!   $Id: 5309,v 7.1 1994/07/27 16:26:10 pepsa Exp $
 COVERPAGE:                                                                                            
  TITLE_1: Star Formation and the Massive Star Population in Blue Compact
  TITLE_2: Dwarf Galaxies: Cycle4Medium
  SCI_CAT: GALAXIES & CLUSTERS
  SCI_SUBCAT: STELLAR POPULATIONS
  PROPOSAL_FOR: GO
  LARGE_PROJ:
  KEY_PROJ:
  TARG_OF_OPP:
  REALTIME:
  TIME_CRIT:
  PI_FNAME: Deidre
  PI_MI:    A.
  PI_LNAME: Hunter
  PI_INST:  Lowell Observatory
  PI_COUNTRY: USA
  PI_PHONE: 602-774-3358
  HOURS_PRI: 9.82
  HOURS_PAR:  0.00
  NUM_PRI:    1
  NUM_PAR:    0
  WF_PC: Y
  OFF_FNAME: Robert
  OFF_LNAME: Millis
  OFF_TITLE: Director
  OFF_INST:  Lowell Observatory
  OFF_ADDR_1: 1400 W. Mars Hill Rd.
  OFF_CITY: Flagstaff
  OFF_STATE: AZ
  OFF_ZIP:   86001
  OFF_COUNTRY: USA
  OFF_PHONE: 602-774-3358

ABSTRACT:
LINE_1: Blue Compact Dwarf galaxies are tiny galaxies that are dominated
LINE_2: by intense, compact star-forming regions that contain thousands
LINE_3: of massive OB and Wolf-Rayet stars. Thus, they present a different
LINE_4: and extreme environment for star formation compared to the
LINE_5: Milky Way and other nearby galaxies for the examination of the
LINE_6: star formation process. The IMF of the massive stars in these
LINE_7: enigmatic galaxies, in fact, is controversial. Global properties
LINE_8: and models have been interpretted as showing considerable variation
LINE_9: in the IMF with the metallicity of the system, while other studies
LINE_10: argue that the IMF is fairly normal. We will resolve this issue
LINE_11: by resolving one BCD into individual massive stars for the first
LINE_12: time. The galaxy, IZW18, is renowned for its low abundances. We will use
LINE_13: UVI-equivalent colors to construct color-magnitude diagrams
LINE_14: and luminosity functions for the massive stars and F469N to
LINE_15: identify evolved Wolf-Rayet stars. We will also examine the
LINE_16: images in order to determine the numbers, physical sizes, and
LINE_17: distributions of the star-forming regions. Halpha images will
LINE_18: be used to examine the effect of the extreme concentration of
LINE_19: massive stars on their environment.

GENERAL_FORM_PROPOSERS:
  LNAME: Thronson
  FNAME: Harley
  MI:    A.
  INST: Univ. of Wyoming
  COUNTRY: USA
  ESA:

GENERAL_FORM_ADDRESS:
  LNAME: Hunter
  FNAME: Deidre
  MI:    A.
  CATEGORY:      PI
  INST: Lowell Observatory
  ADDR_1: 1400 W. Mars Hill Rd.
  CITY: Flagstaff
  STATE: AZ
  ZIP:   86001
  COUNTRY: USA
  PHONE: 602-774-3358
  TELEX: dah@lowell.edu
  LNAME:
  FNAME:
  MI:
  CATEGORY:      CON
  INST:
  ADDR_1:
  ADDR_2:
  ADDR_3:
  CITY:
  STATE:
  ZIP:
  COUNTRY:
  PHONE:
  TELEX:

GENERAL_FORM_TEXT:
 QUESTION:  3
  SECTION:  1
LINE_1: We will obtain F336W, F555W, F814W, F469N, and F656N images
LINE_2: of one blue compact dwarf galaxy, IZw18. The observations
LINE_3: for the broad-band filters include short and long exposures
LINE_4: in order to cover an apparent magnitude of V=19 to 26.
LINE_5: These will enable us to examine the OB star population (V=21
LINE_6: is M_V=-10). The F469N filter will be used
LINE_7: to identify Wolf-Rayet stars, and high resolution Halpha
LINE_8: images will be used to examine the structure of the star-forming
LINE_9: regions. The exposures of the narrow-band filters are as long
LINE_10: as are feasible, since they will be photon-starved for any
LINE_11: reasonable exposure time. The long exposures are multiples in
LINE_12: order to permit CR removal. They should not be split further.

 QUESTION:  4
  SECTION:  1
LINE_1: IZW18 is not resolved on ground-based images.
LINE_2: With HST we will for the first time measure the brightnesses
LINE_3: of individual stars and locate them for future spectroscopy
LINE_4: with HST in order to test statements in the literature that
LINE_5: this type of galaxy has an abnormal IMF.

 QUESTION:  5
  SECTION:  1
LINE_1: None.

 QUESTION:  6
  SECTION:  1
LINE_1: We require flat fields for F336W, F555W, F814W, F469N, and F656N.
LINE_2: We expect the first 3 to be done as part of the standard calibration,
LINE_3: but F469N and F656N may not be. Thus, they need to be scheduled for
LINE_4: calibration as well. We also require photometric calibration of
LINE_5: the 3 broad-band filters, but, again, we would expect this to be
LINE_6: done as part of the standard proceedure.


 QUESTION:  8
  SECTION:  1
LINE_1: None.

 QUESTION:  9
  SECTION:  1
LINE_1: DAH is a member of the WFPCI team and has worked on the stellar
LINE_2: photometry of R136 (Campbell et al. 1992, AJ, 104, 1721).
LINE_3: DAH has also been involved in a GO program to examine superstar
LINE_4: clusters in irregular galaxies (in preparation).

 QUESTION:  10
  SECTION:  1
LINE_1: Computing facilities and software for data analysis, access to
LINE_2: telescopes for any ground-based support that might be necessary.

FIXED_TARGETS:
  TARGNUM: 1
  NAME_1: IZW18
  DESCR_1: E,307
  POS_1: RA = 09H 30M 30.4S +/- 0.1S,
  POS_2: DEC = +55D 27' 46" +/- 2"
  EQUINOX: 1950
  FLUXNUM_1:   1
  FLUXVAL_1:   V=21, TYPE=O
  FLUXNUM_2:   1
  FLUXVAL_2:   E(B-V)=0
  FLUXNUM_3:   2
  FLUXVAL_3:   V=25.6, TYPE=O
  FLUXNUM_4:   2
  FLUXVAL_4:   E(B-V)=0
  COMMENT_1: V=21 is the maximum expected.
  COMMENT_2: V=25.6 is the minimum for S/N=10.

EXPOSURE_LOGSHEET:
  LINENUM:  2.0
  TARGNAME: IZW18
  CONFIG:   WFPC2
  OPMODE:   IMAGE
  APERTURE: PC1-FIX
  SP_ELEMENT: F336W
  PARAM_1:   CR-SPLIT=NO
  NUM_EXP:      3
  TIME_PER_EXP: 1400S
  S_TO_N: 10
  S_TO_N_TIME:
  FLUXNUM_1: 2
  FLUXNUM_2: 2
  PRIORITY: 1
  REQ_1:       CYCLE 4 / 2-8

  LINENUM:  4.0
  TARGNAME: IZW18
  CONFIG:   WFPC2
  OPMODE:   IMAGE
  APERTURE: PC1-FIX
  SP_ELEMENT: F555W
  PARAM_1:   CR-SPLIT=NO
  NUM_EXP:    3
  TIME_PER_EXP: 2200S
  S_TO_N: 10
  S_TO_N_TIME:
  FLUXNUM_1: 2
  FLUXNUM_2: 2
  PRIORITY: 1
  REQ_1: SAME POS FOR 4-8 AS 2;
  REQ_2: GROUP 2-8 WITHIN 7D 

  LINENUM:  6.0
  TARGNAME: IZW18
  CONFIG:   WFPC2
  OPMODE:   IMAGE
  APERTURE: PC1-FIX
  SP_ELEMENT: F814W
  PARAM_1:   CR-SPLIT=NO
  NUM_EXP:       3
  TIME_PER_EXP:  2200S
  S_TO_N: 10
  S_TO_N_TIME:
  FLUXNUM_1: 2
  FLUXNUM_2: 2
  PRIORITY: 1

  LINENUM:  7.0
  TARGNAME: IZW18
  CONFIG:   WFPC2
  OPMODE:   IMAGE
  APERTURE: PC1-FIX
  SP_ELEMENT: F469N
  PARAM_1:   CR-SPLIT=NO
  NUM_EXP:     3
  TIME_PER_EXP: 2300S
  S_TO_N: 10
  S_TO_N_TIME:
  FLUXNUM_1: 1
  FLUXNUM_2: 1
  PRIORITY: 1

  LINENUM:  8.0
  TARGNAME: IZW18
  CONFIG:   WFPC2
  OPMODE:   IMAGE
  APERTURE: PC1-FIX
  SP_ELEMENT: F656N
  PARAM_1:   CR-SPLIT=NO
  NUM_EXP:     3
  TIME_PER_EXP: 1400S
  S_TO_N: 10
  S_TO_N_TIME:
  FLUXNUM_1: 1
  FLUXNUM_2: 1
  PRIORITY: 1

!~~~RPSS~~~,HUNTER,bcd_change.prop,11-FEB-1994 16:09