NGC 3242 and the enigmatic nature of its Low Ionization Structures: MUSE perspective

A planetary nebula (PN) is formed when low-to-intermediate mass stars expel their outer envelopes to the Interstellar Medium during the AGB phase. The UV radiation from the central star ionises the gas, leading to homogeneous nebular structures. However, in some PNe, we observe distinct small-scale structures with a lessened degree of ionisation level. These low-ionisation structures (LISs) are embedded in the PNe, and although there are some theoretical scenarios about their origin, their nature is poorly understood. My study is focused on NGC 3242, a multiple shell PN that contains a pair of LISs. The preliminary results of a 2D spectroscopic analysis of MUSE (Multi Unit Spectroscopic Explorer) via the SATELLITE code have shown that the electron temperature decrease moving outwards, while the electron density is slightly higher at the inner parts of the nebula. Additionally, my analysis confirms that NGC 3242 is a low-ionisation PN and that there is no significant chemical variation. Lastly, the thorough examination of MUSE data has led to the identification of the [C I] λ8727 emission line emitted only from the LISs. This unforeseen result supports the scenario of a photoevaporating dense molecular gas.