Detailed studies of IPHAS sources – II. Sab 19, a true planetary nebula and its mimic crossing the Perseus Arm. Issue 3 (27th October 2020)

• Record Type: Journal Article
• Authors: Guerrero, M A; Ortiz, R; Sabin, L; Ramos-Larios, G; Alfaro, E J
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 501:Issue 3(2021)
• Page Start: 3594
• Page End: 3604
• Publication Date: 2020-10-27
• Subjects: planetary nebulae: general -- planetary nebulae: individual: Sab 19 -- stars: AGB and post-AGB; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/staa3082
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: The INT Photometric Hα Survey (IPHAS) has provided us with a number of new emission-line sources, among which planetary nebulae (PNe) constitute an important fraction. Here we present a detailed analysis of the IPHAS nebula Sab 19 (IPHASX J055242.8+262116) based on radio, infrared, and optical images and intermediate- and high-dispersion long-slit spectra. Sab 19 consists of a roundish 0.10 pc in radius double-shell nebula surrounded by a much larger 2.8 pc in radius external shell with a prominent H-shaped filament. We confirm the nature of the main nebula as a PN whose sub-solar N/O ratio abundances, low ionized mass, peculiar radial velocity, and low-mass central star allow us to catalogue it as a Type III PN. Apparently, the progenitor star of Sab 19 became a PN when crossing the Perseus Arm during a brief visit of a few Myr. The higher N/O ratio and velocity shift ≃ 40 km s −1 of the external shell with respect to the main nebula and its large ionized mass suggest that it is not truly associated with Sab 19, but it is rather dominated by a Strömgren zone in the interstellar medium ionized by the PN central star.