Search Publications
X-ray spectral evolution of the extragalactic Z source LMC X-2
Misra, R.; Agrawal, V. K.
We present the results obtained by a detailed study of the extragalactic Z source LMC X-2, using broad-band Suzaku data and a large (~750ks) data set obtained with the proportional counter array (PCA) onboard the Rossi X-ray Timing Experiment (RXTE). The PCA data allow the study of the complete spectral evolution along the horizontal, normal and f…
ISO observation of molecular hydrogen and fine-structure lines in the photodissociation region IC63
van Dishoeck, E. F.; Bell, T.; Viti, S. +2 more
We wish to constrain the main physical properties of the photodissociation region (PDR) IC63. We present the results of a survey for the lowest pure-rotational lines of H2 with the Short Wavelength Spectrometer and for the major fine-structure cooling lines of OI at 63 and 145µm and CII at 157.7µm with the Long Wavelength Sp…
High-speed knots in the hourglass-shaped planetary nebula Hubble 12
Pollacco, D.; López, J. A.; Rushton, A. P. +5 more
We present a detailed kinematical analysis of the young compact hourglass-shaped planetary nebula Hb 12. We performed optical imaging and long-slit spectroscopy of Hb 12 using the Manchester echelle spectrometer with the 2.1-m San Pedro Mártir telescope. We reveal, for the first time, the presence of end caps (or knots) aligned with the bipolar lo…
Peculiar nature of hard X-ray eclipse in SS433 from INTEGRAL observations
Sunyaev, R. A.; Postnov, K. A.; Cherepashchuk, A. M. +2 more
The analysis of hard X-ray INTEGRAL observations (2003-2008) of superaccreting Galactic microquasar SS433 at precessional phases of the source with the maximum disc opening angle is carried out. It is found that the shape and width of the primary X-ray eclipse are strongly variable, suggesting additional absorption in dense stellar wind and gas ou…
The radius and other fundamental parameters of the F9V star β Virginis
Stello, D.; Tuthill, P. G.; Lacour, S. +10 more
We have used the Sydney University Stellar Interferometer (SUSI) to measure the angular diameter of the F9V star β Virginis (β Vir). After correcting for limb darkening and combining with the revised Hipparcos parallax, we derive a radius of 1.703 +/- 0.022Rsolar (1.3 per cent). We have also calculated the bolometric flux from published…
Superorbital variability in hard X-rays
Farrell, S. A.; Barret, D.; Skinner, G. K.
We present the results of a study with the Swift Burst Alert Telescope in the 14-195 keV range of the long-term variability of five low-mass X-ray binaries with reported or suspected superorbital periods - 4U 1636-536, 4U 1820-303, 4U 1916-053, Cyg X-2 and Sco X-1. No significant persistent periodic modulation was detected around the previously re…
The globular clusters-stellar haloes connection in early-type galaxies
Forte, Juan C.; Vega, E. Irene; Faifer, Favio
This paper explores if, and to what an extent, the stellar populations of early-type galaxies can be traced through the colour distribution of their globular cluster (GC) systems. The analysis, based on a galaxy sample from the Virgo Advanced Camera for Surveys data, is an extension of a previous approach that has been successful in the cases of t…
Evolution of the X-ray luminosity in young HII galaxies
Nandra, K.; Rosa González, D.; Terlevich, E. +5 more
In an effort to understand the correlation between X-ray emission and present star formation rate, we obtained XMM-Newton data to estimate the X-ray luminosities of a sample of actively star-forming HII galaxies. The obtained X-ray luminosities are compared to other well-known tracers of star formation activity such as the far-infrared and the ult…
Photometric selection of z ~ 5 Lyman break galaxies in the ESO Remote Galaxy Survey
Bremer, M. N.; Lehnert, M. D.; Stanway, E. R. +2 more
We describe the selection of a sample of photometrically defined Lyman break galaxies (LBGs) at z ~ 5 using the multiwavelength imaging data of the ESO (European Southern Observatory) Remote Galaxy Survey. The data are drawn from 10 widely separated fields covering a total sky area of 275arcmin2. Starting with a simple colour (R - I >…
Towards multiple-star population synthesis
Eggleton, P. P.
The multiplicities of stars, and some other properties, were collected recently by Eggleton & Tokovinin, for the set of 4559 stars with Hipparcos magnitude brighter than 6.0 (4558 excluding the Sun). In this paper I give a numerical recipe for constructing, by a Monte Carlo technique, a theoretical ensemble of multiple stars that resembles the…