! File: 3857C.PROP ! Database: PEPDB ! Date: 19-FEB-1994:21:59:22 coverpage: title_1: MORPHOLOGY OF GALAXIES IN CLUSTERS AT Z = 0.5 - CONT OF 2373 sci_cat: GALAXIES & CLUSTERS sci_subcat: GALAXY MORPHOLOGY proposal_for: GO longterm: 2 cont_id: 2373 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. ! ! 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: Our original plan was to use the WFC to image 2 fields in line_2: each of 8 clusters 0.36 < z < 0.55 over a period of 2 line_3: years, fields selected from ground-based CCD images. For line_4: each cluster, multicolor photometry for several hundred line_5: objects, and low-resolution spectra for 30-50 representative line_6: galaxies in the fields covering a magnitude range 19 < line_7: m(r) < 23, are available. These fields typically contain line_8: field/cluster galaxies in the ratio of 1/2, so the sample line_9: covers a wide range of environments. Spectra have been line_10: classified according to "activity", as described in the text line_11: and the papers cited. The field centers were chosen to line_12: maximize the number of "active" galaxies. line_14: From our revised Cycle 1 allocation we have acquired 3 hrs line_15: on cluster CL0024+1654 and 6 hours on Cl0939+4713. These line_16: observations demonstrate that morphological information can line_17: be extracted from high-redshift galaxies despite the degraded line_18: imaging performance of HST. The 20% of the light concentrated line_19: in the small PSF core has made it possible to assess the line_20: salient features of morphological classification line_21: like bulge-to-disk ratio and strong spiral structure line_22: 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 line_2: approximately 6 hours on a third cluster CL1446+2621 and line_3: an additional 3 hours on CL0024+1654. line_5: These exposures will be coadded from line_6: single-orbit exposures, done in a single color with filter line_7: F702W, which roughly corresponds to a rest-frame color line_8: between B and V. Information on color distributions formed a line_9: promising though minor part of our original observing plan, line_10: but the prospect of restoring images of high photometric line_11: accuracy through deconvolution is sufficiently daunting that line_12: we will not attempt this unless experiments by others line_13: confirm its feasibility. line_15: We have included exposures of NGC 188 in order to build up a line_16: library of PSF's over the field with filter F702W. It is line_17: important that our exposures be done over a 7 day period line_18: per target in order to deliver the SAME ORIENT so that line_19: the frames may be coadded. We also request that a set of the line_20: PSF exposures of NGC 188 be grouped within the same 7 days line_21: in which each target is observed. ! question: 4 section: 1 line_1: For our original proposal we used CCD images of low-z line_2: cluster spirals to simulate HST observations and concluded line_3: that 20,000 s (8 x 2500 s single-orbit) exposures were line_4: desireable for satisfactory classification. We have obtained line_5: CCD images of spiral galaxies in a low-redshift cluster and line_6: used them to simulate exposures with the WFC, taking into line_7: account telescope and detector efficiency, dark current, line_8: readout noise, resolution, and sampling. line_9: From our 6 orbits of data on Cl0024+1654 and 10 orbits on line_10: CL0939+4713 (Cycle 1), we have confirmed the results of line_11: these simulations that useful morphological data can be extracted, line_12: even with the SA problem, due to the non-negligible power in line_13: the core of the PSF. In these data we clearly see thin line_14: disks and unresolved point-like structures in galaxies with V = 21. line_15: At this time, our plan is to compromise between even line_16: better data and some range of cluster environments, by line_17: choosing to use our 22 allocated hours to image 3 different line_18: clusters at roughly 6 hours each. ! question: 4 section: 2 line_1: NOTE: With the approval of the STScI, this program has now line_2: been revised to include 2 of a total of 10 hours of Director's line_3: Discretionary time which was awarded us in late Spring of 1992. line_4: With this extra 2 hours, we have increased our exposure time on line_5: the target GAL-CLUS-1446+2621 by increasing the number of line_6: exposures to 5 in both Exposure Log lines 4 and 5. The remaining line_7: 8 hours of Director's Discretionary time is being used to study line_8: the cluster Abell 370 in a separate Director's Discretionary line_9: ( GO/DD ) proposal, also in Cycle 2. ! question: 5 section: 1 line_1: Do all exposures PER TARGET within 7 days in this program. line_2: For the first set, do the following: line_3: Do all exposures within 7 days. The exposures in exposure log line_4: line 1 and 1.5 are all to be done at POS TARG +10,-10 and those in line_5: exposure log line 2 are all to be done at POS TARG +12,-7. line_6: The SAME ORIENT should be used for all of the exposures in line_7: lines 1 through 2. Exposure log line 3 is for two short exposures line_8: of NGC 188 in order to determine PSFs across the field of all line_9: 4 chips. They should be done within the same week as exposure line_10: lines 1 through 2, but not necessarily at the SAME ORIENT as the line_11: other ( science ) exposures in 1 through 2. The same instructions line_12: apply to the next set of lines, but SPB says no single shorter exp is needed. line_13: Do all exposures within 7 days. The exposures in exposure log line_14: line 4 are all to be done at POS TARG +10,-10 and those in line_15: exposure log line 5 are all to be done at POS TARG +12,-7. line_16: The SAME ORIENT should be used for all of the exposures in line_17: lines 4 and 5. Exposure log line 6 is for two short exposures line_18: of NGC 188 in order to determine PSFs across the field of all line_19: 4 chips. They should be done within the same week as exposure line_20: lines 4 and 5, but not necessarily at the SAME ORIENT as the line_21: other ( science ) exposures in 4 and 5. NOTE: In the discussion line_22: above, and on the exposure logsheet lines, POS TARG +10,-10 is line_23: intended to roughly duplicate the old POS TARG 0,0 used in the ! question: 5 section: 2 line_1: Cycle 1 versions of this program, and POS TARG +12,-7 is line_2: intended to roughly duplicate the old Cycle 1 usage, POS TARG line_3: 2,3. These changes were made because the STScI redefined the line_4: coordinate system and apertures for the WF/PC. The aperture line_5: WFALL-FIX is used to tie the aperture center to the same line_6: reference point over time in case the WFALL aperture center line_7: location is shifted for any reason by STScI. line_8: ALSO, NOTE THE FOLLOWING: There is a set of specific ORIENT line_9: angles requested for the exposures of the first target, line_10: GAL-CLUS-0024+1653-FLD1A (Exposure Log lines 1 through 2), with line_11: one angle being specified in the special requirements on line_12: Exposure Log line 1, and acceptable alternate ORIENT angles line_13: which are 90 degrees apart with a range +/- 5 degrees line_14: being specified in the comments section of Exposure Log line_15: line 1. So, there is both a specific ORIENT requirement line_16: for this target, and a requirement that all other data for line_17: it be taken at the SAME ORIENT as whichever of the angles line_18: is used for the first exposure. NOTE ALSO THAT SPB HAS SAID THAT EXPOSURE LOG line_19: LINE 1 SHOULD BE USED FOR THE INITIAL ACQUISITION, AND IT HAS BEEN MADE line_20: SHORTER BY 100S, BY STSCI, FOR THAT REASON. THIS ONLY APPLIES TO THE FIRST line_21: TARGET, GAL-CLUS-0024, AND NOT TO THE SECOND, GAL-CLUS-1446, SINCE SPB DID NOT line_22: THINK THERE WOULD BE A PROBLEM WITH THE ACQUISITION TIME FITTNG ALONG WITH THE line_23: SCIENCE EXPOSURE IN THE FIRST ORBIT FOR THAT TARGET. ! question: 7 section: 1 line_1: In order to accomplish our scientific objectives line_2: we must develop methods of moving from images to line_3: parametrized data. Traditionally this has been accomplished line_4: by using the image processing capabilities of the human eye line_5: plus brain, in order to assign morphological classes, line_6: estimate bulge-to-disk ratios, and describe distributions of line_7: color, dust, non-axisymmetric structures, etc. These line_8: classifications are semi-quantitative at best, and useful line_9: results regarding the evolution of galaxy morphology will line_10: depend on having an equivalent sample of observations at low line_11: redshift for which the same subjective criteria can be line_12: applied. With this in mind, Dressler has begun to line_13: obtain CCD images of low redshift clusters 0.02 < z < 0.04 line_14: in seeing of FWHM < 1 arcsecond. With suitable processing, line_15: such data can be used to simulate the HST observations line_16: (similar sampling, S/N, and resolution) in order to provide line_17: calibration images. Thus, although the criteria will line_18: remain subjective in this initial step, it can be applied so line_19: that redshift is the only significant variable, and a good line_20: assessment of differential morphology can be made. Our early line_21: comparison of our first HST images to convolved ground-based line_22: images for low-redshift confirms this approach as instructive line_23: in assessing morphology, even with the SA problem. ! question: 7 section: 2 line_1: We have used our exposures of NGC-188 to produce PSF line_2: models for use in Lucy deconvolution that have line_3: significantly improved our ability to classify these line_4: distant galaxies. ! 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. ! 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. ! !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-0024+1653-FLD1A descr_1: F,404 pos_1: RA= 00H24M00.3S +/-0.1S, pos_2: DEC= +16D53'10.0" +/-1" equinox: 1950.0 rv_or_z: Z=0.40 comment_1: CLUSTER OF GALAXIES AT Z=0.40. ! targnum: 2 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. ! targnum: 3 name_1: NGC188PSF-1 descr_1: C,202 pos_1: RA=00H 47M 32S +/-0.5S, pos_2: DEC= +85D 14' 58" +/-1", equinox: 2000 comment_1: NGC 188 PSF STAR FIELD #1 comment_2: FROM WF/PC GTO COORDS. ! targnum: 4 name_1: NGC188PSF-4 descr_1: C,202 pos_1: RA=00H 46M 51S +/-0.5S, pos_2: DEC= +85D 15' 33" +/-1", equinox: 2000 comment_1: NGC 188 PSF STAR FIELD #4 comment_2: FROM WF/PC GTO COORDS. ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: GAL-CLUS-0024+1653-FLD1A config: WFC opmode: IMAGE aperture: WFALL-FIX sp_element: F702W num_exp: 1 time_per_exp: 2100S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO req_1: CYCLE 2 / 1-6; req_2: POS TARG +10,-10; req_3: GROUP 1-3 WITHIN 7D; req_4: ORIENT 196D +/- 5D / 1-2; req_5: SAME ORIENT FOR 1.5-2 AS 1; comment_1: WFC OFFSET ANGLE = 45.3 DEGREES comment_2: SKY POSITION ANGLE OF FIELD: 331D. comment_3: ORIENT ANGLES OF 16D +/- 5D, 106D comment_4: +/- 5D, 286D +/- 5D ALSO ACCEPTABLE. ! linenum: 1.500 targname: GAL-CLUS-0024+1653-FLD1A config: WFC opmode: IMAGE aperture: WFALL-FIX sp_element: F702W num_exp: 2 time_per_exp: 2200S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO req_1: POS TARG +10,-10; ! linenum: 2.000 targname: GAL-CLUS-0024+1653-FLD1A config: WFC opmode: IMAGE aperture: WFALL-FIX sp_element: F702W num_exp: 3 time_per_exp: 2200S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO req_1: POS TARG +12,-7; comment_1: OFFSET 2 ARCSEC IN RA AND 3 ARCSEC IN comment_2: DEC TO REMOVE POSSIBLE EFFECTS comment_3: ASSOCIATED WITH INDIVIDUAL PIXELS AND comment_4: POINT SPREAD FUNCTIONS. ! linenum: 3.000 targname: NGC188PSF-1 config: WFC opmode: IMAGE aperture: WFALL-FIX sp_element: F702W num_exp: 2 time_per_exp: 40S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: POS TARG +10,-10; comment_1: SHORT EXPOSURE OF NGC188 AT comment_2: POS TARG +10,-10 FOR DETERMINATION comment_3: OF PSF OVER WIDE FIELD IN comment_4: F702W. EXPOSURE TIME MAY HAVE comment_5: TO BE REVISED. ! linenum: 4.000 targname: GAL-CLUS-1446+2621 config: WFC opmode: IMAGE aperture: WFALL-FIX sp_element: F702W num_exp: 5 time_per_exp: 2200S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO req_1: POS TARG +10,-10; ! linenum: 5.000 targname: GAL-CLUS-1446+2621 config: WFC opmode: IMAGE aperture: WFALL-FIX sp_element: F702W num_exp: 5 time_per_exp: 2200S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=NO req_1: POS TARG +12,-7; req_2: ORIENT 305.356D +/- 0.01D comment_1: OFFSET 2 ARCSEC IN RA AND 3 ARCSEC IN comment_2: DEC TO REMOVE POSSIBLE EFFECTS comment_3: ASSOCIATED WITH INDIVIDUAL PIXELS AND comment_4: POINT SPREAD FUNCTIONS. ! linenum: 6.000 targname: NGC188PSF-4 config: WFC opmode: IMAGE aperture: WFALL-FIX sp_element: F702W num_exp: 2 time_per_exp: 40S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: POS TARG +10,-10; comment_1: SHORT EXPOSURE OF NGC188 AT comment_2: POS TARG +10,-10 FOR DETERMINATION comment_3: OF PSF OVER WIDE FIELD IN comment_4: F702W. EXPOSURE TIME MAY HAVE comment_5: TO BE REVISED. ! ! end of exposure logsheet ! No scan data records found