Non-Axisymmetric Pillar Structures due to Embedded Stars in AGN Accretion Discs

Clicks: 9
ID: 333601
2026
Free PDF
Article Quality & Performance Metrics
Overall Quality
Not rated
Combines reader engagement with the AI quality analysis. This article has not been analysed, so there is no overall score — reader engagement is measured and shown alongside.
AI Quality Assessment
Not analyzed
Readership in this journal
Emerging

Ranked #1,277 of 1,339 articles by views in monthly notices of the royal astronomical society

Most read Least read

Bar heights use a square-root scale. Only the 120 most-read articles are drawn; the journal has 1,339 in total.

Mint this article as an NFT
Not yet minted

Create a permanent, verifiable on-chain record of this article on the Scimatic Network. The NFT is held in your Journament account, and you can withdraw it to your own wallet at any time.

5 SUSD one-off · no wallet required
Sign in to mint
Abstract
Abstract Gravitationally unstable outer regions of AGN discs may host in situ formation of massive stars whose heating produces localized vertical “pillars” on the disc surface, in the same region that emits the broad lines. Here we investigate the reverberation-mapping signatures that such pillars would produce. We compute velocity–delay maps Ψ(λ, τ), time-evolving emission-line spectra, and continuum reverberation lag spectra for these structures. We model each pillar as a 2D Gaussian perturbation to the disc height under lamp-post irradiation and weight the line response with Cloudy photoionization grids covering the major BLR lines. We show Hα, Mg ii, and C iv as representative examples. A single pillar produces a localized hotspot in Ψ and a clear “S-wave” pattern in the time-evolving spectrum that persists, though diluted, for N ∼ 100 pillars. Emission-line fluxes are suppressed in shadows behind the pillars, but when normalized by Hβ (or by the local continuum) the line-to-Hβ ratios move in opposite directions: Mg ii/Hβ rises while C iv/Hβ drops. This contrast distinguishes pillars from purely kinematic features that would modulate all lines by similar factors. Across scans of the pillar shape and lamp-post height, the pillar models produce an optical continuum reverberation lag spectrum of the observed magnitude. The once-per-orbit modulation grows with sin i from foreshortening, and at sufficiently high inclination the pillar’s body geometrically self-occults its lamp-facing inner slope, adding a sharper near/far contrast. These signatures provide observational diagnostics for detecting in situ star formation in AGN discs through velocity-resolved reverberation mapping campaigns.
Reference Key
openalex_W7223347109 Use this key to autocite in the manuscript while using SciMatic Manuscript Manager or Thesis Manager
Authors Jiamu Huang, Douglas N. C. Lin, K. Horne
Are you one of these authors? Claim your profile
Journal monthly notices of the royal astronomical society
Year 2026
DOI
10.1093/mnras/stag2020
URL
https://doi.org/10.1093/mnras/stag2020
Keywords Keywords not found

Citations

No citations found. To add a citation, contact the admin at info@scimatic.org

Comments

No comments yet. Be the first to comment on this article.