! Proposal 6439, submission 3 ! PI: Steve Zepf ! Received Thu Apr 4 20:59:33 EST 1996 ! From: zepf@palan.berkeley.edu ! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! $Id: 6439,v 32.1 1997/05/22 14:33:24 pepsa Exp $ ! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! $Id: 6439,v 32.1 1997/05/22 14:33:24 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: Ready ! Phone: 410-338-4546 , E-mail: ready@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. ! Name of Phase I Proposal: archive-0133.zepf.prop ! Date generated: Fri Dec 22 17:34:35 EST 1995 ! Proposal_Information ! Section 4 Title: Using a Cepheid based Distance to Test the Large Peculiar Motions Inferred in the Centaurus Region Proposal_Category: GO Scientific_Category: COSMOLOGY Cycle: 6 Investigators PI_name: Steve Zepf PI_Institution: University of California, Berkeley CoI_Name: Marc Davis CoI_Institution: University of California Contact: ! Y or N (designate at most one contact) CoI_Name: Barry Madore CoI_Institution: NASA/IPAC Extragalactic Database Contact: ! Y or N (designate at most one contact) CoI_Name: Wendy Freedman CoI_Institution: Carnegie Institution of Washington Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) We propose to use the HST and WFPC2 to obtain periods and luminosities for Cepheids in a spiral galaxy in the Centaurus cluster in order to determine its distance. A Cepheid distance to Centaurus is possible with HST and will be a major step in the comparison of observed peculiar velocities with the predictions based on reconstructions of the density field from the spatial distribution of galaxies. The Centaurus region is critical for such tests. Secondary distance indicators (SBFs, Tully-Fisher, and D_n - Sigma) place this galaxy and others in the ``Cen30'' cluster at a distance of only about 2,300 - 2,700 kms, whereas the cluster has a redshift of 3,300 kms\ in the CMB frame. Such a high peculiar velocity is not predicted for this cluster by reconstructions of the density field based on IRAS or optical galaxy distributions. This cluster is the nearest and one of the clearest cases of disagreement between the peculiar motions inferred from secondary distance indicators and those predicted by the density fields. A great deal of theoretical and observational effort has gone into programs to determine Omega in this way. The major obstacle to progress has been discrepancies like those for the Centaurus cluster. To resolve this discrepancy, there is no substitute for directly obtaining Cepheid distances. Questions ! Free format text (please update) Observing_Description: The scientific goals require an observing program in which the target is visited nine times, the first eight in optimized time intervals covering a 50-day window, and the ninth a year later to guard against aliasing for long period objects. The time sequence of the 8 visits is critical to the project. The first six visits will consist of observations in the F55W filter for three orbits in each visit. Each orbit is defined as one exposure which is CR-split into two. Between orbits, the pointing is shifted by 2.5,2.5 WF pixels. The last three visits will consist of two orbits. In this case, we will utilize an integer shift bewteen orbits. In all cases, the F55W filter will be used. Real_Time_Justification: Calibration_Justification: ! Move appropriate text from Real_Time_Justification Additional_Comments: Fixed_Targets ! Section 5.1 Target_Number: 1 Target_Name: NGC4603-POS1 Alternate_Names: Description: galaxy,spiral Position: RA=12H 40M 58.77S +/- 5", ! Most common specification format is DEC=-40D 58' 02.5" +/- 5" ! RA=0H 0M 0.00S +/- 0S, !PLATE-ID=00ZD ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 ! center position commented out below, above is 35"E and 31" N of nucleus !Position: RA=12H 40M 55.68S +/- 5", ! Most common specification format is ! DEC=-40D 58' 33.5" +/- 5" ! RA=0H 0M 0.00S +/- 0S, Equinox: 2000 RV_or_Z: V = 2562 RA_PM: ! Units are seconds of time per year Dec_PM: ! Units are seconds of arc per year Epoch: Annual_Parallax: Flux:SURF(V) = 24 ! 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 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 ! DROP TO GYRO IF NECESSARY [NO REACQuisition] !ORIENTation 29.5D TO 30.5D ORIENTation 95.0D TO 105.0D ! ORIENTation TO FROM ! ORIENTation TO FROM NOMINAL ! SAME ORIENTation AS ! CVZ ! PARallel SCHEDulability 50% ! AFTER [BY [TO ]] ! AFTER ! BEFORE !BETWEEN AND ! GROUP WITHIN