Astrophysics
We describe a new method for robustly testing theoretical predictions of red giant evolution near the tip of the giant branch. When theoretical cumulative luminosity functions are shifted to align the tip in I-band and normalized at a…
We report on the detection of two Halpha-emitting extreme compact objects from deep images of the Abell 634 and Abell 539 clusters of galaxies at z ~ 0.03. Follow up long slit spectroscopy of these two unresolved sources revealed that they…
A neural network mechanism that can compensate for poor optical quality was recently discovered in a biological context. We propose that this mechanism can and should be adopted for astronomical purposes. This would shift emphasis away from…
We performed a near-IR/optical monitoring programme from 1999 to 2005 in order to study the variability properties of the 'Arecibo sample of OH/IR stars' (periods, amplitudes, and colour variations). Here we describe this multi-wavelength…
We present mid-infrared spectra of 5 submillimeter galaxies at z=0.65-2.38 taken with the Spitzer Space Telescope. Four of these sources, at z<1.5, have strong PAH features and their composite spectrum is well fitted by an M82-like spectrum…
We present IRAC (3.6, 4.5, 5.8, and 8.0 micron) observations of the Chamaeleon II molecular cloud. The observed area covers about 1 square degree defined by $A_V >2$. Analysis of the data in the 2005 c2d catalogs reveals a small number of…
We present our chemically consistent GALEV Evolutionary Synthesis models for galaxies and point out differences to previous generations of models and their effects on the interpretation of local and high-redshift galaxy data.
We present here a complete list of contributions to the gravitational wave frequency evolution from compact binaries on circular orbits up to the second post-Newtonian order by including the interaction of magnetic dipole moments,…
We investigate the cosmological Fisher information in the non-linear dark-matter power spectrum in the context of the halo model. We find that there is a plateau in information content on translinear scales which is generic to all…
We performed sub-arcsecond high-sensitivity nterferometric observations of the thermal dust emission at 1.4 mm and 2.8 mm in the disks surrounding LkCa 15 and MWC 480, with the new 750 m baselines of the IRAM PdBI array. This provides a…
Ultra Luminous Infra-Red Galaxies (ULIRGs) -- gas-rich mergers harboring the most extreme star-forming conditions encountered in the local Universe -- are thought to re-enact the galaxy formation processes we are only barely able to glimpse…
We present a new speckle camera designed and built at Observatoire Midi-Pyr\'{e}n\'{e}es. This focal instrument has been used for four years with the 2-meter Bernard Lyot Telescope of Pic du Midi observatory. It can be set in various…
We search for effects of metallicity on B and Be stars in the Small and Large Magellanic Clouds (SMC and LMC) and in the Milky Way (MW). We extend our previous analysis of B and Be stars populations in the LMC to the SMC. The rotational…
The variational method with constraints recently developed by Verkley and Gerkema to describe maximum-entropy atmospheric profiles is generalized to ideal gases but with temperature-dependent specific heats. In so doing, an extended and non…
In this paper we present the results of the analysis of the INTEGRAL data for the black hole transient GRO J1655-40. The observations consist of four ToO (100 ks each) observations's AO-3 spread from February to April of 2005. We present…
Aim: To determine whether or not gas-phase chemical models with homogeneous and time-independent physical conditions explain the many observed molecular abundances in astrophysical sources, it is crucial to estimate the uncertainties in the…
Context: Alpha Centauri is our closest stellar neighbor, at a distance of only 1.3 pc, and its two main components have spectral types comparable to the Sun. This is therefore a favorable target for an imaging search for extrasolar planets.…
We report the detection of nebular emission lines in the optical and mid-infrared spectra of IRAS 17347-3139, a heavily obscured OH/IR star which may be rapidly evolving from the AGB to the PN stage. The presence of emission lines is…
HH30 is a well-known Pre-Main-Sequence star in Taurus. HST observations have revealed a flared, edge-on disk driving a highly-collimated optical jet, making this object a case study for the disk-jet-outflow paradigm. We obtained high…
The main objective of the present work is to ckeck if the star formation efficiency plays a relevant role in the evolution of the relative abundance N/O. We analyze the evolution of the nitrogen-to-oxygen ratio as predicted by a set of…