Repositório Digital

A- A A+

SDSS-IV MaNGA : the impact of diffuse ionized gas on emission-line ratios, interpretation of diagnostic diagrams and gas metallicity measurements

.

SDSS-IV MaNGA : the impact of diffuse ionized gas on emission-line ratios, interpretation of diagnostic diagrams and gas metallicity measurements

Mostrar registro completo

Estatísticas

Título SDSS-IV MaNGA : the impact of diffuse ionized gas on emission-line ratios, interpretation of diagnostic diagrams and gas metallicity measurements
Autor Zhang, Kai
Yan, Renbin
Bundy, Kevin
Bershady, Matthew A.
Haffner, L. Matthew
Walterbos, Rene A. M.
Maiolino, Roberto
Tremonti, Christy A.
Thomas, Daniel B.
Drory, Niv
Jones, Amy P.
Belfiore, Francesco
Sánchez, Sebastián F.
Diamond-Stanic, Aleksandar M.
Bizyaev, D.
Nitschelm, Christian
Andrews, Brett H.
Brinkmann, Jon
Brownstein, Joel R.
Cheung, Edmond
Li, Cheng
Law, David R.
Roman-Lopes, Alexandre
Oravetz, Daniel J.
Pan, K.
Storchi-Bergmann, Thaisa
Simmons, Audrey E.
Abstract Diffuse ionized gas (DIG) is prevalent in star-forming galaxies. Using a sample of 365 nearly face-on star-forming galaxies observed byMapping Nearby Galaxies at APO, we demonstrate how DIG in star-forming galaxies impacts the measurements of emission-line ratios, hence the interpretation of diagnostic diagrams and gas-phase metallicity measurements. At fixed metallicity, DIG-dominated low Hα regions display enhanced [S II]/Hα, [NII]/Hα, [OII]/Hβ and [O I]/Hα. The gradients in these line ratios are determined by metallicity gradients and Hα. In line ratio diagnostic diagrams, contamination by DIG moves HII regions towards composite or low-ionization nuclear emission-line region (LI(N)ER)-like regions. A harder ionizing spectrum is needed to explain DIG line ratios. Leaky HII region models can only shift line ratios slightly relative toHII region models, and thus fail to explain the composite/LI(N)ER line ratios displayed by DIG. Our result favours ionization by evolved stars as a major ionization source forDIG with LI(N)ER-like emission. DIG can significantly bias themeasurement of gas metallicity and metallicity gradients derived using strong-line methods. Metallicities derived using N2O2 are optimal because they exhibit the smallest bias and error. Using O3N2, R23, N2 = [N II]/Hα and N2S2Hα to derive metallicities introduces bias in the derived metallicity gradients as large as the gradient itself. The strong-line method of Blanc et al. (IZI hereafter) cannot be applied to DIG to get an accurate metallicity because it currently contains only HII region models that fail to describe the DIG.
Contido em Monthly notices of the Royal Astronomical Society. Oxford. Vol. 466, no. 3 (Apr. 2017), p. 3217-3243
Assunto Formacao de galaxias
Galáxias ativas
Gas ionizado
Mapeamentos astronômicos
Metalicidade
[en] Galaxies: abundances
[en] Galaxies: active
[en] Galaxies: evolution
[en] Galaxies: fundamental parameters
[en] Galaxies: ISM
Origem Estrangeiro
Tipo Artigo de periódico
URI http://hdl.handle.net/10183/159745
Arquivos Descrição Formato
001022481.pdf (12.88Mb) Texto completo Adobe PDF Visualizar/abrir

Este item está licenciado na Creative Commons License

Este item aparece na(s) seguinte(s) coleção(ões)


Mostrar registro completo

Percorrer



  • O autor é titular dos direitos autorais dos documentos disponíveis neste repositório e é vedada, nos termos da lei, a comercialização de qualquer espécie sem sua autorização prévia.
    Projeto gráfico elaborado pelo Caixola - Clube de Criação Fabico/UFRGS Powered by DSpace software, Version 1.8.1.