2025A&A...704A.123N -
Astronomy and Astrophysics, volume 704A123 (2025/12-1)
Identifying long radio transients with accompanying X-Ray emission as disk-jet precessing black holes: The case of ASKAP J1832-0911.
NATHANAIL A.
Abstract (from CDS):
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_\mathrm{{LT}}=\frac{\pi G M}{a c^3}r^3 $ and solved PLT = 44 min to obtain the black hole mass, M, and dimensionless radius, r = R/Rg. 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, PBZ,; 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 Rg and PLT = 44 min. Equipartition gives B ∼ 105 G at r, leading to PBZ ∼ 10^35 - 39^ erg s–1. With a radiative efficiency of ϵj ∼ 10–2 - 10–1, the predicted Ljet ∼ 10^34 - 36^ erg s–1 matches the observed FX ∼ 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.
Abstract Copyright:
© The Authors 2025
Journal keyword(s):
accretion - accretion disks - black hole physics - relativistic processes - stars: flare - X-rays: bursts
Simbad objects:
9
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