Exploring the Initial B-Field Function of massive stars by simulating magnetic detectability in stars clusters

The origin of stellar magnetic fields in intermediate- and high-mass stars remains an enigma in astronomy. Surveys find that about 10% of these stars in our galaxy exhibit globally organized magnetic fields without any apparent relationship with their stellar or rotational parameters. These magnetic fields are thought to be fossil fields, meaning they are purely dissipative, unlike dynamo-generated fields in low-mass stars. Taking into account the impact of fossil magnetic fields significantly changes their evolutionary tracks due to magnetic braking and mass-loss quenching. We present a study of synthetic star clusters generated with the population model MOSS and with MESA evolutionary models that account for the effects of magnetic braking and mass loss quenching. The values for the magnetic fields are assigned using various “Initial B-ield Functions” (IBF). Lastly, using current observational estimates from spectropolometric measurements, we infer how many stars in our simulated star clusters would have detectable B fields, assuming typical survey observing strategies. Our results show that higher temperatures and luminous stars are easier to detect than their counterparts at different cluster ages. We use these results to disentangle the role of observational biases from that of the true form of the IBF in explaining the properties of known magnetic massive stars.