Search Publications

Extinction law in ultraluminous infrared galaxies at z∼ 1

Kawara, K.; Shimizu, T.; Nozawa, T. +3 more

We analyse the multiwavelength photometric and spectroscopic data of 12 ultraluminous infrared galaxies (ULIRGs) at z∼ 1 and compare them with models of stars and dust in order to study the extinction law and star formation in young infrared (IR) galaxies. Five extinction curves, namely the Milky Way (MW), the pseudo-MW which is MW-like without th…

Are small-scale substructures a universal property of galaxy haloes? The case of the giant elliptical NGC 5128

Rejkuba, M.; Mouhcine, M.; Ibata, R.

We present an analysis of the spatial and chemical substructures in a remote halo field in the nearby giant elliptical galaxy Centaurus A (NGC 5128), situated ∼38 kpc from the centre of the galaxy. The observations were taken with the Advanced Camera for Surveys instrument on-board the Hubble Space Telescope, and reach down to the horizontal branc…

Optical and OH megamaser observations of the starburst galaxy IIZw 096

Klöckner, H. -R.; Plauchu-Frayn, I.; Coziol, R. +4 more

Using the Multi-Element Radio-Linked Interferometer Network (MERLIN), we have acquired a high spatial resolution spectral image of the OH megamaser (OHMM) in the nearby starburst 'galaxy' known as IIZw 096. We have also acquired optical B, V, R, I and Hα images with the 1.5-m telescope in San Pedro Mártir. By comparing the MERLIN observations with…

Observation and modelling of main-sequence star chromospheres - XVI. Rotation of dK5 stars

Houdebine, E. R.

Using two different spectrographs, High Accuracy Radial velocity Planet Search (HARPS) (European Southern Observatory) and SOPHIE (Observatoire de Haute Provence), we have measured v sin i for a sample of dK5 stars. These are the first measurements of v sin i for most of the stars studied here.

We measured v sin i to an accuracy of 0.3 km s

Swift follow-up of unidentified X-ray sources in the XMM-Newton Slew Survey

Read, A. M.; Esquej, P.; O'Brien, P. T. +8 more

We present deep Swift follow-up observations of a sample of 94 unidentified X-ray sources from the XMM-Newton Slew Survey. The X-ray Telescope (XRT) on-board Swift detected 29 per cent of the sample sources; the flux limits for undetected sources suggest the bulk of the Slew Survey sources are drawn from one or more transient populations. We repor…

Weakly broadened iron line in the X-ray spectrum of the ultraluminous X-ray source M82 X-1

Caballero-García, M. D.

We present the best quality XMM-Newton and Suzaku data from M82 X-1 so far. We analyse the spectra of this remarkable ultraluminous X-ray (ULX) source in a self-consistent manner. We have disentangled emission from the host galaxy, responsible for the soft X-ray emission (E≤ 2.5 keV), which is successfully described by a two-temperature thermal em…

Suzaku observations of ejecta-dominated Galactic supernova remnant G346.6-0.2

Hudaverdi, M.; Ercan, E. N.; Sezer, A. +2 more

We present here the results of an X-ray analysis of Galactic supernova remnant G346.6-0.2 observed with Suzaku. K-shell emission lines of Mg, Si, S, Ca and Fe are detected clearly for the first time. Strong emission lines of Si and S imply that the X-ray emission nature of G346.6-0.2 is ejecta-dominated. The ejecta-dominated emission is well fitte…

Probing the ambient medium of GRB 090618 with XMM-Newton observations

Covino, S.; D'Avanzo, P.; Campana, S. +3 more

Long gamma-ray bursts (GRBs) signal the death of massive stars. The afterglow emission can be used to probe the progenitor ambient through a detailed study of the absorption pattern imprinted by the circumburst material as well as the host galaxy interstellar medium on the continuum spectrum. This has been done at optical wavelengths with impressi…

Models of the compact jet in GRS 1915+105

Punsly, Brian

In this article, models are constructed of the compact jet in GRS 1915+105 during an epoch of optimal data capture. On 2003 April 2, the object was observed in the hard X-ray/soft gamma-ray band (INTEGRAL), hard X-ray band (RXTE), near-IR (ESO/New Technology Telescope) and the Very Long Baseline Array (VLBA) (8.3 and 15 GHz). The source was in a s…

Integral field spectroscopy of local LCBGs: NGC 7673, a case study. Physical properties of star-forming regions

Sánchez, S. F.; Pérez-Gallego, J.; Guzmán, R. +4 more

Physical properties of the star-forming regions in the local Luminous Compact Blue Galaxy (LCBG) NGC 7673 are studied in detail using 3D spectroscopic data taken with the PMAS fibre pack (PPAK) integral field unit at the 3.5-m telescope in the Centro Astronómico Hispano Alemán (CAHA). We derive integrated and spatially resolved properties such as …