Anisotropic wind in tidal disruption events
Abstract
Over the coming years, the number of tidal disruption events (TDEs) is expected to substantially increase with observations from the Vera Rubin Observatory (g and r band) and {\it ULTRASAT} (near UV) wide-field surveys. These future samples have great promise to characterize the bottom end of the massive black hole mass function, but existing detections of intermediate mass black hole TDEs are primarily in X-rays, leaving their optical/UV emission largely unexplored. We present a time- and angle-dependent analysis of the outflow produced by dissipation near pericentre in a three-dimensional end-to-end radiation-hydrodynamics simulation of a TDE by a 104 M⊙ black hole with realistic parameters, run with the code RICH. We find that outflow anisotropy produces viewing-angle-dependent observables. Towards the poles and the pericentre region, mass-loss rates are low and bolometric luminosities reach ∼2--$3$ times the Eddington luminosity. Towards the stream, the properties show a stronger dependence on latitude: the mass-loss rate increases and the bolometric luminosity decreases as the line of sight approaches the orbital plane. These denser regions favour Hα and Hβ emission. Despite these variations, all viewing directions show a common spectral evolution, with an initial soft X-ray flare followed (around 1.25tfb≈3~days) by the reprocessing of shock-powered emission into the UV and optical bands. Although the optical/UV luminosities we predict for this TDE are likely too dim for past surveys (e.g. ASAS-SN, ZTF), they are within the detection capabilities of LSST and ULTRASAT to horizons of ∼ 790 and ∼ 340 Mpc, respectively, for the brightest viewing directions.
Related
- Rates of tidal disruption events from constrained cosmological simulations of the local Universe: population properties and implications for transient surveys
- Tidal Disruption Events on FIRE: Illuminating the Cosmic Evolution of Tidal Disruption Rates
- Observational signatures of warped accretion flows in tidal disruption events
- Compact Object Mergers and Micro-Tidal Disruption Events: A Multi-Messenger Probe of Dense Stellar Environments
- A Suppressed Volumetric Rate of High-Luminosity Mid-Infrared Selected Tidal Disruption Events
BibTeX
@misc{martire2026anisotropic,
title = {{Anisotropic wind in tidal disruption events}},
author = {Paola Martire and Elena Maria Rossi and Nicholas Chamberlain Stone and Elad Steinberg and Itamar Giron},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.10213},
eprint = {2609.10213},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.10213},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Anisotropic wind in tidal disruption events
AU - Paola Martire
AU - Elena Maria Rossi
AU - Nicholas Chamberlain Stone
AU - Elad Steinberg
AU - Itamar Giron
PY - 2026
DA - 2026/09/09
PB - arXiv
DO - 10.48550/arxiv.2609.10213
UR - https://arxiv.org/abs/2609.10213
AB - Over the coming years, the number of tidal disruption events (TDEs) is expected to substantially increase with observations from the Vera Rubin Observatory (g and r band) and {\it ULTRASAT} (near UV) wide-field surveys. These future samples have great promise to characterize the bottom end of the massive black hole mass function, but existing detections of intermediate mass black hole TDEs are primarily in X-rays, leaving their optical/UV emission largely unexplored. We present a time- and angle-dependent analysis of the outflow produced by dissipation near pericentre in a three-dimensional end-to-end radiation-hydrodynamics simulation of a TDE by a 10^4 M_⊙ black hole with realistic parameters, run with the code RICH. We find that outflow anisotropy produces viewing-angle-dependent observables. Towards the poles and the pericentre region, mass-loss rates are low and bolometric luminosities reach ∼2--$3$ times the Eddington luminosity. Towards the stream, the properties show a stronger dependence on latitude: the mass-loss rate increases and the bolometric luminosity decreases as the line of sight approaches the orbital plane. These denser regions favour Hα and Hβ emission. Despite these variations, all viewing directions show a common spectral evolution, with an initial soft X-ray flare followed (around 1.25t_fb≈3~days) by the reprocessing of shock-powered emission into the UV and optical bands. Although the optical/UV luminosities we predict for this TDE are likely too dim for past surveys (e.g. ASAS-SN, ZTF), they are within the detection capabilities of LSST and ULTRASAT to horizons of ∼ 790 and ∼ 340 Mpc, respectively, for the brightest viewing directions.
ER -