Looking for Super-Massive Neutron Stars

Informazioni relative al progetto

LOVE-NEST

ID dell’accordo di sovvenzione: 101002352

DOI

10.3030/101002352

Data della firma CE 25 Maggio 2021

Data di avvio 1 Dicembre 2021

Data di completamento 31 Agosto 2027

Finanziato da

• EXCELLENT SCIENCE - European Research Council (ERC)

Costo totale

€ 1 997 625,00

Contributo UE

€ 1 997 625,00

Coordinato da

NORGES TEKNISK-NATURVITENSKAPELIGE UNIVERSITET NTNU
Norway

Periodic Reporting for period 2 - LOVE-NEST (Looking for Super-Massive Neutron Stars)

Periodo di rendicontazione: 2023-06-01 al 2024-11-30

Sintesi del contesto e degli obiettivi generali del progetto

What is the maximum mass that a neutron star can support before collapsing into a black hole?
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.

Lavoro eseguito dall’inizio del progetto fino alla fine del periodo coperto dalla relazione e principali risultati finora ottenuti

The main results of LOVE-NEST so far include:

-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.

Progressi oltre lo stato dell’arte e potenziale impatto previsto (incluso l’impatto socioeconomico e le implicazioni sociali più ampie del progetto fino ad ora)

Expected results include:

-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.

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