! $Id: 5271,v 4.1 1994/07/27 16:13:34 pepsa Exp $ coverpage: title_1: WFPC2 ERO OBSERVATIONS OF THE MOST DISTANT GALAXY 4C41.17 sci_cat: GALAXIES & CLUSTERS sci_subcat: DISTANT GALAXIES proposal_for: SMC/ERO pi_title: DR. pi_fname: WILLIAM pi_mi: B. pi_lname: SPARKS pi_inst: STSCI pi_country: USA pi_phone: 410-338-4843 keywords_1: FORMATION, EVOLUTION, AGN, RADIO GALAXY, MORPHOLOGY, keywords_2: RADIO hours_pri: 39.00 num_pri: 10 wf_pc: Y funds_amount: 185951 funds_length: 24 funds_date: MAR-90 pi_position: ASTRONOMER ! end of coverpage abstract: line_1: We have recently developed the most efficient technique known for finding line_2: distant galaxies. In our sample of 33 4C sources, at least 8 are galaxies with line_3: z < 2, and 2 have z > 3.7 The galaxies emit bright narrow Lyman alpha which is line_4: extended, usually by several arcseconds. Their optical continua are also line_5: extended. These high-redshift objects show the striking alignment between line_6: their optical and radio emission that we (unexpectedly) found to be a general line_7: property of distant radio galaxies. Here we propose to study the most distant line_8: known galaxy with the HST. Our program is directed towards imaging the line_9: galaxy in the continuum with the PC to obtain morphological information line_10: about the various components. Our distant radio galaxies are the only line_11: high-redshift objects that can be mapped in detail with the HST. This line_12: project will provide unique information about the properties of galaxies in line_13: the early universe, close to the epoch of their formation. line_14: The aim of this specific program is to make Early Release Observations of line_15: 4C41.17 as a test of the capabilities of WFPC2 in meeting the goals of the line_16: original program established before the spherical aberration was known. line_17: Unlike the original GO 2438, however, the PC is used here instead of the WFC. ! ! end of abstract general_form_proposers: lname: SPARKS fname: WILLIAM title: P.I. mi: B. inst: STSCI country: USA ! lname: MILEY fname: GEORGE title: DR. mi: K. inst: LEIDEN UNIVERSITY country: NETHERLANDS esa: X ! lname: VAN BREUGEL fname: WIL title: DR. inst: IGPP, LAWERENCE LIVERMORE NAT. LAB. country: USA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: We intend to obtain WFPC2 images of this object through a broad line_2: band filter longward of Ly alpha, F702W. ( This duplicates the line_3: original F702W which was done in Cycle 1 and has been approved line_4: for a repeat in a Cycle 4 GO proposal on which Van Breugel is PI. ) line_5: The exposure time in this program will be divided into several line_6: exposures for best cosmic ray rejection, but otherwise each line_7: exposure should be as long as possible in order to go as deep as line_8: possible for the given read noise. Thus we are asking for each line_9: subexposure to be about 2400 sec or about a half orbit. These line_10: times could be adjusted up or down a bit to maximize the efficiency. line_11: For example the individual exposoures could be reduced to 30 minutes line_12: if necessary for acquistion, and the number of exposures increased line_13: accordingly. Individual exposures should not be less than 30 minutes. line_14: The basic objective is to go as deep as possible in these exposures. line_15: All observations were originally done with coarse-track guiding, line_16: but fine lock is chosen here in this ERO proposal due to the line_17: increased likelihood of damage to the teflon coating of some FGS line_18: components which oscillate more in coarse track, & since PC is used. line_23: CRITICAL IMPLEMENTATION NOTES FOLLOW IN THE SECTION BELOW. ! question: 3 section: 2 line_1: All observations in this program should be made at the SAME POS. line_2: The GROUP NO GAP special requirement is intended to help ensure line_3: that the observations are scheduled to obtain the data at the line_4: SAME POS and within a relatively short amount of time for the line_5: purposes of EARLY RELEASE to the public. line_6: No attempt has been made to duplicate the entire four chip WFC line_7: field of view imaged in Cycle 1 since the target of interest falls line_8: on a single chip, and since, unlike the original GO program, this line_9: single chip is the WFPC2 PC chip instead of a WFC chip. There may line_10: well be some overlap, however, depending on the roll angle at line_11: which these observations are taken. In the original Cycle 1 WFC line_12: exposures, the ORIENT angle chosen was critical since the wider line_13: field of view of the WFC chip included a bright star which at some line_14: ORIENT angles would have caused a CCD column to bleed across the line_15: chip and obscure the target. We have now re-examined the Cycle 1 line_16: data and have found that although this star may appear on the PC line_17: chip at some ORIENT angles, it should never be at an angle which line_18: allows bleeding across the target. We have therefore removed the line_19: absolute ORIENT angle restrictions from this ERO program. As stated line_20: above, the SAME POS requirement is intended to ensure that all data line_21: in this program is taken with matching orientation angles and position, line_22: and the GROUP NO GAP is intended to help keep the SAME POS feasible, line_23: and to ensure that all the data is taken in a timely manner ( close in ! question: 3 section: 3 line_1: time ) for early release. line_2: Note that SAME POS = SAME POSITION _and_ SAME ORIENT by definition line_3: in the Phase II proposal instructions. line_4: Exposures are broken into two groups which may be combined as long as line_5: critical requirements SAME POS and GROUP NO GAP are maintained. GROUP line_6: NO GAP may be relaxed to GROUP WITHIN for some relatively short period line_7: of time (7D, for example) if necessary for scheduling, so long as the line_8: SAME POS requirement is still met. line_10: NOTE: The two groups of exposures ( mentioned in the previous paragraph ) line_11: in Exp Log lines 1 and 2 of the original ERO 5271 submission have been line_12: combined into one Exp Log line by OPB during the implementation of the line_13: proposal. Although the absolute ORIENT angle has now been dropped, the line_14: SAME POS and GROUP NO GAP requirements still apply and have been included line_15: on the Exp Log line comment lines. ! question: 6 section: 1 line_1: All observations are to be done in the Cycle 4 SMC/ERO period. line_2: No constraints on the specific ORIENT angle are now specified, unlike the line_3: original Cycle 1 WFC program, since we have now found that a bright star in line_4: the field will NOT bloom down onto the target when using the PC. The data line_5: should all be taken at the SAME POS, and should all be taken together as line_6: GROUP NO GAP in order to ensure its availability for a timely early public line_7: release. Note that SAME POS = SAME POSITION _and_ SAME ORIENT by definition line_8: in the Phase II proposal instructions. GROUP WITHIN (for some short period line_9: of time such as 7D, for example) may be substituted for GROUP NO GAP if line_10: necessary for scheduling, so long as the SAME POS special requirement is line_11: still met. ! !end of general form text general_form_address: lname: SPARKS fname: WILLIAM title: DR. category: PI inst: STSCI country: USA ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: 4C41.17 name_2: 0647+41 descr_1: E,315,325 pos_1: RA= 06H 47M 20.793S +/- 0.03S, pos_2: DEC=+41D 34' 04.55" +/- 0.3" equinox: 1950 rv_or_z: Z=3.800 fluxnum_1: 1 fluxval_1: SURF(V)=26.5 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: 4C41.17 config: WFPC2 opmode: IMAGE aperture: PC1 sp_element: F702W num_exp: 7 time_per_exp: 2100S s_to_n: 10 fluxnum_1: 1 priority: 1 param_1: CR-SPLIT = NO req_1: CYCLE 4; comment_1: ALL EXPOSURES SHOULD BE DONE comment_2: AT "SAME POSITION" AND "SAME comment_3: ORIENT" ANGLE FOR PURPOSES OF comment_4: COADDITION OF DATA. ALL SHOULD comment_5: BE DONE AS "GROUP NO GAP" AS comment_6: WELL. ! ! end of exposure logsheet ! No scan data records found