Search Publications
The XMM-Newton view of Plaskett's star and its surroundings
Rauw, G.; Pollock, A. M. T.; Stevens, I. R. +1 more
XMM-Newton data of Plaskett's star (HD 47129) are used in order to analyse its X-ray spectrum and variability and hence to derive further constraints on the wind interaction in this early-type binary (O6 I + O7.5 I) system.
Conventional models fail to provide a consistent fit of the European Photon Imaging Camera (EPIC) and Reflexion Grating …The hot, warm and cold gas in Arp 227 - an evolving poor group
Trinchieri, G.; Rampazzo, R.; Sheth, K. +6 more
Arp 227 represents a prototypical example of an interacting mixed pair of galaxies located in a low-density environment. We investigate the gas properties of the pair in the X-ray, Hα, HI and CO bands. We also detect two additional members of the group in HI which indicates that the pair constitutes the dominant members of a loose group.
The …On the reliability of CIVλ1549 as an abundance indicator for high-redshift star-forming galaxies
Pettini, Max; Steidel, Charles C.; Crowther, Paul A. +1 more
We reconsider the use of the equivalent width of CIVλ1549, EW(CIV), as an indicator of the oxygen abundance in star-forming galaxies, as proposed by Heckman et al. for nearby starbursts. We refine the local calibration of EW(CIV) versus log(O/H) by using a restricted wavelength window which minimizes blending with interstellar absorption lines. Wh…
Double-barred galaxies at intermediate redshifts: a feasibility study
Lisker, Thorsten; Debattista, Victor P.; Ferreras, Ignacio +1 more
Despite the increasing number of studies of barred galaxies at intermediate and high redshifts, double-barred (S2B) systems have only been identified in the nearby (z <= 0.04) universe thus far. In this feasibility study, we demonstrate that the detection and analysis of S2Bs is possible at intermediate redshifts (0.1 <~ z <~ 0.5) with th…
The X-ray properties of the dwarf Magellanic-type galaxy NGC 55
Warwick, R. S.; Roberts, T. P.; Stobbart, A. -M.
We present an analysis of the X-ray properties of the Magellanic-type galaxy NGC 55 based on two contiguous XMM-Newton observations. We detect a total of 137 X-ray sources in the field of view, down to a flux of ~5 × 10-15ergcm-2s-1 (0.3-6 keV), 42 of which are located within the optical confines of the galaxy. On …
Constraints on the nature of dust particles by infrared observations
Ábrahám, P.; Birkmann, S. M.; Laureijs, R. J. +2 more
The far-infrared (FIR) emissivity of dust is an important parameter characterizing the physical properties of the grains. With the availability of stellar data bases and FIR data from Infrared Space Observatory (ISO), it is possible to compare the optical and infrared properties of dust, and derive the FIR emissivity with respect to the optical ex…
GMOS IFU observations of the stellar and gaseous kinematics in the centre of NGC 1068
Gerssen, Joris; Miller, Bryan W.; Turner, James E. H. +2 more
We present a data cube covering the central 10 arcsec of the archetypal active galaxy NGC 1068 over a wavelength range 4200-5400 Åobtained during the commissioning of the integral field unit (IFU) of the Gemini Multi-object Spectrograph (GMOS) installed on the Gemini-North telescope. The data cube shows a complex emission line morphology in the [O…
A data-driven Bayesian approach for finding young stellar populations in early-type galaxies from their ultraviolet-optical spectra
Raychaudhury, Somak; Nolan, Louisa A.; Harva, Markus O. +1 more
Efficient predictive models and data analysis techniques for the analysis of photometric and spectroscopic observations of galaxies are not only desirable, but also required, in view of the overwhelming quantities of data becoming available. We present the results of a novel application of Bayesian latent variable modelling techniques, where we ha…
XMM-Newton observations of the Seyfert 1 AGN H0557-385
Page, M. J.; Branduardi-Raymont, G.; Blustin, A. J. +1 more
We present XMM-Newton observations of the Seyfert 1 active galactic nucleus (AGN) H0557-385. We have conducted a study into the warm absorber present in this source, and using high-resolution Reflection Grating Spectrometer (RGS) data we find that the absorption can be characterized by two phases: a phase with log ionization parameter ξ of 0.50 (w…
Analysis of δ Librae including Hipparcos astrometry
Demircan, O.; Bakış, V.; Hadrava, P. +3 more
New spectroscopy of the classical Algol system δ Lib, combined with high-quality optical and infrared photometry, provides the basis for a good understanding of the close binary system's main parameters. Detailed analysis of the photometry reveals the significant role of a third light source, pointing to the existence of a companion to the eclipsi…