Probing the precise location of the radio core in the TeV blazar Mrk 501 with VERA at 43 GHz

Shoko Koyama, Motoki Kino, Akihiro Doi, Kotaro Niinuma, Kazuhiro Hada, Hiroshi Nagai, Mareki Honma, Kazunori Akiyama, Marcello Giroletti, Gabriele Giovannini, Monica Orienti, Naoki Isobe, Jun Kataoka, David Paneque, Hideyuki Kobayashi, Keiichi Asada

    Research output: Contribution to journalArticle

    3 Citations (Scopus)

    Abstract

    We investigate the position of the radio core in a blazar by multi-epoch astrometric observations at 43 GHz. Using the VLBI Exploration of Radio Astrometry (VERA), we have conducted four adjacent observations in 2011 February and another four in 2011 October, and succeeded in measuring the position of the radio core in the TeV blazar Mrk 501 relative to a distant compact quasar NRAO 512. During our observations, we find that (1) there is no positional change within ∼0.2 mas or ∼2.0 pc de-projected with ±1 σ error for the weighted-mean phase-referenced positions of the Mrk 501 core relative to NRAO 512 over four adjacent days, and (2) there is an indication of position change for the 3C 345 core relative to NRAO 512. By applying our results to the standard internal shock model for blazars, we constrain the bulk Lorenz factors of the ejecta.

    Original languageEnglish
    Article number67
    JournalPublications of the Astronomical Society of Japan
    Volume67
    Issue number4
    DOIs
    Publication statusPublished - 2015 May 25

    Keywords

    • Astrometry
    • Galaxies: active
    • Galaxies: individual (Mrk 501 3C 345, NRAO 512)
    • Radio continuum: galaxies
    • Techniques: interferometric

    ASJC Scopus subject areas

    • Astronomy and Astrophysics
    • Space and Planetary Science

    Fingerprint Dive into the research topics of 'Probing the precise location of the radio core in the TeV blazar Mrk 501 with VERA at 43 GHz'. Together they form a unique fingerprint.

  • Cite this

    Koyama, S., Kino, M., Doi, A., Niinuma, K., Hada, K., Nagai, H., Honma, M., Akiyama, K., Giroletti, M., Giovannini, G., Orienti, M., Isobe, N., Kataoka, J., Paneque, D., Kobayashi, H., & Asada, K. (2015). Probing the precise location of the radio core in the TeV blazar Mrk 501 with VERA at 43 GHz. Publications of the Astronomical Society of Japan, 67(4), [67]. https://doi.org/10.1093/pasj/psu144