July 16, 2026

Multimessenger prospects of quasi-periodic eruptions

Vojtěch Witzany, Alessia Franchini, Matteo Bonetti, and Luca Broggi Quasi-Periodic Eruptions (QPEs) are recurring soft X-ray transients that may be generated by inspirals of stellar-mass objects spiraling into supermassive black holes, known as extreme mass ratio inspirals (EMRIs). Independently, EMRIs and the gravitational-wave signals they generate are one of the key targets for the Laser Interferometer Space Antenna (LISA). What is the potential of a coincident detection of EMRIs both as a QPE and by LISA?

March 4, 2026

Two-body relaxation in the EMRI-TDE disk model for Quasi Periodic Eruptions

Chiara Maria Allievi, Luca Broggi, Alberto Sesana, and Matteo Bonetti Quasi Periodic Eruptions (QPEs) are luminous bursts of soft X-rays recently discovered in galactic nuclei. They repeat on timescales of hours to weeks, superimposed to an otherwise stable quiescent X-ray level, consistent with emission from a radiatively efficient accretion flow around relatively low-mass massive black holes (MBHs). Although their physical origin is still debated, their quasi- periodicity naturally arises within the ’impact model’, in which the X-ray bursts are generated by the interaction between a stellar black hole (sBH) or a star in a close orbit around the central MBH and the accretion disk formed by a tidal disruption event (TDE).

September 3, 2025

Eccentricity distribution of extreme mass ratio inspirals

D. Mancieri, L. Broggi, M. Vinciguerra, A. Sesana, and M. Bonetti We present realistic eccentricity distributions for extreme mass ratio inspirals (EMRIs) forming via the two-body relaxation channel in nuclear star clusters, tracking their evolution up to the final plunge onto the central Schwarzschild massive black hole (MBH). We find that EMRIs can retain significant eccentricities at plunge, with a distribution peaking at \(e_\mathrm{pl}≈0.2\), and a considerable fraction reaching much higher values.