Search Publications
The sizes and kinematic structure of absorption systems towards the lensed quasar APM08279+5255
Petitjean, P.; Pettini, M.; Lewis, G. F. +4 more
We have obtained spatially resolved spectra of the z_em=3.911 triply imaged QSO APM08279+5255 using the Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space Telescope (HST). We study the line of sight equivalent width (EW) differences and velocity shear of high and low ionization absorbers (including a damped Lyman alpha [DLA] sys…
A Synoptic X-Ray Study of M31 with the Chandra High Resolution Camera
Williams, Benjamin F.; Kong, Albert K. H.; King, A. R. +4 more
We have obtained 17 epochs of Chandra High Resolution Camera (HRC) snapshot images, each covering most of the M31 disk. The data cover a total baseline of ~2.5 yr and contain a mean effective exposure of 17 ks. We have measured the mean fluxes and long-term light curves for 166 objects detected in these data. At least 25% of the sources show signi…
External and Internal Reconnection in Two Filament-Carrying Magnetic Cavity Solar Eruptions
Moore, Ronald L.; Sterling, Alphonse C.
We observe two near-limb solar filament eruptions, one of 2000 February 26 and the other of 2002 January 4. For both we use 195 Å Fe XII images from the Extreme-Ultraviolet Imaging Telescope (EIT) and magnetograms from the Michelson Doppler Imager (MDI), both of which are on the Solar and Heliospheric Observatory (SOHO). For the earlier event we a…
Multipoint investigation of the source region of storm-time chorus
Santolík, O.; Gurnett, D.; Pickett, J.
Available from http://www.copernicus.org/site/EGU/annales/22/7/2555.htm?FrameEngine=false;
Near-Infrared Observations at 1.56 Microns of the 2003 October 29 X10 White-Light Flare
Xu, Yan; Cao, Wenda; Liu, Chang +5 more
We present high-resolution observations of an X10 white-light flare in solar NOAA Active Region 10486 obtained with the Dunn Solar Telescope (DST) at the National Solar Observatory/Sacramento Peak on 2003 October 29. Our investigation focuses on flare dynamics observed in the near-infrared (NIR) continuum at 1.56 µm. This is the first report…
The isolated neutron star X-ray pulsars RX J0420.0-5022 and RX J0806.4-4123 : New X-ray and optical observations
Haberl, F.; Motch, C.; Gänsicke, B. T. +6 more
We report on the analysis of new X-ray data obtained with XMM-Newton and Chandra from two ROSAT-discovered X-ray dim isolated neutron stars (XDINs).
An 850 Micron SCUBA Survey of the Hubble Deep Field-North GOODS Region
Wang, W. -H.; Barger, A. J.; Cowie, L. L.
The Hubble Deep Field-North (HDF-N) is one of the best-studied extragalactic fields, and ultradeep optical, radio, X-ray, and mid-infrared wide-field images are available for this area. Here we present an 850 µm survey around the HDF-N, covering most of the area imaged by the Advanced Camera for Surveys as a part of the Great Observatories O…
X-ray source populations in the Galactic plane
Warwick, R. S.; Watson, M. G.; Helfand, D. J. +1 more
We present the first results from the XMM-Newton Galactic Plane Survey (XGPS). In the first phase of the programme, 22 pointings were used to cover a region of approximately 3 deg2 between 19° and 22° in Galactic longitude and +/-0.6° in latitude. In total we have resolved over 400 point X-ray sources, at >= 5σ significance, down to …
Relativistic spectral features from X-ray-illuminated spots and the measure of the black hole mass in active galactic nuclei
Bianchi, S.; Guainazzi, M.; Matt, G. +2 more
Narrow spectral features in the 5-6 keV range were recently discovered in the X-ray spectra of a few active galactic nuclei. We discuss the possibility that these features are due to localized spots which occur on the surface of an accretion disc following its illumination by flares. We present detailed line profiles as a function of orbital phase…
Metals and Dust in Intermediate-Redshift Damped Lyα Galaxies
York, Donald G.; Kulkarni, Varsha P.; Lauroesch, James T. +3 more
We report on spectroscopic observations with the Multiple Mirror Telescope for 11 damped Lyα absorbers (DLAs) or strong DLA candidates at 0.1<z<1.5, including several absorbers discovered in the Sloan Digital Sky Survey. In particular, we have measured absorption lines of Zn II, Cr II, Ni II, Fe II, Mn II, Ti II, Ca II, and Si II. These meas…