add to statement of need

docs/source/index.rst

@@ -12,6 +12,13 @@ projects utilized to achieve this. Accessing simulation data is done using yt.
 Trident is used to generate synthetic sightlines/lightrays and generate synthetic
 spectra. Spectacle is used to fit voigt profiles to spectra and extract absorbers.
 
+Observational studies generate large absorber catalogs by studying the absorption
+line spectra of distant quasars, as their light passes through intervening galaxies.
+Salsa can generate similar catalogs from cosmological and galactic simulations,
+allowing research to study these simulations from an observers perspective. This
+can give new insights into the data as well as help facilitate comparisons and
+collaboration between simulations and observations
+
 In addition a novel method for extracting absorbers, the SPICE method. This uses
 cell level data to extract absorbers from a Trident lightray and returns a great
 deal of information that can be further analyzed.

paper.md

@@ -69,25 +69,30 @@ Absorption Line Surveyor Application). SALSA is a package that generates
 synthetic absorber catalogs by studying the LightRays and/or spectra generated
 using Trident. SALSA provides an automated pipeline to process large numbers of
 LightRays and extract absorber information into a catalog for further analysis.
-Two separate methods are made available to extract absorbers. The “Spectacle
-method” uses the Python package Spectacle[^2] to fit Voigt profiles to the
-synthetic spectra generated by Trident (see \autoref{fig:1}) [@spectacle]. This
-method provides traditional absorption line information (e.g. Doppler broadening,
-equivalent width, etc.) and thus creates synthetic absorber catalogs very similar
-to those made from observational studies.
+One large benefit to studying these synthetic catalogs is the ability to directly
+compare to observational catalogs. This can give new insights into the
+data as well as help facilitate collaboration between simulators and observers.
 
 # Summary
 
-The “SPICE (Simple Procedure for Iterative Cloud Extraction) method” is a novel
-method that uses cell level data from the simulation to find the contiguous
-groups of cells which will meaningfully contribute absorption line features to
-the synthetic spectra. It does this through an iterative process that isolates
-the regions along the LightRay with the highest number density values and
-returns those regions with observationally detectable column densities as
-individual absorbers (see \autoref{fig:1} or for more details, the documentation[^3]).
-This method provides direct access to the information contained in the simulation
-(e.g. temperature, velocity, metallicity, etc.) and, in turn, more information
-than can be provided by spectral absorption line analysis alone.
+Two separate methods are made available to extract absorbers. The “Spectacle
+method” uses the Python package Spectacle[^2] to fit Voigt profiles to the
+synthetic spectra generated by Trident (see \autoref{fig:1}) [@spectacle]. This
+method provides traditional absorption line information (e.g. Doppler
+broadening, equivalent width, etc.) and thus creates synthetic absorber
+catalogs very similar to those made from observational studies.
+
+The second method, called the “SPICE (Simple Procedure for Iterative Cloud
+Extraction) method”, is a novel method that uses cell level data from the
+simulation to find the contiguous groups of cells which will meaningfully
+contribute absorption line features to the synthetic spectra. It does this
+through an iterative process that isolates the regions along the LightRay with
+the highest number density values and returns those regions with
+observationally detectable column densities as individual absorbers (see
+\autoref{fig:1} or for more details, the documentation[^3]). This method
+provides direct access to the information contained in the simulation (e.g.
+temperature, velocity, metallicity, etc.) and, in turn, more information than
+can be provided by spectral absorption line analysis alone.
 
 ![These plots were generated using FOGGIE simulation data [@Peeples:2019]. The
 top plot shows the number density profile of O VI along the length of the