of significant $q$ difference between massive and dwarf galaxies, as reported above, is probably caused by the presence of an outlier with exceptionally large $q$ (above the top dotted line) and low FIR luminosity in the massive galaxy sample[^7].

Our flux densities are compared with the empirical relation (grey solid line in Figure \[fig:frc\] and \[fig:lir\_q\], $q=2.34$) established with the IRAS and NVSS catalogues [@2001ApJ...554..803Y]. The $q=2.34$ line is slightly offset with our best-fit power law model for full sample (with upper limits) by $\sim0.15$ dex. It still lies within the 95% confidence band, but only marginally at the faint end ($F_\mathrm{FIR}\lesssim3\times10^{-14}\mathrm{W\,m^{-2}}$). The massive galaxies follow the empirical relation better than dwarf galaxies. For detections, the best-fit power law model implies the deviation from the constant $q$ at faint end. The median or average $q$ of dwarf galaxies is found to be statistically different from the empirical value (see Table \[tab:stats\]). By directly comparing our Figure \[fig:lir\_q\] with Figure 6 of @2001ApJ...554..803Y, we find they are highly consistent, in sense of clustering of low-luminosity galaxies ($L_\mathrm{60\mu m,equiv}<10^9\,\mathrm{L_\odot}$) above the $q=2.34$ line. But our result extends to much lower luminosity regime ($>10^6\,\mathrm{L_\odot}$ versus $>10^8\,\mathrm{L_\odot}$).

The slightly different results from using or 