Search Publications
Chemical abundances in Orion protoplanetary discs: integral field spectroscopy and photoevaporation models of HST 10
Tsamis, Y. G.; Walsh, J. R.; Henney, W. J. +2 more
Photoevaporating protoplanetary discs (proplyds) in the vicinity of hot massive stars, such as those found in Orion, are important objects of study for the fields of star formation, early disc evolution, planetary formation and H II region astrophysics. Their element abundances are largely unknown, unlike those of the main-sequence stars or the ho…
The variable X-ray emission of PSR B0943+10
Tiengo, A.; Mereghetti, S.; Esposito, P. +1 more
The old pulsar PSR B0943+10 (P = 1.1 s, characteristic age τ = 5 Myr) is the best example of mode-switching radio pulsar. Its radio emission alternates between a highly organized state with regular drifting subpulses (B mode) and a chaotic emission pattern (Q mode). We present the results of XMM-Newton observations showing that the X-ray propertie…
The merger Seyfert galaxy Arp 220: line and continuum absorption and emission
Contini, M.
The line and continuum spectra of the merger galaxy Arp 220 are analysed with the aim of investigating the ionizing and heating sources. We refer to radio, optical, infrared and X-ray spectra. The results show that in agreement with other merger galaxies, the optical lines are emitted from gas photoionized by the active galactic nucleus (AGN) and …
Hot gas, cold gas and sub-haloes in a Lyman α blob at redshift 2.38
Scarlata, Claudia; Dopita, Michael A.; Woodgate, Bruce E. +5 more
We present integral field spectroscopy of a Lyman α blob at redshift 2.38, with a spectral resolution three times better than previous published work. As with previous observations, the blob has a chaotic velocity structure, much of which breaks up into multiple components. Our spectroscopy shows, however, that some of these multiple components ar…
Herschel-ATLAS/GAMA: What determines the far-infrared properties of radio galaxies?
de Zotti, G.; Cooray, A.; Ibar, E. +20 more
We perform a stacking analysis of Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) data in order to obtain isothermal dust temperatures and rest-frame luminosities at 250 µm (L250), for a well-defined sample of 1599 radio sources over the H-ATLAS Phase 1/Galaxy and Mass Assembly (GAMA) area. The radio sample is generat…
Stokes imaging of AM Her systems using 3D inhomogeneous models - II. Modelling X-ray and optical data of CP Tucanae
Costa, J. E. R.; Rodrigues, C. V.; Silva, K. M. G. +3 more
The viewing geometry of the polar CP Tuc that better explains its optical and X-ray light curves is controversial. Previous modelling of white-light polarimetric data considered the partial self-eclipse of an extended inhomogeneous emitting region. Alternatively, phase-dependent absorption has been used to reproduce the X-ray data. This paper pres…
The X-ray properties of optically selected clusters of galaxies
Böhringer, H.; Pratt, G. W.; Croston, J. H. +7 more
We present the results of Chandra and Suzaku X-ray observations of nine moderate-redshift (0.16 < z < 0.42) clusters discovered via the Red-sequence Cluster Survey (RCS). Surface brightness profiles are fitted to β-models, gas masses are determined, integrated spectra are extracted within R2500, and X-ray temperatures and luminosi…
Swift J045106.8-694803: a highly magnetized neutron star in the Large Magellanic Cloud
Udalski, A.; Bartlett, E. S.; Bird, A. J. +3 more
We report the analysis of a highly magnetized neutron star in the Large Magellanic Cloud (LMC). The high-mass X-ray binary pulsar Swift J045106.8-694803 has been observed with Swift X-ray telescope (XRT) in 2008, the Rossi X-ray Timing Explorer (RXTE) in 2011 and the X-ray Multi-Mirror Mission-Newton (XMM-Newton) in 2012. The change in spin period…
Discovery of the spectroscopic binary nature of three bright southern Cepheids
Szabados, L.; Derekas, A.; Anderson, R. I. +4 more
We present an analysis of spectroscopic radial velocity and photometric data of three bright Galactic Cepheids: LR Trianguli Australis (LR TrA), RZ Velorum (RZ Vel) and BG Velorum (BG Vel). Based on new radial velocity data, these Cepheids have been found to be members of spectroscopic binary systems. The ratio of the peak-to-peak radial velocity …
IRAS 19520+2759: a 105 L⊙ massive young stellar object driving a collimated outflow
Sahai, R.; Sánchez Contreras, C.; Palau, Aina +2 more
The theory of massive star formation currently suffers from a scarce observational base of massive young stellar objects to compare with. In this paper, we present interferometric 12CO (1-0), 13CO (1-0), C18O (1-0) and 2.6 mm continuum images of the infrared source IRAS 19520+2759 together with complementary single…