deletions | additions       diff --git a/figures/fig_for_inclass_nova1/caption.tex b/figures/fig_for_inclass_nova1/caption.tex  index 4447b83..d25908b 100644  --- a/figures/fig_for_inclass_nova1/caption.tex  +++ b/figures/fig_for_inclass_nova1/caption.tex 
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\itshape  Consider the attached image of a nova observed with the millimeter telescope CARMA at 96 GHz (Panel A). Histograms of pixel values are shown in Panels B and C (Panel C is just a zoom-in of a region on Panel B); these are just like the histograms you made in DS9's \verb|Scale Parameters|. The pixel values after calibration are expressed as flux density per pixel (units of mJy/pixel). The plotted range ($-2$ to $36\,\mathrm{mJy/pixel}$) includes all pixels in the image.  \noindent 1) \begin{enumerate}  \item  Estimate the average background value ($\bar{S}$) and explain your reasoning.\\ reasoning.  \noindent 2) \item  Estimate the standard deviation of the background ($\sigma$), and explain your reasoning.\\ reasoning.  \noindent 3) \item  Estimate the peak flux density of the nova ($S_{\mathrm{max}}$), and explain your reasoning.\\ reasoning.  \noindent 4) \item  Astronomers usually only take detections seriously if they are 5 or more $\sigma$ significant---that is, if the detected source is at least five times brighter than the standard deviation of the background. In other words, the source's peak flux should be $S_{\mathrm{max}} > (\bar{S} + 5 \sigma)$. Estimate how many sigma the peak flux density of the nova is, and show your reasoning. Would this detection be taken seriously by other astronomers?  \end{enumerate}  \end{quote}