35,736 research outputs found

    Vision, Action, and Make-Perceive

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    In this paper, I critically assess the enactive account of visual perception recently defended by Alva Noë (2004). I argue inter alia that the enactive account falsely identifies an object’s apparent shape with its 2D perspectival shape; that it mistakenly assimilates visual shape perception and volumetric object recognition; and that it seriously misrepresents the constitutive role of bodily action in visual awareness. I argue further that noticing an object’s perspectival shape involves a hybrid experience combining both perceptual and imaginative elements – an act of what I call ‘make-perceive.

    The MUSE-Wide Survey: A first catalogue of 831 emission line galaxies

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    We present a first instalment of the MUSE-Wide survey, covering an area of 22.2 arcmin2^2 (corresponding to ∼\sim20% of the final survey) in the CANDELS/Deep area of the Chandra Deep Field South. We use the MUSE integral field spectrograph at the ESO VLT to conduct a full-area spectroscopic mapping at a depth of 1h exposure time per 1 arcmin2^2 pointing. We searched for compact emission line objects using our newly developed LSDCat software based on a 3-D matched filtering approach, followed by interactive classification and redshift measurement of the sources. Our catalogue contains 831 distinct emission line galaxies with redshifts ranging from 0.04 to 6. Roughly one third (237) of the emission line sources are Lyman α\alpha emitting galaxies with 3<z<63 < z < 6, only four of which had previously measured spectroscopic redshifts. At lower redshifts 351 galaxies are detected primarily by their [OII] emission line (0.3≲z≲1.50.3 \lesssim z \lesssim 1.5), 189 by their [OIII] line (0.21≲z≲0.850.21 \lesssim z \lesssim 0.85), and 46 by their Hα\alpha line (0.04≲z≲0.420.04 \lesssim z \lesssim 0.42). Comparing our spectroscopic redshifts to photometric redshift estimates from the literature, we find excellent agreement for z<1.5z<1.5 with a median Δz\Delta z of only ∼4×10−4\sim 4 \times 10^{-4} and an outlier rate of 6%, however a significant systematic offset of Δz=0.26\Delta z = 0.26 and an outlier rate of 23% for Lyα\alpha emitters at z>3z>3. Together with the catalogue we also release 1D PSF-weighted extracted spectra and small 3D datacubes centred on each of the 831 sources.Comment: 24 pages, 14 figures, accepted for publication in A&A, data products are available for download from http://muse-vlt.eu/science/muse-wide-survey/ and later via the CD

    LSDCat: Detection and cataloguing of emission-line sources in integral-field spectroscopy datacubes

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    We present a robust, efficient, and user-friendly algorithm for detecting faint emission-line sources in large integral-field spectroscopic datacubes together with the public release of the software package LSDCat (Line Source Detection and Cataloguing). LSDCat uses a 3-dimensional matched filter approach, combined with thresholding in signal-to-noise, to build a catalogue of individual line detections. In a second pass, the detected lines are grouped into distinct objects, and positions, spatial extents, and fluxes of the detected lines are determined. LSDCat requires only a small number of input parameters, and we provide guidelines for choosing appropriate values. The software is coded in Python and capable to process very large datacubes in a short time. We verify the implementation with a source insertion and recovery experiment utilising a real datacube taken with the MUSE instrument at the ESO Very Large Telescope.Comment: 14 pages. Accepted for publication in Astronomy & Astrophysics. The LSDCat software is available at https://bitbucket.org/Knusper2000/lsdcat, v2 corrected typos and language editin

    Morphing a Stereogram into Hologram

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    This paper develops a simple and fast method to reconstruct reality from stereoscopic images. We bring together ideas from robust optical flow techniques, morphing deformations and lightfield 3D rendering in order to create unsupervised multiview images of a scene. The reconstruction algorithm provides a good visualization of the virtual 3D imagery behind stereograms upon display on a headset-free Looking Glass 3D monitor. We discuss the possibility of applying the method for live 3D streaming optimized via an associated lookup table.Comment: PDF, 8 pages, 4 Fig
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