A New Class of Changing-Look LINERs
| Autor: | Charlotte Ward, Erin Kara, Shrinivas R. Kulkarni, Matteo Giomi, Adam A. Miller, S. Bradley Cenko, Maria T. Patterson, Jesper Sollerman, Russ R. Laher, Richard Dekany, Sjoert van Velzen, Michael Porter, Daniel Stern, Lin Yan, Thomas Kupfer, Suvi Gezari, David L. Shupe, U. Christoffer Fremling, Richard Walters, Chow-Choong Ngeow, Frank J. Masci, Tiara Hung, Ben Rusholme, Eric C. Bellm, Sara Frederick, Dmitry A. Duev, Nadejda Blagorodnova, Ulrich Feindt, James D. Neill, Kaushik De, Matthew J. Graham |
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| Rok vydání: | 2019 |
| Předmět: |
Active galactic nucleus
010504 meteorology & atmospheric sciences Astronomy Astrophysics::High Energy Astrophysical Phenomena FOS: Physical sciences Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences Spectral line law.invention law 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics Forbidden mechanism Spectroscopy 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics 0105 earth and related environmental sciences Physics High Energy Astrophysical Phenomena (astro-ph.HE) Astronomy and Astrophysics Light curve Astrophysics - Astrophysics of Galaxies Galaxy Accretion (astrophysics) Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) Astrophysics - High Energy Astrophysical Phenomena Flare |
| Zdroj: | The Astrophysical Journal, 883, 1-30 The Astrophysical Journal, 883, 1, pp. 1-30 |
| ISSN: | 0004-637X |
| DOI: | 10.48550/arxiv.1904.10973 |
| Popis: | We report the discovery of six active galactic nuclei (AGN) caught "turning on" during the first nine months of the Zwicky Transient Facility (ZTF) survey. The host galaxies were classified as LINERs by weak narrow forbidden line emission in their archival SDSS spectra, and detected by ZTF as nuclear transients. In five of the cases, we found via follow-up spectroscopy that they had transformed into broad-line AGN, reminiscent of the changing-look LINER iPTF 16bco. In one case, ZTF18aajupnt/AT2018dyk, follow-up HST UV and ground-based optical spectra revealed the transformation into a narrow-line Seyfert 1 (NLS1) with strong [Fe VII, X, XIV] and He II 4686 coronal lines. Swift monitoring observations of this source reveal bright UV emission that tracks the optical flare, accompanied by a luminous soft X-ray flare that peaks ~60 days later. Spitzer follow-up observations also detect a luminous mid-infrared flare implying a large covering fraction of dust. Archival light curves of the entire sample from CRTS, ATLAS, and ASAS-SN constrain the onset of the optical nuclear flaring from a prolonged quiescent state. Here we present the systematic selection and follow-up of this new class of changing-look LINERs, compare their properties to previously reported changing-look Seyfert galaxies, and conclude that they are a unique class of transients well-suited to test the uncertain physical processes associated with the LINER accretion state. Comment: Submitted to ApJ, 31 pages, 17 Figures (excluding Appendix due to file size constraints but will be available in electronic version) |
| Databáze: | OpenAIRE |
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