Jets from SANE super-Eddington accretion discs: morphology, spectra, and their potential as targets for ngEHT. Issue 2 (19th December 2022)

• Record Type: Journal Article
• Authors: Curd, Brandon; Emami, Razieh; Anantua, Richard; Palumbo, Daniel; Doeleman, Sheperd; Narayan, Ramesh
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 519:Issue 2(2023)
• Page Start: 2812
• Page End: 2837
• Publication Date: 2022-12-19
• Subjects: accretion, accretion discs -- black hole physics -- MHD -- radiative transfer; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stac3716
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We present general relativistic radiation magnetohydrodynamics (GRRMHD) simulations of super-Eddington accretion flows around supermassive black holes (SMBHs), which may apply to tidal disruption events (TDEs). We perform long duration ($t\ge 81, 200\, GM/c^3$ ) simulations that achieve mass accretion rates ≳11 times the Eddington rate and produce thermal synchrotron spectra and images of their jets. Gas flowing beyond the funnel wall expands conically and drives a strong shock at the jet head while variable mass ejection and recollimation, along the jet axis, results in internal shocks and dissipation. Assuming the ion temperature ( T i ) and electron temperature ( T e ) in the plasma are identical, the radio/submillimetre spectra peak at >100 GHz and the luminosity increases with BH spin, exceeding $\sim 10^{41} \, \rm {erg\, s^{-1}}$ in the brightest models. The emission is extremely sensitive to T i / T e as some models show an order-of-magnitude decrease in the peak frequency and up to four orders-of-magnitude decline in their radio/submillimetre luminosity as T i / T e approaches 20. Assuming a maximum VLBI baseline distance of 10 Gλ, 230 GHz images of T i / T e = 1 models shows that the jet head may be bright enough for its motion to be captured with the EHT (ngEHT) at D ≲ 110 (180) Mpc at the 5σ significance level. Resolving emission from internal shocks requires D ≲ 45 Mpc for both the EHT or ngEHT.