Identifying long radio transients with accompanying X-Ray emission as disk-jet precessing black holes: The case of ASKAP J1832-0911

Research Center for Astronomy and Applied Mathematics, Academy of Athens, Athens 11527, Greece

^⋆ Corresponding author: anathanail@academyofathens.gr

Received: 17 June 2025
Accepted: 23 September 2025

Abstract

Aims. In this work we investigate whether the 2-min bursts every 44 min from ASKAP J1832-0911 can be explained by Lense-Thirring precession of an intermediate-mass black hole (IMBH) accretion disk launching a jet as an alternative to magnetar or white dwarf models.

Methods. We derived the Lense-Thirring period P_LT = πGM/ac³r³ and solved P_LT = 44 min to obtain the black hole mass, M, and dimensionless radius, r = R/R_g. We estimated the equipartition field, B, at r while assuming an advection dominated accretion flow or a magnetically arrested disk accretion model; we computed the Blandford-Znajek power, P_BZ,; and we compared the resulting jet luminosity to the observed radio and X-ray fluxes at D ≈ 4.5 kpc. We also describe a coherent emission model based on a merging plasmoid close to the black hole.

Results. For a ∼ 0.3 − 0.9, an IMBH with M ∼ 10³ − 10⁵ M_⊙ yields r ∼ 10 − 40 R_g and P_LT = 44 min. Equipartition gives B ∼ 10⁵ G at r, leading to P_BZ ∼ 10^{35 − 39} erg s⁻¹. With a radiative efficiency of ϵ_j ∼ 10⁻² − 10⁻¹, the predicted L_jet ∼ 10^{34 − 36} erg s⁻¹ matches the observed F_X ∼ 10⁻¹² erg cm⁻² s⁻¹ and radio flux. The variability at ≲100 s could be clear evidence supporting this model.

Conclusions. The IMBH precessing-jet model simultaneously explains the periodicity, energetics, and duty cycle of ASKAP J1832-0911. Only high time resolution X-ray timing (in order to exclude ∼s pulsations) and multi-frequency radio polarimetry (to confirm a flat, low-polarization spectrum) can definitively distinguish the IMBH model from magnetar or white dwarf scenarios.