Search Publications
Detecting Outflows from Cataclysmic Variables in the Optical
Honeycutt, R. K.; Kafka, S.
Cataclysmic variables (CVs) often show evidence of bipolar winds that carry away mass and angular momentum, likely affecting the evolution of the system. For the most part, it has only been possible to study such winds by means of the P Cygni profiles seen in space-UV resonance lines. We demonstrate that optical P Cygni profiles in two He I lines …
XMM-Newton observations of seven soft X-ray excess quasi-stellar objects
Schartel, N.; O'Brien, P. T.; Page, K. L. +1 more
XMM-Newton observations of seven quasi-stellar objects (QSOs) are presented and the EPIC spectra analysed. Five of the active galactic nuclei (AGN) show evidence for Fe Kα emission, with three being slightly better fitted by lines of finite width; at the 99 per cent level they are consistent with being intrinsically narrow, though. The broad-band …
An XMM-Newton Observation of the Seyfert 1 Galaxy 1H 0419-577 in an Extreme Low State
O'Brien, P. T.; Reeves, J. N.; Page, K. L. +1 more
Previous observations of the luminous Seyfert 1 galaxy 1H 0419-577 have found its X-ray spectrum to range from that of a typical Seyfert 1 galaxy with a 2-10 keV power-law index of Γ~1.9 to a much flatter power law of Γ~1.5 or less. We report here a new XMM-Newton observation that allows the low-state spectrum to be studied in much greater detail …
XMM-Newton observations of the ultraluminous nuclear X-ray source in M 33
Rodriguez, J.; Foschini, L.; Ho, L. C. +5 more
We present observations with XMM-Newton of M 33 X-8, the ultraluminous X-ray source (L0.5-10 keV ≈ 2× 1039 erg/s) closest to the centre of the galaxy. The best-fit model is similar to the typical model of Galactic black holes in very high state. Comparison with previous observations indicates that the source is still in a ver…
Dust and Ionized Gas in Nine Nearby Early-Type Galaxies Imaged with the Hubble Space Telescope Advanced Camera for Surveys
Ford, H. C.; Menanteau, F.; Illingworth, G. D. +6 more
We present V and I continuum images and Hα+[N II] maps of nine early-type galaxies observed with the Wide Field Channel of the Advanced Camera for Surveys on the Hubble Space Telescope. Dust and ionized gas are detected in all galaxies. The optical nebulae are primarily concentrated on the nuclei and extend out to radii of a few hundred parsecs in…
Optical Spectroscopy of K-Selected Extremely Red Galaxies
Soifer, B. T.; Yan, Lin; Thompson, David
We have obtained spectroscopic redshifts for 24 sources from a sample of bright, K-selected extremely red objects (EROs) using the Keck I Telescope. These EROs have high-resolution morphologies from the Hubble Space Telescope and were selected with a median Ks magnitude of 18.7 and F814W-Ks>4 mag (Yan & Thompson 2003).…
Detection of the southern counterpart of the Jovian northern polar cusp: Shared properties
Prangé, Renée; Pallier, Laurent
A transient auroral feature in the northern (N) polar region of Jupiter, referred to as an `auroral flare' [Waite et al., 2001], or as the N polar cusp [Pallier and Prangé, 2001], strangely seemed to lack any southern (S) counterpart. Here, using a new HST/STIS dataset, we find a similar bright spot in the south. We suggest that both features are …
Circumstellar dust shells of hot post-AGB stars
Parthasarathy, M.; Gauba, G.
Parameters of the circumstellar dust shells of 15 hot post-AGB stars have been derived using a radiative transfer code (DUSTY). Combining the optical, near and far-infrared (ISO, IRAS) data of the stars, we have reconstructed their spectral energy distributions (SEDs) and estimated the dust temperatures, mass loss rates, angular radii of the inner…
XMM-Newton observations of 3C 273
Done, C.; O'Brien, P. T.; Reeves, J. N. +4 more
A series of nine XMM-Newton observations of the radio-loud quasar 3C 273 are presented, concentrating mainly on the soft excess. Although most of the individual observations do not show evidence for iron emission, co-adding them reveals a weak, broad line (EW ~56 eV). The soft excess component is found to vary, confirming previous work, and can be…
A comparison of wave mode identification techniques
Belmont, G.; André, M.; Sahraoui, F. +6 more
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