1. Главная
  2. Ресурсы
  3. Библиотечный поиск
Alternativediagnostic diagramsand the ‘forgotten’population of weakline galaxies in theSDSS R. Cid FernandesG. StasińskaM. Schlickmann2010 год

Alternative diagnostic diagrams and the ‘forgotten’ population of weak line galaxies in the SDSS
статья из журнала

Полный текстСтраница публикацииПубликация в OpenAlex
Аннотация: A numerous population of weak line galaxies (WLGs) is often left out of statistical studies on emission line galaxies (ELGs) due to the absence of an adequate classification scheme, since classical diagnostic diagrams, like [OIII]/Hb vs [NII]/Ha (the BPT diagram), require the measurement of at least 4 emission lines. This paper aims to remedy this situation by transposing the usual divisory lines between Star Forming (SF) and AGN hosts, and between Seyferts and LINERs to diagrams that are more economical in terms of line quality requirements. By doing this, we rescue from the classification limbo a substantial number of sources and modify the global census of ELGs. More specifically: (1) We use the SDSS DR7 to constitute a suitable sample of 280k ELGs, 1/3 of which are WLGs. (2) Galaxies with strong emission lines are classified using the widely applied criteria of Kewley et al (2001), Kauffmann et al (2003), Stasinska et al (2006) and Kewley et al (2006). (3) We transpose these classification schemes to alternative diagrams keeping [NII]/Ha as a horizontal axis, but replacing Hb by a stronger line (Ha or [OII]), or substituting [OIII]/Hb ratio with the equivalent width of Ha. Optimized equations for the transposed divisory lines are provided. (4) We show that nothing significant is lost in the translation, but that the new diagrams allow one to classify up to 50% more ELGs. (5) Introducing WLGs in the census of galaxies in the local Universe increases the proportion of metal-rich SF galaxies and especially LINERs. (abridged)
Год издания: 2010
Авторы: R. Cid Fernandes, G. Stasińska, M. Schlickmann, A. Mateus, N. Vale Asari, W. Schoenell, L. Sodré
Издательство: Oxford University Press
Источник: Monthly Notices of the Royal Astronomical Society
Ключевые слова: Galaxies: Formation, Evolution, Phenomena, Astronomy and Astrophysical Research, Astrophysical Phenomena and Observations
Другие ссылки: Monthly Notices of the Royal Astronomical Society (PDF)
Monthly Notices of the Royal Astronomical Society (HTML)
arXiv (Cornell University) (PDF)
arXiv (Cornell University) (HTML)
hal.science (HTML)
arXiv (Cornell University) (PDF)
arXiv (Cornell University) (HTML)
DataCite API (HTML)