Search Publications
The deuterium abundance in the z= 0.7 absorber towards QSO PG1718+4807
Webb, J. K.; Carswell, R. F.; Lanzetta, K. M. +1 more
We report on a further analysis of the ratio of deuterium to hydrogen (D/H) using Hubble Space Telescope (HST) spectra of the z= 0.701 Lyman limit system towards the quasi-stellar object (QSO) PG1718+481. Initial analyses of this absorber found it gave a high D/H value, 1.8-3.1 × 10-4, inconsistent with several higher redshift measureme…
HST and UKIRT imaging observations of z~ 1 6C radio galaxies - I. The data
Eales, S.; Rawlings, S.; Röttgering, H. J. A. +3 more
The results of Hubble Space Telescope and UKIRT imaging observations are presented for a sample of 11 6C radio galaxies with redshifts 0.85 < z < 1.5. The observations of the 6C sources reveal a variety of different features, similar to those observed around the higher power 3CR sources of similar redshifts. However, the extent and luminosit…
A triple nucleus in the brightest cluster galaxy in Abell 193
Seigar, Marc S.; Lynam, Paul D.; Chorney, Nicole E.
We present a ground-based, near-infrared, K-band image and a Hubble Space Telescope (HST) WFPC2 image of the brightest cluster galaxy in Abell 193 (IC 1695). This object was selected as the central cluster galaxy using X-ray information. Both images reveal a triple nucleus structure. Previously, this galaxy was thought to have only two nuclei. We …
The warm absorber of the type 1 Seyfert galaxy H1419+480
Barcons, X.; Carrera, F. J.; Ceballos, M. T.
The bright type 1 Seyfert galaxy H1419+480 (z~ 0.072), whose X-ray colours from earlier HEAO-1 and ROSAT missions suggested a complex X-ray spectrum, has been observed with XMM-Newton. The EPIC spectrum above 2 keV is well fitted by a power law with photon index Γ= 1.84 +/- 0.01 and an Fe Kα line of equivalent width ~250 eV. At softer energies, a …
Balmer absorption variability and the disc wind of V592 Cassiopeiae
Prinja, R. K.; Wagner, R. M.; Howell, S. B. +1 more
We present results from time-series optical spectroscopy of the low-inclination, nova-like cataclysmic variable, V592 Cas. The data span the wavelength range from ~4000 to 5000 Å, and include Balmer lines (Hβ to Hɛ) as well as He I and He II. The Balmer lines are generally characterized by shallow absorption troughs with superimposed narrower cent…
Spectral response of the pulsationally induced shocks in the atmosphere of BW Vulpeculae
Smith, Myron A.; Jeffery, C. Simon
BW Vulpeculae (BW Vul) is remarkable for exciting an extremely strong radial pulsation mode which grows through its outer envelope and forms visible shock features in the atmosphere. Material propelled upwards by the shock returns violently to the lower photosphere where it creates a second shock just before the start of the next cycle. We have ob…
HST/WFPC2 snapshot imaging of symbiotic stars
Eyres, S. P. S.; Bode, M. F.; Brocksopp, C.
The results of a HST/WFPC2 snapshot imaging survey of selected symbiotic stars in 1999/2000 are presented. Seven sources - HD 149427 (PC 11), PU Vul, RT Ser, He2-104 (Southern Crab), V1329 Cyg (HBV 475), V417 Cen and AS 201 - were observed in filters F218W (ultraviolet continuum), F502N ([O III]λλ 4959, 5007) and F656N (Hαλ 6563); an eighth source…
XMM-Newton observations of an absorbed z= 0.67 QSO: no dusty torus?
Georgakakis, A.; Georgantopoulos, I.; Griffiths, R. E. +4 more
We present XMM-Newton observations of AX J0341.4-4453, a mildly reddened AV < 7 quasi-stellar object (QSO) at a redshift of z= 0.672. The XMM-Newton spectrum shows a large obscuring column NH~ 1023 cm-2 corresponding to AV~ 70, in agreement with previous results based on the lower limit of …
A search for X-ray variability in the open cluster NGC 2516
Ramsay, Gavin; Harra, Louise; Kay, Hilary
We present the results of a search for X-ray variability in the Galactic open cluster NGC 2516. This cluster has been observed on eight occasions using XMM-Newton, making it an excellent target for such a study. We find four sources that show significant variability, implying the detection of one significantly variable source every 25 ks. All sour…
A study of velocity fields in the transition region of ɛ Eri (K2 V)
Jordan, C.; Sim, S. A.
Analyses of the widths and shifts of optically thin emission lines in the ultraviolet spectrum of the active dwarf ɛ Eri (K2 V) are presented. The spectra were obtained using the Space Telescope Imaging Spectrograph on the Hubble Space Telescope and the Far Ultraviolet Spectroscopic Explorer. The linewidths are used to find the non-thermal energy …