! $Id: 5707,v 9.1 1994/11/01 21:52:33 pepsa Exp $ ! 5707_v4.prop - Ray A. Lucas - 1 November, 1994 ! Added small dither between exposures - RAL 11/1/94 ! Added more explanatory text about ORIENTs to GF text. - RAL 11/1/94 ! File origin: 3857C.PROP coverpage: title_1: MORPHOLOGY OF GALAXIES IN CLUSTERS AT Z = 0.5 - CONT OF 2373: title_2: CYCLE 4 CARRY-OVER sci_cat: GALAXIES & CLUSTERS sci_subcat: GALAXY MORPHOLOGY proposal_for: GO/CAR longterm: 2 cont_id: 3857 pi_fname: ALAN pi_lname: DRESSLER pi_inst: CARNEGIE OBSERVATORIES pi_country: USA pi_phone: 818-304-0245 hours_pri: 11.00 num_pri: 2 wf_pc: Y funds_amount: 138240 funds_length: 12 off_fname: JOHN off_lname: LIVELY off_title: DIR., ADMIN. & FIN. off_inst: CARNEGIE INSTITUTION OF WASHINGTON off_addr_1: 1530 P. ST., N.W. off_city: WASHINGTON off_state: DC off_zip: 20005 off_country: USA off_phone: 202-387-6400 ! end of coverpage abstract: line_1: We outline a continuing program to study galaxy evolution through the line_2: investigation of galaxy morphology as a function of lookback time. The line_3: development of disks and bulges, the role of mergers, interactions, and other line_4: environmental influences, are expected to be visible over the range 0 < z < 1 line_5: as judged by the spectrophotometric evolution already observed over this line_6: redshift range. We propose in Cycle 2 to continue our efforts by imaging with line_7: the Wide Field Camera two additional fields containing rich clusters of galaxies line_8: at z = 0.5 for which extensive photometry and spectroscopy already exist. The line_9: fields include a range of environments, from the dense cores of clusters to line_10: isolated field galaxies. These data will be used primarily to classify images line_11: according to traditional morphological categories and will be used, within line_12: the constraints implied by deconvolution techniques, to measure surface line_13: brightness distributions and bulge-to-disk ratios. A brief description is line_14: given of how the data are applicable to specific questions, like the line_15: cause of enhanced starburst activity found for high-z galaxies. line_16: NOTE: The portion of the program contained in this observing program ID 5707 line_17: consists of the unfinished portion of the CL1446 observations left over from line_18: Cycle 2 and is now being done with WFPC2 instead of WFPC-I. ! ! end of abstract general_form_proposers: lname: DRESSLER fname: ALAN title: P.I. inst: CARNEGIE OBSERVATORIES country: USA ! lname: BUTCHER fname: HARVEY inst: KAPTEYN OBSERVATORY country: NETHERLANDS esa: Y ! lname: OEMLER fname: AUGUSTUS, JR. inst: DEPARTMENT OF ASTRONOMY, YALE U. country: USA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: NOTE: Q3 SECTIONS 1 & 2 BELOW DESCRIBE THE ORIGINAL WFPC-I OBS. line_2: SKIP TO GF Q3 SECTION 3 FOR CARRYOVER PROGRAM 5707 DESCRIPTION. line_3: Our original plan was to use the WFC to image 2 fields in line_4: each of 8 clusters 0.36 < z < 0.55 over a period of 2 line_5: years, fields selected from ground-based CCD images. For line_6: each cluster, multicolor photometry for several hundred line_7: objects, and low-resolution spectra for 30-50 representative line_8: galaxies in the fields covering a magnitude range 19 < line_9: m(r) < 23, are available. These fields typically contain line_10: field/cluster galaxies in the ratio of 1/2, so the sample line_11: covers a wide range of environments. Spectra have been line_12: classified according to "activity", as described in the text line_13: and the papers cited. The field centers were chosen to line_14: maximize the number of "active" galaxies. line_15: From our revised Cycle 1 allocation we have acquired 3 hrs line_16: on cluster CL0024+1654 and 6 hours on Cl0939+4713. These line_17: observations demonstrate that morphological information can line_18: be extracted from high-redshift galaxies despite the degraded line_19: imaging performance of HST. The 20% of the light concentrated line_20: in the small PSF core has made it possible to assess the line_21: salient features of morphological classification line_22: like bulge-to-disk ratio and strong spiral structure line_23: with of order 6 hours of exposure on clusters at z = 0.4. ! question: 3 section: 2 line_1: With our time in Cycle 2, we have scheduled approximately line_2: 6 hours on a third cluster CL1446+2621 and an additional line_3: 3 hours on CL0024+1654. These exposures will be coadded from line_4: single-orbit exposures, done in a single color with filter line_5: F702W, which roughly corresponds to a rest-frame color line_6: between B and V. Information on color distributions formed a line_7: promising though minor part of our original observing plan, line_8: but the prospect of restoring images of high photometric line_9: accuracy through deconvolution is sufficiently daunting that line_10: we will not attempt this unless experiments by others line_11: confirm its feasibility. line_12: NOTE: ALL GF Q3 TEXT ABOVE THIS POINT IS FROM THE OLD ORIGINAL line_13: CYCLE 2 PROGRAM, AND IS REFERRING TO THE PROGRAM AS IT WAS line_14: DESIGNED FOR THE WFPC-I OBSERVATIONS, WHICH ALSO INCLUDED line_15: PSF EXPOSURES OF NGC 188 FOR USE WITH DECONVOLUTIONS, ETC. line_16: THE SPECIFIC DETAILS PERTAINING TO THE CYCLE 4 CARRY-OVER line_17: PROGRAM GO/CAR 5707 ARE CONTAINED IN GF QUESTION 3 SECTION 3, line_18: BELOW. ! question: 3 section: 3 line_1: THIS SECTION DESCRIBES THE SPECIFIC DETAILS FOR IMPLEMENTATION line_2: OF THE CYCLE 4 CARRY-OVER PROGRAM GO/CAR 5707. line_3: This carry-over program consists of 2 exposures of the galaxy line_4: cluster GAL-CLUS-1446+2621. The first should be taken with the line_5: WFALL-FIX aperture chosen, and the special requirement POS TARG line_6: +10.0,+10.0 used to place the Fixed Target List coords at the apex. line_7: The second exposure should also use the WFALL-FIX aperture, but a line_8: small dither should be applied by use of the special requirement line_9: POS TARG +10.3,+10.3. This should place the second exposure 3" line_10: ( exactly 3 WFC pixels ) off in both x and y from the first, line_11: allowing us to deal effectively with hot pixels, etc. The use of line_12: NO GAP and SAME ORIENT special requirements will help us keep the line_13: offsets at a level of accuracy which will still allow us to register line_14: the two images well enough to do effective cosmic ray removal. The 3 line_15: pixel offset is small enough that field distortions and non-overlapping line_16: areas between the two images should be minimized, yet large enough to line_17: allow us to identify and deal with hot pixels and most chip defects, line_18: etc. Both exposures should be of the same duration, in this case 2200s line_19: each. Each exposure is intended to essentially fill an orbit ( or most line_20: of one ) but to still be of equal exposure time. An absolute ORIENT of line_21: 305.356D +/- 0.01D is given in order to match as much as possible the line_22: field of view of the previous data taken with WFPC-I. ! question: 3 section: 4 line_1: A SUMMARY OF THE CURRENT GO/CAR 5707 CARRY-OVER REQUIREMENTS FOLLOWS: line_2: 1). WFALL-FIX aperture with POS TARG +10.0,+10.0 ( FTL coords at apex ) line_3: for the first exposure, and POS TARG +10.3,+10.3 for the second line_4: exposure, yielding a 3-WFC-pixel dither in both x and y between the line_5: first and second exposures. We should be able to align the two line_6: frames well enough to do effective cosmic ray removal during the line_7: data reduction, provided the two exposures are tied together with a line_8: NO GAP special requirement in order to keep the offset well line_9: registered, using the same guide stars on the same pointing during line_10: the observations. line_11: 2). SAME ORIENT for both exposures line_12: 3). SEQ NO GAP ( do both together, one after another ) line_13: 4). 2x2200s exposures ( 2 orbits, with 1 exposure / orbit ), and line_14: without a CR-SPLIT ( i.e. CR-SPLIT = NO ) line_15: 5). ORIENT=305.356D +/- 0.01D in order to cover richest field of cluster line_16: in previous WFPC-I data. Opposite and orthogonal angles may be OK line_17: as well, but we prefer and request that we be consulted if any such line_18: change is necessary. ( Please consult with the PI, Alan Dressler, line_19: and/or Ray Lucas, at STScI, if an alternate ORIENT is needed. ) line_20: NOTE THAT THE ORIGINAL ORIENT ANGLE IN GO 3857 WAS U3=125.356D, BUT line_21: THE ORIENT ANGLE IN THIS CARRYOVER PROGRAM WAS TAKEN FROM THE CHANGE line_22: THAT WAS MADE TO 3857 IN AN ATTEMPT TO DO THE SECOND HALF AT 180D line_23: OFF WITH WFPC-I BEFORE THE REFURBISHMENT MISSION. ( CONT'D, BELOW.) ! question: 3 section: 5 line_1: DOING THE CARRYOVER AT 180D FROM THE ORIGINAL ALSO APPEARS TO HAVE line_2: THE ADVANTAGE OF CAUSING FEWER GALAXIES TO BE LOST OFF THE MISSING line_3: WF1 THAN IF THE ORIGINAL U3 ORIENT=125.356D HAD BEEN USED IN THIS line_4: PROGRAM. DOING THE CARRYOVER PROGRAM AT U3 ORIENT=305.356D MEANS line_5: THAT THE OLD WF4 FIELD WILL NOW FALL ON THE NEW WF2, THE OLD WF1 WILL line_6: NOW FALL ON THE NEW WF3, THE OLD WF2 WILL NOW FALL ON THE NEW WF4, line_7: AND WHAT APPEARS TO HAVE BEEN THE SPARSEST FIELD, THE OLD WF3, WILL line_8: NOW FALL ON ( AND OFF OF ) THE NEW PC1. ! question: 5 section: 1 line_1: NOTE: THIS IS TEXT FOR THE NEW CYCLE 4 CARRY-OVER PROGRAM. line_2: See the summary in GF Question 3, Sections 3, 4, and 5 ( immediately line_3: above ) for a summary of our scheduling requirements for the Cycle 4 line_4: carry-over program GO/CAR 5707. ! question: 9 section: 1 line_1: We are presently involved in analyzing our first WFC images, line_2: of cluster CL0024+1654 and CL0939+4713, as described in the line_3: above text. line_4: NOTE: QUESTION 9 TEXT IS OLD TEXT. ! question: 10 section: 1 line_1: Dressler and Oemler each have access to a MicroVAX line_2: computer with image display capability. Each MicroVAX is line_3: part of a VAX system, supplied and maintained individually line_4: by Carnegie Observatories and Yale which includes a variety line_5: of I/O devices and access to BITNET and other communication line_6: networks. line_7: NOTE: QUESTION 10 TEXT IS OLD TEXT. ! !end of general form text general_form_address: lname: DRESSLER fname: ALAN category: PI inst: CARNEGIE OBSERVATORIES addr_1: 813 SANTA BARBARA ST. city: PASADENA state: CA zip: 91101 country: USA phone: 818-304-0245 ! ! end of general_form_address records fixed_targets: ! targnum: 1 name_1: GAL-CLUS-1446+2621 descr_1: F,404 pos_1: RA= 14H47M16.5S +/-0.1S, pos_2: DEC= +26D20'20.0" +/-1" equinox: 1950.0 rv_or_z: Z=0.37 comment_1: CLUSTER OF GALAXIES AT Z=0.37. ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: ! linenum: 1.000 targname: GAL-CLUS-1446+2621 config: WFPC2 opmode: IMAGE aperture: WFALL-FIX sp_element: F702W num_exp: 1 time_per_exp: 2200S priority: 1 param_1: CR-SPLIT=NO req_1: POS TARG +10.0,+10.0; req_2: ORIENT 305.356D +/- 0.01D; req_3: SAME ORIENT FOR 2 AS 1; req_4: SEQ 1-2 NO GAP; req_5: CYCLE 4; comment_1: DO BOTH EXPOSURES AT THE SAME ORIENT comment_2: ANGLE, BUT DITHER BY 3" (3 WFC PIXELS) comment_3: IN X AND Y BETWEEN THEM. DO IN comment_4: SEQUENTIAL ORDER WITH NO GAP IN comment_5: BETWEEN. POS TARG +10,+10 PLACES FTL comment_6: COORDS AT PYRAMID APEX FOR THIS EXP. ! linenum: 2.000 targname: GAL-CLUS-1446+2621 config: WFPC2 opmode: IMAGE aperture: WFALL-FIX sp_element: F702W num_exp: 1 time_per_exp: 2200S priority: 1 param_1: CR-SPLIT=NO req_1: POS TARG +10.3,+10.3; req_2: CYCLE 4; comment_1: DITHER BY USING POS TARG +10.3,+10.3 comment_2: WHICH PLACES FTL COORDS 3" (3 WFC comment_3: PIXELS) OFF THE APEX IN X AND Y FOR comment_4: THIS SECOND EXPOSURE. ALTERNATE ORIENT comment_5: ANGLES OF 215.356D, 125.356D, AND comment_6: 36.356D MAY BE ACCEPTABLE IF NEEDED. ! ! end of exposure logsheet ! No scan data records found