Search Publications

PKS2250-41: a case study for triggering

Villar-Martín, M.; Morganti, R.; Tadhunter, C. N. +3 more

We present the results of a multiwavelength study of the z = 0.31 radio source PKS2250-41. Integral field unit and long-slit spectroscopy obtained using VIMOS and FORS1 on the VLT, and archival Hubble Space Telescope optical imaging observations are used to study the morphology, kinematics and ionization state of the extended emission-line region …

Peering through the stellar wind of IGR J19140+0951 with simultaneous INTEGRAL/RXTE observations

Rodriguez, J.; Shaw, S. E.; Hannikainen, D. C. +1 more

We have used the RXTE and INTEGRAL satellites simultaneously to observe the high-mass X-ray binary (HMXB) IGR J19140+0951. The spectra obtained in the 3-80 keV range have allowed us to perform a precise spectral analysis of the system along its binary orbit. The spectral evolution confirms the supergiant nature of the companion star and the neutro…

High-resolution polarimetry of Parsamian 21: revealing the structure of an edge-on FUOri disc

Apai, D.; Ábrahám, P.; Kóspál, Á. +6 more

We present the first high spatial resolution near-infrared direct and polarimetric observations of Parsamian 21, obtained with the Nasmyth Adaptive Optics System-CONICA instrument at the Very Large Telescope (VLT). We complemented these measurements with archival infrared observations, such as Hubble Space Telescope (HST)/Wide Field Planetary Came…

A method to search for strong galaxy-galaxy lenses in optical imaging surveys

Dell'Antonio, Ian P.; Kubo, Jeffrey M.

We present a semi-automated method to search for strong galaxy-galaxy lenses in optical imaging surveys. Our search technique constrains the shape of strongly lensed galaxies (or arcs) in a multiparameter space, which includes the third-order (octopole) moments of objects. This method is applied to the Deep Lens Survey (DLS), a deep ground-based w…

Detectable signatures of cosmic radiative feedback

Salvaterra, R.; Burigana, C.; Schneider, R. +3 more

We use a semi-analytical model to study the impact of reionization, and the associated radiative feedback, on galaxy formation. Two feedback models have been considered: (i) a standard prescription, according to which star formation is totally suppressed in galaxies with circular velocity below a critical threshold (model CF06) and (ii) a characte…

A phenomenological model of galaxy clusters

Diego, J. M.; Ascasibar, Y.

We present a simple model to describe the dark matter density, the gas density and the gas temperature profiles of galaxy clusters. Analytical expressions for these quantities are given in terms of only five free parameters with a clear physical meaning: the mass M of the dark matter halo (or the characteristic temperature T₀), the char…

Optical spectroscopy of Arp220: the star formation history of the closest ULIRG

Tadhunter, C. N.; González Delgado, R. M.; Rodríguez Zaurín, J.

We present long-slit, optical spectra of the merging system Arp220, obtained using the William Herschel Telescope (WHT) on La Palma. These data were taken as a part of a large study of ultraluminous infrared galaxies (ULIRGs) with the aim of investigating the evolution and star formation histories of such objects. Spectral synthesis modelling has …

Constraining the mass of the GRB 030329 progenitor

Hayes, Matthew; Östlin, Göran; Sollerman, Jesper +2 more

The long-duration gamma-ray burst (GRB) GRB 030329, associated with the supernova (SN) SN 2003dh, occurred inside a star-forming dwarf galaxy at redshift z = 0.1685. The low redshift, and a rich set of archival Hubble Space Telescope (HST) images, makes this GRB well suited for a detailed study of the stellar population in the immediate vicinity o…

Observation and modelling of main-sequence stellar chromospheres - VII. Rotation and metallicity of dM1 stars

Houdebine, E. R.

We have measured v sini and metallicity from high-resolution spectroscopic observations of a selected sample of dM1-type stars.

To measure v sini, we first selected three template stars known for their slow rotation or their very low activity levels and then cross-correlated their spectra with those of our target stars. The excess broadening …

A limit on the number density of bright z ~ 7 galaxies

Lehnert, Matthew D.; Stanway, Elizabeth R.; Bremer, Malcolm N. +2 more

We present a survey of bright optical dropout sources in two deep, multiwavelength surveys comprising 11 widely separated fields, aimed at constraining the galaxy luminosity function at z ~ 7 for sources at 5-10L*(z = 6). Our combined survey area is 225arcmin² to a depth of J_AB = 24.2 (3σ) and 135arcmin² to J = 25.…