deletions | additions       diff --git a/subsection_Comparison_with_X_ray__.tex b/subsection_Comparison_with_X_ray__.tex  index c3aa9f3..d3f2606 100644  --- a/subsection_Comparison_with_X_ray__.tex  +++ b/subsection_Comparison_with_X_ray__.tex 
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Both \cite{Liu_2011} and \cite{Koss_2012} use imaging spectroscopy to select data points for dual (pair) AGN samples. A small pair separation is also present in both studies with most of the Lui AGN detections at separation less than 100 kpc, and those of \cite{Koss_2012} found at separations less than 30 kpc. Both papers note that the luminosities of AGN pairs increase with a decrease in separation between galaxies (in a pair), suggesting that mergers promote AGN activity (\cite{Liu_2011} , \cite{Koss_2012}). Both papers also acknowledge the limitations experienced in selecting the appropriate sample data due to SDSS’ fixed fiber size. On this point, Koss notes that due to SDSS fiber being 3”, it is sensitive to smaller physical scales.  Koss studies a sample of 167 X-ray selected AGN pairs at $z<0.05$ from the BAT survey. Using the following: radial velocity differences $< 300 km.s^{−1}$, pair separation from 1 to 100 kpc to exclude sources classified as composites by their optical emission line properties, as sample selection criteria. At separation $<15 kpc$ ,Koss defined a sample of 16 out of 167 pairs from BAT, and 20 out of 1988 pair were identified from the SDSS. Koss' aim was to discover the the peak black hole growth during the merging process. process paying particular attention to the relationship between dual AGNs and the stellar mass ratios or ANG in paired samples.  This study also encounters limitations due to the SDSS hardware, causing incompleteness data collection at close scales (small redshift). These limitations are overcome by using emission line diagnostics. The study by \cite{Koss_2012}provides evidence for merging events enhancing AGN activity as their results show that the X-ray luminosity of both AGN (in an AGN pair), increases strongly with decreasing pair separation.