! $Id: 5386,v 4.1 1994/07/27 17:23:19 pepsa Exp $
coverpage:
title_1: STELLAR POPULATIONS OF THE LEO II DWARF SPHEROIDAL GALAXY
sci_cat: COOL STARS
sci_subcat: STELLAR POPULATIONS
proposal_for: GO
pi_fname: KENNETH
pi_mi: J
pi_lname: MIGHELL
pi_inst: COLUMBIA UNIVERSITY
pi_country: USA
pi_phone: 212-854-6899
hours_pri: 4.08
num_pri: 1
wf_pc: Y
off_fname: BETH
off_lname: ISRAEL
off_title: ASSOC. DIRECTOR
off_inst: 1770
off_addr_1: OFFICE OF PROJECTS AND GRANTS
off_addr_2: 405 LOW MEMORIAL LIBRARY
off_addr_3: COLUMBIA UNIVERSITY
off_city: NEW YORK
off_state: NY
off_zip: 10027
off_country: USA
off_phone: 212-854-6851
! end of coverpage
abstract:
line_1: We propose to obtain deep V and I photometry of the Leo II dwarf spheroidal
line_2: galaxy using the WFPC2 and the F555W and F791 filters. We will produce a deep
line_3: HR diagram of this Local Group galaxy which will be analyzed to determine its
line_4: age and star formation history. This galaxy has luminous carbon stars and an
line_5: anomalously red horizontal branch which indicates the presence of at least some
line_6: intermediate age stars, and suggests that Leo II is younger than the Draco and
line_7: Ursa Minor dwarf spheroidals.
!
! end of abstract
general_form_proposers:
lname: MIGHELL
fname: KENNETH
mi: J
inst: 1770
country: USA
!
lname: RICH
fname: R. MICHAEL
inst: 1770
country: USA
!
! end of general_form_proposers block
general_form_text:
question: 3
section: 1
line_1: Leo II has a distance modulus (m-M)=21.85 (Demers & Harris 1983). An
line_2: intermediate-age turnoff would occur at V=25; an old trunoff at V=26.
line_3: We seek (V-I) color errors less than 0.30 mag for a F0 star at V=27.
line_4: A 4800 second exposure in F555W gives S/N=7.9 and a 4800 second exposure
line_5: in F791W gives S/N=5.1. The combined color error is 0.28 mag.
line_7: Filter: F555W has QT_integral = 0.0250
line_8: Star: V=27, F0 star has AB_V=0.030 (average of 500 and 600 nm)
line_9: Stellar flux: I=(2.5E+11)*(QT_integral)*10**(-0.4(V+AB_V))=0.096 e/sec
line_10: Sky: WF -> V=27.1 (Leo II is near the ecliptic), AB_V = 0.035
line_11: Sky flux: B=(2.5E+11)*(QT_integral)*10**(-0.4(V+AB_V))=0.087 e/sec
line_12: Total Exposure: T=4800 sec
line_13: S/N correction: C=0.261 (WF Center & Corner, avgerage of 400 and 800 nm)
line_14: S/N=I*SQRT((T*C)/(B+I))= 7.9 in 4800 sec
line_16: Filter: F791W has QT_integral = 0.0169
line_17: Star: V=27, F0 star has AB_V=0.080 (800 nm)
line_18: Stellar flux: I=(2.5E+11)*(QT_integral)*10**(-0.4(V+AB_V))=0.062 e/sec
line_19: Sky: WF -> V=27.1 (Leo II is near the ecliptic), AB_V = -0.55
line_20: Sky flux: B=(2.5E+11)*(QT_integral)*10**(-0.4(V+AB_V))=0.101 e/sec
line_21: Total Exposure: T=4800 sec
line_22: S/N correction: C=0.226 (WF Center & Corner, 800 nm)
line_23: S/N=I*SQRT((T*C)/(B+I))= 5.1 in 4800 sec
!
question: 3
section: 2
line_1:
line_2: We will take 2x80 sec exposures with ATD-GAIN=15 and 4x1200 sec exposures with
line_4: ATD-GAIN=7 for both filters (F555W and F791W). The short high-gain exposures
line_5: increase the dynamic range of the long low-gain exposures.
line_7: We would like all the exposures to be taken together as one group with only
line_8: interruptions due to Earth occultations (GROUP 1-4 NO GAP). We would like
line_9: all exposures to be made at the same position in the sky with the same
line_10: telescope roll angle (SAME POS FOR 2-4 AS 1). Each 1200 second exposure will
line_11: be split in half (CR-SPLIT=0.5) to minimize cosmic-ray contamination.
!
question: 4
section: 1
line_1: See answer to question 4.a. on the HST Cycle 4 proposal general form.
!
question: 5
section: 1
line_1:
!
question: 6
section: 1
line_1:
!
!
question: 8
section: 1
line_1:
!
question: 9
section: 1
line_1: See answer to question 9. on the HST Cycle 4 proposal general form.
!
question: 10
section: 1
line_1: See answer to question 10. on the HST Cycle 4 proposal general form.
!
!end of general form text
general_form_address:
lname: MIGHELL
fname: KENNETH
mi: J
category: PI
inst: 1770
addr_1: DEPT. OF ASTRONOMY
addr_2: COLUMBIA UNIVERSITY
addr_3: 538 WEST 120TH STREET
city: NEW YORK
state: NY
zip: 10027
country: USA
phone: 212-854-6899
telex: MIGHELL@FIGARO.PHYS.COLUMBIA.EDU
!
! end of general_form_address records
fixed_targets:
targnum: 1
name_1: LEO-II
descr_1: E, 308
pos_1: RA = 11H 13M 32.00S +/- 0.10S,
pos_2: DEC = +22D 09' 30" +/- 0.10"
equinox: 2000.0
comment_1: POSITION CHOSEN TO AVOID BRIGHT
comment_2: STAR NEAR THE CENTER OF THE GALAXY
fluxnum_1: 1
fluxval_1: V=12.4
fluxnum_2: 2
fluxval_2: B-V=1.0
!
! end of fixed targets
! No solar system records found
! No generic target records found
exposure_logsheet:
linenum: 1.000
targname: LEO-II
config: WFPC2
opmode: IMAGE
aperture: PC1
sp_element: F555W
num_exp: 2
time_per_exp: 80S
s_to_n: 7.9
s_to_n_time: 4800S
fluxnum_1: 1
priority: 1
param_1: ATD-GAIN=15, CR-SPLIT=NO
req_1: CYCLE 4; PCS MODE F;
!
linenum: 2.000
targname: LEO-II
config: WFPC2
opmode: IMAGE
aperture: PC1
sp_element: F555W
num_exp: 4
time_per_exp: 1200S
s_to_n: 7.9
s_to_n_time: 1200S
fluxnum_1: 1
priority: 1
param_1: ATD-GAIN=7,
param_2: CR-SPLIT=0.5,
param_3: CR-TOLERANCE=0.0
req_1: CYCLE 4; PCS MODE F;
!
linenum: 3.000
targname: LEO-II
config: WFPC2
opmode: IMAGE
aperture: PC1
sp_element: F814W
num_exp: 2
time_per_exp: 80S
s_to_n: 5.1
s_to_n_time: 4800S
fluxnum_1: 1
priority: 1
param_1: ATD-GAIN=15,
param_2: CR-SPLIT=NO,
req_1: CYCLE 4; PCS MODE F;
!
linenum: 4.000
targname: LEO-II
config: WFPC2
opmode: IMAGE
aperture: PC1
sp_element: F814W
num_exp: 4
time_per_exp: 1200S
s_to_n: 5.1
s_to_n_time: 4800S
fluxnum_1: 1
priority: 1
param_1: ATD-GAIN=7,
param_2: CR-SPLIT=0.5,
param_3: CR-TOLERANCE=0.0
req_1: CYCLE 4; PCS MODE F;
req_2: GROUP 1-4 NO GAP;
req_3: SAME POS FOR 2-4 AS 1;
!
! end of exposure logsheet
! No scan data records found