Search Publications
Hubble and Spitzer Space Telescope Observations of the Debris Disk around the nearby K Dwarf HD 92945
Bryden, G.; Stapelfeldt, K. R.; Ford, H. C. +9 more
We present the first resolved images of the debris disk around the nearby K dwarf HD 92945, obtained with the Hubble Space Telescope's (HST 's) Advanced Camera for Surveys. Our F606W (Broad V) and F814W (Broad I) coronagraphic images reveal an inclined, axisymmetric disk consisting of an inner ring about 2farcs0-3farcs0 (43-65 AU) from the star an…
Hinode Observations Suggesting the Presence of a Local Small-scale Turbulent Dynamo
Lites, B. W.
Analysis of observations from the Hinode/Solar Optical Telescope spectropolarimeter (SP) yields results that are consistent with the operation of a small-scale turbulent dynamo in the upper solar convection zone. Examination of 45 Hinode data sets obtained in 2007 reveals only a very small correlation of the net polarity imbalance of the regions o…
Investigation of intermittency and generalized self-similarity of turbulent boundary layers in laboratory and magnetospheric plasmas: towards a quantitative definition of plasma transport features
Zelenyi, Lev M.; Budaev, V. P.; Savin, Sergei P.
A comparative analysis of the fundamental properties of fluctuations in the vicinity of boundaries in fusion plasmas and in plasmas of magnetospheric turbulent boundary layers (TBLs) shows the similarity of their basic statistical characteristics, including the scaling of the structure functions and mutifractal parameters. Important features obser…
A Cold, Tenuous Solar Flare: Acceleration Without Heating
Kontar, Eduard P.; Fleishman, Gregory D.; Nita, Gelu M. +1 more
We report the observation of an unusual cold, tenuous solar flare, which reveals itself via numerous and prominent non-thermal manifestations, while lacking any noticeable thermal emission signature. RHESSI hard X-rays and 0.1-18 GHz radio data from OVSA and Phoenix-2 show copious electron acceleration (1035 electrons s-1 abo…
An extended XMM-Newton observation of the Seyfert galaxy NGC 4051 - I. Evidence for a shocked outflow
Vaughan, S.; Pounds, K. A.
An extended XMM-Newton observation of the Seyfert 1 galaxy NGC 4051 has revealed a rich absorption line spectrum indicating the presence of a photoionized outflow with a wide range of velocities and ionization parameter. At low continuum fluxes an emission line spectrum is well defined with both narrow and broad emission components of several abun…
A View of the Narrow-line Region in the Infrared: Active Galactic Nuclei with Resolved Fine-structure Lines in the Spitzer Archive
Elbaz, D.; Sturm, E.; Armus, L. +5 more
We queried the Spitzer archive for high-resolution observations with the Infrared Spectrograph of optically selected active galactic nuclei (AGNs) for the purpose of identifying sources with resolved fine-structure lines that would enable studies of the narrow-line region (NLR) at mid-infrared wavelengths. By combining 298 Spitzer spectra with 6 I…
Evolution of Brightest Cluster Galaxy Structural Parameters in the Last ~6 Gyr: Feedback Processes Versus Merger Events
Cava, A.; Varela, J.; Moles, M. +4 more
We present results on the evolution of the structural parameters of two samples of brightest cluster galaxies (BCGs) in the last 6 Gyr. The nearby sample of BCGs consists of 69 galaxies from the WINGS survey spanning a redshift range of 0.04 < z < 0.07. The intermediate-redshift (0.3 < z < 0.6) sample is formed by 20 BCGs extracted fro…
GOODS-Herschel: the impact of galaxy-galaxy interactions on the far-infrared properties of galaxies
Magnelli, B.; Altieri, B.; Aussel, H. +15 more
Aims: We study the impact of galaxy-galaxy interactions on the far-infrared properties of galaxies and its evolution at 0 < z < 1.2.
Methods: Using the high-z galaxies in the fields of Great Observatories Origins Deep Survey (GOODS) observed by the Herschel Space Observatory in the framework of the GOODS-Herschel key program and th…
Characterization of Seven Ultra-wide Trans-Neptunian Binaries
Kavelaars, J. J.; Petit, Jean-Marc; Jones, Lynne +3 more
The low-inclination component of the Classical Kuiper Belt is host to a population of extremely widely separated binaries. These systems are similar to other trans-Neptunian binaries (TNBs) in that the primary and secondary components of each system are of roughly equal size. We have performed an astrometric monitoring campaign of a sample of seve…
Ordered magnetic fields around radio galaxies: evidence for interaction with the environment
Guidetti, D.; Parma, P.; Laing, R. A. +2 more
We present detailed imaging of Faraday rotation and depolarization for the radio galaxies 0206+35, 3C 270, 3C 353 and M 84, based on Very Large Array observations at multiple frequencies in the range 1365 to 8440 MHz. All of the sources show highly anisotropic banded rotation measure (RM) structures with contours of constant RM perpendicular to th…