Search Publications
UIR bands in the ISO SWS spectrum of the carbon star TU Tauri
Hony, S.; Tielens, A. G. G. M.; Boersma, C.
Polycyclic Aromatic Hydrocarbon (PAH) molecules are thought to form in the ejecta of carbon-rich Asymptotic Giant Branch (AGB) stars. Fifty ISO SWS spectra of warm carbon-rich AGB stars have been investigated for the Unidentified IR (UIR) emission due to fluorescence by PAH molecules. In this sample the binary star TU Tau, which has a blue compani…
Near-infrared imaging polarimetry of dusty young stars
Barlow, M. J.; Gledhill, T. M.; Lowe, K. T. E. +1 more
We have carried out JHK polarimetric observations of 11 dusty young stars, by using the polarimeter module IRPOL2 with the near-infrared camera UIST on the 3.8-m United Kingdom Infrared Telescope (UKIRT). Our sample targeted systems for which UKIRT-resolvable discs had been predicted by model fits to their spectral energy distributions. Our observ…
Photometric Identification of Type Ia Supernovae at Moderate Redshift
Johnson, Benjamin D.; Crotts, Arlin P. S.
Large photometric surveys with the aim of identifying many Type Ia supernovae (SNe) at moderate redshift are challenged in separating these SNe from other SN types. We are motivated to identify Type Ia SNe based only on broadband photometric information, since spectroscopic determination of the SN type, the traditional method, requires significant…
Oxygen Abundances in the Milky Way Using X-Ray Absorption Measurements toward Galaxy Clusters
Mushotzky, R. F.; Baumgartner, W. H.
We present measurements of the oxygen abundance of the Milky Way's ISM by observing the K-shell X-ray photoionization edge toward galaxy clusters. This effect is most easily observed toward objects with Galactic columns (nH) of a few times 1021 cm-2. We measure X-ray column densities toward 11 clusters and find tha…
Evidence for colliding winds in WR 25 from XMM-Newton observations of X-ray variability
Corcoran, M. F.; Pollock, A. M. T.
The Wolf-Rayet star WR 25 in the Carina Nebula is a surprisingly bright X-ray source, and amongst the brightest WR stars in X-rays. It is a suspected binary star, though its binary nature has been a matter of controversy. We report here observations of WR 25 from the XMM-Newton archive which showed an increase in X-ray luminosity of more than a fa…
Coronal Emission Measures and Abundances for Moderately Active K Dwarfs Observed by Chandra
Wood, Brian E.; Linsky, Jeffrey L.
We have used Chandra to resolve the nearby 70 Oph (K0 V+K5 V) and 36 Oph (K1 V+K1 V) binary systems for the first time in X-rays. The LETG/HRC-S spectra of all four of these stars are presented and compared with an archival LETG spectrum of another moderately active K dwarf, ɛ Eri. Coronal densities are estimated from O VII line ratios and emissio…
Venus before Venus Express
Taylor, Fredric W.
An overview is given of current knowledge and mysteries about the planet Venus, with emphasis on those aspects that are intended to be studied with the Venus Express mission following orbit insertion at the planet in March 2006.
Chemical Enrichment of the Complex Hot ISM of the Antennae Galaxies. II. Physical Properties of the Hot Gas and Supernova Feedback
Zezas, A.; Raymond, J. C.; King, A. R. +5 more
We investigate the physical properties of the interstellar medium (ISM) in the merging pair of galaxies known as the Antennae (NGC 4038/4039), using the deep co-added ~411 ks Chandra ACIS-S data set. The method of analysis and some of the main results from the spectral analysis, such as metal abundances and their variations from ~0.2 to ~20-30 tim…
The Magnetic Field Strength in the Wall of the Local Bubble toward l, b ~ 300°, 0°
Andersson, B. -G.; Potter, S. B.
We present polarization measurements in the region around l, b = 300°, 0°, toward stars with well-determined distances, primarily in the range 40-200 pc. We argue that these observations trace polarization caused by dust in the wall of the Local Bubble (LB). Using a Chandrasekhar-Fermi analysis, we derive a plane-of-the-sky magnetic field strength…
Chandra and Hubble Space Telescope Study of the Globular Cluster NGC 288
Anderson, Scott F.; Kong, Albert K. H.; Verbunt, Frank +5 more
We report on the Chandra X-Ray Observatory observations of the globular cluster NGC 288. We detect four X-ray sources within the core radius and seven additional sources within the half-mass radius down to a limiting luminosity of LX=7×1030 ergs s-1 (assuming cluster membership) in the 0.3-7 keV band. We also obser…