Abstract: Optically bright, wide separation double (gravitationally lensed) quasars can be easily monitored, leading to light curves of great importance in determining the Hubble constant and other cosmological parameters, as well as the structure of active nuclei and haloes of galaxies. Searching for new double quasars in the Sloan Digital Sky Survey III (SDSS-III) data base, we discovered SDSS J1442+4055. This consists of two bright images (r ? 18?19) of the same distant quasar at z = 2.575. The two quasar images are separated by ?2 ??. .?? 1, show significant parallel flux variations and can be monitored from late 2015. We also found other two double quasar candidates, SDSS J1617+3827 (z = 2.079) and SDSS J1642+3200 (z = 2.264), displaying evidence for the presence of a lensing object and parallel flux variations, but requiring further spectroscopic observations to be confirmed as lensed quasars.

Autoría

Descargar referencia