The Census of High- and Medium-mass Protostars ( CHaMP ) is the first large-scale ( 280 ^ { \circ } < l < 300 ^ { \circ } , -4 ^ { \circ } < b < 2 ^ { \circ } ) , unbiased , sub-parsec resolution survey of Galactic molecular clumps and their embedded stars .
Barnes et al .
( 2011 ) presented the source catalog of \sim 300 clumps based on HCO ^ { + } ( 1-0 ) emission , used to estimate masses M .
Here we use archival mid-infrared to mm continuum data to construct spectral energy distributions .
Fitting two-temperature grey-body models , we derive bolometric luminosities , L .
We find the clumps have 10 \lesssim L / L _ { \odot } \lesssim 10 ^ { 6.5 } and 0.1 \lesssim L / M / [ L _ { \odot } / M _ { \odot } ] \lesssim 10 ^ { 3 } , consistent with a clump population spanning a range of instantaneous star formation efficiencies from 0 to \sim 50 \% .
We thus expect L / M to be a useful , strongly-varying indicator of clump evolution during the star cluster formation process .
We find correlations of the ratio of warm to cold component fluxes and of cold component temperature with L / M .
We also find a near linear relation between L / M and Spitzer -IRAC specific intensity ( surface brightness ) , which may thus also be useful as a star formation efficiency indicator .
The lower bound of the clump L / M distribution suggests the star formation efficiency per free-fall time is \epsilon _ { ff } < 0.2 .
We do not find strong correlations of L / M with mass surface density , velocity dispersion or virial parameter .
We find a linear relation between L and L _ { HCO ^ { + } ( 1 - 0 ) } , although with large scatter for any given individual clump .
Fitting together with extragalactic systems , the linear relation still holds , extending over 10 orders of magnitude in luminosity .
The complete nature of the CHaMP survey over a several kiloparsec-scale region allows us to derive a measurement at an intermediate scale bridging those of individual clumps and whole galaxies .