A Family Tree of Optical Transients from Narrow-Line Seyfert 1 Galaxies

Abstract

The Zwicky Transient Facility (ZTF) has discovered five new events belonging to an emerging class of AGN undergoing smooth flares with large amplitudes and rapid rise times. This sample consists of several transients that were initially classified as supernovae with narrow spectral lines. However, upon closer inspection, all of the host galaxies display resolved Balmer lines characteristic of a narrow-line Seyfert 1 (NLSy1) galaxy. The transient events are long-lived, over 400 days on average. We report UV and X-ray follow-up of the flares and observe persistent UV-bright emission, with two of the five transients detected with luminous X-ray emission, ruling out a supernova interpretation. We compare the properties of this sample to previously reported flaring NLSy1 galaxies, and find that they fall into three spectroscopic categories: Transients with 1) Balmer line profiles and Fe II complexes typical of NLSy1s, 2) strong He II profiles, and 3) He II profiles including Bowen fluorescence features. The latter are members of the growing class of AGN flares attributed to enhanced accretion reported by Trakhtenbrot et al. (2019). We consider physical interpretations in the context of related transients from the literature. For example, two of the sources show high amplitude rebrightening in the optical, ruling out a simple tidal disruption event scenario for those transients. We conclude that three of the sample belong to the Trakhtenbrot et al. (2019) class, and two are TDEs in NLSy1s. We also aim to understand why NLSy1s are preferentially the sites of such rapid enhanced flaring activity.

arXiv commentSubmitted to ApJ, 27 pages, 11 figures

References in corpus (93)

• LSST: from Science Drivers to Reference Design and Anticipated Data Products
• The Galaxy Evolution Explorer: A Space Ultraviolet Survey Mission
• The Zwicky Transient Facility: System Overview, Performance, and First Results
• Reverberation Measurements for 17 Quasars and the Size-Mass-Luminosity Relations in Active Galactic Nuclei
• Methods and results of an automatic analysis of a complete sample of Swift-XRT observations of GRBs
• A Catalog of Quasar Properties from SDSS DR7
• First Results from the Catalina Real-time Transient Survey
• The Zwicky Transient Facility: Data Processing, Products, and Archive
• The eROSITA X-ray telescope on SRG
• The Zwicky Transient Facility: Science Objectives
• Mid-Infrared Selection of AGN with the Wide-Field Infrared Survey Explorer. I. Characterizing WISE-Selected AGN in COSMOS
• WISeREP - An Interactive Supernova Data Repository
• The Pan-STARRS1 Surveys
• On the black hole - bulge mass relation in active and inactive galaxies
• Mid-Infrared Selection of Active Galactic Nuclei with the Wide-Field Infrared Survey Explorer. II. Properties of WISE-Selected Active Galactic Nuclei in the NDWFS Boötes Field
• Revised Catalog of GALEX Ultraviolet Sources. I. The All-sky Survey: GUVcat_AIS
• The Discovery of the First "Changing Look" Quasar: New Insights into the Physics & Phenomenology of AGN
• Seventeen Tidal Disruption Events from the First Half of ZTF Survey Observations: Entering a New Era of Population Studies
• The Zwicky Transient Facility: Surveys and Scheduler
• A Comprehensive Study of 2 000 Narrow Line Seyfert 1 Galaxies from the Sloan Digital Sky Survey: I. The Sample
• A Systematic Search for Changing-Look Quasars in SDSS
• A systematic search for close supermassive black hole binaries in the Catalina Real-Time Transient Survey
• The first XMM-Newton slew survey catalogue: XMMSL1
• Caltech Core-Collapse Project (CCCP) observations of type IIn supernovae: typical properties and implications for their progenitor stars
• Updating quasar bolometric luminosity corrections
• The Simultaneous Optical-to-X-ray Spectral Energy Distribution of Soft X-ray Selected AGN observed by Swift
• The effect of radiation pressure on virial black hole mass estimates and the case of Narrow Line Seyfert 1 galaxies
• A tidal disruption event coincident with a high-energy neutrino
• Flash Spectroscopy: Emission Lines from the Ionized Circumstellar Material around $<10$-Day-Old Type II Supernovae
• The SED Machine: a robotic spectrograph for fast transient classification
• Fully-Automated Reduction of Longslit Spectroscopy with the Low Resolution Imaging Spectrometer at Keck Observatory
• Optical-Ultraviolet Tidal Disruption Events
• PS16dtm: A Tidal Disruption Event in a Narrow-line Seyfert 1 Galaxy
• 1ES 1927+654: An AGN Caught Changing Look on a Timescale of Months
• A Mid-IR Selected Changing-Look Quasar and Physical Scenarios for Abrupt AGN Fading
• A tidal disruption flare in a massive galaxy? Implications for the fuelling mechanisms of nuclear black holes
• Changing-Look Quasar Candidates: First Results from Follow-up Spectroscopy of Highly Optically Variable Quasars
• The ASAS-SN Catalog of Variable Stars III: Variables in the Southern TESS Continuous Viewing Zone
• A large fraction of hydrogen-rich supernova progenitors experience elevated mass loss shortly prior to explosion
• The GROWTH Marshal: A Dynamic Science Portal for Time-Domain Astronomy
• A Catalog of Narrow Line Seyfert 1 Galaxies from the Sloan Digital Sky Survey Data Release 12
• Towards an Understanding of Changing-Look Quasars: An Archival Spectroscopic Search in SDSS
• The Lick AGN Monitoring Project 2011: Fe II Reverberation from the Outer Broad-Line Region
• Superluminous supernovae
• Evidence for rapid disk formation and reprocessing in the X-ray bright tidal disruption event AT 2018fyk
• A Fully Automated Integral Field Spectrograph Pipeline for the SEDMachine: pysedm
• The Zwicky Transient Facility Alert Distribution System
• Investigating the nature of narrow-line Seyfert 1 galaxies with high-energy spectral complexity
• Evolution of Active Galaxies: Black-hole Mass - Bulge relations for Narrow Line Objects
• A new physical interpretation of optical and infrared variability in quasars
• Understanding extreme quasar optical variability with CRTS: I. Major AGN flares
• ASASSN-14ko is a Periodic Nuclear Transient in ESO 253-G003
• Understanding extreme quasar optical variability with CRTS: II. Changing-state quasars
• The first tidal disruption flare in ZTF: from photometric selection to multi-wavelength characterization
• Discovery of transient infrared emission from dust heated by stellar tidal disruption flares
• A New Class of Changing-Look LINERs
• Narrow-Line Seyfert 1s: 15 Years Later
• The Broad Absorption Line Tidal Disruption Event iPTF15af: Optical and Ultraviolet Evolution
• A new class of flares from accreting supermassive black holes
• The swan song: the disappearance of the nucleus of NGC 4051 and the echo of its past glory
• Transient processing and analysis using $\text{AMPEL}$: Alert Management, Photometry and Evaluation of Lightcurves
• Dependence of the optical/UV variability on the emission line properties and Eddington ratio in active galactic nuclei
• The Discovery and Nature of Optical Transient CSS100217:102913+404220
• Tidal disruption events in active galactic nuclei
• Correlation Analysis of a Large Sample of Narrow-Line Seyfert 1 Galaxies: Linking Central Engine and Host Properties
• TDE Hosts are Green and Centrally Concentrated: Signatures of a Post-Merger System
• On the geometry of broad emission region in quasars
• A population of highly energetic transient events in the centres of active galaxies
• Radio-loud Narrow Line Seyfert 1 under a different perspective: a revised black hole mass estimate from optical spectropolarimetry
• The swansong in context: long-timescale X-ray variability of NGC 4051
• Minidisks in Binary Black Hole Accretion
• Abundance Anomalies In Tidal Disruption Events
• To TDE or not to TDE: The luminous transient ASASSN-18jd with TDE-like and AGN-like qualities
• Optical Variability of Narrow-Line Seyfert 1 Galaxies
• NLS1 galaxies and estimation of their central black hole masses from the X-ray excess variance method
• Extreme X-ray Variability In The Narrow-Line QSO PHL 1092
• catsHTM - A tool for fast accessing and cross-matching large astronomical catalogs
• Infrared echo and late-stage rebrightening of nuclear transient PS1-10adi: exploring Torus by tidal disruption event in active galactic nuclei
• Rapid "Turn-on" of type 1 AGN in a quiescent early type galaxy SDSS1115+0544
• AT 2019avd: A novel addition to the diverse population of nuclear transients
• Two stripped envelope supernovae with circumstellar interaction -- but only one really shows it
• A Uniformly Selected Sample of Low-Mass Black Holes in Seyfert 1 Galaxies. II. The SDSS DR7 Sample
• A Tidal Disruption Event Candidate Discovered in the Active Galactic Nucleus SDSS J022700.77-042020.6
• Late-time observations of the extraordinary Type II supernova iPTF14hls
• Discovery and Follow-up of the Unusual Nuclear Transient OGLE17aaj
• Tidal Disruptions of Main Sequence Stars of Varying Mass and Age: Inferences from the Composition of the Fallback Material
• Four (Super)luminous Supernovae from the First Months of the ZTF Survey
• Helium-rich Superluminous Supernovae From the Zwicky Transient Facility
• J004457+4123 (Sharov 21): not a remarkable nova in M31 but a background quasar with a spectacular UV flare
• Spectral features of tidal-disruption candidates and alternative origins for such transient flares
• Evidence of Rapid Optical Variability In Selected Narrow-Line Seyfert 1 Galaxies
• A Candidate Tidal Disruption Event in a Quasar at z=2.359 from Abundance Ratio Variability
• X-ray Reverberation Mapping and Dramatic Variability of Seyfert 1 Galaxy 1H 1934-063

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