23 research outputs found
Gravitational Lensing at Millimeter Wavelengths
With today's millimeter and submillimeter instruments observers use
gravitational lensing mostly as a tool to boost the sensitivity when observing
distant objects. This is evident through the dominance of gravitationally
lensed objects among those detected in CO rotational lines at z>1. It is also
evident in the use of lensing magnification by galaxy clusters in order to
reach faint submm/mm continuum sources. There are, however, a few cases where
millimeter lines have been directly involved in understanding lensing
configurations. Future mm/submm instruments, such as the ALMA interferometer,
will have both the sensitivity and the angular resolution to allow detailed
observations of gravitational lenses. The almost constant sensitivity to dust
emission over the redshift range z=1-10 means that the likelihood for strong
lensing of dust continuum sources is much higher than for optically selected
sources. A large number of new strong lenses are therefore likely to be
discovered with ALMA, allowing a direct assessment of cosmological parameters
through lens statistics. Combined with an angular resolution <0.1", ALMA will
also be efficient for probing the gravitational potential of galaxy clusters,
where we will be able to study both the sources and the lenses themselves, free
of obscuration and extinction corrections, derive rotation curves for the
lenses, their orientation and, thus, greatly constrain lens models.Comment: 69 pages, Review on quasar lensing. Part of a LNP Topical Volume on
"Dark matter and gravitational lensing", eds. F. Courbin, D. Minniti. To be
published by Springer-Verlag 2002. Paper with full resolution figures can be
found at ftp://oden.oso.chalmers.se/pub/tommy/mmviews.ps.g
ALMA imaging of the cold molecular and dusty disk in the type 2 active nucleus of the Circinus galaxy
Galaxie
Physics of ULIRGs with MUSE and ALMA: the PUMA project. IV. No tight relation between cold molecular outflow rates and AGN luminosities
Galaxie
N-body simulations of gravitational dynamics
We describe the astrophysical and numerical basis of N-body simulations, both
of collisional stellar systems (dense star clusters and galactic centres) and
collisionless stellar dynamics (galaxies and large-scale structure). We explain
and discuss the state-of-the-art algorithms used for these quite different
regimes, attempt to give a fair critique, and point out possible directions of
future improvement and development. We briefly touch upon the history of N-body
simulations and their most important results.Comment: invited review (28 pages), to appear in European Physics Journal Plu
Gas and dust cooling along the major axis of M 33 (HerM33es). Herschel/PACS [C II] and [O I] observations
Galaxie
Convergence ou divergence régionale ?
National audienceRevue de la littérature empirique concernant la convergence des régions et ses différentes mesures. AprÚs avoir rappelé les fondements macro-économiques des différentes mesures de la convergence, en particulier les théories de la croissance, les auteurs précisent les différentes mesures de la convergence utilisées, les raffinements économétriques développés ces derniÚres années dans ce domaine et les principaux résultats qui en découlent. Ils s'intéressent ensuite aux théories de la localisation et leurs prédictions en termes de convergence régionale, avant de faire à nouveau l'état des lieux critique des travaux empiriques issus de ces théories
The spatial sorting and matching of skills and firms
In this paper we make use of a matched employer-employee database for Italy to look at the spatial distribution of wages. Using this rich database we aim to open up the black box of agglomeration economies exploiting the micro dimension of interaction among economic agents, both individuals and firms. We provide evidence that firm size and, especially, skills are sorted across space and account for a large portion of the spatial wage variation. Our data also support the assortative matching hypothesis, which we show not to be driven by co-location of good workers and firms. Finally, we point out that assortative matching is negatively related to local market size