Search Publications
The reversal of the star formation-density relation in the distant universe
Daddi, E.; Elbaz, D.; Popesso, P. +11 more
Aims:We study the relationship between the local environment of galaxies and their star formation rate (SFR) in the Great Observatories Origins Deep Survey, GOODS, at z∼1.
Methods: We use ultradeep imaging at 24 µm with the MIPS camera onboard {Spitzer} to determine the contribution of obscured light to the SFR of galaxies over the redsh…
Hubble Space Telescope time-series photometry of the planetary transit of HD 189733: no moon, no rings, starspots
Bouchy, F.; Moutou, C.; Pont, F. +7 more
We monitored three transits of the giant gas planet around the nearby K dwarf HD 189733 with the ACS camera on the Hubble Space Telescope. The resulting very-high accuracy lightcurve (signal-to-noise ratio near 15 000 on individual measurements, 35 000 on 10-min averages) allows a direct geometric measurement of the orbital inclination, radius rat…
A new calibration of Galactic Cepheid period-luminosity relations from B to K bands, and a comparison to LMC relations
Arriagada, P.; McArthur, B. E.; Benedict, G. F. +8 more
Context: The universality of the Cepheid period-luminosity (PL) relations has been under discussion since metallicity effects were assumed to play a role in the value of the intercept and, more recently, of the slope of these relations.
Aims: The goal of the present study is to calibrate the Galactic PL relations in various photometric bands (…
The innermost region of AGN tori: implications from the HST/NICMOS type 1 point sources and near-IR reverberation
Hönig, S. F.; Kishimoto, M.; Weigelt, G. +1 more
Spatially resolving the innermost region of the putative torus-like structure in an active galactic nucleus (AGN) is one of the main goals of high-spatial-resolution studies. This could be done in the near-IR observations of type 1 AGNs where we directly see the hottest dust grains in the torus. We discuss two critical issues in such studies. One …
The CFHTLS strong lensing legacy survey. I. Survey overview and T0002 release sample
Alard, C.; Gavazzi, R.; Fort, B. +10 more
Aims:We present data from the CFHTLS Strong Lensing Legacy Survey (SL2S). Due to the unsurpassed combined depth, area and image quality of the Canada-France-Hawaii Legacy Survey it is becoming possible to uncover a large, statistically well-defined sample of strong gravitational lenses which spans the dark halo mass spectrum predicted by the conco…
The peculiar horizontal branch morphology of the Galactic globular clusters NGC 6388 and NGC 6441: new insights from UV observations
Djorgovski, S. G.; Zoccali, M.; Busso, G. +9 more
Context: In this paper we present multiband optical and UV Hubble Space Telescope photometry of the two Galactic globular clusters
Aims: We investigate the properties of their anomalous horizontal branches in different photometric planes in order to shed light on the nature of the ph…
A multi-wavelength study of z = 3.15 Lyman-α emitters in the GOODS South Field
Watson, D.; Fynbo, J. P. U.; Rosati, P. +7 more
Context: Lyα-emitters have proven to be excellent probes of faint, star-forming galaxies in the high redshift universe. However, although the sample of known emitters is increasingly growing, their nature (e.g. stellar masses, ages, metallicities, star-formation rates) is still poorly constrained.
Aims: We aim to study the nature of Lyα-emitte…
The luminosity function of high-redshift quasi-stellar objects. A combined analysis of GOODS and SDSS
Brandt, W. N.; Vanzella, E.; Grazian, A. +5 more
Aims:In this work the luminosity function of QSOs is measured in the redshift range 3.5<z<5.2 for the absolute magnitude interval -21<M145<-28. Determining the faint-end of the luminosity function at these redshifts provides important constraints on models of the joint evolution of galaxies and AGNs.
Methods: We have def…
ACS imaging of star clusters in M 51. I. Identification and radius distribution
Bastian, N.; Larsen, S. S.; Gieles, M. +3 more
Context: Size measurements of young star clusters are valuable tools to put constraints on the formation and early dynamical evolution of star clusters.
Aims: We use HST/ACS observations of the spiral galaxy M 51 in F435W, F555W and F814W to select a large sample of star clusters with accurate effective radius measurements in an area covering …
Lyα emission in high-redshift galaxies
Noll, S.; Heidt, J.; Appenzeller, I. +4 more
Context: A significant fraction of the high-redshift galaxies show strong Lyα emission lines. For redshifts z > 5, most known galaxies belong to this class. However, so far not much is known about the physical structure and nature of these objects.
Aims: Our aim is to analyse the Lyα emission in a sample of high-redshift UV-continuum select…