! File: 4085C.PROP ! Database: PEPDB ! Date: 20-FEB-1994:08:02:06 coverpage: title_1: THE STELLAR POPULATION IN BAADES WINDOW, WFPC title_2: GTO AUGMENTATION, CYCLE 2 sci_cat: STELLAR POPULATIONS proposal_for: AUG/WFC cont_id: 3640 pi_title: PROF. pi_fname: JAMES pi_mi: A. pi_lname: WESTPHAL pi_inst: CALTECH pi_country: USA pi_phone: (818)-356-4900 keywords_1: BAADES WINDOW, GALACTIC BULGE hours_pri: 8.75 num_pri: 4 pi_position: PROF. PLANETARY SCI. ! end of coverpage abstract: line_1: The target is a selected field within "Baade's Window" line_2: where the stellar population of the galactic bulge can line_3: be observed with less obscuration than in neighboring line_4: areas. It lies 3.8 degrees from the direction to the line_5: galactic center. The bulge population is known to line_6: contain stars more metal-rich than those found anywhere line_7: else in the Galaxy, and it is believed to be similar to line_8: the stellar population in elliptical galaxies. The goal line_9: of this HST-WF/PC program is to extend the H-R diagram line_10: and luminosity function of the bulge population to much line_11: fainter limits than possible with groundbased tele- line_12: scopes. The inferred IMF will be compared with those line_13: of less metal-rich populations. ! ! end of abstract general_form_proposers: lname: WESTPHAL fname: JAMES mi: A. inst: CALTECH country: USA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: This project involves ten orbits of WFC exposures, line_2: all of them at the same target position and roll angle, line_3: in a selected portion of Baade's Window (BW), which is line_4: located about 11 arcmin NW of NGC6522. Five of the line_5: ten orbits will be devoted to 2000-sec CR-split line_6: exposures with F555W, four orbits to 2000-sec CR-split line_7: exposures with F785LP, and one orbit to shorter line_8: exposures with both filters. The nine long-exposure line_9: frame pairs will be combined with the four essentially line_10: identical WFC frame pairs of Baade's Window obtained line_11: 18 August 1991. In order to preserve field area and to line_12: minimize star identification problems in the presence line_13: of optical distortion, we prefer the field orientation line_14: of the new observations to be the same (within 5 line_15: degrees) as that of the frames of 18 August 1991. line_16: Short exposures of fields within NGC 188 will provide line_17: the PSF data required for processing the BW data. ! question: 4 section: 1 line_1: From earlier work by our team, we know what magnitude line_2: limits can be reached with the WFC in the presence of line_3: the spherical aberration of the HST primary. The line_4: threshold of detection occurs when the total count line_5: for the whole of a star image reaches about 600 DN, line_6: where 1 DN equals 7.5 electrons. Plugging that value line_7: into the relations between DN and stellar magnitudes line_8: (Holtzman et al, ApJ 369, L35, 1991), we find detection line_9: thresholds for single full-orbit exposures to be 24.5 line_10: mag for F555W and 23.0 mag for F785LP. Practical line_11: limits for stellar photometry, especially in the line_12: presence of crowding, lie about 2 mag brighter than line_13: detection thresholds. Combining the new HST observa- line_14: tions with those obtained in 1991, we expect photometry line_15: in Baade's Window to reach 23.5 mag with F555W and line_16: 22.0 mag with F785LP. These limits can be compared line_17: with Terndrup's results (AJ 96, 884, 1988) in Baade's line_18: Window, which ended at V = 20.0 mag due to crowding. line_19: That is approximately where the turnoff from the main line_20: sequence lies, so the groundbased data did not sample line_21: the main sequence. The capabilities of the HST WFC line_22: are needed in order to obtain the luminosity function line_23: of the bulge population and to derive the IMF. ! question: 5 section: 1 line_1: For the reason given under Item 2, there is a strong line_2: preference for having the same field orientation (i.e., line_3: the same spacecraft roll angle) as that used for the line_4: Baade Window frames of 18 August 1991. The tolerance line_5: is +/- 5 degrees. We hope that this can be achieved line_6: by choice of observing date, without requiring a line_7: special roll of the spacecraft. Any special roll line_8: maneuver costing a reduction of exposure time would line_9: not be acceptable. ! question: 7 section: 1 line_1: The images of our Baade Window field will all be reduced line_2: by the same procedures we described in Holtzman et al, line_3: ApJ 369, L35, 1991. All of the long-exposure frames line_4: obtained with each of the two filters will then be line_5: added. Adjustments of position and orientation will be line_6: made by the same procedure we have used in connection line_7: with WF/PC calibration frames of Omega Centauri during line_8: SV1321. An H-R diagram will be plotted and discussed. line_9: A luminosity function will be derived following the pro- line_10: cedures used by Terndrup, and implications concerning line_11: the initial mass function (IMF) will be assessed. ! question: 8 section: 1 line_1: We request that the PSF observations in NGC 188 be line_2: obtained within +/- 7 days of the observations of the line_3: Baade Window field. ! !end of general form text general_form_address: lname: BAUM fname: WILLIAM mi: A. category: CON inst: UNIVERSITY OF WASHINGTON addr_1: F/M 20 city: SEATTLE state: WA zip: 98105 country: USA phone: (206)-527-4306 ! lname: LIGHT fname: ROBERT mi: M. category: CON inst: UCSC addr_1: LICK OBSERVATORY city: SANTA CRUZ state: CA zip: 95064 country: USA phone: (408-459-3081 ! lname: HUNTER fname: DEIDRE mi: A. category: CON inst: LOWELL OBSERVATORY addr_1: 1400 W MARS HILL ROAD city: FLAGSTAFF state: AZ zip: 86001 country: USA phone: (602)-774-3358 ! lname: WESTPHAL fname: JAMES mi: A. title: PROF. category: PI inst: CALTECH addr_1: M/S 170-25 addr_2: DIVISION OF GEOLOGICAL addr_3: & PLANETARY SCIENCES city: PASADENA state: CA zip: 91125 country: USA phone: (818)-356-4900 ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: FIELD180310-295143 name_2: BAADES WINDOW descr_1: E,301,913 pos_1: RA= 18H 03M 10.0S +/-0.1S, pos_2: DEC= -29D 51' 43" +/-1" equinox: 2000.0 comment_1: BULGE POPULATION; 0.6 KPC comment_2: FROM NUCLEUS OF OUR GALAXY ! targnum: 2 name_1: NGC188-A descr_1: C,202,913 pos_1: RA= 00H 47M 51S +/-0.5S, pos_2: DEC= +85D 14' 45" +/-1", equinox: 2000.0 comment_1: PSF STAR FIELD comment_2: OFFSET 1 ! targnum: 3 name_1: NGC188-B descr_1: C,202,913 pos_1: RA= 00H 46M 51S +/-0.5S, pos_2: DEC= +85D 15' 40" +/-1", equinox: 2000.0 comment_1: PSF STAR FIELD comment_2: OFFSET 2 ! targnum: 4 name_1: NGC188-C descr_1: C,202,913 pos_1: RA= 00H 47M 51S +/-0.5S, pos_2: DEC= +85D 15' 55" +/-1", equinox: 2000.0 comment_1: PSF STAR FIELD comment_2: OFFSET 3 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 sequence_1: DEFINE sequence_2: PSF targname: # config: WFC opmode: IMAGE aperture: WFALL sp_element: F555W num_exp: 2 time_per_exp: 26S priority: # param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: GROUP 1-2 NO GAP comment_1: GTO AUGMENTATION, CYCLE 2 comment_2: WAB/RML 3/18/92 ! linenum: 2.000 sequence_1: ^ targname: # config: WFC opmode: IMAGE aperture: WFALL sp_element: F785LP num_exp: 2 time_per_exp: 100S priority: # param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES ! linenum: 11.000 targname: FIELD180310-295143 config: WFC opmode: IMAGE aperture: WFALL sp_element: F555W num_exp: 2 time_per_exp: 200S priority: 1 param_1: PRE-FLASH=YES, param_2: CR-SPLIT=NO req_1: GROUP 11-12 NO GAP; req_2: GROUP 11-14 WITHIN 1D; req_3: AT 18-AUG-1992 +/- 7D; req_4: CYCLE 2 / 11-23; req_5: PCS MODE C / 11-23; req_6: POS TARG 10,-10 / 11-23; req_7: GROUP 11-23 WITHIN 7D comment_1: ALL BW EXPOSURES ARE TO BE comment_2: TAKEN NEAR 18-AUG-1991 SO comment_3: THAT THE ORIENTATION OF THE comment_4: FIELD IS CLOSE TO THAT OF comment_5: CYCLE 1 DATA. ! linenum: 12.000 targname: FIELD180310-295143 config: WFC opmode: IMAGE aperture: WFALL sp_element: F785LP num_exp: 2 time_per_exp: 200S priority: 1 param_1: PRE-FLASH=YES, param_2: CR-SPLIT=NO req_1: SAME POS FOR 12-14 AS 11; req_2: SAME ORIENT FOR 12-14 AS 11 ! linenum: 13.000 targname: FIELD180310-295143 config: WFC opmode: IMAGE aperture: WFALL sp_element: F555W num_exp: 4 time_per_exp: 2000S priority: 1 param_1: PRE-FLASH=NO, param_2: CR-SPLIT=0.5, param_3: CR-TOLERANCE=0.0 comment_1: EACH OF THE 4 EXPS IS INTENDED TO FIT comment_2: WITHIN ONE ORBIT. MODIFY THE 2000S comment_3: EXP TIME +/- 20 PERCENT TO ACCOMPLISH comment_4: THIS, BUT RESPECT THE EQUAL SPLIT. ! linenum: 14.000 targname: FIELD180310-295143 config: WFC opmode: IMAGE aperture: WFALL sp_element: F785LP num_exp: 4 time_per_exp: 2000S priority: 1 param_1: PRE-FLASH=NO, param_2: CR-SPLIT=0.5, param_3: CR-TOLERANCE=0.0 comment_1: EACH OF THE 4 EXPS IS INTENDED TO FIT comment_2: WITHIN ONE ORBIT. MODIFY THE 2000S comment_3: EXP TIME +/- 20 PERCENT TO ACCOMPLISH comment_4: THIS, BUT RESPECT THE EQUAL SPLIT. ! linenum: 21.000 sequence_1: USE sequence_2: PSF targname: NGC188-A priority: 1 req_1: GROUP 21-23 WITHIN 1D; ! linenum: 22.000 sequence_1: USE sequence_2: PSF targname: NGC188-B priority: 1 req_1: SAME ORIENT FOR 22-23 AS 21; ! linenum: 23.000 sequence_1: USE sequence_2: PSF targname: NGC188-C priority: 1 ! ! end of exposure logsheet ! No scan data records found