9 research outputs found
The slowly evolving role of environment in a spectroscopic survey of star formation in Mâ > 5 Ă 108 Mâ galaxies since z ⌠1
We present a deep [O II] emission-line survey of faint galaxies (22.5< KAB <24) in the Chandra Deep Field South (CDFS) and the Faint Infra-Red Extragalactic Survey (FIRES) field. With these data we measure the star formation rate (SFR) in galaxies in the stellar mass range 8.85 âČ log (M*/Mâ) âČ 9.5 at 0.62 < z < 0.885, to a limit of SFR ⌠0.1 Mâ yrâ1. The presence of a massive cluster (MS1054â03) in the FIRES field, and of significant large-scale structure in the CDFS field, allows us to study the environmental dependence of SFRs amongst this population of low-mass galaxies. Comparing our results with more massive galaxies at this epoch, with our previous survey [Redshift One LDSS-3 Emission Line Survey (ROLES)] at the higher redshift z ⌠1, and with Sloan Digital Sky Survey (SDSS) Stripe 82 data, we find no significant evolution of the stellar mass function of star-forming galaxies between z = 0 and z ⌠1, and no evidence that its shape depends on environment. The correlation between specific star formation rate (sSFR) and stellar mass at z ⌠0.75 has a power-law slope of ÎČ âŒ â0.2, with evidence for a steeper relation at the lowest masses. The normalization of this correlation lies as expected between that corresponding to z ⌠1 and the present day. The global SFR density is consistent with an evolution of the form (1 + z)2 over 0 < z < 1, with no evidence for a dependence on stellar mass. The sSFR of these star-forming galaxies at z ⌠0.75 does not depend upon the density of their local environment. Considering just high-density environments, the low-mass end of the sSFRâM* relation in our data is steeper than that in Stripe 82 at z = 0, and shallower than that measured by ROLES at z = 1. Evolution of low-mass galaxies in dense environments appears to be more rapid than in the general field
The Means of Management Control
In the understanding of managerial control over work, the labour process literature has been very influential. Recent critical contributions from the sociological tradition have, however, served to so fragment the underlying perspective that its coherence is now threatened. This paper seeks to demonstrate how a dialectical analysis can lay the basis for a viable amended approach. The need for a dialectical framework has often been urged - illustrations of such a perspective in operation, however, are rare. Using a series of examples, this paper argues that the dialectic of work control can be revealed by focussing on two phenomena: the 'levels' and 'circuits' of control
Euclid. I. Overview of the Euclid mission
International audienceThe current standard model of cosmology successfully describes a variety of measurements, but the nature of its main ingredients, dark matter and dark energy, remains unknown. Euclid is a medium-class mission in the Cosmic Vision 2015-2025 programme of the European Space Agency (ESA) that will provide high-resolution optical imaging, as well as near-infrared imaging and spectroscopy, over about 14,000 deg^2 of extragalactic sky. In addition to accurate weak lensing and clustering measurements that probe structure formation over half of the age of the Universe, its primary probes for cosmology, these exquisite data will enable a wide range of science. This paper provides a high-level overview of the mission, summarising the survey characteristics, the various data-processing steps, and data products. We also highlight the main science objectives and expected performance