5922( 5) - 08/29/95 18:01 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 5922 Version: 5 Check-in Date: ********** 1.Proposal Title: HST Observations of Hawaii Deep Survey Fields ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Galaxies & Clusters GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Lennox L. Cowie Institute for Astronomy CoI: Antoinette Cowie Institute for Astronomy N CoI: Esther M. Hu Institute for Astronomy N ------------------------------------------------------------------------------------ 6. Abstract Detailed morphological classification of galaxies at high redshifts requires angular resolution of around 0.1^ \ FWHM and cannot be carried out from the ground. We propose to use the WFPC2 to observe the Hawaii deep survey fields SSA4 and SSA17 in the wide I\ band. These 2^ * 2^ \ fields have been observed at wavelengths, 3400 Angstrom, 4500 Angstrom, 5500 Angstrom, 8400 Angstrom and 2.1 micron to $5 Sigma galaxy detection limits of a microJy or below (K = 22, V = 27). All galaxies with B <= 24, I <= 22\ and K <= 19 now have determined redshifts and have been typed on the basis of their spectra, as have 65\ 19\ and 20. The proposed WFPC2 observations will be used to type the K <= 20\ galaxy sample and to study the evolution of the galaxy type mix, surface brightness profiles, and merger rates as a function of absolute magnitude and redshift. This program is a continuation of an approved Cycle 4 proposal, where the fields SSA22 and SSA13 are being imaged to the same depth. This data set has not yet been obtained. ------------------------------------------------------------------------------------ 5922( 5) - 08/29/95 18:01 - [ 2] Observations Description ------------------------ For a `typical' I = 23\ galaxy, the central surface brightness in a wide-field pixel is 27, and the measured typical value at 1^ \ is approximately I = 29\ in a WFC pixel. The latter value produces a count rate of 1.0 * 10^-2 e^- /sec/pixel\ through the F814W filter. By comparison the sky background at the field ecliptic latitudes is I = 27.2\ per WFC pixel giving 4 * 10^-2 e^- /sec/pixel. Assuming 1800s sub-exposures to provide clean cosmic ray rejection and sky cleaning, and 5e^-/pixel read noise, the sky-dominated noise/exposure/pixel becomes 11e^-\ and the S/N = 1.3 in 0.5 hrs. Requiring a S/N = 5/pixel then implies an eight-hour exposure. Simulations made using the ground-based observations of Fig. 2, faded and shrunk as they would appear at the appropriate redshifts, show that this S/N should be adequate for classification. The proposed WFPC2 observations for the I < 23\ galaxies should in fact be very similar in resolution and S/N to the galaxies shown in Fig. 2. We request observations on two fields since, because of clustering effects, each field is dominated by a small number of velocity groupings. The WFC regions contain 34 galaxies at K <= 20\ in the two fields, 31 of which have I\ magnitudes less than 23 and should be classifiable. This sample size should be large enough to discern gross trends in the type mix and surface brightness profiles and to determine if there is enhanced merger activity in the high-z\ population. The data analysis will be carried out on an existing Sparc 10 workstation belonging to the P.I. Existing IDL programs will be used to process the frames using median sky generation and cosmic ray rejection routines. Image enhancement will be performed on subsampled data using the Lucy-Richardson algorithm and these images used for final taxonomic classification. Surface brightness fits will be carried out on both the unsharpened and the sharpened data using iterative fits to obtain deconvolved disk and bulge profiles. Comparison with an existing wide-field (1.5 deg^2) K <= 15, z < 0.2\ sample observed with 0.5^ \ FWHM ground-based imaging will be used to analyze the evolution of type mix, surface brightness and merger rates as a function of z. The data will also provide the deepest images for point sources and compact objects with a 5 Sigma\ detection limit of I = 28, and we will analyze the number density of these objects as well as attempt to determine their colors by cross correlating with the ground-based data. Real Time Justification ----------------------- None. None. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 5922( 5) - 08/29/95 18:01 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: OVERNIGHT Email: , ------------------------------------------------------------------------------------ 5922( 5) - 08/29/95 18:01 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SSA4 UNIDENTIFIED, BLANK RA=3H 54M 57.3S +/- 0.01S, B1950 Z=0.0 V=20 B-V=0.4 FIELD DEC=01D 01' 00.0" +/- 0.01" Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1950 0.0 0. 0.0 2 SSA17 UNIDENTIFIED, BLANK RA=17H 04M 59.8S +/- 0.01S, B1950 Z=0.0 V=20 B-V=0.4 FIELD DEC=43D 59' 34.7" +/- 0.01" Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1950 0.0 0. 0.0 5922( 5) - 08/29/95 18:01 - [ 5] Visit: 01 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SSA4 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2300S POS TARG 0,0 LOW-SKY FIX ------------------------------------------------------------------------------------------------------------------------------------ 2 SSA4 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2600S POS TARG 0,5 LOW-SKY FIX ------------------------------------------------------------------------------------------------------------------------------------ 3 SSA4 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2600S POS TARG 5,0 LOW-SKY FIX ------------------------------------------------------------------------------------------------------------------------------------ 4 SSA4 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2600S POS TARG 0,-5 LOW-SKY FIX ------------------------------------------------------------------------------------------------------------------------------------ 5 SSA4 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2600S POS TARG -5,0 LOW-SKY FIX ------------------------------------------------------------------------------------------------------------------------------------ 5922( 5) - 08/29/95 18:01 - [ 6] Visit: 02 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SSA17 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2300S POS TARG 0,0 LOW-SKY FIX ------------------------------------------------------------------------------------------------------------------------------------ 2 SSA17 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2600S POS TARG 0,5 LOW-SKY FIX ------------------------------------------------------------------------------------------------------------------------------------ 3 SSA17 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2600S POS TARG 5,0 LOW-SKY FIX ------------------------------------------------------------------------------------------------------------------------------------ 4 SSA17 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2600S POS TARG 0,-5 LOW-SKY FIX ------------------------------------------------------------------------------------------------------------------------------------ 5 SSA17 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2600S POS TARG -5,0 LOW-SKY FIX ------------------------------------------------------------------------------------------------------------------------------------ 5922( 5) - 08/29/95 18:01 - [ 7] Summary Form for Proposal 5922 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Galaxies & Clusters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements POS TARG 0,0 LOW-SKY POS TARG 0,5 LOW-SKY POS TARG 5,0 LOW-SKY POS TARG 0,-5 LOW-SKY POS TARG -5,0 LOW-SKY ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names SSA4 SSA17 ------------------------------------------------------------------------------------------------------------------------------------