! File: 2436C.PROP ! Database: PEPDB ! Date: 17-FEB-1994:06:27:44 coverpage: title_1: THE STARBURST GALAXY NGC 5102 sci_cat: GALAXIES & CLUSTERS sci_subcat: NEARBY GALAXIES proposal_for: GO pi_title: PROF. pi_fname: KENNETH pi_mi: C pi_lname: FREEMAN pi_inst: MT STROMLO & SIDING SPRING OBSERVATORIES pi_country: AUSTRALIA pi_phone: 61-62-490264 keywords_1: GALAXIES, STARBURST, LUMINOSITY FUNCTION, MASS keywords_2: FUNCTION hours_pri: 5.40 num_pri: 3 wf_pc: Y funds_amount: 104723 funds_length: 24 funds_date: JUN-90 pi_position: PROFESSOR off_fname: A. off_mi: W. off_lname: RODGERS off_title: PROFESSOR off_inst: MT. STROMLO AND SIDING SPRING OBS. off_addr_1: PRIVATE BAG, WODEN PO off_city: CANBERRA off_state: ACT off_zip: 2606 off_country: AUSTRALIA off_phone: 61 62 490266 off_telex: AA62270 ! end of coverpage abstract: line_1: NGC 5102 is a nearby (4 Mpc) galaxy of classical SO appearance which has line_2: undergone a recent starburst in its nucleus, bulge and disk. Because it is line_3: so close, it provides a unique opportunity to investigate the IMF of a typical line_4: starburst, the mass of starburst matter relative to the underlying older line_5: population, and the effect of the starburst on the largescale structure of this line_6: galaxy. PC images will be used to derive the luminosity function and IMF for line_7: the starburst matter in two regions of NGC 5102, at different distances from line_8: the nucleus. In the inner high surface brightness region, the crucial massive line_9: end of the mass function (stars more massive than 8 Ms) is accessible. In the line_10: outer disk, where the surface brighness is lower, we will be able to derive the line_11: mass function for stars more massive than 5 Ms. This proposal is part of a line_12: larger program on this important galaxy, involving extensive ground based line_13: optical and radio observations. The HST is required for its high spatial line_14: resolution, which enables faint stars of the starburst to be detected against line_15: the high background surface brightness of this galaxy. ! ! end of abstract general_form_proposers: lname: NORMAN fname: COLIN title: DR. mi: A inst: STSCI country: USA ! lname: FREEMAN fname: KENNETH title: PROF. mi: C inst: MT STROMLO & SIDING SPRING OBSERVATORIES country: AUSTRALIA ! lname: SCOVILLE fname: NICHOLAS title: DR. mi: Z inst: CALTECH country: USA ! lname: QUINN fname: PETER title: DR. mi: J inst: MT STROMLO & SIDING SPRING OBSERVATORIES country: AUSTRALIA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: The observations will be made with the PC, because its field size is line_2: well suited to the program and its adequate sampling of the image profile line_3: is required. We will use the wideband filters F439W and F569W, because line_4: they will provide satisfactory transformations to the standard BV system line_5: and they give the best signal to noise ratio for observations of our blue line_6: stars against the redder diffuse background of this galaxy. line_8: The first field is centered about 35 arcsec from the nucleus, along the major line_9: axis, towards the SW, for the purpose of deriving the luminosity function in the line_10: bulge region. The proposed exposures in the two filters will give a S/N line_11: ratio larger than 4.0 for early type stars with V = 26 near the nucleus, and line_12: correspondingly fainter at larger distances. The exposures will be split into line_13: two or three parts, to minimize blooming from foreground stars and to allow line_14: discrimination of the fainter cosmic ray events. The second field is centered at line_15: about 100 arcsec from the nucleus, in the same direction; this field covers the line_16: transition region between the bulge and the disk. The field centers have been line_17: adjusted to minimize the number of stars in each field that are bright enough to line_18: cause blooming, and the field area affected by blooming will be negligible. We line_19: have also chosen a field outside the galaxy, to be observed in an identical way line_20: to the first two fields, in order to derive the local Galactic background line_21: luminosity function accurately . ! question: 4 section: 1 line_1: The HST is required for this program, because its high spatial resolution allows line_2: photometry of faint stars against the background surface brightness distribution line_3: of this galaxy. From the ground, such photometry is so limited that our program line_4: would be impossible. For example, in the disk of NGC 5102, where the surface line_5: brightness is about 21.2 B mag per square arcsec, the limiting magnitude from line_6: the ground is about B = 24.5, and only a very restricted portion of the upper line_7: end of the mass function would be observable (about 16 to 40 Ms). However, the line_8: innermost parts of NGC 5102 are particularly important, because of the likely line_9: connection of starbursts and bulge formation and in these regions ground based line_10: work is impossible. For example, at about 5 arcsec from the nucleus, the line_11: background surface brightness is about 18.5 B mag per square arcsec, and the line_12: faintest stars that could be detected under the best groundbased conditions line_13: have B = 22. (We recall that the brightest stars that have been detected in the line_14: disk of NGC 5102 have B = 22). line_16: We have started an extensive program of groundbased optical CCD imaging and line_17: spectroscopy to investigate the structure and kinematics of the young line_18: and older populations in NGC 5102 and the chemical properties of the resolved line_19: HII regions. We are also involved with CO single dish and interferometer line_20: observations of NGC 5102, and will undertake HI synthesis observations with the line_21: Australia Telescope in about one year. ! question: 5 section: 1 line_1: Our primary aim is to derive the mass function in NGC 5102, over a range of line_2: distances from the nucleus. Two fields in NGC 5102 are a bare minimum, plus a line_3: field away from the galaxy for estimating the Galactic background luminosity line_4: function. The problem is to measure magnitudes and colors of faint blue stars line_5: against the redder diffuse background of NGC 5102. We have estimated S/N line_6: ratios for the wide band filters and find that F439W and F569W are the best for line_7: this purpose. In the disk of NGC 5102, a 3000 sec exposure gives a S/N ratio line_8: larger than 3 for a star with V = 27; we can then estimate the mass function line_9: over the mass range 5 to 40 Ms. In the inner regions, where the surface line_10: brightness is higher, a 3000 sec exposure gives a S/N ratio of 4 for a star line_11: with V = 26. The corresponding mass range is then 8 to 40 Ms. While this range line_12: is more restricted than in the outer regions, it will give us the important line_13: bright end of the mass function. To obtain a significantly larger mass range in line_14: the inner regions of NGC 5102 would require very much longer exposures. line_16: Each exposure should be split into 1500 sec parts, to reduce line_17: problems with cosmic rays and blooming. Two such exposures is the minimum line_18: number for this purpose. line_20: Spacecraft time was estimated from the formulae given in the instructions for line_21: use of the RPSS Resource Estimator, with 325 min total exposure time, 87 min line_22: overheads and 40 min acquisition time. The total estimated unocculted spacecraft line_23: time is 452 min and the efficiency is 72%. ! question: 6 section: 1 line_1: Not applicable. ! question: 7 section: 1 line_1: Point spread function fitting codes will be used to derive instrumental color line_2: magnitude diagrams for the resolved stars in each field. Ground based line_3: observations of the comparison field will be used to transform the instrumental line_4: F439W, F569W system to the standard B,V system. At this stage, we do not know line_5: whether crowding of resolved images will be a problem; in any case, we will line_6: estimate the completeness as a function of magnitude and background surface line_7: brightness by the usual procedure of randomly inserting artificial stars into line_8: the data. We can then subtract the comparison field color magnitude distribution line_9: from those of the corrected galaxy fields to derive uncontaminated galaxy field line_10: samples.Theoretical color magnitude distributions, convolved with the line_11: observational errors, will then be fitted to the galaxy field samples to derive line_12: the mass functions, using estimates of metallicity derived from ground based line_13: spectroscopy of the HII regions. In the outer parts of NGC 5102, we will resolve line_14: the brightest stars of the underlying old population. However, these will not line_15: contaminate our starburst sample, because our colors will be accurate enough line_16: to distinguish old red giants from A stars of the starburst population. We will line_17: avoid data near the dustlanes, although the extreme weakness of the dustlanes line_18: suggests that internal reddening is negligible. Further analysis line_19: will address the questions discussed in the scientific justification, such as line_20: the total mass of starburst matter relative to the older population, and the line_21: variation of the most recent epoch of star formation with radius. For the line_22: gas expulsion physics and the relation of age with kinematics, we will line_23: combine results from the PC data with our groundbased observations. ! question: 8 section: 1 line_1: We would be grateful if scheduling could ensure that residual images from line_2: previous observations do not contaminate our images. ! question: 9 section: 1 line_1: Not applicable ! question: 10 section: 1 line_1: The data analysis capabilities of STScI and Mt Stromlo Observatory (MSO) will be line_2: used for data analysis. The hardware and software required is already available line_3: and in use at both institutions. Graduate students at JHU and MSO will work on line_4: particular aspects of this project. Australian radio and optical facilities (the line_5: Australia Telescope, MSO 2.3-m telescope, AAT) will be used for much of the line_6: associated ground based observations. ! !end of general form text general_form_address: lname: FREEMAN fname: KENNETH mi: C title: DR. category: PI inst: MT. STROMLO AND SIDING SPRING OBSERVATORIES addr_1: PRIVATE BAG, WODEN P.O. city: CANBERRA, ACT zip: 2606 country: AUSTRALIA phone: 61-62-490264 telex: AA62270 ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: NGC5102-F1 descr_1: GALAXY; TYPE=S0; BULGE pos_1: RA = 13H 19M 05.0S +/- 1", pos_2: DEC = -36D 22' 32" +/- 1" equinox: 1950 rv_or_z: V = 454 comment_1: SURF-BKG +/- VALUES GIVE RANGE comment_2: OF SURF-BKG WITHIN PC FOV. fluxnum_1: 1 fluxval_1: V = 26 +/- 0.5, TYPE = B5 V fluxnum_2: 2 fluxval_2: B = 26 +/- 0.5 fluxnum_3: 3 fluxval_3: SURF-BKG(V) = 19.6 +/- 1.0 fluxnum_4: 4 fluxval_4: SURF-BKG(B) = 20.2 +/- 1.0 ! targnum: 2 name_1: NGC5102-F2 descr_1: GALAXY; TYPE=S0; DISK pos_1: RA = 13H 19M 01.3S +/- 1", pos_2: DEC = -36D 23' 20" +/- 1" equinox: 1950 rv_or_z: V = 454 comment_1: SURF-BKG +/- VALUES GIVE RANGE comment_2: OF SURF-BKG WITHIN PC FOV. fluxnum_1: 1 fluxval_1: V = 26 +/- 0.5, TYPE = B5 V fluxnum_2: 2 fluxval_2: B = 26 +/- 0.5 fluxnum_3: 3 fluxval_3: SURF-BKG(V) = 21.5 +/- 0.5 fluxnum_4: 4 fluxval_4: SURF-BKG(B) = 22.1 +/- 0.5 ! targnum: 3 name_1: NGC5102-F3 descr_1: GALAXY; TYPE=S0; BACKGROUND pos_1: RA = 13H 19M 32.7S +/- 1", pos_2: DEC = -36D 21' 37" +/- 1" equinox: 1950 rv_or_z: V = 454 fluxnum_1: 1 fluxval_1: V = 26 +/- 0.5 fluxnum_2: 2 fluxval_2: B = 26 +/- 0.5 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: NGC5102-F1 config: PC opmode: IMAGE aperture: ALL sp_element: F439W num_exp: 3 time_per_exp: 25M s_to_n: 7 s_to_n_time: 75M fluxnum_1: 2 fluxnum_2: 4 priority: 1 param_2: PRE-FLASH=YES, param_3: CLOCKS=YES, param_4: CR-SPLIT=NO req_1: POS TARG +0.0,+0.0 / 1-6; req_2: GROUP 1-2 NO GAP comment_1: S_TO_N ESTIMATE USED SURF-BKG comment_2: VALUE AT CENTER OF PC FOV. ! linenum: 2.000 targname: NGC5102-F1 config: PC opmode: IMAGE aperture: ALL sp_element: F569W num_exp: 1 time_per_exp: 50M s_to_n: 10 fluxnum_1: 1 fluxnum_2: 3 priority: 1 param_1: PURGE=YES, param_2: PRE-FLASH=YES, param_3: CLOCKS=YES req_1: SAME ORIENT FOR 2 AS 1 comment_1: S_TO_N ESTIMATE USED SURF-BKG comment_2: VALUE AT CENTER OF PC FOV. ! linenum: 3.000 targname: NGC5102-F2 config: PC opmode: IMAGE aperture: ALL sp_element: F439W num_exp: 1 time_per_exp: 50M s_to_n: 7 fluxnum_1: 2 fluxnum_2: 4 priority: 1 param_2: PRE-FLASH=YES, param_3: CLOCKS=YES req_1: GROUP 3-4 NO GAP ! linenum: 4.000 targname: NGC5102-F2 config: PC opmode: IMAGE aperture: ALL sp_element: F569W num_exp: 1 time_per_exp: 50M s_to_n: 15 fluxnum_1: 1 fluxnum_2: 3 priority: 1 param_1: PURGE=YES, param_2: PRE-FLASH=YES, param_3: CLOCKS=YES req_1: SAME ORIENT FOR 4 AS 3 ! linenum: 5.000 targname: NGC5102-F3 config: PC opmode: IMAGE aperture: ALL sp_element: F439W num_exp: 1 time_per_exp: 50M s_to_n: 7 fluxnum_1: 2 priority: 1 param_1: PRE-FLASH=YES, param_2: CLOCKS=YES req_1: GROUP 5-6 NO GAP ! linenum: 6.000 targname: NGC5102-F3 config: PC opmode: IMAGE aperture: ALL sp_element: F569W num_exp: 1 time_per_exp: 50M s_to_n: 15 fluxnum_1: 1 priority: 1 param_1: PRE-FLASH=YES, param_2: CLOCKS=YES req_1: SAME ORIENT FOR 6 AS 5 ! ! end of exposure logsheet ! No scan data records found