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Session 13 - Large Scale Structure & Cosmology.
Display session, Monday, January 13
The angular size-redshift relation for double-lobed radio sources, intially proposed as a cosmological test, is believed to depend on non-cosmological effects such as size evolution, luminosity-size correlations, and orientation effects. However, due to inhomogeneous source samples, previous studies have failed to agree on even the general trends governing the characteristics of these objects. The FIRST survey offers an unprecedented opportunity for studying double-lobed sources. Using available redshift information we are investigating the redshift, luminosity, and size distribtutions for several hundred sources. Unlike, previous work in this area, our preliminary results reveal a flattening in the size-redshift plane past z=1, independent of the above-mentioned effects, perhaps indicating that cosmological effects become important. We are also differentiating between radio galaxies and quasars in order to test whether the properties of these two samples are consistent with unification schemes. In addition, we have proposed to obtain redshift information for a homogeneous sub-sample of double-lobed sources, thus providing the first complete sample for use in such studies. The FIRST project is supported by grants from the National Geographic Society, the National Science Foundation, NATO, IGPP, Columbia University, and Sun Microsystems.
Program listing for Monday