Integral field spectroscopy of the planetary nebula NGC 3242 and the puzzling nature of its low-ionization structures

• Autores: Konstantinou, L.; Akras, S.; Garcia Rojas, J.; Bouvis, K.; Gonçalves, D. R.; Monteiro, H.; Boumis, P.; Mari, María Belén; Aleman, I.; Monreal-Ibero, A.
• Año de publicación: 2025
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: techniques: imaging spectroscopy; ISM: abundances; dust; extinction; planetary nebulae: general
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Context. We investigate the physico-chemical properties of the planetary nebula (PN) NGC 3242 in both 1D and 2D, using integral field unit (IFU) data. This PN has a complex morphology with multiple shells and contains a pair of structures with a lower degree of ionization compared to the main nebular components. The origin of these so-called low-ionization structures (LISs) remains a mystery. Aims. With the capabilities offered by IFU spectroscopy, we aim to gain a better understanding of the behavior of nebular properties in the LISs and examine the spatial distribution of physico-chemical parameters in NGC 3242. Methods. Data from the Multi Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope (VLT) were used in order to perform a spatially resolved physico-chemical analysis of NGC 3242. The analysis was performed both in 2D, based on emission line maps, as well as in 1D, via simulations of long-slit spectroscopy, with pseudo-slits. Results. Through the deeper investigation of MUSE data, we detected new structures perpendicular to the pair of LISs of NGC 3242, which are mainly seen in the light of [S III] and [N II]. In addition, two arc-like structures were revealed. Moreover, an inner jet-like structure was found through its [Fe III] emission. The interaction of the jet with the rim may be related to the formation of knots and blobs. The higher value of Te , is estimated from the [S III] diagnostic lines, followed by Te ([N II]), Te(H I) and, finally, Te (He I). In all cases, Te is higher at the inner nebular structures. Regarding electron density, ne , is lower at the LISs, while an increase is observed at the nebular rim. Diagnostic diagrams confirm that NGC 3242 is a highly ionized nebula. Moreover, for the first time, the MUSE data have unveiled the atomic line [C I] λ8727 in this PN, which is primarily emitted from the LISs. This finding suggests that these structures may consist of a molecular core surrounded by neutral and ionized gas.
Fil: Konstantinou, L.. National Observatory of Athens; Grecia. University Of Patras (university Of Patras);
Fil: Akras, S.. National Observatory of Athens; Grecia
Fil: Garcia Rojas, J.. Universidad de La Laguna; España
Fil: Bouvis, K.. University Of Patras (university Of Patras); . National Observatory of Athens; Grecia
Fil: Gonçalves, D. R.. Universidade Federal do Rio de Janeiro; Brasil
Fil: Monteiro, H.. Universidade Federal de Itajuba; Brasil
Fil: Boumis, P.. National Observatory of Athens; Grecia
Fil: Mari, María Belén. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina
Fil: Aleman, I.. No especifíca;
Fil: Monreal-Ibero, A.. Leiden University; Países Bajos