! $Id: 5383,v 4.1 1994/07/27 17:21:18 pepsa Exp $ coverpage: title_1: THE WOLF-RAYET POPULATION OF GIANT HII REGIONS IN NGC 2403: title_2: CYCLE4 MEDIUM sci_cat: GALAXIES & CLUSTERS sci_subcat: STELLAR POPULATIONS proposal_for: GO pi_fname: LAURENT pi_lname: DRISSEN pi_country: USA pi_phone: (410) 338 4864 hours_pri: 8.89 num_pri: 2 wf_pc: Y off_fname: HERVEY S. off_lname: STOCKMAN off_title: DEPUTY DIRECTOR off_inst: 3470 off_addr_1: 3700 SAN MARTIN DRIVE off_city: BALTIMORE off_state: MD off_zip: 21218 off_country: USA off_phone: (410) 338 4730 ! end of coverpage abstract: line_1: Wolf-Rayet (WR) stars, the evolved descendants of the most massive line_2: O stars, play a very active role in the ecology of starburst regions line_3: by injecting huge amounts of mechanical energy into their surrounding line_4: interstellar medium, and by ejecting heavy elements through their line_5: powerful winds. The WR population of Giant HII regions (GHRs) has line_6: so far been investigated in a very small number of nearby objects. line_7: We propose to significantly increase this sample by imaging the line_8: four most massive GHRs in the late-type spiral galaxy NGC 2403 with line_9: a filter (F439N) centered on the strongest WR emission line, HeII 4686. line_10: This will allow for the first time a direct determination of the line_11: number of WR stars in GHRs of high metallicity and therefore line_12: provide important constraints for evolutionary models of massive stars. line_13: We will also obtain narrow-band OIII images to study the line_14: effects of WR stars on the morphology of their parent GHR. ! ! end of abstract general_form_proposers: lname: DRISSEN fname: LAURENT inst: 3470 country: USA ! lname: SHARA fname: MICHAEL mi: M inst: 3470 country: USA ! lname: ROY fname: JEAN-RENE inst: 4638 country: CANADA ! lname: MOFFAT fname: ANTHONY inst: 4648 country: CANADA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: We will image 2 Giant HII regions in NGC 2403 (centered on PC1) line_2: with 4 filters: F439W to be used as a reference continuum; F469N line_3: centered on the most prominent WR line, HeII 4686; F547M, to line_4: eliminate very red stars (such as red supergiants), which could line_5: appear brighter in the F469N filter than in F439W; and F502N, line_6: to determine the morphology of the gas surrounding the most massive line_7: stars. At the same time, the other CCDs (WF2, WF3 and WF4) will line_8: image the field of NGC 2403 and detect field WR stars. line_9: All images will be obtained with the CR-SPLIT=NO requirement, line_10: but multiple exposures with the same filter are requested. line_11: All four CCDs will be read out. ! question: 3 section: 2 line_1: ! question: 4 section: 1 line_1: The two Giant HII Regions in NGC 2403 included in this proposal line_2: have been observed from the ground under very good seeing conditions line_3: at the CFHT. Spectra of these targets have already been obtained line_4: and show the presence of Wolf-Rayet stars. However, these observations line_5: are severely limited by the spatial resolution imposed by the seeing line_6: since the WR excess at 4686 A is strongly diluted by the light of line_7: other stars. The estimates number of WR stars based on these line_8: ground-based data could be in error by large factors. line_9: The high resolution provided by HST images (0.1"=1.6 pc at the line_10: distance of NGC 2403) is twice as good as the resolution of line_11: ground-based imagery in M33, where the on and off-band imaging line_12: technique has been succesful in investigating the WR population of line_13: NGC 595 and NGC 604. ! question: 5 section: 1 line_1: Not Applicable ! question: 6 section: 1 line_1: Not Applicable ! ! question: 8 section: 1 line_1: Not applicable ! question: 9 section: 1 line_1: GO-2441: Search for WR stars in local Group Giant HII Regions, line_2: Moffat (PI), Drissen and Shara. line_4: GO-2416: Imaging and spectroscopy of super-metal poor galaxies, Roy CoI. line_6: GO-3605: UV Spectropolarimetry of AG Car, Drissen (Co-I), line_8: GO-3605: Extreme Stellar Winds and Post Main-Sequence Evolution, line_9: Drissen (Co-I) line_11: GO-2472 Binaries in Globular Clusters, Shara (PI) line_13: GO-3872 Blue Stragglers in the Cores of Globular Clusters, Shara line_14: Although none of the above program are directly related to NGC 2403, line_15: most of them aim at studying the properties of massive stars and line_16: massive star populuation in starburst regions. line_18: GO-2441. PC images of NGC 595 and NGC 604 in M33 and NGC 3603 in the line_19: Galaxy were obtained in order to study their Wolf-Rayet population. line_20: We were able to determine the number and absolute magnitudes of W-R line_21: stars in each region and to obtain a preliminary value of the IMF line_22: slope. One paper has been published and one is in preparation. ! question: 10 section: 1 line_1: Drissen and Shara have direct access to STScI computing facilities line_2: and expertise. STScI has excellent support facilities, including a line_3: library, an extensive computer network, a publications department, line_4: and will provide the secretarial support. The PI and co-Is have SUN line_5: Sparkstations with 5 Gbyte of disk space available for data reduction; line_6: IRAF and STSDas are available at STScI, Montr\'eal and Laval line_7: Universities. Summer students are available in Montr\'eal and Laval. ! !end of general form text general_form_address: lname: DRISSEN fname: LAURENT category: PI inst: 3470 addr_1: 3700 San Martin Drive city: Baltimore state: MD zip: 21218 country: USA phone: (410) 338 4864 telex: drissen@stsci.edu ! lname: category: CON ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: NGC2403-298 descr_1: D,203 pos_1: RA=07H32M17.9S, pos_2: DEC=+65D43'21", pos_3: REGION, pos_4: R=15" equinox: 1950 rv_or_z: V=+165 comment_1: THIS IS A CVZ TARGET comment_2: MAGNITUDE IS FOR FAINTEST WR STAR fluxnum_1: 1 fluxval_1: V=23.0 +/- 0.5, TYPE=WR ! targnum: 2 name_1: NGC2403-174 descr_1: D,203 pos_1: RA=07H31M56.5S, pos_2: DEC=+65D43'40", pos_3: REGION, pos_4: R=15" equinox: 1950 rv_or_z: V=+79 comment_1: THIS IS A CVZ TARGET comment_2: MAGNITUDE IS FOR FAINTEST WR STAR fluxnum_1: 1 fluxval_1: V=23.0 +/- 0.5, TYPE=WR ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: NGC2403-298 config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F439W num_exp: 3 time_per_exp: 900S s_to_n: 15 fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO req_1: CYCLE 4; ! linenum: 2.000 targname: NGC2403-298 config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F469N num_exp: 5 time_per_exp: 2200S s_to_n: 10 fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO req_1: CYCLE 4; req_2: SAME POS FOR 2-4 AS 1 ! linenum: 3.000 targname: NGC2403-298 config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F547M num_exp: 2 time_per_exp: 700S s_to_n: 15 fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO req_1: CYCLE 4; ! linenum: 4.000 targname: NGC2403-298 config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F502N num_exp: 1 time_per_exp: 1000S s_to_n: 10 fluxnum_1: 1 priority: 1 req_1: CYCLE 4; ! linenum: 5.000 targname: NGC2403-174 config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F439W num_exp: 3 time_per_exp: 900S s_to_n: 15 fluxnum_1: 1 priority: 2 param_1: CR-SPLIT=NO req_1: CYCLE 4; ! linenum: 6.000 targname: NGC2403-174 config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F469N num_exp: 5 time_per_exp: 2200S s_to_n: 10 fluxnum_1: 1 priority: 2 param_1: CR-SPLIT=NO req_1: CYCLE 4; req_2: SAME POS FOR 6-8 AS 5 ! linenum: 7.000 targname: NGC2403-174 config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F547M num_exp: 2 time_per_exp: 700S s_to_n: 15 fluxnum_1: 1 priority: 2 param_1: CR-SPLIT=NO req_1: CYCLE 4; ! linenum: 8.000 targname: NGC2403-174 config: WFPC2 opmode: IMAGE aperture: PC1-FIX sp_element: F502N num_exp: 1 time_per_exp: 1000S s_to_n: 10 fluxnum_1: 1 priority: 2 req_1: CYCLE 4; ! ! end of exposure logsheet ! No scan data records found