Periodic Reporting for period 2 - LOVE-NEST (Looking for Super-Massive Neutron Stars)
Reporting period: 2023-06-01 to 2024-11-30
Until recently the record was 2 Solar masses. Theory tells us that this limit cannot be much higher than 3 Solar masses. Knowing the answer has a major impact on gravitational wave astronomy and nuclear physics.
LOVE-NEST is focused on a new population of neutron stars in compact binaries known as “spiders”, because we have strong evidence that they harbor supermassive neutron stars.
The first goal is to find them by using optical photometry.
The second goal is to measure accurately their masses, using a new technique that our group pioneered.
The third goal is to model, simulate and understand the interaction between the relativistic pulsar wind and its surroundings.
The impact of LOVE-NEST will further reach:
• the nuclear physics community: the maximum neutron star mass depends on the microscopic interactions between particles in the core at densities of more than 1E15 g/cm3.
• the rising field of gravitational wave astronomy: the signal and outcome of a double neutron star merger depends on the maximum neutron star mass.
-2022. X-ray variability disk state. Discovery of break frequencies in the X-ray power spectra of two transitional millisecond pulsars.
-2023. Irradiation in spiders: a broad view. Explained the dichotomy between two vs. one maximum in the optical light curves of spiders.
-2023. Found that the optical luminosity is correlated with the orbital period.
-2024. Revealed an invisible black widow undetected at all wavelengths except radio.
-2024. Found variable asymmetry and a new potential supermassive neutron star.
-2024. Found a face-on redback that mimicks a black widow.
-2024. Discovered new spider candidates.
-Precise measurements of another 3-4 massive neutron stars.
-New X-ray counterparts to black widow pulsars.
-Evolutionary tracks of compact binary millisecond pulsars, linked to their corresponding spin evolution.
-GR-MHD simulations of the disk state including for the first time radiative transfer.