SIMBAD references

We investigate how uncertainties in flux measurements affect the results from modified blackbody spectral energy distribution (SED) fits. We show that an inverse correlation between the dust temperature T and spectral index β naturally arises from least-squares fits due to the uncertainties, even for sources with a single T and β. Fitting SEDs to noisy fluxes solely in the Rayleigh-Jeans regime produces unreliable T and β estimates. Thus, for long wavelength observations (λ ≳ 200 µm), or for warm sources (T ≳ 60 K), it becomes difficult to distinguish sources with different temperatures. We assess the role of noise in recent observational results that indicate an inverse and continuously varying T-β relation. Though an inverse and continuous T-β correlation may be a physical property of dust in the interstellar medium, we find that the observed inverse correlation may be primarily due to noise.