Hidden IR structures in NGC40
- We present the analysis of infrared (IR) observations of the planetary nebula NGC40 together with spectral analysis of its [WC]-type central starHD826. Spitzer IRS observations were used to produce spectral maps centred at polycyclic aromatic hydrocarbons (PAH) bands and ionic transitions to compare their spatial distribution. The ionic lines show a clumpy distribution of material around the main cavity of NGC40, with the emission from [Ar II] being the most extended, whilst the PAHs show a rather smooth spatial distribution. Analysis of ratio maps shows the presence of a toroidal structure mainly seen in PAH emission, but also detected in a Herschel PACS 70 mu m image. We argue that the toroidal structure absorbs the UV flux from HD826, preventing the nebula to exhibit lines of high-excitation levels as suggested by previous authors. We discuss the origin of this structure and the results from the spectral analysis of HD826 under the scenario of a late thermal pulse.
| Author details: | Jesus A. ToaláORCiD, Gerardo Ramos-LariosORCiD, Martin A. GuerreroORCiD, Helge Tobias TodtORCiD |
|---|---|
| DOI: | https://doi.org/10.1093/mnras/stz624 |
| ISSN: | 0035-8711 |
| ISSN: | 1365-2966 |
| Title of parent work (English): | Monthly notices of the Royal Astronomical Society |
| Subtitle (English): | Signpost of an ancient born-again event |
| Publisher: | Oxford Univ. Press |
| Place of publishing: | Oxford |
| Publication type: | Article |
| Language: | English |
| Date of first publication: | 2019/03/02 |
| Publication year: | 2019 |
| Release date: | 2021/02/17 |
| Tag: | ISM: molecules; infrared: ISM; planetary nebulae: individual: NGC40; stars: carbon; stars: evolution; stars: winds, outflows |
| Volume: | 485 |
| Issue: | 3 |
| Number of pages: | 10 |
| First page: | 3360 |
| Last Page: | 3369 |
| Funding institution: | UNAM DGAPA PAPIIT project [IA100318]; Fundacion Marcos Moshinsky; CONACyTConsejo Nacional de Ciencia y Tecnologia (CONACyT); PRODEP (Mexico); FEDER fundsEuropean Union (EU) [AYA 2014-57280-P]; National Aeronautics and Space AdministrationNational Aeronautics & Space Administration (NASA) |
| Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
| DDC classification: | 5 Naturwissenschaften und Mathematik / 52 Astronomie / 520 Astronomie und zugeordnete Wissenschaften |
| Peer review: | Referiert |
| Institution name at the time of the publication: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Theoretische Physik und Astrophysik |
| Publishing method: | Open Access / Green Open-Access |
