! Proposal 5938, submission 1 ! PI: C. Megan Urry ! Received Fri Feb 24 13:31:56 EST 1995 ! From: pesce@stsci.edu ! Hubble Space Telescope Cycle 5 (1995) Phase II Proposal Template ! $Id: 5938,v 6.1 1996/03/14 18:51:48 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: Ray Lucas ! Phone: 410 338-4716 , E-mail: lucas@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. ! Date generated: Sat Dec 17 10:54:48 EST 1994 ! Proposal_Information ! Section 4 Title: The Underlying Nature of Nearby BL Lac Objects Proposal_Category: GO Scientific_Category: AGN Cycle: 5 Investigators PI_name: C. Megan Urry PI_Institution: Space Telescope Science Institute CoI_Name: Joseph E. Pesce CoI_Institution: Space Telescope Science Institute Contact: Y ! Y or N (designate at most one contact) CoI_Name: Renato Falomo CoI_Institution: Osservatorio Astronomico di Padova Contact: ! Y or N (designate at most one contact) CoI_Name: Mauro Giavalisco CoI_Institution: Space Telescope Science Institute Contact: ! Y or N (designate at most one contact) CoI_Name: Rita M. Sambruna CoI_Institution: Space Telescope Science Institute Contact: ! Y or N (designate at most one contact) CoI_Name: Riccardo Scarpa CoI_Institution: Osservatorio Astronomico di Padova Contact: ! Y or N (designate at most one contact) CoI_Name: Aldo Treves CoI_Institution: SISSA/ISAS Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) The host galaxies and near environments of BL Lac objects are an important clue to their underlying nature, revealing whether they are relativistically beamed low-luminosity radio galaxies or luminous distant quasars gravitationally microlensed by foreground galaxies. In the former case, the host galaxies should be bright ellipticals in rich cluster environments; in the latter, the BL Lac nuclei should be off- center and some host galaxies should be spirals. High resolution imaging may also reveal the presence of close companions, indicative of the importance of interactions to the blazar phenomenon. We propose to study the host galaxies and environments of four radio-selected BL Lac objects from a well-defined, complete sample at redshiftS ~< 0.3. No comparable HST data exist or are planned for any BL Lac objects. Questions ! Free format text (please update) Observing_Description: We propose WFPC2 images in the F814W filter (which corresponds approximately R at the median sample redshift). We will obtain several short exposures to get the central point source without saturating the detector and several medium and long ones to get the galaxy fuzz. The target may be saturated (and may bleed) in the medium and long exposures. We will rotate the spacecraft between exposure series to better characterize the PSF (i.e. short exp., medium exp., long exp., roll, short, medium, long), and the two visits per target MUST be sequential, in consecutive orbits, with no intervention but the roll. The point source will be centered in the PC to get the best resolution in the inner part of the galaxy; the WF chips will give the outer parts of the galaxy and the near environment (~< 400 kpc projected distance from the BL Lac object). We calculated the required integration time to get a S/N ratio of 3 at the 23 mag/arcsec^2 isophote which simulations show is sufficient to determine the host galaxy properties. After filling out the orbits, we get substantially longer integrations in some cases. The filter chosen is frequently used; no special calibration exposures are required but PSF monitoring in this filter would greatly enhance our program. Real_Time_Justification: We have no special scheduling requirments. Calibration_Justification: ! Move appropriate text from Real_Time_Justification We have no special calibration requirments. PSF monitoring in the PC with the F814W filter would help us better subtract the nuclear point source, which is expected to be the limiting factor in detecting the host galaxy. Additional_Comments: We require the spacecraft to roll between sets of observations (one set of short exposure, medium exposure, and long exposure per orbit). It is imperative that for each target the two visits are sequential, in consecutive orbits, with no intervention but the roll. Fixed_Targets ! Section 5.1 Target_Number:1 Target_Name:PKS2254+074 Alternate_Names: Description:GALAXY,BL Lac Position:RA=22H 57M 17.3S +/- 0.5S, DEC=+07D 43' 12.3" +/- 0.5" ! Most common specification format is ! RA=0H 0M 0.00S +/- 0S, ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: J2000 RV_or_Z: Z = 0.19 RA_PM: ! Units are seconds of time per year Dec_PM: ! Units are seconds of arc per year Epoch: Annual_Parallax: Flux: V=16.7 +/- 1.4 ! Include at least V and B-V Comments: Fixed_Targets ! Section 5.1 Target_Number:2 Target_Name:QSO0814+425 Alternate_Names: Description:GALAXY,BL Lac Position:RA=08H 18M 16.0S +/- 0.5S, DEC=+42D 22' 45.4" +/- 0.5" ! Most common specification format is ! RA=0H 0M 0.00S +/- 0S, ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: J2000 RV_or_Z: Z = 0.258 RA_PM: ! Units are seconds of time per year Dec_PM: ! Units are seconds of arc per year Epoch: Annual_Parallax: Flux: V=18.3 +/- 0.5 ! Include at least V and B-V Comments: ! This is a template for a single visit containing a single exposure ! Repeat exposure and visit blocks as needed ! visit 1 for 2254 (#1) Visits ! Section 6 Visit_Number: 1 Visit_Requirements: ! Section 7.1 ! Uncomment or copy visit level special requirements needed ! Most of these requirements (including ORIENT) will limit scheduling ! PCS MODE [Fine | Gyro] ! GUIDing TOLerance ! ORIENTation TO ! ORIENTation TO FROM ! ORIENTation TO FROM NOMINAL ! SAME ORIENTation AS ! CVZ ! PARallel ! AFTER [BY [TO ]] ! AFTER ! BEFORE ! BETWEEN AND ! GROUP WITHIN