HEAT mtg: Suvi Gezari & Joanna Berteaud, UMD-ASTR

White Dwarf Tidal Disruption Events

Suvi Gezari, UMD-ASTR

Abstract: I will present a white board talk on why white dwarf tidal disruption events are powerful probes of intermediate-mass black holes in the Universe, and what the most promising observational signatures are to identify them.

Glitches and anti-glitches in the magnetar 1E2259+586

Joanna Berteaud, UMD-ASTR

Abstract: 1E2259+586 is a magnetar, i.e., a young, isolated neutron star with a long spin period and a large spin-down rate, implying a large surface dipole magnetic field strength. Magnetars are usually observed as bright and pulsating X-ray sources exceeding their rotational energy losses. Hence, unlike the less-magnetic rotation-powered pulsars, magnetars are believed to be powered through the decay of their large inferred magnetic fields. The timing of 1E2259+586, monitored since 1996, shows abrupt spin-downs and spin-ups called glitches and anti-glitches. These glitches can be radiatively quiet, suggesting that these phenomena originate in the neutron star interior, and that their triggering mechanism do not necessarily have to be connected to the magnetosphere. We analyzed NICER data of 1E2259+586 collected between 2018 and 2025 and report on the discovery of new timing discontinuities.

Host: Jillian Chin Rastinejad