! Hubble Space Telescope Cycle 5 (1995) Phase II Proposal Template ! $Id: 5974,v 4.1 1995/12/12 20:38:06 pepsa Exp $ ! ! Refer to the HST Phase II Proposal Instructions to fill this out ! ! Anything after a "!" is ignored, and may be deleted ! ! All keywords with multiple entries are comma delimited except the ! Visit_Requirements and Special_Requirements keywords which can be ! delimited with carriage returns or semi-colons, but not commas ! ! For help call your Program Coordinator: Doug Van Orsow ! Phone: 410 338-4568 , E-mail: vanorsow@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. ! Name of Phase I Proposal: lehnert-756.prop ! Date generated: Sun Dec 18 09:58:08 EST 1994 ! Proposal_Information ! Section 4 Title: The Evolution of Radio-Loud Quasars Proposal_Category: GO Scientific_Category: Quasars Cycle: 5 Investigators PI_name: Matthew Lehnert PI_Institution: Institute of Geophysics and Planetary Physics CoI_Name: Wil van Breugel CoI_Institution: Institute of Geophysics and Planetary Physics, LLNL, 7000 East Ave., L-413, Livermore, CA 94550 Contact: ! Y or N (designate at most one contact) CoI_Name: Vijay Kapahi CoI_Institution: National Center for Radio Astrophysics, TIFR, Pune 411 007, India Contact: ! Y or N (designate at most one contact) CoI_Name: Timothy Heckman CoI_Institution: Dept. of Physics & Astron, Johns Hopkins University, Baltimore, MD 21218 Contact: ! Y or N (designate at most one contact) CoI_Name: Patrick McCarthy CoI_Institution: Carnegie Observatories, 813 Santa Barbara St., Pasadena, CA 91101 Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) The co-moving space density of highly luminous quasars has decreased by roughly 3 orders of magnitude from z=2-3 to the current epoch. Understanding the physical processes responsible for this decrease could profoundly influence how we think the universe and galaxies have evolved. We therefore propose to conduct a broad-band imaging survey of the host galaxies of 20 radio-loud quasars over a large redshift range (~0.3 to 2.7) using WFPC2. HST observations are crucial for separating the ``blinding'' nuclear emission (AGN) from that of the extended ``fuzz'' (parent galaxy). The quasars are selected from a complete sample and span a range of radio properties. Filters are chosen such that all the quasars will be imaged at rest-wavelengths near 2000 Angstrom . These data will allow us to study the properties and evolution of quasar host galaxies at constant wavelength over look-back times of 25 to 85% of the age of the universe. When compared with the so far much better studied radio galaxies in other HST programs, we will be able to address the important question of whether radio-loud quasars and radio galaxies are members of the same parent population as is fashionable in the AGN unification schemes, and investigate how the hosts of luminous AGN have evolved over the epochs where luminous quasars have become virtually extinct. Questions ! Free format text (please update) Observing_Description: Quasar Sample To investigate the astrophysically important issues raised in the scientific justification, we propose to image a small sample of 20 radio-loud quasars using a broad- band filter and the Planetary Camera on HST. These quasars all have redshifts of between 0.276 and 2.667 and are chosen from the Molonglo Reference Catalog of radio sources. We have split the sample into three redshift bins (z<0.7, 0.7 -0.5). 0.05in Continuum Imaging: Our choice of continuum filter is dictated by three criteria. First, the filter bandpass should exclude bright emission lines. Second, the filter should be among the most efficient broad-band filters available on the WFPC2 and also correspond roughly to common ground-based filters to yield `real' magnitudes. Third, the central wavelength should correspond roughly to a uniform rest wavelength in all the quasars over the whole redshift range. The most suitable choices are F336W (~U, for quasars with z<0.7), F439W (~B, for quasars with 0.7