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SUMMARY:Atomic processes in gaseous nebulae
DTSTART;VALUE=DATE-TIME:20110714T150000Z
DTEND;VALUE=DATE-TIME:20110714T170000Z
DTSTAMP;VALUE=DATE-TIME:20260711T203302Z
UID:indico-contribution-5168@events.saip.org.za
DESCRIPTION:Speakers: Andri Prozesky (Unisa)\nThe atomic physics relevant 
 to gaseous nebulae is critically examined using modeling software with par
 ticular emphasis on recombination spectral lines that occur in the radio r
 egime. The spectral line intensities that we observe from nebulae can be d
 educed if we know the population structure of the bound electrons in the g
 as under non-thermal equilibrium conditions. The population structure of h
 ydrogen is solved for various environments using a capture-collision-casca
 de model.\n \nThe validity of assuming Case B of Baker & Menzel (1938) whe
 n modeling astronomical nebulae is investigated. It is known that Case B i
 s appropriate for levels with small principle quantum numbers (n < 40)\, b
 ut this assumption should be re-examined for high energy levels which are 
 relevant to radio recombination lines.\n \nThe effect of an ambient radiat
 ion field on the population structure is examined and processes that are s
 timulated by a radiation field are included in the model. This is done as 
 a preliminary investigation to extend the model to a full photoionization 
 code that will be geometry-dependent and include an external radiation fie
 ld as well as the diffuse field that is emitted by the nebula itself.\n\nh
 ttps://events.saip.org.za/event/7/contributions/5168/
LOCATION: Asteria
URL:https://events.saip.org.za/event/7/contributions/5168/
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