Scale invariance and viscosity of a two-dimensional Fermi gas

We investigate the collective excitations of a harmonically trapped two-dimensional Fermi gas from the collisionless (zero sound) to the hydrodynamic (first sound) regime. The breathing mode, which is sensitive to the equation of state, is observed at a frequency two times the dipole mode frequency for a large range of interaction strengths and temperatures, and the amplitude of the breathing mode is undamped. This provides evidence for a dynamical SO(2,1) scaling symmetry of the two-dimensional Fermi gas. Moreover, we investigate the quadrupole mode to measure the shear viscosity of the two-dimensional gas and study its temperature dependence

E0102-VR: Exploring the scientific potential of Virtual Reality for observational astrophysics

Virtual Reality (VR) technology has been subject to a rapid democratization in recent years, driven in large by the entertainment industry, and epitomized by the emergence of consumer-grade, plug-and-play, room-scale VR devices. To explore the scientific potential of this technology for the field of observational astrophysics, we have created an experimental VR application: E0102-VR. The specific scientific goal of this application is to facilitate the characterization of the 3D structure of the oxygen-rich ejecta in the young supernova remnant 1E 0102.2-7219 in the Small Magellanic Cloud. Using E0102-VR, we measure the physical size of two large cavities in the system, including a (7.0 ± 0.5) pc-long funnel structure on the far-side of the remnant. The E0102-VR application, albeit experimental, demonstrates the benefits of using human depth perception for a rapid and accurate characterization of complex 3D structures. Given the implementation costs (time-wise) of a dedicated VR application like E0102-VR, we conclude that the future of VR for scientific purposes in astrophysics most likely resides in the development of a robust, generic application dedicated to the exploration and visualization of 3D observational datasets, akin to a “ds9-VR”

J/psi production in p-A collisions at 158 and 400 GeV: recent results from the NA60 experiment

The NA60 experiment has studied muon pair production in p-A and In-In collisions at the CERN SPS. We present new results on nuclear effects on J/psi production in p-A at 158 GeV, the same energy used for collecting A-A data at the SPS. We then compare nuclear effects with previous results from fixed target experiments, and with the results obtained from a p-A data sample taken by NA60 at 400 GeV. Based on the 158 GeV results, we calculate the expected J/psi suppression in In-In and Pb-Pb collisions due to cold nuclear matter effects, and we extract a new estimate for the anomalous suppression at SPS energies. Finally, we show preliminary results on J/psi polarization in p-A collisions.Comment: 4 pages, 4 figures - To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse

Shock Wave Expansion, Decoupling and Acoustic Signals in LIBS Measurements under Martian Atmospheric Conditions

In laboratory studies, we investigated the generation of laser-induced shock waves and the accompanying acoustic signal in a simulated martian atmosphere

SHOCK WAVE EXPANSION, DECOUPLING AND ACOUSTIC SIGNALS IN LIBS MEASUREMENTS UNDER MARTIAN ATMOSPHERIC CONDITIONS

In laboratory studies, we investigated the generation of laser-induced shock waves and the accompanying acoustic signal in a simulated martian atmosphere