Extragalactic neutrino-emission induced by supermassive and stellar mass black hole mergers

Abstract

The recent detections of binary stellar mass black hole mergers by the LIGO and Virgo Collaborations suggest that such mergers are common occurrences. Galaxy mergers further indicate that supermassive black holes in centers of galaxies also merge and are typically expected to have had at least one merger in their lifetime, possibly many. In the presence of a jet, these mergers are almost always accompanied by a change of the jet direction and a connected jet precession motion, leading to interactions of the jet with ambient matter and producing very high-energy particles, and consequently high-energy gamma-rays and neutrinos. In this work, we investigate the possibility under which conditions such mergers could be the sources of the diffuse astrophysical neutrino flux measured by the IceCube Neutrino Observatory. The main free parameters in the calculation concern the frequency of the mergers and the fraction of energy that is transferred from the gravitationally released energy to neutrinos. We show that the merger rate for SMBBHs must lie between ∼10−7 and 10−5 Gpc−3 yr−1. The ratio of energy going to neutrinos during such mergers lies then between ∼10−6 − 3 · 10−4. For stellar mass BBH mergers, the rate needs to be ∼10–100 Gpc−3 yr−1 and the expected ratio of neutrino to gravitational wave energy lies in a comparable range as for SMBBHs, ∼2 · 10−5–10−3. These values lie in a reasonable parameter range, so that the production of neutrinos at the level of the detected neutrino flux is a realistic possibility.

Probing the Dark Matter density with gravitational waves from super-massive binary black holes

“…Future gravitational wave data from identified sources might allow to reduce the impact of astrophysical uncertainties. This could possibly lead to multi-messenger probes of super-massive binary black holes: connections with the astrophysical flux of high-energy neutrinos probed by IceCube are suggested in [78].…”

Acceleration and Spectral Redistribution of Cosmic Rays in Radio-jet Shear Flows

“…UHECRs also include nuclei such as oxygen and heavier ions (Mayotte et al 2022;The Pierre Auger Collaboration et al 2023). Radio galaxies with a selection of relativistic jets aimed at Earth (possibly up to four jets in the case of a supermassive black hole merger (e.g., Gergely & Biermann 2009), which appear as flat spectrum radio sources (Blandford 1979), are prime candidates as a source of UHECRs (Ginzburg & Syrovatskii 1963;Hillas 1984;Biermann & Strittmatter 1987;Jaroschewski et al 2023). All their activity may be traced to mergers of two central supermassive black holes following a merger of two galaxies (Toomre & Toomre 1972;Press & Schechter 1974;Gergely & Biermann 2009).…”

Neutrino Cadence of TXS 0506+056 Consistent with Supermassive Binary Origin

“…Once a periodicity can be confirmed in neutrinos, a theoretical model including all wavelengths can be developed. We can also learn from the measurements of the diffuse flux as discussed in Jaroschewski et al (2022). Here, we evaluate the possibility that the detected diffuse flux is composed of the emission from a combination of SMBBHs and BBHs, as suggested by the ultrahigh-energy cosmic-ray data.…”

“…It can be best explained by gamma absorption as outlined later. First evidence that neutrino sources must be connected to gamma absorption was already seen in the first signal of the diffuse neutrino flux (Kimura et al 2015;Murase et al 2016). Even here, theoretical models are in need of gamma-ray absorption in order not to overshoot the diffuse gamma-ray flux as measured by Fermi (Murase et al 2013;Ahlers & Halzen 2015).…”