Search Publications
Moving Magnetic Features in and out of Penumbral Filaments
Ravindra, B.
A time sequence of high-resolution SOHO/MDI magnetograms, Dopplergrams, and continuum images is used to study the moving magnetic features (MMFs) in and out of penumbral filaments. Precursors of MMFs have been observed inside the penumbral filaments. One hundred and fifteen out of 127 well-observed individual MMFs in the moat of two sunspots have …
Halo Structures of Gravitational Lens Galaxies
Kochanek, Christopher S.; Falco, Emilio E.; Yoo, Jaiyul +1 more
We explore the halo structure of four gravitational lenses with well-observed, thin Einstein rings. We find that the gravitational potentials are well described by ellipsoidal density distributions in the sense that the best-fit nonellipsoidal models have parameters consistent with their ellipsoidal counterparts. We find upper limits on the standa…
High Spatial Resolution T-ReCS Mid-Infrared Imaging of Luminous Infrared Galaxies
Colina, Luis; Rieke, George H.; Alonso-Herrero, Almudena +4 more
We present diffraction-limited (FWHM~0.3") Gemini/T-ReCS mid-infrared (MIR; N-band or narrowband at 8.7 µm) imaging of four luminous infrared galaxies (LIRGs) drawn from a representative local sample. The MIR emission in the central few kiloparsecs is strikingly similar to that traced by Paα and generally consists of bright nuclear emission …
A Massive Bipolar Outflow and a Dusty Torus with Large Grains in the Preplanetary Nebula IRAS 22036+5306
Sahai, R.; Sánchez Contreras, C.; Patel, N. A. +2 more
We report high angular resolution (~1") CO J=3-2 interferometric mapping using the Submillimeter Array (SMA) of IRAS 22036+5306 (I22036), a bipolar preplanetary nebula (PPN) with knotty jets discovered in our HST snapshot survey of young PPNs. In addition, we have obtained supporting lower resolution (~10") CO and 13CO J=1-0 observation…
A strong vortex in Saturn's South Pole
Hueso, R.; Sánchez-Lavega, A.; Rojas, J. F. +1 more
Saturn's southern pole was observed at high resolution by the Cassini Imaging Science Subsystem (ISS) during the spacecraft insertion orbit in July 2004. Cloud tracking of individual features on images taken at a wavelength of 938 nm reveal the existence of a strong polar vortex enclosed by a jet with maximum speed of 160±10 ms relative to System …
The nuclear regions of NGC 7582 from [Ne II] spectroscopy at 12.8 µm - an estimate of the black hole mass
Siebenmorgen, R.; Wold, M.; Lacy, M. +1 more
We present a high-resolution (R≈16 000) spectrum and a narrow-band image centered on the [Ne II]12.8 µm line of the central kpc region of the starburst/Seyfert 2 galaxy
Enceladus: Cosmic Gymnast, Volatile Miniworld
Kargel, Jeffrey S.
The exploration of Saturn by the Cassini/Huygens mission has yielded a rich collection of data about the planet and its rings and moons, in particular its small satellite Enceladus and giant satellite Titan. Once believed too small to be active, Enceladus has been found to be one of the most geologically dynamic objects in the solar system. Among …
Flux Rope Model of the 2003 October 28-30 Coronal Mass Ejection and Interplanetary Coronal Mass Ejection
Chen, J.; Yurchyshyn, V. B.; Skoug, R. M. +2 more
A numerical model of an erupting solar flux rope is shown to reproduce both quantitative near-Sun properties of the 2003 October 28 coronal mass ejection and the timing, strength, and orientation of the fields measured in situ at 1 AU. Using a simple erupting flux rope model, we determine the best-fit parameters for this event. Our analysis shows …
New Dust Belts of Uranus: One Ring, Two Ring, Red Ring, Blue Ring
de Pater, Imke; Showalter, Mark R.; Hammel, Heidi B. +1 more
We compared near-infrared observations of the recently discovered outer rings of Uranus with Hubble Space Telescope results. We find that the inner ring, R/2003 U 2, is red, whereas the outer ring, R/2003 U 1, is very blue. Blue is an unusual color for rings; Saturn's enigmatic E ring is the only other known example. By analogy to the E ring, R/20…
XMM-Newton observation of the Be/neutron star system RX J0146.9+6121: a soft X-ray excess in a low luminosity accreting pulsar
Mereghetti, S.; La Palombara, N.
We report on the XMM-Newton observation of the Be/neutron star X-ray binary system RX J0146.9+6121, a long period (~23 m) pulsar in the NGC 663 open cluster. The X-ray luminosity decreased by a factor of two compared to the last observation carried out in 1998, reaching a level of ∼1×1034 erg s-1, the lowest ever observed in …