Christer Watson edited sectionAnalysis__sub.tex  over 8 years ago

Commit id: 4caa6949fc58bc5b3bbb398de2a32193bcf21bbe

deletions | additions      

       

\kappa = \kappa_{1.3mm} \left(\frac{\lambda}{1.3mm}\right)^{-\beta}\nonumber\\  \end{eqnarray*}  where {\bf m$_H$ is the mass of hydrogen} and 3.73 x 10$^{-16}$ converts the surface brightness from Jy/(1\arcsec beam) to SI units. We make the following assumptions: $\kappa_{1.3mm}$ = 0.11 $\frac{m^2}{kg}$, appropriate for ice-covered dust grains from \citet{1994A&A...291..943O}, $\theta$=15.0\arcsec , the beamsize of the GBT at 49 GHz, the mean molecular weight $\mu$ = 2.3 and dust to mass ratio $R_d$ = 1/100. Note that B$_\nu$, B$_{mod}$ and $\kappa$ all require a choice of frequency or wavelength. However, these dependencies cancel in the final calculation of N$_{tot}$. These results are summarized in Table \ref{mbb}, where we report the flux density at five wavelength bands for each CS detection, the best-fit temperature, the total column density and the CS abundance. We estimate the error in determining the extended flux to be dominated by defining the edge of the object. The GBT beam is tapered along the edges to minimize ringing {\bf These sources all appear extended  in the side-lobes. We have used a simple cut-off at the edge of Herschel bands and some lie is confused regions. Thus,  the beam. gas sampled by FIR and CS are likely different.  This difference in beam produces should lead to  a 20\% uncertainty in cautious association between  the {\bf HiGal} fluxes reported below. To estimate the uncertainty in dust temperatures and  the model results, CS emission. As a rough benchmark,  we fit the data after adjusting estimated  the fluxes either effect of a 20\% change  up or down by in FIR flux on  the 20\% uncertainty. calculated properties.  The results indicate an uncertainty where a change  of 4 K in temperature and 20\% in column density. density.}  For those sources where the modified blackbody model was a poor fit, as judged by eye, we have excluded the temperature, column density and abundance. The cause for the poor fit in these cases appeared to be caused by emission extending well outside the the GBT beam. For these poorly-fit sources, the fluxes reported here probably do not represent the emission from the same object. For those sources with a double-Gaussian CS line profile, we add the CS column densities calculated using both Gaussians. If this shape is caused by optical depth effects, as we discuss below, than the reported column density would be a lower limit.