JHK′ imaging photometry of Seyfert 1 active galactic nuclei and quasars. I. Multiaperture photometry

Keigo Enya*, Yuzuru Yoshii, Yukiyasu Kobayashi, Takeo Minezaki, Masahiro Suganuma, Hiroyuki Tomita, Bruce A. Peterson

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    8 Citations (Scopus)


    Near-infrared JHK′ imaging photometry was obtained of 331 AGNs consisting mainly of Seyfert 1 active galactic nuclei (AGNs) and quasars (QSOs). This sample was selected to cover a range of radio emission strength, redshift from z = 0 to 1, and absolute B magnitude from MB = -29 mag to -18 mag. Among low-z AGNs with z < 0.3, Seyfert 1-1.5 AGNs are distributed over a region from a location typical of " galaxies " to a location typical of "QSOs" in the two-color J-H to H-K′ diagram, but Seyfert 1.8-2 AGNs are distributed around the location of " galaxies. " Moreover, bright AGNs with respect to absolute B magnitude are distributed near the location of " QSOs," while faint AGNs are near the location of " galaxies." The distribution of such low-z AGNs in this diagram was found to have little dependence on their 6 cm radio flux. The near-infrared colors of the AGNs observed with an aperture of 7 pixels (7.″49) are more QSO-like than those observed with larger apertures up to 15 pixels (16.″1). This aperture effect may be explained by contamination from the light of host galaxies within larger apertures. This effect is more prominent for less luminous AGNs.

    Original languageEnglish
    Pages (from-to)23-29
    Number of pages7
    JournalAstrophysical Journal, Supplement Series
    Issue number1
    Publication statusPublished - Jul 2002


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