Compact Steep-Spectrum Radio Sources and Ambient Medium Density

Abstract

Analytical and statistical methods,with some plausible assumptions, have been used in this work to show presence of dense medium around compact steep-spectrum sources in our sample. This is done by carrying out regression analyses using our estimated jet’s internal densities (n_j ) and some other source parameters for possible deductions. Results indicate that n_j-D and n_j-n_e data (where D and n_e are respectively, observed source linear size and ambient medium density) show strong correlations and yield power-law relations of the forms, n_j~D^(-3.54±0.02) and n_j~n_e^(1.68±0.08). A comparison with obtained theoretical relations suggestively indicates presence of dense gases around these sources. In addition, a simple linear regression analysis of ν_p-n_j data shows that jet’s particles may be responsible (in addition to the ambient gases) for the observed spectral turnover characteristic of compact steep spectrum sources.