24 research outputs found
WALLABY Pilot Survey: the Potential Polar Ring Galaxies NGC~4632 and NGC~6156
We report on the discovery of two potential polar ring galaxies (PRGs) in the
WALLABY Pilot Data Release 1 (PDR1). These untargetted detections,
cross-matched to NGC 4632 and NGC 6156, are some of the first galaxies where
the Hi observations show two distinct components. We used the iDaVIE virtual
reality software to separate the anomalous gas from the galactic gas and find
that the anomalous gas comprises ~ 50% of the total H i content of both
systems. We have generated plausible 3D kinematic models for each galaxy
assuming that the rings are circular and inclined at 90 degrees to the galaxy
bodies. These models show that the data are consistent with PRGs, but do not
definitively prove that the galaxies are PRGs. By projecting these models at
different combinations of main disk inclinations, ring orientations, and
angular resolutions in mock datacubes, we have further investigated the
detectability of similar PRGs in WALLABY. Assuming that these galaxies are
indeed PRGs, the detectability fraction, combined with the size distribution of
WALLABY PDR1 galaxies, implies an incidence rate of ~ 1% - 3%. If this rate
holds true, the WALLABY survey will detect hundreds of new polar ring galaxies.Comment: Accepted to MNRAS -- Corrected Table
Geological discontinuity persistence: Implications and quantification
Persistence of geological discontinuities is of great importance for many rock-related applications in earth sciences, both in terms of mechanical and hydraulic properties of individual discontinuities and fractured rock masses. Although the importance of persistence has been identified by academics and practitioners over the past decades, quantification of areal persistence remains extremely difficult; in practice, trace length from finite outcrop is still often used as an approximation for persistence. This paper reviews the mechanical behaviour of individual discontinuities that are not fully persistent, and the implications of persistence on the strength and stability of rock masses. Current techniques to quantify discontinuity persistence are then examined. This review will facilitate application of the most applicable methods to measure or predict persistence in rock engineering projects, and recommended approaches for the quantification of discontinuity persistence. Furthermore, it demonstrates that further research should focus on the development of persistence quantification standards to promote our understanding of rock mass behaviours including strength, stability and permeability
Sprachecke des Allgemeinen Deutschen Sprachvereins : Mr., Miß und Mrs. ; Immer wieder Kanzleideutsch
Was kann der Lehrer thun, um die Herzen der Jugend für die Sache des Sprachvereins zu gewinnen?
Sprachecke des Allgemeinen Deutschen Sprachvereins : wird "von" mit dem ersten Fall verbunden
Autograaf tundmatule
Palleske, Emil, 1823-1880, saksa näitleja, kirjanik ja kirjandusajaloolaneSentens kuupäeva ja autogrammig