An analysis of continuum antenna temperatures observed in the Green Bank Telescope ( GBT ) spectrometer bandpasses is presented for observations toward SgrB2 ( N-LMH ) .
Since 2004 , we have identified four new prebiotic molecules toward this source by means of rotational transitions between low energy levels ; concurrently , we have observed significant continuum in GBT spectrometer bandpasses centered at 85 different frequencies in the range of 1 to 48 GHz .
The continuum heavily influences the molecular spectral features since we have observed far more absorption lines than emission lines for each of these new molecular species .
Hence , it is important to understand the nature , distribution , and intensity of the underlying continuum in the GBT bandpasses for the purposes of radiative transfer , i.e. , the means by which reliable molecular abundances are estimated .
We find that the GBT spectrometer bandpass continuum is consistent with optically-thin , non-thermal ( synchrotron ) emission with a flux density spectral index of -0.7 and a Gaussian source size of \sim 143 ^ { \prime \prime } at 1 GHz that decreases with increasing frequency as \nu ^ { -0.52 } .
Some support for this model is provided by high frequency Very Large Array ( VLA ) observations of SgrB2 .