Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 5399 Report Date: 18-Jul-95:17:18 Version: ********** Check-in Date: ********** 1.Proposal Title: ULTRADEEP HST IMAGING OF THE HAWAII DEEP SURVEY FIELDS ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID GALAXIES & CLUSTERS GO Sub Category SURVEYS ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Lennox Cowie INSTITUTE FOR ASTRONOMY,UNIV USA 808-956-8134 ------------------------------------------------------------------------------------ 7. 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 SSA13 and SSA22 in the wide I band. These 2' x 2' fields have been observed at wavelengths 2200A (HST cycle 1),3400A,4500A,8400A and 2.1 micron to 5 sigma galaxy detection limits of a microJy or below (K=22, V=27). All galaxies with B<24 and K<19 now have determined redshifts and have been typed on the basis of their spectra as have 65 percent of the galaxies between K=19-20. SSA13 is a candidate field for the Japan-Hawaii ISO deep survey which will be the deepest 10 micron observation carried out with the ISO satellite. 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 rate as a function of absolute magnitude and redshift. The program was accepted in Cycle 1 for both wide band WFPC and 2200A FOC observations. After the discovery of the aberration the allocated time was concentrated into the 2200A FOC studies. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 12.00 par: 0 10. Num targs pri: 2 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: WF/PC ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 5399 PI: Lennox Cowie Proposal Title: ULTRADEEP HST IMAGING OF THE HAWAII DEEP SURVEY FIELDS ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Lennox Cowie 2192 USA Esther Hu 2192 USA Antoinette Songaila 2192 USA John Kormendy 2192 USA Kenneth Chambers 2192 USA ------------------------------------------------------------------------------------ 3. Description of proposed observations. A total of six hours of on-target time through the wide I filter (F814W) is required for each of the two fields (SSA13 and SSA22). The fields should be centered on the geometric center of the four CCD chips and oriented so that the N -S direction lies parallel to the chip edges to optimise the field coverage. The preferred orientation is with the PC at the NE but this is not essential. The observations of SSA22 are broken into two groups of six 2400 second exposures each. The observations of SSA13 are broken into a single group of six 2600 second exposures each, with the individual exposure time being set by the read noise on the PC. Any significant reduction below these times would impact the noise on the PC portion of the field. Each of the six exposures should be spatially separated from the others to allow the use of median techniques, and we have specified a dithering pattern using 5 arcsec offsets to achieve this. In order to fully optimise this we also require that the exposures be obtained sequentially. Because of the multiple exposures we do not require CR-SPLIT. In order to optimise the scheduling, all exposures _must_ be identical and a minimum of _five_ individual exposures is required. Page 3 ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. (a) The resolution necessary to carry out this program cannot currently be achieved from the ground. The highest angular resolution images we have obtained from the ground (FWHM approx. 0.5 arcsec) are not good enough to achieve the program goals even with the use of image restoration techniques. Ultradeep ground- and space-based imaging has been carried out at 2200 A (HST Cycle 1), 3400 A, 4500 A, 5500 A, 8400 A, and 21,000 A and in the soft x-rays (ROSAT 50,000 sec exposures). All K < 20 and B < 24 galaxies in the fields have been observed spectroscopically, and complete redshift samples and spectroscopic types have been obtained for all K < 19 nd B < 24 galaxies, and for 65 percent of the K = 19 - 20 sample. We will attempt to complete the K = 20 sample with allocated time on the Keck 10-meter telescope. (b) For a 'typical' I = 23 galaxy, the central surface brightness in a wide-field pixel is 27, and the measured typical value at 1 arcsec approximately I = 29 in a WFC pixel. The latter value produces a count rate of 1.0 x 10-2 e/s/pixel through the F814W filter. By comparison, the sky background at the field ecliptic latitudes is I = 27.2 per WFC pixel, giving 4 x 10-2 e/s/pixel. Assuming 1800s sub-exposures to provide clean cosmic-ray rejection and sky cleaning, and 7e/pixel read noise, the sky dominated noise/exposure/pixel becomes 11e and the S/N = 1.4 in 0.5 hrs. Requiring S/N = 5/pixel then implies a six-hour exposure. Simulations made using the ground-based observations of Figure 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 S/N and resolution to the galaxies shown in Figure 2. We request observations on two fields since each field is dominated by a small number of velocity groupings because of clustering effects. 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. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. Not applicable. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. Not applicable. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. Not applicable. ------------------------------------------------------------------------------------ 9. Description of previous HST work. (a) P2365 'HST Images of Ground-Based Deep Survey Fields', L. L. Cowie, S. J. Lilly P2403 'Hot Gas in the ISM', L. L. Cowie, E. B. Jenkins, A. Songaila P3543 'The Deep Ultraviolet Sky', S. J. Lilly, L. L. Cowie, E. M. Hu (b) The present program was originally approved in P2365 of Cycle 1. When the aberration was discovered, the deep high- resolution WFPC imaging was dropped and 2200 A imaging with the FOC was emphasised. P3543 provided 2200 A imaging of a further field, but because of the f/48 FOC problem, no data have been obtained. (c) Data were obtained only in the last year and are still being analyzed for P2365. Data are fully analyzed for P2403 and a paper is currently being prepared for publication describing the distribution and origin of high ionization species in the galactic disk (J. S. Huang, A. Songaila, L. L. Cowie and E. B. Jenkins). Page 4 ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). The analysis will be carried out using an existing Sparc 10 workstaion, including exabyte and CD ROM dirves, plus 2.1 Gbytes of disk and 96 Mbytes of RAM. Photographic images will be prepared using the Institute for Astronomy's (IFA) high resoltion Solitaire film writer. Additional spectrographic follow-up to complete redshift identification to K = 20 will be carried out using University of Hawaii time on the Keck 10-meter telescope. Extension of the bright-end K = 15 galaxy sample to 16 will be carried out by J. S. Huang as his Ph. D. thesis, using the University of Hawaii's 24-inch and 88-inch telescopes and NICMOS3 and Tek 2048 cameras. ------------------------------------------------------------------------------------ 11. Address Information Name: Lennox Cowie Category: PI Institution: 2192 Address: Institute for Astronomy 2680 Woodlawn Dr. City: Honolulu State: HI Zip Code: 96822 Country: USA Telephone: 808-056-8134 Telex (or e-mail): cowie@UHIFA.IFA.HAWAII.EDU ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 5399 [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial |Acqui|FLX| Flux data No | Name | Description | Position |Eqnx | Vel. |Prblm|REF| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 1 SSA22 E, RA = 22H 15M 1.00S +/- 1950.0 1 V=21.0 325 0.15S, 2 I=23.0 DEC = 00D 00' 00.0" +/- 0.1", ------------------------------------------------------------------------------------------------------------------------------------ 2 SSA13 E, RA = 13H 10M 1.00S +/- 1950.0 1 V=21.0 325 0.15S, 2 I=23.0 DEC = 43D 00' 31.0" +/- 0.1", ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5399 [ 6] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1.1 SSA22 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2400S 5 2 1 CYCLE 4 / 1.1-2.6 FIX SEQ 1.1-1.6 NO GAP Comments: SIX EXPOSURES SHOULD BE SEQUENTIAL WITH EACH EXPOSURE SEPARATED BY 5 ARCSECONDS FROM PRECEDING EXPOSURE ------------------------------------------------------------------------------------------------------------------------------------ 1.2 SSA22 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2400S 5 2 1 POS TARG +5.0,0.0 FIX SAME ORIENT FOR 1.2-1.76 AS 1.1 ------------------------------------------------------------------------------------------------------------------------------------ 1.3 SSA22 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2400S 5 2 1 POS TARG +5.0,+5.0 FIX ------------------------------------------------------------------------------------------------------------------------------------ 1.4 SSA22 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2400S 5 2 1 POS TARG +0.0,+5.0 FIX ------------------------------------------------------------------------------------------------------------------------------------ 1.5 SSA22 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2400S 5 2 1 POS TARG -5.0,+5.0 FIX ------------------------------------------------------------------------------------------------------------------------------------ 1.6 SSA22 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2400S 5 2 1 POS TARG -5.0,0.0 FIX ------------------------------------------------------------------------------------------------------------------------------------ 1.71 SSA22 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2400S 5 2 1 SEQ 1.71-1.76 NO FIX GAP Comments: SIX EXPOSURES SHOULD BE SEQUENTIAL WITH EACH EXPOSURE SEPARATED BY 5 ARCSECONDS FROM PRECEDING EXPOSURE ------------------------------------------------------------------------------------------------------------------------------------ 1.72 SSA22 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2400S 5 2 1 POS TARG +5.0,0.0 FIX ------------------------------------------------------------------------------------------------------------------------------------ 1.73 SSA22 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2400S 5 2 1 POS TARG +5.0,+5.0 FIX ------------------------------------------------------------------------------------------------------------------------------------ 1.74 SSA22 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2400S 5 2 1 POS TARG +0.0,+5.0 FIX ------------------------------------------------------------------------------------------------------------------------------------ 1.75 SSA22 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2400S 5 2 1 POS TARG -5.0,+5.0 FIX ------------------------------------------------------------------------------------------------------------------------------------ 1.76 SSA22 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2400S 5 2 1 POS TARG -5.0,0.0 FIX ------------------------------------------------------------------------------------------------------------------------------------ 2.1 SSA13 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2600S 5 2 2 SEQ 2.1-2.6 NO GAP FIX Comments: SIX EXPOSURES SHOULD BE SEQUENTIAL WITH EACH EXPOSURE SEPARATED BY 5 ARCSECONDS FROM PRECEDING EXPOSURE ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5399 [ 7] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 2.2 SSA13 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2600S 5 2 2 POS TARG +5.0,+0.0 FIX SAME ORIENT FOR 2.2-2.6 AS 2.1 ------------------------------------------------------------------------------------------------------------------------------------ 2.3 SSA13 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2600S 5 2 2 POS TARG +5.0,+5.0 FIX ------------------------------------------------------------------------------------------------------------------------------------ 2.4 SSA13 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2600S 5 2 2 POS TARG +0.0,+5.0 FIX ------------------------------------------------------------------------------------------------------------------------------------ 2.5 SSA13 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2600S 5 2 2 POS TARG -5.0,+5.0 FIX ------------------------------------------------------------------------------------------------------------------------------------ 2.6 SSA13 WFPC2 IMAGE WFALL- F814W CR-SPLIT=NO 1 2600S 5 2 2 POS TARG -5.0,0.0 FIX ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 5399 [ 8] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 12.00 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category GALAXIES & CLUSTERS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category SURVEYS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 4 / 1.1-2.6; SEQ 1.1-1.6 NO GAP POS TARG +5.0,0.0; SAME ORIENT FOR 1.2-1.76 AS 1.1 POS TARG +5.0,+5.0 POS TARG +0.0,+5.0 POS TARG -5.0,+5.0 POS TARG -5.0,0.0 SEQ 1.71-1.76 NO GAP POS TARG +5.0,0.0 SEQ 2.1-2.6 NO GAP POS TARG +5.0,+0.0; SAME ORIENT FOR 2.2-2.6 AS 2.1 POS TARG -5.0,0.0; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names SSA22 SSA13 ------------------------------------------------------------------------------------------------------------------------------------