Paper detail

Identifying Long Radio Transients with Accompanying X-Ray Emission as Disk-Jet Precessing Black Holes: The Case of ASKAP J1832-0911

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 Blandford-Znajek jet, as an alternative to magnetar or white-dwarf models. Methods: We derive the Lense-Thirring period $ P_{\rm LT}=\frac{πG M}{a c^3}r^3 $ and solve $P_{\rm LT}=44$ min for black-hole mass M and dimensionless radius $r=R/R_g$. We estimate the equipartition field B at r, compute the Blandford-Znajek power $P_{\rm BZ}$, and the power expected from a gap at the black hole magnetosphere, and compare the resulting jet luminosity to the observed radio and X-ray fluxes at $D\approx4.5$ kpc. We also evaluate expected high-frequency variability and the angular size for Very Long Baseline Interferometry (VLBI) observations. Results: For $a\sim0.3\!-\!0.9$, an IMBH with $M\sim10^3\!-\!10^5\,M_\odot$ yields $r\sim10\!-\!40\,R_g$ and $P_{\rm LT}=44$ min. Equipartition gives $B\sim10^5$ G at r, leading to $P_{\rm BZ}\sim10^{35\!-\!39}$ erg ${\rm s^{-1}}$. With radiative efficiency $ε_j\sim10^{-2}\!-\!10^{-1}$, the predicted $L_{\rm jet}\sim10^{34\!-\!36}$ erg ${\rm s^{-1}}$ matches the observed $F_X\sim10^{-12}$ erg ${\rm cm^{-2}}$ ${\rm s^{-1}}$ and radio flux, variability on $\lesssim100$ s could be a smoking gun of 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 (to check $\sim$s pulsations) and multi-frequency radio polarimetry can definitively distinguish it from magnetar or white-dwarf scenarios.