Young hidden pulsars

Massive stars end their lives in supernova explosions, leaving behind compact remnants that enclose the ember of the star, often a pulsar. The supernova remnant (SNR) and pulsar harbor vital information on the explosion mechanism that destroyed their predecessor. Studying these systems helps us to unravel e.g., the violent fates of massive stars and the formation of neutron stars. The youngest and most energetic pulsars create a pulsar wind nebulae (PWNe), which acts as a calorimeter. Finding younger and more energetic systems will thus lead us to pin down the initial energetics of pulsars, also elucidating the young-pulsar/Fast Radio Burst (FRB) connection.
This thesis focuses on finding young pulsars and understanding their environments. First, in Chapter 2 we conclude on the nature of the high-energy source HESS J1943+213, compatible with being either a PWN or a BL Lac object. Next, in Chapter 3 we explore to what extent PWNe and SNRs can negatively impact pulsar signal propagation. We find that for Galactic pulsars this effect is minimal. In Chapter 4 we aim to find young pulsars in SNRs and PWNe and report on a pulsar candidate in PWN G141.2+5.0. Finally, in Chapter 5 we report on the flux calibration verification we carried out as part of the scientific commissioning of ALERT, the Apertif LOFAR Exploration of the Radio Transient Sky.