Medium-resolution Optical and Near-infrared Spectral Atlas of 16 2MASS-selected NIR-red Active Galactic Nuclei at z ∼ 0.3

Dohyeong Kim, Myungshin Im, Gabriela Canalizo, Minjin Kim, Ji Hoon Kim, Jong Hak Woo, Yoon Chan Taak, Jae Woo Kim, Mariana Lazarova

Research output: Contribution to journalArticle

1 Scopus citations

Abstract

We present medium-resolution spectra (R ∼ 2000-4000) at 0.4-1.0 μm and 0.7-2.5 μm of 16 active galactic nuclei (AGNs) selected with red color in the near-infrared (NIR) of J - K > 2.0 mag at z ∼ 0.3. We fit the Hβ, Hα, Pβ, and Pα lines from these spectra to obtain their luminosities and line widths. We derive the E(B - V) color excess values of the NIR-red AGNs using two methods, one based on the line-luminosity ratios and another based on the continuum slopes. The two E(B - V) values agree with each other at rms dispersion ∼0.249. About half of the NIR-red AGNs have g′ - K < 5 magnitude, and we find that these NIR-red, but blue in optical-NIR AGNs, have E(B - V) ∼ 0, suggesting that a significant fraction of the NIR color-selected red AGNs are unobscured or only mildly obscured. After correcting for the dust extinction, we estimate the black hole (BH) masses and the bolometric luminosities of the NIR-red AGNs using the Paschen lines to calculate their Eddington ratios (λ Edd). The median Eddington ratios of nine NIR-red AGNs (log(λEdd) ≃ -0.654 ± 0.176) are only mildly higher than those of unobscured type 1 AGNs ((log(λEdd) ≃ -0.961 ± 0.008). Moreover, we find that the M BH relation for three NIR-red AGNs is consistent with that of unobscured type 1 AGNs at similar redshift. These results suggest that the NIR-red color selection alone is not effective at picking up dusty, intermediate-stage AGNs.

Original languageEnglish (US)
Article number37
JournalAstrophysical Journal, Supplement Series
Volume238
Issue number2
DOIs
StatePublished - Oct 2018

Keywords

  • galaxies: Seyfert
  • galaxies: active
  • galaxies: evolution
  • quasars: emission lines
  • quasars: general
  • quasars: supermassive black holes

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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