F. Ochsenbein

University of Strasbourg, Strasbourg, Alsace, France

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Publications (171)30.39 Total impact

  • Q. Parker, I. Bojicic, D. Frew, T. Day, A. Acker, Francois Ochsenbein
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    ABSTRACT: There have been a LOT of new Galactic PNe discovered over the last 15 years, more than doubling the totals accrued by all telescopes over the previous 200+ years.. The scope of PNe studies for these ~3500 GPN should reflect this new landscape, coloured and nuanced by these new discoveries and the massive, new high sensitivity, high resolution, multi-wavelength imaging surveys now available. Following this motivation we provide, for the first time, an accessible, reliable on-line "one-stop" shop for essential, up-to date information for all known Galactic PN. We aim to: * Reliably remove the many PN mimics/false ID's that have biased previous compilations and subsequent studies * Provide accurate, updated positions, sizes, morphologies, radial velocities, fluxes, multi-wavelength imagery and spectroscopy * Link to CDS/Vizier and hence provide archival history for each object * Provide an SQL interface to sift, select, browse, collate, investigate, download and visualise the complete currently known Galactic PNe diaspora * ence to provide the community with the most complete data with which to undertake new science!
    03/2014;
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    ABSTRACT: The Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) is a high impact scientific program which will see its final official release open to the world in 2012. That release will seal the legacy aspect of the survey which has already produced a large collection of scientific articles with topics ranging from cosmology to the Solar system. The survey core science was focused on dark energy and dark matter: the full realization of the scientific potential of the data set gathered between 2003 and 2009 with the MegaCam wide-field imager mounted at the CFHT prime focus is almost complete with the Supernovae Legacy Survey (SNLS) team preparing its third and last release (SNLS5), and the CFHTLenS team planning the release based around the cosmic shear survey later this year. While the data processing center TERAPIX offered to the CFHTLS scientific community regular releases over the course of the survey in its data acquisition phase (T0001-T0006), the final release took three years to refine in order to produce a pristine data collection photometrically calibrated at better than the percent both internally and externally over the total survey surface of 155 square degrees in all five photometric bands (u*, g’, r’, i’, z’). This final release, called T0007, benefits from the various advances in photometric calibration MegaCam has benefited through the joint effort between SNLS and CFHT to calibrate MegaCam at levels unexplored for an optical wide-field imager. T0007 stacks and catalogs produced by TERAPIX will be made available to the world at CADC while the CDS will offer a full integration of the release in its VO tools from VizieR to Aladin. The photometric redshifts have been produced to be released in phase with the survey. This proceeding is a general introduction to the survey and aims at presenting its final release in broad terms.
    Proc SPIE 09/2012;
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    ABSTRACT: Canada and France joined a large fraction (~50%) of their dark and grey telescope time from mid-2003 to early 2009 for a large project, the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). The data acquisition and calibration has been a major undertaking for the Canadian and French communities: more than 2300 hours over 5 years (an equivalent of 450 nights) have been devoted to the survey using the wide field optical imaging camera MegaCam, a 1°x1° field of view 340 Megapixel camera. The CFHTLS comprises 2 components: "CFHTLS Deep", 4 independent 1deg2 MegaCam pointing, and "CFHT Wide" comprising 171 MegaCam pointings covering ~155deg2 in 4 contiguous independent patches. All areas are located far from the galactic plane, and their central positions are: -------------------------------------------------- Field RA (J2000) Dec Galactic position -------------------------------------------------- W1 02:18 -07:00 172.468 -61.242 W2 08:54 -04:15 232.067 +24.743 W3 14:17:54 +54:30:31 098.850 +58.390 W4 22:13:18 +01:19 063.243 -42.511 D1 02:25:59 -04:29:40 171.993 -58.054 D2 10:00:28 +02:23:30 236.616 +42.227 D3 14:19:27 +52:40:56 096.227 +59.642 D4 22:15:31 -17:43:56 039.271 -52.925 -------------------------------------------------- This final release of the CFHTLS benefits greatly from vastly improved flat-fielding and photometric calibration techniques developed by the Supernovae Legacy Survey (SNLS) team and CFHT which allows us to significantly improve the precision of our photometric calibration compared to previous releases. The astrometric accuracy reaches 0.02arcsec internal and 0.2arcsec external. The set of filters used for the survey are close to the SDSS filter set; their characteristics and a comparison to SDSS can be found at http://www3.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/megapipe/docs/filters.html Please ee the documentation file "T0007-doc.pdf" for details concerning this T0007 release. (2 data files).
    VizieR Online Data Catalog. 09/2012;
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    ABSTRACT: Since the unifying Strasbourg-ESO Catalogue of Galactic Planetary Nebulae (SECGPN) a large number of new discoveries have been made thanks to improved surveys and discovery techniques. The increasingly heterogeneous published population of Galactic PNe, that we have determined totals < 2850 PNe, is becoming more difficult to study on the whole without a centralised repository. We introduce a consolidated and interactive online database with object classifications that reflect the latest multi-wavelength data and the most recent results. The extensible database, hosted by the Centre de Donnees astronomique de Strasbourg (CDS), will contain a wealth of observed data for large, well-defined samples of PNe including coordinates, multi-wavelength images, spectroscopy, line intensities, radial velocities and central star information. It is anticipated that the database will be publicly released early 2012.
    Proceedings of the International Astronomical Union 10/2011;
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    ABSTRACT: This document describes the list of controlled terms used to build the Unified Content Descriptors, Version 1+ (UCD1+). The document describing the UCD1+ can be found at the URL: http://www.ivoa.net/Documents/latest/UCD.html. This document reviews the structure of the UCD1+ and presents the current vocabulary.
    10/2011;
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    ABSTRACT: This document describes the current understanding of the IVOA controlled vocabulary for describing astronomical data quantities, called Unified Content Descriptors (UCDs). The present document defines a new standard (named UCD1+) improving the first generation of UCDs (hereafter UCD1). The basic idea is to adopt a new syntax and vocabulary requiring little effort for people to adapt softwares already using UCD1. This document also addresses the questions of maintenance and evolution of the UCD1+. Examples of use cases within the VO, and tools for using UCD1+ are also described.
    10/2011;
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    ABSTRACT: This document describes the structures making up the version 1.2 of the VOTable standard, which supersedes the version 1.1 of 08 August 2004. The differences between versions 1.1 and 1.2 are summarized in the last section. The main part of this document describes the adopted part of the VOTable standard; it is followed by appendices presenting extensions which have been proposed and/or discussed, but which are not part of the standard.
    10/2011;
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    ABSTRACT: According to what is stated in the IVOA Recommendation "An IVOA standard for Unified Content Descriptors", a procedural document should be created in order to maintain (add, change, suppress words) the standard list of UCD1+ words "The UCD1+ Controlled Vocabulary". This document describes the procedure to maintain the standard list of UCD1+ words.
    10/2011;
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    ABSTRACT: Scientific results strongly rely on previous studies, experiments, and observations. A huge quantity of data is produced by astronomers and needs to be available to the whole community. To support astronomers in their daily research work, the Centre de Données astronomiques de Strasbourg (Strasbourg astronomical data center – CDS) collects, verifies, homogenizes, and organizes information – in particular, those published in academic journals – in the most appropriate and comprehensible way. This CDS goal can reach the highest level of quality only through a close collaboration with journals, authors, and referees. This paper presents the succession of processes leading published data to the CDS databases, focusing on the strategy that maintains a high level of quality. Authors and referees are strongly encouraged to actively contribute to this endeavor. A few examples of how CDS databases are used through CDS services are also presented.
    EAS Publications Series 12/2010; 49:135 - 157.
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    ABSTRACT: Since the emergence of electronic publications in the early 1990s, astronomy has played a pioneering role in the development and implementation of new capabilities and services. As a data center, the CDS contributed significantly to this evolution: a synergy between data centers and journal editors started in the 1990s with the publication of large tables and data sets in electronic form and contributed to an efficient linking of publications with existing databases like SIMBAD or NED. This collaborative work, carried out in practice by information scientists, illustrates a new role for us who now have to deal with both editor and database requirements. After a short description of the CDS, we present our peculiar responsibilities related to the publication process: ensuring, prior to publication, that the link from selected objects quoted by the authors in their papers to the SIMBAD database is correct and maintained in the long term, that the tables and their complete descriptions are accessible through VizieR, and that the data and bibliography are correctly entered in SIMBAD. The Dictionary of Nomenclature, which plays an important role in these procedures, is briefly presented. Finally, the skills we developed for these activities are shortly discussed.
    10/2010;
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    ABSTRACT: We dreamed of it, we developed it, and now we use it. DJIN is a powerful tool that recognizes astronomical object names in full texts. DJIN is very efficient and helpful for the SIMBAD team who have been dealing with an ever increasing number of astronomical articles. DJIN detects most of the astronomical object names quoted in full-text articles, but the team still has to check and validate the names, to deal with new identifiers, to verify cross-identifications and to update SIMBAD with new astronomical data (position, magnitudes, etc.). That is, the team work is concentrated on value-added aspects, the best use of the team's expertise. This was an important consideration in the design of the software. DJIN provides more than just the recognition of names; it says how many times an astronomical object is cited in a text (whatever its identifier is), where it is cited (title, abstracts, keyword, tables, figures, text, etc.) and keeps track of the relation between the identifiers and articles. DJIN is fully integrated in the SIMBAD process, and interfaces the updating software used daily by the team. It is also a starting point for new features like linking SIMBAD and NED, and computing the relevance of each paper attached to one object. DJIN has been fully tested by the whole team to check both the quality of detection and the tool's ergonomics. Team feedback has been critical for the success of this difficult and risky endeavor. In this paper we describe this tool, and our experience after two years of usage; we discuss also the the significant changes in our daily work that DJIN has triggered.
    10/2010;
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    ABSTRACT: The new release of the SPECFIND radio cross-identification catalogue, SPECFIND V2.0, is presented. It contains 107488 cross-identified objects with at least three radio sources observed at three independent frequencies. Compared to the previous release the number of entry radio catalogues is increased from 20 to 97 containing 115 tables. This large increase was only made possible by the development of four tools at CDS which use the standards and infrastructure of the Virtual Observatory (VO). This was done in the framework of the VO-TECH European Design Study of the Sixth Framework Program. We give an overview of the different classes of radio sources that a user can encounter. Due to the increase of frequency coverage of the input radio catalogues, this release demonstrates that the SPECFIND algorithm is able to detect spectral breaks around a frequency of ~1 GHz. Comment: 11 pages, 10 figures, accepted for publication in A&A
    Astronomy and Astrophysics 12/2009; · 5.08 Impact Factor
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    ABSTRACT: The SPECFIND catalogue of radio cross-identifications and spectra, which is available in VizieR (Ochsenbein et al. 2000), has been used to search for Gigahertz peaked source candidates. These sources were observed quasi-simultaneously with the Effelsberg 100-m radio telescope at 6 cm (4.85~GHz), 2.8~cm (10.45 GHz), and 9 mm (32 GHz). It turned out that this is an efficient procedure to discover new Gigahertz peaked sources, which are believed to be AGNs at the beginning of their radio evolution. A new SPECFIND V2.0 catalogue is presented. It contains the cross-identification of 87000 radio objects from 105 catalogues or 3.76 million radio sources. With an increase of 8% of available sources we increase the number of radio objects with associated radio spectra by 25%. Going from 20 catalogues in the previous SPECFIND release to 105 catalogues in the new release was only possible due to the development of three Virtual Observatory (VO) tools within the European VO-TECH project. These new tools (i) identify pertinent radio catalogues in the VO registry using Unified Content Descriptors (UCDs), (ii) extract relevant data, and (iii) normalize these for the determination of radio spectra.
    07/2009;
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    ABSTRACT: The Working Group FITS (WG-FITS) is the international control authority for the Flexible Image Transport System (FITS) data format. The WG-FITS was formed in 1988 by a formal resolution of the IAU XX General Assembly in Baltimore (MD, USA), 1988, to maintain the existing FITS standards and to approve future extensions to FITS.
    Proceedings of the International Astronomical Union 01/2009; 4(27A):366-368.
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    ABSTRACT: We describe an online system for automated classification of X-ray sources, ClassX, and we present preliminary results of classification of the three major catalogs of ROSAT sources, ROSAT All-Sky Survey (RASS) Bright Source Catalog, RASS Faint Source Catalog, and WGACAT, into six class categories: stars, white dwarfs, X-ray binaries, galaxies, active galactic nuclei, and clusters of galaxies. ClassX is based on a machine-learning technology. It represents a system of classifiers, each classifier consisting of a considerable number of oblique decision trees. These trees are built as the classifier is "trained" to recognize various classes of objects using a training sample of sources of known object types. Each source is characterized by a preselected set of parameters, or attributes; the same set is then used as the classifier conducts classification of sources of unknown identity. The ClassX pipeline features an automatic search for X-ray source counterparts among heterogeneous data sets in online data archives using Virtual Observatory protocols; it retrieves from those archives all the attributes required by the selected classifier and inputs them to the classifier. The user input to ClassX is typically a file with target coordinates, optionally complemented with target IDs. The output contains the class name, attributes, and class probabilities for all classified targets. We discuss ways to characterize and assess the classifier quality and performance, and we present the respective validation procedures. On the basis of both internal validation and external verification, we conclude that the ClassX classifiers yield reasonable and reliable classifications for ROSAT sources and have the potential to broaden class representation significantly for rare object types.
    The Astrophysical Journal 12/2008; 616(2):1284. · 6.73 Impact Factor
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    ABSTRACT: The business meeting began with a brief review of the current rules and procedures of the WG, which are documented on the WG web page. Four regional FITS committees have been established by the WG, covering North American, Europe, Japan, and Australian/New Zealand, to provide advice to the WG on pending proposals. While it is recognized that this committee structure might need to be revised to provide representation to other regions, the current system is working well, and there were no motions to make any changes at this time.
    Proceedings of the International Astronomical Union 12/2007; 3(26B):218-218.
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    ABSTRACT: At the 2003 Sydney IAU meeting, Marion Schmitz (Caltech, USA) took over the chair of the Commission 5 Working Group Designations, succeeding Helene Dickel. The Working Group Designations of IAU Commission 5 clarifies existing astronomical nomenclature and helps astronomers avoid potential problems when designating their sources. The most important function of WG Designations during the period 2003-2005 was overseeing the IAU REGISTRY FOR ACRONYMS (for newly discovered astronomical sources of radiation: see the website <http://cdsweb.u-strasbg.fr/cgi-bin/DicForm>) which is sponsored by the WG and operated by the Centre de Données de Strasbourg (CDS). The Clearing House, a subgroup of the WG, screens the submissions for accuracy and conformity to the IAU Recommendations for Nomenclature (<http://cdsweb.u-strasbg.fr/iau-spec.html>). From its beginning in 1997 through August 2006, there have been 132 submissions and 111 acceptances. Attempts to register asterisms, common star names, and suspected variable stars were rejected. The past three years saw 61 acronyms submitted with 50 of them being accepted. (GIRL - yes; WOMEN - no).
    Proceedings of the International Astronomical Union 12/2007; 3(26B):217-217.
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    ABSTRACT: Commission 5 has been very active during the IAU XXVI General Assembly in Prague: the Commission, its Working Groups and its Task Force held business meetings. In addition, Commission 5 sponsored two Special Sessions: Special Session 3 on The Virtual Observatory in Action: New Science, New Technology, and Next Generation Facilities which was held for three days 17 22 August, and Special Session 6 on Astronomical Data Management, which was held on 22 August. Commission 5 also participated in the organisation of Joint Discussion 16 on Nomenclature, Precession and New Models in Fundamental Astronomy, which was held 22-23 August. The General Assembly and Commission 5 web sites provides links to detailed information about all these meetings.
    Proceedings of the International Astronomical Union 12/2007; 3(26B):212-216.
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    ABSTRACT: The CDS value-added bibliographic services, SIMBAD and VizieR, are updated daily. Most of the information comes from the astronomical literature and the update mechanism is different for different types of information. The semi-automated SIMBAD data flow is described and the synergy between astronomers, specialized librarians and computer engineers is discussed.
    09/2007; 377:43.
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    ABSTRACT: A new version of SIMBAD, SIMBAD4, has been developed at the CDS. Basically, everything that SIMBAD does today will be possible with the new version but not necessarily in the same way. The new features will concern the queries, flux, object types and hierarchical links.
    09/2007; 377:197.