Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (1)

Search Parameters:
Keywords = NGC 7293

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
6 pages, 2227 KB  
Article
Irradiation Investigation: Exploring the Molecular Gas in NGC 7293
by Jesse Bublitz, Joel Kastner, Pierre Hily-Blant, Thierry Forveille, Miguel Santander-García, Valentin Bujarrabal, Javier Alcolea and Rodolfo Montez
Galaxies 2020, 8(2), 32; https://doi.org/10.3390/galaxies8020032 - 8 Apr 2020
Cited by 3 | Viewed by 3263
Abstract
Background: Many planetary nebulae retain significant quantities of molecular gas and dust despite their signature hostile radiation environments and energetic shocks. Photoionization and dissociation by extreme UV and (often) X-ray emission from their central stars drive the chemical processing of this material. Their [...] Read more.
Background: Many planetary nebulae retain significant quantities of molecular gas and dust despite their signature hostile radiation environments and energetic shocks. Photoionization and dissociation by extreme UV and (often) X-ray emission from their central stars drive the chemical processing of this material. Their well-defined geometries make planetary nebulae ideal testbeds for modeling the effects of radiation-driven heating and chemistry on molecular gas in photodissociation regions. Methods: We have carried out IRAM 30m/APEX 12m/ALMA radio studies of the Helix Nebula and its molecule-rich globules, exploiting the unique properties of the Helix to follow up our discovery of an anti-correlation between HNC/HCN line intensity ratio and central star UV Luminosity. Results: Analysis of HNC/HCN across the Helix Nebula reveals the line ratio increases with distance from the central star, and thus decreasing incident UV flux, indicative of the utility of the HNC/HCN ratio as a tracer of UV irradiation in photodissociation environments. However, modeling of the observed regions suggests HNC/HCN should decrease with greater distance, contrary to the observed trend. Conclusion: HNC/HCN acts as an effective tracer of UV irradiation of cold molecular gas. Further model studies are required. Full article
(This article belongs to the Special Issue Workplans II: Workshop for Planetary Nebula Observations)
Show Figures

Figure 1

Back to TopTop