Don't Breathe: It's a Trap

Saha, A.; Markowitz, D.

doi:10.1164/ajrccm-conference.2023.207.1_meetingabstracts.a1356

Cited by 1 publication

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“…We also undertook detailed spectroscopic follow-up of a CLAGN candidate, ZTF19aagwzod, which was discovered after an optical flare to have transitioned from a Seyfert 1.9 to Seyfert 1 classification (Frederick et al 2020). This object has since been the subject of detailed multiwavelength follow-up, indicating the presence of X-ray variability but no X-ray spectral evolution (Saha et al 2023). The broad-line profile of ZTF19aagwzod is typical for DPEs which are well described by a circular disk model.…”

Section: Spectroscopic Monitoring Of Two Unusual Dpes and Amentioning

confidence: 99%

“…The four follow-up spectra taken from 2020 January 23 to 2020 December 6 show a stable disk profile with very little change over the course of the year following the flare (Figure 8). The combination of optical Baldwin, Phillips, and Terlevich (BPT) line ratios, indicating that AGN activity has persisted for millennia prior to this event, and lack of X-ray spectral evolution led Saha et al (2023) to conclude that the change of classification from Seyfert 1.9 to Seyfert 1 associated with the optical flare was due to a temporary instability in the accretion flow. The lack of evolution in the disk profile suggests that the disk structure stabilized quickly after the optical flare.…”

Section: Ztf18aarywbt: Asymmetric Radio Jets and An Evolving Disk Pro...mentioning

confidence: 99%

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Panic at the ISCO: Time-varying Double-peaked Broad Lines from Evolving Accretion Disks Are Common among Optically Variable AGNs

Ward,

Gezari,

Nugent

et al. 2024

ApJ

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About 3%–10% of Type I active galactic nuclei (AGNs) have double-peaked broad Balmer lines in their optical spectra originating from the motion of gas in their accretion disk. Double-peaked profiles arise not only in AGNs, but occasionally appear during optical flares from tidal disruption events and changing-state AGNs. In this paper, we identify 250 double-peaked emitters (DPEs) among a parent sample of optically variable broad-line AGNs in the Zwicky Transient Facility (ZTF) survey, corresponding to a DPE fraction of 19%. We model spectra of the broad Hα emission-line regions and provide a catalog of the fitted accretion disk properties for the 250 DPEs. Analysis of power spectra derived from the 5 yr ZTF light curves finds that DPE light curves have similar amplitudes and power-law indices to other broad-line AGNs. Follow-up spectroscopy of 12 DPEs reveals that ∼50% display significant changes in the relative strengths of their red and blue peaks over long 10–20 yr timescales, indicating that broad-line profile changes arising from spiral arm or hotspot rotation are common among optically variable DPEs. Analysis of the accretion disk parameters derived from spectroscopic modeling provides evidence that DPEs are not in a special accretion state, but are simply normal broad-line AGNs viewed under the right conditions for the accretion disk to be easily visible. We include inspiraling supermassive black hole binary candidate SDSSJ1430+2303 in our analysis, and discuss how its photometric and spectroscopic variability is consistent with the disk-emitting AGN population in the ZTF survey.

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Section: Spectroscopic Monitoring Of Two Unusual Dpes and Amentioning

confidence: 99%

Section: Ztf18aarywbt: Asymmetric Radio Jets and An Evolving Disk Pro...mentioning

confidence: 99%