! File: 4425C.PROP ! Database: PEPDB ! Date: 22-FEB-1994:11:25:03 coverpage: title_1: SEARCH FOR OPTICAL COUNTERPARTS OF X-RAY SOURCES IN NEARBY title_2: CLUSTERS CYC3-HIGH sci_cat: HOT STARS sci_subcat: X-RAY BINARIES proposal_for: GO pi_fname: CHARLES pi_mi: D pi_lname: BAILYN pi_inst: YALE UNIVERSITY pi_country: USA hours_pri: 4.45 num_pri: 3 wf_pc: Y funds_length: 12 off_fname: SUZANNE off_mi: K off_lname: POLMAR off_inst: 3900 off_addr_1: GRANTS AND CONTRACTS ADMINISTRATION off_addr_2: 12 PROSPECT PLACE off_city: NEW HAVEN off_state: CT off_zip: 06511 off_country: USA off_phone: (203) 432-2460 ! end of coverpage abstract: line_1: We propose deep broadband PC observations of 3 nearby globular line_2: clusters (NGC 6397, NGC 6121=M4, and NGC 6656=M22) to search line_3: for optical counterparts of low luminosity X-ray sources. ROSAT line_4: observations of unprecedented depth are scheduled for these clusters: line_5: preliminary data already in hand reveal the presence of multiple line_6: sources in the core of NGC 6397. In addition, these HST observations line_7: will enable us to search for unusual populations in the cores of line_8: these clusters, and determine the main sequence luminosity function, line_9: which will provide a test of dynamical models of cluster evolution. ! ! end of abstract general_form_proposers: lname: BAILYN fname: CHARLES title: PI mi: D inst: YALE UNIVERSITY country: USA ! lname: GRINDLAY fname: JONATHAN mi: E inst: CENTER FOR ASTROPHYSICS country: USA ! lname: CALLANAN fname: PAUL inst: CENTER FOR ASTROPHYSICS country: USA ! lname: COOL fname: ADRIENNE inst: CENTER FOR ASTROPHYSICS country: USA ! lname: COHN fname: HALDAN mi: N inst: INDIANA UNIVERSITY country: USA ! lname: LUGGER fname: PHYLLIS mi: M inst: INDIANA UNIVERSITY country: USA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: As required by the TAC, we are restricting ourselves to observations line_2: of NGC6397, for which X-ray observations have already been obtained. line_3: Because our Cycle 2 observations provided less F675W coverage than line_4: anticipated (330s total rather than 600s), we will perform one line_5: F675W exposure as well as the proposed F439W exposures, to obtain line_6: equal depth in F675W and F439W (see details in section 4). Without line_7: the additional F675W exposure, additional F439W exposures alone line_8: would be useless, since the point of our project is to determine line_9: the COLOR of potential optical counterparts of X-ray sources. As line_10: proposed, we will also perform one short F439W exposure to analyze line_11: bright stars which will be saturated in the longer exposures. The line_12: resulting total exposure time of 450s in F675W and 1640s in F439W line_13: are somewhat shorter than in our original proposal, but several line_14: interesting candidates have already been identified from our Phase 2 line_15: results, so we expect that we will be able to achieve our science line_16: objectives with the exposures requested here, and detailed below. line_18: F439W exposures: 4x400s 1x40s line_19: F675W exposure: 120s ! question: 4 section: 1 line_1: The central regions of globular clusters are too crowded to observe line_2: from the ground below the main sequence, hence we require HST line_3: observations. ! question: 4 section: 2 line_1: By analogy with already analyzed HST observations of M4, we expect line_2: our total of 430s of F675W exposures to reach stars 5 to 5.5 line_3: magnitudes below the main sequence turnoff (see Phase 1 proposal line_4: for details). The F439W filter provides sensitivity of about 1/3 line_5: that of the F675W filter. Combined with the red color of most of line_6: the stars and the interstellar reddening towards NGC6397, we expect line_7: that a factor of approximately 4 more exposure time will be required line_8: in the F439W filter to provide equal depth. The proposed 1640s of line_9: exposure in the F439W filter will provide the required depth. ! question: 5 section: 1 line_1: none ! question: 6 section: 1 line_1: none ! question: 7 section: 1 line_1: Data will be reduced at our home institutions, using a slightly line_2: modified version of DAOPHOT. Preliminary reductions will be done line_3: at Yale, and compared to X-ray maps prepared at the CfA. Workers line_4: at Indiana will perform more detailed reductions and comparisons line_5: with theoretical models. ! question: 8 section: 1 line_1: ROSAT results for NGC6397 have already been obtained and analyzed. line_2: Ground based followup observations will be scheduled using Yale's line_3: guaranteed time on the CTIO 1m class telescopes for spring of line_4: 1994. A related proposal (proposal number 4571, PI Grindlay) line_5: has been accepted as a medium priority cycle 3 proposal, and line_6: has also proceeded to phase 2. ! question: 9 section: 1 line_1: GO-2555, PI Grindlay line_2: GO-3851, PI Grindlay line_3: AR-3793, PI Bailyn line_4: All of the above are relevant to this project, results discussed below. line_5: GO-2237, PI Bookbinder. This proposal is unrelated to this project, line_6: and only preliminary results have been obtained so far. ! question: 9 section: 2 line_1: GO-2555: Several interesting candidates have been identified line_2: GO-3851: Several interesting candidates have been identified, and line_3: are being followed up from the ground, and in proposal 4571. line_4: AR-3793: Several conference reports have been published, and a line_5: journal paper is in preparation. Several new data reduction line_6: techniques have been developed which will be used in the analysis line_7: of the data obtained in this project. ! question: 9 section: 3 line_1: 4 conference reports have been published. ! question: 10 section: 1 line_1: The CfA, Yale, and Indiana all support extensive networks of line_2: scientific workstations which will be sued to reduce the data line_3: obtained through this proposal. Telescope time obtained through line_4: the agreement governing the use of Yale's 1m telescope by CTIO will line_5: be used to obtain ground based data. Summer salary for the PI line_6: will be obtained from other grant sources. ! !end of general form text general_form_address: lname: BAILYN fname: CHARLES mi: D category: PI inst: Yale University addr_1: ASTRONOMY DEPT. addr_2: YALE UNIVERSITY addr_3: P.O. BOX 6666 city: NEW HAVEN state: CT zip: 06511 country: USA phone: (203) 432-3022 ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: NGC6397 descr_1: C; 201 pos_1: RA = 17H 40M 41.74S +/- 0.06S, pos_2: DEC = -53D 40' 24.94" +/- 0.1S equinox: J2000 pm_or_par: N fluxnum_1: 1 fluxval_1: V=21 +/- 0 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: NGC6397 config: PC opmode: IMAGE aperture: PC6-FIX sp_element: F439W wavelength: 449.0-450.0 num_exp: 1 time_per_exp: 40S param_1: CR-SPLIT = NO req_1: ORIENT 77.5D +/- 5.0D; req_2: CYCLE 3; req_3: GROUP 1-3 NO GAP ! linenum: 2.000 targname: NGC6397 config: PC opmode: IMAGE aperture: PC6-FIX sp_element: F439W wavelength: 449.0-450.0 num_exp: 4 time_per_exp: 400S param_1: CR-SPLIT = NO req_1: ORIENT 77.5D +/- 5.0D; req_2: CYCLE 3 ! linenum: 3.000 targname: NGC6397 config: PC opmode: IMAGE aperture: PC6-FIX sp_element: F675W wavelength: 675.0-676.0 num_exp: 1 time_per_exp: 120S param_1: CR-SPLIT = NO req_1: ORIENT 77.5D +/- 5.0D; req_2: CYCLE 3 ! ! end of exposure logsheet ! No scan data records found