Published in The Astrophysical Journal, Volume 869, Issue 2 (143), December 1, 2018, pages 1-16.
The definitive version is available at https://doi.org/10.3847/1538-4357/aaec75.
NGC 1275 is one of the most conspicuous active galactic nuclei (AGN) in the local universe. The radio jet currently emits a flux density of ~10 Jy at ~1 mm wavelengths, down from the historic high of ~65 Jy in 1980. Yet, the nature of the AGN in NGC 1275 is still controversial. It has been debated whether this is a broad emission line (BEL) Seyfert galaxy, an obscured Seyfert galaxy, a narrow line radio galaxy, or a BL Lac object. We clearly demonstrate a persistent Hβ BEL over the last 35 yr with a full width at half maximum (FWHM) of 4150–6000 km s−1. We also find a prominent Pα BEL (FWHM ≈ 4770 km s−1) and a weak C iv BEL (FWHM ≈ 4000 km s−1), Hβ/C iv ≈ 2. A far-UV Hubble Space Telescope observation during suppressed jet activity reveals a low luminosity continuum. The Hβ BEL luminosity is typical of broad line Seyfert galaxies with similar far-UV luminosity. X-ray observations indicate a softer ionizing continuum than what would be expected for a broad line Seyfert galaxy with similar far-UV luminosity. This is the opposite of the expectation of advection-dominated accretion. The AGN continuum appears to be thermal emission from a low luminosity, optically thick, accretion flow with a low Eddington ratio, ~0.0001. The soft, weak, ionizing continuum is consistent with the relatively weak C iv BEL. Evidence that the BEL luminosity is correlated with the jet millimeter-wave luminosity is presented. It appears that the accretion rate regulates jet power.
Copyright © 2018 American Astronomical Society
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