VLBI astrometry up to 130 GHz using multi frequency calibration

Maria Rioja Capellan, R. Dodson, T.S. S. Jung, B. W. Sohn

    Research output: Chapter in Book/Conference paperConference paper

    Abstract

    Simultaneous observations at multiple frequency bands have the potential to overcome the fundamental limitation imposed by the atmospheric propagation in mm-VLBI observations. The propagation effects place a severe limit in the sensitivity achievable in mm-VLBI, reducing the time over which the signals can be coherently combined, and preventing the use of phase referencing and astrometric measurements. We carried out simultaneous observations at 22, 43, 87 and 130 GHz of a group of five AGNs, the weakest of which is ca. 200 mJy at 130 GHz, with angular separations ranging from 3.6 to 11 degrees, using the KVN. We analysed this data using the Frequency Phase Transfer (FPT) and the Source Frequency Phase Referencing (SFPR) techniques, which use the observations at a lower frequency to correct those at a higher frequency. The results of the analysis provide an empirical demonstration of the increase in the coherence times at 130 GHz from a few tens of seconds to about twenty minutes, with FPT, and up to many hours with SFPR. Moreover the astrometric analysis provides high precision relative position measurements between two frequencies, including, for the first time, astrometry at 130 GHz.

    Original languageEnglish
    Title of host publication2016 URSI Asia-Pacific Radio Science Conference, URSI AP-RASC 2016
    EditorsSangwook Nam, Kazuya Kobayashi, Piergiorgio Uslenghi
    PublisherIEEE, Institute of Electrical and Electronics Engineers
    Pages48-51
    Number of pages4
    ISBN (Electronic)9781467388016
    ISBN (Print)9781467388016
    DOIs
    Publication statusPublished - 19 Oct 2016
    Event2016 URSI Asia-Pacific Radio Science Conference, URSI AP-RASC 2016 - Seoul, Korea, Republic of
    Duration: 21 Aug 201625 Aug 2016

    Conference

    Conference2016 URSI Asia-Pacific Radio Science Conference, URSI AP-RASC 2016
    CountryKorea, Republic of
    CitySeoul
    Period21/08/1625/08/16

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  • Cite this

    Rioja Capellan, M., Dodson, R., Jung, T. S. S., & Sohn, B. W. (2016). VLBI astrometry up to 130 GHz using multi frequency calibration. In S. Nam, K. Kobayashi, & P. Uslenghi (Eds.), 2016 URSI Asia-Pacific Radio Science Conference, URSI AP-RASC 2016 (pp. 48-51). [7601374] IEEE, Institute of Electrical and Electronics Engineers. https://doi.org/10.1109/URSIAP-RASC.2016.7601374