Search Publications
Re-flaring of a Post-flare Loop System Driven by Flux Rope Emergence and Twisting
Cheng, X.; Ding, M. D.; Zhang, J. +3 more
In this Letter, we study in detail the evolution of the post-flare loops on 2005 January 15 that occurred between two consecutive solar eruption events, both of which generated a fast halo coronal mass ejection (CME) and a major flare. The post-flare loop system, formed after the first CME/flare eruption, evolved rapidly, as manifested by the unus…
The Complex Structure of the Multi-phase Galactic Wind in a Starburst Merger
Shih, Hsin-Yi; Rupke, David S. N.
Neutral outflows have been detected in many ultraluminous infrared galaxies (ULIRGs) via the Na I D λλ5890, 5896 absorption-line doublet. For the first time, we have mapped and analyzed the two-dimensional kinematics of a cool neutral outflow in a ULIRG, F10565+2448, using the integral field unit on Gemini North to observe the Na I D feature. At t…
Adaptive Optics Observations of B0128+437: A Low-mass, High-redshift Gravitational Lens
Lagattuta, David J.; Fassnacht, Christopher D.; Auger, Matthew W.
We use high-resolution adaptive optics (AO) imaging on the Keck II telescope to study the gravitational lens B0128+437 in unprecedented detail, allowing us to resolve individual lensed quasar components and, for the first time, detect and measure properties of the lensing galaxy. B0128+437 is a small-separation lens with known flux-ratio and astro…
A Tentative Identification of HCN Ice on Triton
Nakamura, R.; Burgdorf, M.; Cruikshank, D. P. +5 more
Spectra of Triton between 1.8 and 5.5 µm, obtained in 2007 May and 2009 November, have been analyzed to determine the global surface composition. The spectra were acquired with the grism and the prism of the Infrared Camera on board AKARI with spectral resolutions of 135 and 22, respectively. The data from 4 to 5 µm are shown in this L…
Water Masers associated with Star Formation in the Antennae Galaxies
Darling, Jeremy; Johnson, Kelsey; Brogan, Crystal
We present Very Large Array (VLA) observations with 80 mas resolution (~9 pc) of the recently discovered Galactic-analog (GA)-H2O masers in the Antennae interacting galaxies (NGC 4038/NGC 4039; Arp244). Three regions of water maser emission are detected: two in the "interaction region" (IAR) and the third ~5farcs6 (gsim600 pc) west of t…
Trans-Neptunian Objects with Hubble Space Telescope ACS/WFC
Fuentes, Cesar I.; Holman, Matthew J.; Trilling, David E. +1 more
We introduce a novel search technique that can identify trans-Neptunian objects in three to five exposures of a pointing within a single Hubble Space Telescope (HST) orbit. The process is fast enough to allow the discovery of candidates soon after the data are available. This allows sufficient time to schedule follow-up observations with HST withi…
The Binary Fraction of the Young Cluster NGC 1818 in the Large Magellanic Cloud
de Grijs, Richard; Hu, Y.; Deng, L. +2 more
We use high-resolution Hubble Space Telescope imaging observations of the young (~15-25 Myr old) star cluster NGC 1818 in the Large Magellanic Cloud to derive an estimate for the binary fraction of F stars (1.3 < M sstarf/M sun < 1.6). This study provides the strongest constraints yet on the binary fraction in a young s…
The Redshifted Excess in Quasar C IV Broad Emission Lines
Punsly, Brian
In this paper, the Evans and Koratkar Atlas of Hubble Space Telescope Faint Object Spectrograph Spectra of Active Galactic Nuclei and Quasars is used to study the redward asymmetry in C IV broad emission lines (BELs). It is concluded that there is a highly significant correlation between the spectral index from 10 GHz to 1350 Å and the amount of e…
Comparison of a Global Magnetic Evolution Model with Observations of Coronal Mass Ejections
van Ballegooijen, A. A.; Nandy, Dibyendu; Yeates, A. R. +3 more
The relative importance of different initiation mechanisms for coronal mass ejections (CMEs) on the Sun is uncertain. One possible mechanism is the loss of equilibrium of coronal magnetic flux ropes formed gradually by large-scale surface motions. In this paper, the locations of flux rope ejections in a recently developed quasi-static global evolu…
Granular-scale Magnetic Flux Cancellations in the Photosphere
Kubo, M.; Lites, B. W.; Low, B. C.
We investigate the evolution of five granular-scale magnetic flux cancellations just outside the moat region of a sunspot by using accurate spectropolarimetric measurements and G-band images with the Solar Optical Telescope (SOT) aboard Hinode. The opposite-polarity magnetic elements approach a junction of the intergranular lanes and then collide …