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Integral Field Spectroscopy of the Extended Emission-Line Region of 3C 249.1
Fu, Hai; Stockton, Alan
We present Gemini Multiobject Spectrograph integral field spectroscopy of the extended emission-line region associated with quasar 3C 249.1. The kinematics of the ionized gas measured from the [O III] λ5007 line is rather complex and cannot be explained globally by a simple dynamical model, but some clouds can be modeled individually as having loc…
On the complex X-ray structure tracing the motion of Geminga
Caraveo, P. A.; Bignami, G. F.; de Luca, A. +2 more
A deep (100 ks) XMM-Newton observation of Geminga has shown two faint tails of diffuse X-ray emission, extending for ~2' behind the pulsar, well aligned with the proper motion (PM) direction. We report here on a recent ~20 ks Chandra observation, which unveils a new structure, ~25'' long and ~5'' thick, starting at the pulsar position and perfectl…
The Hyades Binary θ2 Tauri: Confronting Evolutionary Models with Optical Interferometry
Hajian, Arsen R.; Hummel, C. A.; Johnston, K. J. +5 more
We determine the masses and magnitude difference of the components of the Hyades spectroscopic binary θ2 Tauri. We find that both components appear to be less massive and/or brighter than predicted from some recent evolutionary models. The rapid rotation and unknown rotational inclination of both components introduce uncertainty in thei…
Searching for the sources responsible for cosmic reionization: Probing the redshift range 7 < z < 10 and beyond
Stark, Daniel P.; Ellis, Richard S.
We review recent observations that suggest that the global star formation rate density of UV-bright galaxies is declining monotonically with redshift over 3 < z < 7 and illustrate the challenges that a continuation of this decline poses in explaining the assembled stellar mass in several z ∼ 6 galaxies deduced from recent Spitzer data. A pla…
A Spectroscopic Observation of a Magnetic Reconnection Site in a Small Flaring Event
Hara, Hirohisa; Ichimoto, Kiyoshi; Delaboudinière, Jean-Pierre +1 more
We have observed two types of coronal bidirectional flows in a flare with a small energy release through a spectroscopic observation of the Fe X emission line at 6374 Å with a ground-based coronagraph at the Norikura Solar Observatory. We find a bidirectional flow of +/-3 km s-1 above the top of a flare loop. Remarkable increases of the…
Response of the mid-altitude cusp to rapid rotations of the IMF
Escoubet, C. P.; Pitout, F.; Fazakerley, A. N. +3 more
On 12 August 2003, the four Cluster spacecraft crossed the mid-altitude cusp one after the other a minute or two apart. Shortly after the cusp crossing, two of the Cluster observed three structures poleward of the cusp that appeared and grew in successive satellite passes. In these structures, high fluxes of low-energy magnetosheath-like ions and …
Comments on the amplitude-phase relationship of asteroid lightcurves. Effects of topography, surface scattering properties, and obliquity
Rodrigo, R.; Gutiérrez, P. J.; Ortiz, J. L. +2 more
Aims.We present a theoretical study on the amplitude-phase relationship (APR) for lightcurves of simulated asteroids.
Methods: .In support of the Rosetta (ESA) mission, we developed a numerical model for the investigation of the light reflectance properties of asteroidal bodies. The code is able to deal with irregular and chemically inhomogene…
Fast Segmentation of Solar Extreme Ultraviolet Images
De Wit, T. Dudok
A segmentation scheme for identifying large-scale structures (coronal holes, active regions, etc.) in solar extreme ultraviolet images, is presented. Unlike standard approaches, both the image intensity and the relative contribution of different wavelengths are used. Spectral information is important for compensating luminosity changes. The approa…
Unveiling the nature of the highly absorbed X-ray source SAX J1748.2-2808 with XMM-Newton
Mereghetti, S.; Parmar, A. N.; Sidoli, L. +2 more
We report on the results of an EPIC XMM-Newton observation of the faint source SAX J1748.2-2808 and the surrounding field. This source was discovered during the BeppoSAX Galactic center survey performed in 1997-1998. A spatial analysis resulted in the detection of 31 sources within the EPIC field of view. SAX J1748.2-2808 is clearly resolved into …
The Circumstellar Structure of the Class I Protostar TMC-1 (IRAS 04381+2540) from Hubble Space Telescope NICMOS Data
Terebey, Susan; Van Buren, David; Brundage, Michael +1 more
The class I protostar TMC-1 (IRAS 04381+2540) is oriented favorably for determining the properties of its circumstellar envelope and outflow cavity. Deep, high spatial resolution Hubble Space Telescope (HST) NICMOS images at 1.6 µm exhibit both a narrow jet and a wide-angle conical outflow cavity. Model images of the scattered-light distribu…