Space instrumentation

Abstract:

We present near-infrared spectroscopic observations of star-forming galaxies at z ∼ 1.4 with FMOS on the Subaru Telescope. We observed K-band selected galaxies in the SXDS/UDS fields with K ≤ 23.9mag, 1.2 ≤ zph ≤ 1.6,M ≥ 109.5M, and expected F(Hα) ≥ 10-16 erg s-1cm-2; 71 objects in the sample have significant detections of H?. For these objects, excluding possible AGNs, identified from the BPT diagram, gas-phase metallicities were obtained from the [N II] /Hα line ratio. The sample is split into three stellar-mass bins, and the spectra are stacked in each stellar-mass bin. The mass-metallicity relation obtained at z ∼ 1.4 is located between those at z ∼ 0.8 and z ∼ 2.2. We constrain the intrinsic scatter to be ∼0.1 dex, or larger in the mass-metallicity relation at z ∼ 1.4; the scatter may be larger at higher redshifts. We found trends that the deviation from the mass-metallicity relation depends on the SFR (Star-formation rate) and the half light radius: Galaxies with higher SFR and larger half light radii show lower metallicities at a given stellar mass. One possible scenario for the trends is the infall of pristine gas accreted from IGM, or through merger events. Our data points show larger scatter than the fundamental metallicity relation (FMR) at z ∼ 0.1, and the averagemetallicities slightly deviate fromthe FMR. The compilation of themass- metallicity relations at z ∼ 3 to z ∼ 0.1 shows that they evolve smoothly from z ∼ 3 to z ∼ 0 without changing the shape so much, except for the massive part at z ∼ 0. © 2012 Astronomical Society of Japan.

Abstract:

Atmospheric Waves Workshop; Noordwijk, Netherlands, 9-10 November 2011 Experts in observations and modeling of atmospheric waves from the Earth and planetary atmospheric science communities came together at a November 2011 workshop held at the European Space Agency's (ESA) European Space Research and Technology Centre (ESTEC) site in the Netherlands to discuss the nature of waves observed in Venus's atmosphere and their comparison to those on Earth and Mars. ESA's Venus Express (VEx) satellite and ground-based observers find atmospheric waves at many scales. Migrating solar tides and other planetary-scale waves are observed in cloud-tracking wind vectors and temperature fields. Mesoscale gravity waves (GWs) can also be seen at a variety of levels from the cloud base up to the thermosphere, evident in imagery and in vertical profiles of temperature, density, and aerosol abundance. This workshop focused particularly on GWs, as their role in the atmospheric circulation is still poorly understood. © 2012 American Geophysical Union. All Rights Reserved.

Abstract:

As a demonstration of the capabilities of the new Oxford SWIFT integral field spectrograph, we present first observations for a set of 14 early-type galaxies in the core of the Coma cluster. Our data consist of I- and z-band spatially resolved spectroscopy obtained with the Oxford SWIFT spectrograph, combined with r-band photometry from the SDSS archive for 14 early- type galaxies. We derive spatially resolved kinematics for all objects from observations of the calcium triplet absorption features at \sim 8500 {AA} . Using this kinematic information we classify galaxies as either Fast Rotators or Slow Rotators. We compare the fraction of fast and slow rotators in our sample, representing the densest environment in the nearby Universe, to results from the ATLAS3D survey, finding the slow rotator fraction is \sim 50 per cent larger in the core of the Coma cluster than in the Virgo cluster or field, a 1.2 {\sigma} increase given our selection criteria. Comparing our sample to the Virgo cluster core only (which is 24 times less dense than the Coma core) we find no evidence of an increase in the slow rotator fraction. Combining measurements of the effective velocity dispersion {\sigma_e} with the photometric data we determine the Fundamental Plane for our sample of galaxies. We find the use of the average velocity dispersion within 1 effective radius, {\sigma_e}, reduces the residuals by 13 per cent with respect to comparable studies using central velocity dispersions, consistent with other recent integral field Fundamental Plane determinations.

Abstract:

The European Venus Explorer (EVE) mission described in this paper was proposed in December 2010 to ESA as an 'M-class' mission under the Cosmic Vision programme. It consists of a single balloon platform floating in the middle of the main convective cloud layer of Venus at an altitude of 55 km, where temperatures and pressures are benign (~25°C and ~0. 5 bar). The balloon float lifetime would be at least 10 Earth days, long enough to guarantee at least one full circumnavigation of the planet. This offers an ideal platform for the two main science goals of the mission: study of the current climate through detailed characterization of cloud-level atmosphere, and investigation of the formation and evolution of Venus, through careful measurement of noble gas isotopic abundances. These investigations would provide key data for comparative planetology of terrestrial planets in our solar system and beyond. © 2011 Springer Science+Business Media B.V.