! $Id: 5214,v 5.1 1994/07/27 15:57:12 pepsa Exp $ coverpage: title_1: THE GREAT ATTRACTOR title_2: MEASUREMENT OF SURFACE BRIGHTNESS FLUCTUATIONS sci_cat: GALAXIES & CLUSTERS sci_subcat: EVOLUTION/COSMOLOGY proposal_for: GTO/WF2 pi_fname: JOHN pi_mi: T pi_lname: TRAUGER pi_inst: 2370 pi_country: USA num_pri: 1 wf_pc: Y ! end of coverpage abstract: line_1: We propose to measure velocity as a function of distance for a string line_2: of elliptical galaxies starting at the Hydra-Centaurus Supercluster line_3: and ending in the Shapley Supercluster. Relative distance measurements line_4: will be made from surface brightness fluctuations in PC images of these line_5: galaxies with the aid of the technique pioneered by John Tonry. We aim line_6: to test the predictions of the Great Attractor model in which the line_7: microwave dipole anisotropy is produced as a result of our acceleration line_8: into a mass concentration just beyond the Hydra Centaurus supercluster. ! ! end of abstract general_form_proposers: lname: TRAUGER fname: JOHN title: PI mi: T inst: JPL country: USA ! lname: MOULD fname: JEREMY inst: CALTECH country: USA ! lname: CLARKE fname: JOHN inst: UNIV. OF MICHIGAN country: USA ! lname: HOESSEL fname: JOHN inst: UNIV. OF WISCONSIN country: USA ! lname: GALLAGHER fname: JAY inst: UNIV. OF WISCONSIN country: USA ! lname: HOLTZMAN fname: JOHN inst: LOWELL OBSERVATORY country: USA ! lname: HESTER fname: JEFF inst: ARIZONA STATE UNIV. country: USA ! lname: WESTPHAL fname: JAMES inst: CALTECH country: USA ! lname: BURROWS fname: CHRIS inst: STSCI country: USA ! lname: CRISP fname: DAVID inst: JPL country: USA ! lname: GRIFFITHS fname: RICHARD inst: JOHNS HOPKINS UNIV country: USA ! ! end of general_form_proposers block general_form_text: ! ! ! question: 3 section: 1 line_1: To assure the highest possible signal to noise ratio in the regions of these line_2: galaxies exceeding 40 DN/pixel in total, the exposures will be CR-SPLIT into line_3: three or four parts. ! question: 4 section: 1 line_1: The key here is to measure the variance in the number of stars per pixel line_2: contributing to the observed unresolved galaxy image. The smaller the pixel and line_3: higher the resolution the larger the fractional variance. With 43 mas pixels line_4: WFPC2 is the premier instrument for this kind of observation. line_5: We have carried out simulations using the modelled PSF for the PC in WFPC2. It line_6: is a simple matter to coadd of order a million m_I stars placed at a distance line_7: of, say, 30 Mpc on a 64 x 64 grid until they reach the predicted intensity in a line_8: typical PC image of a gE galaxy. We used the DAOPHOT ADDSTAR program to obtain line_9: results like those in Figure 1. Photon noise is included. The power spectrum of line_10: this image is shown in Figure 2 and is seen to be a scaled version of the power line_11: spectrum of the PSF plus white noise (see Figure 3). The scaling factor (i.e. line_12: the height of the power spectrum above the high frequency noise baseline) is line_13: inversely proportional to distance. line_14: Our repeated simulations indicate that an uncertainty in distance of < 6% is line_15: obtained on a gE galaxy at a distance of 60 Mpc in 2200 seconds. In principle, line_16: we can obtain similar accuracy on more distant galaxies by scaling the exposure line_17: times to yield the same number of detected photons. line_18: Each observation will require a PSF star. ! !end of general form text general_form_address: lname: Trauger fname: John mi: T category: PI inst: 2370 addr_1: JPL addr_2: 4800 Oak Grove Drive city: Pasadena state: CA zip: 91109 country: USA phone: 354 9594 ! ! end of general_form_address records fixed_targets: targnum: 2 name_1: NGC4373 descr_1: E,303 pos_1: RA=12H25M17.8S +/- 2", pos_2: DEC=-39D45'35.6" +/- 2" equinox: 2000 pm_or_par: N rv_or_z: V=3415 fluxnum_1: 1 ! targnum: 5 name_1: N4373-PSF descr_1: E,303 pos_1: RA=12H25M24.6S +/- 1", pos_2: DEC=-39D44'46.3" +/- 1" equinox: 2000 pm_or_par: N fluxnum_1: 1 fluxval_1: V=14.92 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: NGC4373 config: WFPC2 opmode: IMAGE aperture: WFALL-FIX sp_element: F814W num_exp: 1 time_per_exp: 1900S priority: 1 param_1: CR-SPLIT=NO, param_2: ATD-GAIN=7, req_1: GROUP 1-6 NO GAP; req_2: GROUP 1-6 WITHIN 1D; req_3: POS TARG 33,33; req_4: CYCLE 4 / 1-6 comment_1: CENTER THE GALAXY ON THE PC ! linenum: 1.100 targname: NGC4373 config: WFPC2 opmode: IMAGE aperture: WFALL-FIX sp_element: F814W num_exp: 1 time_per_exp: 1100S priority: 1 param_1: CR-SPLIT=NO, param_2: ATD-GAIN=7, req_1: GROUP 1-6 NO GAP; req_2: GROUP 1-6 WITHIN 1D; req_3: POS TARG 33,33; req_4: CYCLE 4 / 1-6 comment_1: CENTER THE GALAXY ON THE PC ! linenum: 2.000 targname: NGC4373 config: WFPC2 opmode: IMAGE aperture: WFALL-FIX sp_element: F814W num_exp: 1 time_per_exp: 1100S priority: 1 param_1: CR-SPLIT=NO, param_2: ATD-GAIN=7, req_1: POS TARG 34,34; req_2: SAME ORIENT FOR 2 AS 1 ! linenum: 2.100 targname: NGC4373 config: WFPC2 opmode: IMAGE aperture: WFALL-FIX sp_element: F814W num_exp: 1 time_per_exp: 1900S priority: 1 param_1: CR-SPLIT=NO, param_2: ATD-GAIN=7, req_1: POS TARG 34,34; req_2: SAME ORIENT FOR 2 AS 1 ! linenum: 3.000 targname: NGC4373 config: WFPC2 opmode: IMAGE aperture: WFALL-FIX sp_element: F814W num_exp: 1 time_per_exp: 500S priority: 1 param_1: CR-SPLIT=NO param_2: ATD-GAIN=7 req_1: SAME POS FOR 3 AS 2; req_2: SAME ORIENT FOR 3 AS 1 ! linenum: 4.000 targname: N4373-PSF config: WFPC2 opmode: IMAGE aperture: WFALL-FIX sp_element: F814W num_exp: 1 time_per_exp: 10S priority: 1 param_1: CR-SPLIT=NO param_2: ATD-GAIN=7 req_1: POS TARG 34,34; req_2: SAME ORIENT FOR 4 AS 1 comment_1: PSF STAR IS 14.9 MAG 20" AWAY ! linenum: 5.000 targname: N4373-PSF config: WFPC2 opmode: IMAGE aperture: WFALL-FIX sp_element: F814W num_exp: 1 time_per_exp: 20S priority: 1 param_1: CR-SPLIT=NO param_2: ATD-GAIN=15 req_1: POS TARG 34,34; req_2: SAME ORIENT FOR 5 AS 1 ! linenum: 6.000 targname: N4373-PSF config: WFPC2 opmode: IMAGE aperture: WFALL-FIX sp_element: F814W num_exp: 1 time_per_exp: 10S priority: 1 param_1: CR-SPLIT=NO param_2: ATD-GAIN=7 req_1: POS TARG 33,33; req_2: SAME ORIENT FOR 6 AS 1 ! ! end of exposure logsheet ! No scan data records found