.; Keeton, Charles R.; Momcheva, Ivelina G. +2 more
Using new photometric and spectroscopic data in the fields of nine strong gravitational lenses that lie in galaxy groups, we analyze the effects of both the local group environment and line-of-sight (LOS) galaxies on the lens potential. We use Monte Carlo simulations to derive the shear directly from measurements of the complex lens environment, p…
L1157-B1: Water and Ammonia as Diagnostics of Shock Temperature
Codella, C.; Ceccarelli, C.; Caselli, P. +5 more
We investigate the origin and nature of the profiles of water and ammonia observed toward the L1157-B1 clump as part of the HIFI CHESS survey using a new code coupling a gas-grain chemical model with a parametric shock model. First results from the unbiased survey reveal different molecular components at different excitation conditions coexisting …
The Cluster Lensing and Supernova Survey with Hubble (CLASH): Strong-lensing Analysis of A383 from 16-band HST/WFC3/ACS Imaging
Infante, L.; Zheng, W.; Molino, A. +38 more
We examine the inner mass distribution of the relaxed galaxy cluster A383 (z = 0.189), in deep 16 band Hubble Space Telescope/ACS+WFC3 imaging taken as part of the Cluster Lensing And Supernova survey with Hubble (CLASH) multi-cycle treasury program. Our program is designed to study the dark matter distribution in 25 massive clusters, and balances…