Search Publications
The energy balance of polars revisited
Cropper, Mark; Ramsay, Gavin
In the EXOSAT and ROSAT eras, a significant number of polars were found to show a soft/hard X-ray ratio much greater than that expected from the standard accretion shock model. This was known as the `soft X-ray excess'. We have made an snapshot survey of polars using XMM-Newton and determined their soft/hard ratios. We find that less than one in f…
Reconstruction of two-dimensional magnetopause structures from Cluster observations: verification of method
Balogh, A.; Dandouras, I.; Lavraud, B. +7 more
Available from http://www.copernicus.org/site/EGU/annales/22/4/1251.htm?FrameEngine=false;
The Possible Detection of Cosmological Reionization Sources
Panagia, N.; Fall, S. Michael; Stiavelli, M.
We compare the available catalogs of z~6 galaxies in the Hubble Ultra- Deep Field and in the Great Observatories Origins Deep Survey with the expected properties of the sources of cosmological reionization from our previous theoretical study. Our approach is based on the mean surface brightness of the sources required for reionization and depends …
Relativistic O VIII Emission and Ionized Outflow in NGC 4051 Measured with XMM-Newton
Page, M. J.; Mason, K. O.; Cordova, F. A. +4 more
We present XMM-Newton Reflection Grating Spectrometer observations of the soft X-ray spectrum of NGC 4051 and explore their implications for the inner accretion disk and ionized outflow in the active galactic nucleus. We fit the soft X-ray excess with a relativistically broadened O VIII recombination spectrum, including the entire line series and …
Modeling an X-ray flare on Proxima Centauri: Evidence of two flaring loop components and of two heating mechanisms at work
Audard, M.; Güdel, M.; Peres, G. +1 more
We model in detail a flare observed on Proxima Centauri with the EPIC-PN on board XMM-Newton at high statistics and high time resolution and coverage. Time-dependent hydrodynamic loop modeling is used to describe the rise and peak of the light curve, and a large fraction of the decay, including its change of slope and a secondary maximum, over mor…
Ionized gas kinematics and massive star formation in NGC 1530
Knapen, J. H.; Relaño, M.; Beckman, J. E. +1 more
We present emission line mapping of the strongly barred galaxy NGC 1530 obtained using Fabry-Pérot interferometry in H\alpha, at significantly enhanced angular resolution compared with previously published studies. The main point of the work is to examine in detail the non-circular components of the velocity field of the gas, presumably induced by…
Testing Radiatively Inefficient Accretion Flow Theory: An XMM-Newton Observation of NGC 3998
Ptak, A.; Ho, L. C.; Terashima, Y. +1 more
We present the results of a 10 ks XMM-Newton observation of NGC 3998, a ``type I'' LINER galaxy (i.e., with significant broad Hα emission). Our goal is to test the extent to which radiatively inefficient accretion flow (RIAF) models and/or scaled-down active galactic nuclei (AGNs) models are consistent with the observed properties of NGC 3998. A p…
Resolving OB Systems in the Carina Nebula with the Hubble Space Telescope Fine Guidance Sensor
Gies, Douglas R.; Walborn, Nolan R.; Moffat, Anthony F. J. +4 more
We observed 23 OB stars in the Carina Nebula (NGC 3372) with the Hubble Space Telescope's Fine Guidance Sensor 1r (FGS1r) in its high angular resolution mode. Five of these OB stars are newly resolved binaries with projected separations ranging from 0.015" to 0.352" (37 to 880 AU at a distance of 2.5 kpc), and V-band magnitude differences ranging …
Cassini VIMS observations of the Galilean satellites including the VIMS calibration procedure
Sotin, C.; Brown, R. H.; Baines, K. H. +22 more
The Visual and Infrared Mapping Spectrometer (VIMS) observed the Galilean satellites during the Cassini spacecraft's 2000/2001 flyby of Jupiter, providing compositional and thermal information about their surfaces. The Cassini spacecraft approached the jovian system no closer than about 126 Jupiter radii, about 9 million kilometers, at a phase ang…
On the Determination of Michelson Doppler Imager High-Degree Mode Frequencies
Schou, J.; Korzennik, S. G.; Rabello-Soares, M. C.
The characteristics of the solar acoustic spectrum are such that mode lifetimes get shorter and spatial leaks get closer in frequency as the degree of a mode increases for a given order. A direct consequence of this property is that individual p-modes are resolved only at low and intermediate degrees and that at high degrees individual modes blend…