deletions | additions       diff --git a/section_OH_Megamasers_label_sec__.tex b/section_OH_Megamasers_label_sec__.tex  index e7baa52..041aeb7 100644  --- a/section_OH_Megamasers_label_sec__.tex  +++ b/section_OH_Megamasers_label_sec__.tex 
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\cite{Darling_2007} extended this search by exploring the connection between star formation rate (calculated from IR luminosity) and the line luminosity of CO. A linear relationship exists between the IR and CO luminosities for star-forming galaxies over many orders of magnitude \citep{Gao_2004}. \citet{Darling_2007} finds the OH mega-maser hosts break this linear trend XXX FIGURE XXX, suggesting that the hosts of OH mega-masers are undergoing a special triggered star formation event due to the merger.  Further differences between the OH mega-maser hosts and LIRGs without maser emission were found by \citet{willett2011_I,willett_2011_II}. \citet{willett2011_I,willett2011_II}.  In these two papers, the authors use Spitzer IRS spectroscopy to study LIRGs and ULIRGs that were part of the \citet{darling2002_paperIII} survey, both detections and non-detections. The medianed spectra of all sources is shown in Figure \ref{fig:oh_IR_spectra}. There is a clear difference between the galaxies with and without OH mega-masers. Notably, hosts of OH mega-masers show deeper absorption features near 10 and 18 $\mu$m, and the slope at longer wavelengths is steeper. \citet{ivezic1997} show that these are features due to an increase in dust opacity. This also shifts the peak of the IR emission to a maximum between 35-53$\mu$m, which is likely the pumping mechanism for the OH masers \citep{darling2012}. By also comparing with a dense gas tracer, HCN, \citet{Darling_2007} finds a high dense molecular gas fraction, L$_{\mathrm{HCN}}$/L$_{\mathrm{IR}} \gt 0.07$...