We report the discovery of a spectacular ``post-starbust quasar'' UN J1025-00400 (B=19 and z=0.634). The optical spectrum is a chimera, dominated by a quasar in the blue, but in the red shows a large Balmer jump and deep Balmer absorption lines indicative of a young stellar population. Keck spectropolarimetry shows no intrinsic optical polarization. A Keck K-band image (0.5arcsec FWHM) fails to resolve the quasar from the starburst, but does reveal surrounding asymmetric fuzz and a nearby companion, suggestive of a galactic interaction. Stellar synthesis population models can reproduce the starlight component with a 400-Myr-old instantaneous burst of 2*E(10) M_⊙. While starbursts and interactions have been previously associated with quasars, no quasar ever before has been seen with such a luminous young stellar population. The extreme nature of this object provides a unique test case to investigate the connection between galaxy interactions, starbursts, and AGN activity.
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 1998