192,959 research outputs found

    Galaxy Nurseries: Crowdsourced analysis of slitless spectroscopic data

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    We present the results of Galaxy Nurseries project, which was designed to enable crowdsourced analysis of slitless spectroscopic data by volunteer citizen scientists using the Zooniverse online interface. The dataset was obtained by the WFC3 Infrared Spectroscopic Parallel (WISP) Survey collaboration and comprises NIR grism (G102 and G141) and direct imaging. Volunteers were instructed to evaluate indicated spectral features and decide whether it was a genuine emission line or more likely an artifact. Galaxy Nurseries was completed in only 40 days, gathering 414,360 classifications from 3003 volunteers for 27,333 putative emission lines. The results of Galaxy Nurseries demonstrate the feasibility of identifying genuine emission lines in slitless spectra by citizen scientists. Volunteer responses for each subject were aggregated to compute fRealf_{\mathrm{Real}}, the fraction of volunteers who classified the corresponding emission line as "Real". To evaluate the accuracy of volunteer classifications, their aggregated responses were compared with independent assessments provided by members of the WISP Survey Science Team (WSST). Overall, there is a broad agreement between the WSST and volunteers' classifications, although we recognize that robust scientific analyses typically require samples with higher purity and completeness than raw volunteer classifications provide. Nonetheless, choosing optimal threshold values for fRealf_{\mathrm{Real}} allows a large fraction of spurious lines to be vetoed, substantially reducing the timescale for subsequent professional analysis of the remaining potential lines.Comment: Accepted for publication in Research Notes of the AA

    ASAS Light Curves of Intermediate Mass Eclipsing Binaries and the Parameters of HI Mon

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    We present a catalog of 56 candidate intermediate mass eclipsing binary systems extracted from the 3rd data release of the All Sky Automated Survey. We gather pertinent observational data and derive orbital properties, including ephemerides, for these systems as a prelude to anticipated spectroscopic observations. We find that 37 of the 56, or ~66% of the systems are not identified in the Simbad Astronomical Database as known binaries. As a specific example, we show spectroscopic data obtained for the system HI Mon (B0 V + B0.5 V) observed at key orbital phases based on the computed ephemeris, and we present a combined spectroscopic and photometric solution for the system and give stellar parameters for each component.Comment: 83 pages, 63 figure

    Multi-wavelength photometric variation of PG1605+072

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    In a large coordinated attempt to further our understanding of the pp-mode pulsating sdB star PG1605+072, the Multi-Site Spectroscopic Telescope (MSST) collaboration has obtained simultaneous time-resolved spectroscopic and photometric observations. The photometry was extended by additional WET data which increased the time base. This contribution outlines the analysis of the MSST photometric light curve, including the four-colour BUSCA data from which chromatic amplitudes have been derived, as well as supplementary FUV spectra and light curves from two different epochs. These results have the potential to complement the interpretation of the published spectroscopic information.Comment: 6 pages, to be published in "Interpretation of asteroseismic data", proceedings of the HELAS NA5 Workshop, eds. W. Dziembowski, M. Breger and M. Thompson, Communications in Asteroseismology, 15

    THE CANADA-FRANCE REDSHIFT SURVEY II: Spectroscopic Program; Data for the 0000-00 and 1000+25 Fields

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    This paper describes the methods used to obtain the spectroscopic data and construct redshift catalogs for the Canada-France deep Redshift Survey (CFRS). The full data set consists of more than one thousand spectra, of objects with 17.5 < I_{AB} < 22.5, obtained from deep multi-slit data with the MARLIN and MOS-SIS spectrographs at the CFHT. The final spectroscopic catalog contains 200 stars, 591 galaxies with secure redshifts in the range 0 < z < 1.3, 6 QSOs, and 146 objects with very uncertain or unknown redshifts, leading to an overall success rate of identification of 85%. Additionally, 67 objects affected by observational problems have been placed in a supplemental list. We describe here the instrumental set up, and the observing procedures used to efficiently gather this large data set. New optimal ways of packing spectra on the detector to significantly increase the multiplexing gain offered by multi-slit spectroscopy are described. Dedicated data reduction procedures have been developed under the IRAF environment to allow for fast and accurate processing. Very strict procedures have been followed to establish a reliable list of final spectroscopic measurements. Fully independent processing of the data has been carried out by three members of the team for each data set associated with a multi-slit mask, and final redshifts were assigned only after the careful comparison of the three independent measurements. A confidence class scheme was established. We strongly emphasize the benefits of such procedures. Finally, we present the spectroscopic data obtained for 303 objects in the 0000-00 and 1000+25 fields. The success rate in spectroscopic identification isComment: 16 uuencoded postcript pages with figures 4,5,8,9 and 12. Other (large) figures available from the authors. Large data table not yet released. Also available at http://www.dao.nrc.ca/DAO/SCIENCE/science.html and coming soon on a CFRS homepage. Accepted June 19, scheduled for the Dec 10 issue of Ap

    The VIMOS Public Extragalactic Survey (VIPERS): First Data Release of 57 204 spectroscopic measurements

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    We present the first Public Data Release (PDR-1) of the VIMOS Public Extragalactic Survey (VIPERS). It comprises 57 204 spectroscopic measurements together with all additional information necessary for optimal scientific exploitation of the data, in particular the associated photometric measurements and quantification of the photometric and survey completeness. VIPERS is an ESO Large Programme designed to build a spectroscopic sample of ' 100 000 galaxies with iAB < 22.5 and 0.5 < z < 1.5 with high sampling rate (~45%). The survey spectroscopic targets are selected from the CFHTLS-Wide five-band catalogues in the W1 and W4 fields. The final survey will cover a total area of nearly 24 deg2, for a total comoving volume between z = 0.5 and 1.2 of ~4x10^7 h^(-3)Mpc^3 and a median galaxy redshift of z~0.8. The release presented in this paper includes data from virtually the entire W4 field and nearly half of the W1 area, thus representing 64% of the final dataset. We provide a detailed description of sample selection, observations and data reduction procedures; we summarise the global properties of the spectroscopic catalogue and explain the associated data products and their use, and provide all the details for accessing the data through the survey database (http://vipers.inaf.it) where all information can be queried interactively.Comment: Accepted for publication in A&A Added and/or replaced some figure, added section on DataBase interface, expaned Introductio
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