EMILI - An Aid to Emission Line Identification in Emission-Line Regions

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Scientific paper

Deep, high-resolution emission spectra of emission-line regions reveal literally hundreds of weak lines which may not be quickly or accurately identifiable manually. We present software, dubbed ``EMILI'' for Emission Line Identifier, currently under development, that can aid in making such identifications, specifically in planetary nebulae and H \small II \normalsize regions. This software will become public domain in the near future. EMILI begins with a user-supplied list of line wavelengths, fluxes, and associated errors. The observed object's systemic velocity, and a model of the ionization energy dependence of the expansion velocity are calculated from user pre-identified strong lines. These line's strengths are also used to calculate the ionization corrections for all ions Z<=30 and ionization stage up to 30, and consequent ionic abundances as modified from base solar values. For each observed unidentified line, a master transition list (van Hoof 2001, Atomic Line List v2.04) is consulted for all transitions within a certain multiple of the line's wavelength uncertainty. The observed line's wavelength is then corrected for systemic motion and the ionization dependent expansion velocity. A predicted flux is calculated for each transition based upon the transition's parent ion's abundance and other attributes. For the transitions with the strongest predicted flux, the input line-list is searched for other lines of the same multiplet which have ratios of observed fluxes approximately equal to the ratios of statistical weights and Einstein coefficients. Finally each transition is ranked on the basis of how well its calculated flux matches the observed value, the agreement between the corrected wavelength of the observed line and the transition's rest wavelength, and on the numbers of other multiplet lines identified within the input list. This determines a set of likely identifications for each line which is presented to the user.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

EMILI - An Aid to Emission Line Identification in Emission-Line Regions does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with EMILI - An Aid to Emission Line Identification in Emission-Line Regions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and EMILI - An Aid to Emission Line Identification in Emission-Line Regions will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1238132

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.