Dielectronic recombination and stability of warm gas in active galactic nuclei

Susmita Chakravorty, Ajit K. Kembhavi, Martin Elvis, Gary Ferland, N. R. Badnell

Research output: Contribution to journalLetterpeer-review

22 Scopus citations


Understanding the thermal equilibrium (stability) curve may offer insights into the nature of the warm absorbers often found in active galactic nuclei. Its shape is determined by factors such as the spectrum of the ionizing continuum and the chemical composition of the gas. We find that the stability curves obtained under the same set of the above-mentioned physical factors, but using recently derived dielectronic recombination rates, give significantly different results, especially in the regions corresponding to warm absorbers, leading to different physical predictions. Using the current rates we find a larger probability of having a thermally stable warm absorberat 105 K than previous predictions and also a greater possibility for its multiphase nature. The results obtained with the current dielectronic recombination rate coefficients are more reliable because the warm absorber models along the stability curve have computed coefficient values, whereas previous calculations relied on guessed averages for these because of a lack of available data.

Original languageEnglish
Pages (from-to)L24-L28
JournalMonthly Notices of the Royal Astronomical Society: Letters
Issue number1
StatePublished - Feb 2008


  • Galaxies: active
  • ISM: abundances
  • ISM: atoms
  • ISM: lines and bands
  • Quasars: absorption lines

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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