Toward a more complete optical census of active galactic nuclei via spatially resolved spectroscopy

• Verfasst von: Comerford, Julia M. [VerfasserIn]
• Verfasst von: Negus, James [VerfasserIn]
• Verfasst von: Barrows, R. Scott [VerfasserIn]
• Verfasst von: Wylezalek, Dominika [VerfasserIn]
• Verfasst von: Greene, Jenny E. [VerfasserIn]
• Verfasst von: Müller Sánchez, Francisco [VerfasserIn]
• Verfasst von: Nevin, Rebecca [VerfasserIn]
• Titel: Toward a more complete optical census of active galactic nuclei via spatially resolved spectroscopy
• Verf.angabe: Julia M. Comerford, James Negus, R. Scott Barrows, Dominika Wylezalek, Jenny E. Greene, Francisco Müller-Sánchez, and Rebecca Nevin
• E-Jahr: 2022
• Jahr: 2022 March 2
• Umfang: 15 S.
• Fussnoten: Gesehen am 21.04.2022
• Titel Quelle: Enthalten in: The astrophysical journal / 1
• Ort Quelle: London : Institute of Physics Publ., 1995
• Jahr Quelle: 2022
• Band/Heft Quelle: 927(2022), 1, Artikel-ID 23, Seite 1-15
• ISSN Quelle: 1538-4357
• DOI: doi:10.3847/1538-4357/ac496a
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 179951319X

Abstract

While emission line flux ratio diagnostics are the most common technique for identifying active galactic nuclei (AGNs) in optical spectra, applying this approach to single-fiber spectra of galaxies can omit entire subpopulations of AGNs. Here, we use spatially resolved spectroscopy from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey to construct a sample of 10 galaxies where Baldwin-Philips-Terlevich line flux ratio diagnostics classify each galaxy’s central 3″ spectrum as LINER or star-forming, while >10% of the spaxels in the galaxy’s MaNGA footprint are classified as Seyfert. We obtain Chandra observations of these 10 galaxies with off-nuclear Seyfert regions to determine whether AGNs are actually present in them. Our main result is that 7-10 (depending on strictness of criteria) of the galaxies host one or more X-ray AGNs, even though none of them were classified as AGNs based on their single-fiber optical spectra. We find that these AGNs were not identified in the single-fiber spectra because they are AGNs in the nuclei of companion galaxies, low-luminosity AGNs, dust-obscured AGNs, and/or flickering AGNs. In summary, we find that off-nuclear AGN signatures may increase the number of known AGNs by a factor of two over what conventional single nuclear fiber spectra identify. Our results show that spatially resolved spectroscopy can be leveraged to reveal a more complete census of AGNs that are traditionally missed by single-fiber spectra.