We present the dependence of electron temperature fluctuations of O++ and H+ by the chemical abundances of oxygen and nitrogen. Models assume that hydrogen density is uniform in one case and non uniform in the second ...We present the dependence of electron temperature fluctuations of O++ and H+ by the chemical abundances of oxygen and nitrogen. Models assume that hydrogen density is uniform in one case and non uniform in the second case, which vary with the distance from the central star. The abundances of oxygen and nitrogen change by scale factor 5 and 1/5. Our analysis suggests that temperature fluctuations are consistent with photoionization. Using the cloudy photoionization code, we found a reasonable close agreement of the computed value with the one that was done before this work. Our simulation also shows that how change of abundances affects temperature fluctuations and its value is less than 0.01.展开更多
We present phoionization model calculations of ionization fraction of hydrogen, helium and oxy-gen at low density of photoionized nebulae using the photoionization code CLOUDY. The ionization parameter is between -2.0...We present phoionization model calculations of ionization fraction of hydrogen, helium and oxy-gen at low density of photoionized nebulae using the photoionization code CLOUDY. The ionization parameter is between -2.0 ≤ log(U) ≤ 1.0, and we study them by changing the abundances of oxy-gen from -2.5 ≤ log(O/H) ≤ -5.0. This was tested first by Campbell (1988) [1]. But, this was differ-ent in highest abundances of oxygen, filling factor and carbon abundances. We change the abun-dances of carbon by 0.5 dex of solar value, to avoid formation CO in the process. We include the charge transfer interaction between oxygen ions and hydrogen atom. Based on this process, we have calculated the ionization profiles of O0, O+, O2+ O3+ and O4+ in the presence and absence of charge exchange between hydrogen and oxygen. In this work, we assumed the effective rate of co-efficient for the charge transfer is the order of ≈10-9 cm-3-s-1.展开更多
文摘We present the dependence of electron temperature fluctuations of O++ and H+ by the chemical abundances of oxygen and nitrogen. Models assume that hydrogen density is uniform in one case and non uniform in the second case, which vary with the distance from the central star. The abundances of oxygen and nitrogen change by scale factor 5 and 1/5. Our analysis suggests that temperature fluctuations are consistent with photoionization. Using the cloudy photoionization code, we found a reasonable close agreement of the computed value with the one that was done before this work. Our simulation also shows that how change of abundances affects temperature fluctuations and its value is less than 0.01.
文摘We present phoionization model calculations of ionization fraction of hydrogen, helium and oxy-gen at low density of photoionized nebulae using the photoionization code CLOUDY. The ionization parameter is between -2.0 ≤ log(U) ≤ 1.0, and we study them by changing the abundances of oxy-gen from -2.5 ≤ log(O/H) ≤ -5.0. This was tested first by Campbell (1988) [1]. But, this was differ-ent in highest abundances of oxygen, filling factor and carbon abundances. We change the abun-dances of carbon by 0.5 dex of solar value, to avoid formation CO in the process. We include the charge transfer interaction between oxygen ions and hydrogen atom. Based on this process, we have calculated the ionization profiles of O0, O+, O2+ O3+ and O4+ in the presence and absence of charge exchange between hydrogen and oxygen. In this work, we assumed the effective rate of co-efficient for the charge transfer is the order of ≈10-9 cm-3-s-1.
