3D Astrophysics Newsletter

2016_6_2_gilles6.2 Today´s new entry

3D visualization of astronomy data cubes using immersive displays

Gilles Ferrand, Jayanne English, Pourang Irani

Abstract: We report on an exploratory project aimed at performing immersive 3D visualization of astronomical data, starting with spectral-line radio data cubes from galaxies. This work is done as a collaboration between the Department of Physics and Astronomy and the Department of Computer Science at the University of Manitoba. We are building our prototype using the 3D engine Unity, because of its ease of use for integration with advanced displays such as a CAVE environment, a zSpace tabletop, or virtual reality headsets. We address general issues regarding 3D visualization, such as: load and convert astronomy data, perform volume rendering on the GPU, and produce physically meaningful visualizations using principles of visual literacy. We discuss some challenges to be met when designing a user interface that allows us to take advantage of this new way of exploring data. We hope to lay the foundations for an innovative framework useful for all astronomers who use spectral line data cubes, and encourage interested parties to join our efforts. This pilot project addresses the challenges presented by frontier astronomy experiments, such as the Square Kilometre Array and its precursors.

Comments: presentation given at CASCA conference on 2016/06/01
Publication: astro-ph (http://arxiv.org/abs/1607.08874v1)
Submitted by: Gilles Ferrand

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3D Astrophysics Newsletter

6.1 Today´s new entry:

OGLE-ing the Magellanic System: Three-Dimensional Structure of the Clouds and the Bridge Using Classical Cepheids

2016_5_AniaAnna M. Jacyszyn-Dobrzeniecka, D. M. Skowron, P. Mróz, J. Skowron, I. Soszyński, A. Udalski, P. Pietrukowicz, S. Kozłowski, Ł. Wyrzykowski, R. Poleski, M. Pawlak, M. K. Szymański, K. Ulaczyk

Abstract: We analyzed a sample of 9418 fundamental-mode and first-overtone classical Cepheids from the OGLE-IV Collection of Classical Cepheids. The distance to each Cepheid was calculated using the period–luminosity relation for the Wesenheit magnitude, fitted to our data. The classical Cepheids in the LMC are situated mainly in the bar and in the northern arm. The eastern part of the LMC is closer to us and the plane fit to the whole LMC sample yields the inclination i = 24.◦2±0.◦7 and position angle P.A. = 151.◦4±1.◦7. We redefined the LMC bar by extending it in the western direction and found no offset from the plane of the LMC contrary to previous studies. On the other hand, we found that the northern arm is offset from a plane by about −0.5 kpc, which was not observed before. The age distribution of the LMC Cepheids shows one maximum at about 100 Myr. We demonstrate that the SMC has a non-planar structure and can be described as an extended ellipsoid. We identified two large ellipsoidal off-axis structures in the SMC. The northern one is located closer to us and is younger, while the south-western is farther and older. The age distribution of the SMC Cepheids is bimodal with one maximum at 110 Myr, and another one at 220 Myr. Younger stars are located in the closer part of this galaxy while older ones are more distant. We classified nine Cepheids from our sample as Magellanic Bridge objects. These Cepheids show a large spread in three-dimensions although five of them form a connection between the Clouds. The closest one is closer than any of the LMC Cepheids, while the farthest one – farther than any SMC Cepheid. All but one Cepheids in the Magellanic Bridge are younger than 300 Myr. The oldest one can be associated with the SMC Wing.

Journal: Acta Astronomica, Vol. 66 (2016) pp. 149–196
URL of preprint: https://arxiv.org/pdf/1602.09141v2.pdf
Submitted by: Ania Jacyszyn-Dobrzeniecka