• Login
    View Item 
    •   Maryland Shared Open Access Repository Home
    • ScholarWorks@UMBC
    • UMBC College of Natural and Mathematical Sciences
    • UMBC Physics Department
    • View Item
    •   Maryland Shared Open Access Repository Home
    • ScholarWorks@UMBC
    • UMBC College of Natural and Mathematical Sciences
    • UMBC Physics Department
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Near-infrared and gamma-ray monitoring of TANAMI gamma-ray bright sources

    Thumbnail
    Files
    aa21094-13.pdf (446.5Kb)
    Links to Files
    https://www.aanda.org/articles/aa/abs/2013/07/aa21094-13/aa21094-13.html
    Permanent Link
    https://doi.org/10.1051/0004-6361/201321094
    http://hdl.handle.net/11603/18137
    http://simbad.u-strasbg.fr/simbad/sim-ref?querymethod=bib&simbo=on&submit=submit+bibcode&bibcode=2013A%26A...555A...2N
    https://ned.ipac.caltech.edu/cgi-bin/objsearch?search_type=Search&refcode=2013A%26A...555A...2N
    http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=J/A+A/555/A2
    Collections
    • UMBC Center for Space Sciences and Technology (CSST) / Center for Research and Exploration in Space Sciences & Technology II (CRSST II)
    • UMBC Physics Department
    Metadata
    Show full item record
    Author/Creator
    Nesci, R.
    Tosti, G.
    Pursimo, T.
    Ojha, R.
    Kadler, M.
    Date
    2013-06-18
    Type of Work
    5 pages
    Text
    journal articles
    Citation of Original Publication
    Near-infrared and gamma-ray monitoring of TANAMI gamma-ray bright sources R. Nesci, G. Tosti, T. Pursimo, R. Ojha and M. Kadler A&A, 555 (2013) A2 , https://doi.org/10.1051/0004-6361/201321094
    Rights
    This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.
    © ESO 2013
    Abstract
    Context. Spectral energy distribution and its variability are basic tools for understanding the physical processes operating in active galactic nuclei (AGN). Aims. In this paper we report the results of a one-year near-infrared (NIR) and optical monitoring of a sample of 22 AGN known to be gamma-ray emitters, aimed at discovering correlations between optical and gamma-ray emission. Methods. We observed our objects with the Rapid Eye Mount (REM) telescope in J,H,K, and R bands nearly twice every month during their visibility window and derived light curves and spectral indexes. We also analyzed the gamma-ray data from the Fermi gamma-ray Space Telescope, making weekly averages. Results. Six sources were never detected during our monitoring, proving to be fainter than their historical Two micron all sky survey (2MASS) level. All of the sixteen detected sources showed marked flux density variability, while the spectral indexes remained unchanged within our sensitivity limits. Steeper sources showed, on average, a larger variability. From the NIR light curves we also computed a variability speed index for each detected source. Only one source (PKS 0208-512) underwent an NIR flare during our monitoring. Half of the sources showed a regular flux density trend on a one-year time scale, but do not show any other peculiar characteristic. The broadband spectral index αro appears to be a good proxy of the NIR spectral index only for BL Lac objects. No clear correlation between NIR and gamma-ray data is evident in our data, save for PKS 0537−441, PKS 0521−360, PKS 2155−304, and PKS 1424−418. The gamma-ray/NIR flux ratio showed a large spread, QSO being generally gamma-louder than BL Lac, with a marked correlation with the estimated peak frequency (νpeak) of the synchrotron emission.


    Albin O. Kuhn Library & Gallery
    University of Maryland, Baltimore County
    1000 Hilltop Circle
    Baltimore, MD 21250
    www.umbc.edu/scholarworks

    Contact information:
    Email: scholarworks-group@umbc.edu
    Phone: 410-455-3021


    If you wish to submit a copyright complaint or withdrawal request, please email mdsoar-help@umd.edu.

     

     

    My Account

    LoginRegister

    Browse

    This CollectionBy Issue DateTitlesAuthorsSubjectsType

    Statistics

    View Usage Statistics


    Albin O. Kuhn Library & Gallery
    University of Maryland, Baltimore County
    1000 Hilltop Circle
    Baltimore, MD 21250
    www.umbc.edu/scholarworks

    Contact information:
    Email: scholarworks-group@umbc.edu
    Phone: 410-455-3021


    If you wish to submit a copyright complaint or withdrawal request, please email mdsoar-help@umd.edu.