TY - JOUR
T1 - Dielectronic recombination and stability of warm gas in active galactic nuclei
AU - Chakravorty, Susmita
AU - Kembhavi, Ajit K.
AU - Elvis, Martin
AU - Ferland, Gary
AU - Badnell, N.R.
PY - 2008/2
Y1 - 2008/2
N2 - 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 absorber at 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.
AB - 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 absorber at 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.
KW - thermal equilibrium
KW - active galactic nuclei
KW - ionizing continuum
KW - dielectronic recombination
KW - physics
UR - http://arxiv.org/PS_cache/arxiv/pdf/0711/0711.1137v1.pdf
UR - http://dx.doi.org/10.1111/j.1745-3933.2007.00414.x
U2 - 10.1111/j.1745-3933.2007.00414.x
DO - 10.1111/j.1745-3933.2007.00414.x
M3 - Article
VL - 384
SP - L24-L28
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 1
ER -