5910( 0) - 07/18/95 18:35 - [ 1]
PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only
ID: 5910
Version: **********
Check-in Date: **********
1.Proposal Title:
The Far-Field Hubble Constant
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2. Scientific Category 3. Proposal For 4. Cycle
Galaxies & Clusters GO 5
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5. Investigators
Contact?
PI: Tod R. Lauer National Optical Astronomy Observatories
CoI: Edward A. Ajhar NOAO N
CoI: Jon A. Holtzman Lowell Observatory N
CoI: Marc Postman STScI N
CoI: John L. Tonry MIT N
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6. Abstract
We request deep, near-IR (F814W) WFPC2 images of five nearby Brightest Cluster
Galaxies (BCG) to calibrate the BCG Hubble diagram by the Surface Brightness
Fluctuation (SBF) method. Lauer & Postman (1992) show that the BCG Hubble diagram
measured out to 15,000 km s^-1 is highly linear. Calibration of the Hubble diagram
zeropoint by SBF will thus yield an accurate far-field measure of H_0 based on the
entire volume within 15,000 km s^-1, thus circumventing any strong biases caused by
local peculiar velocity fields. This method of reaching the far field is contrasted
with those using distance ratios between Virgo and Coma, or any other limited sample
of clusters. HST is required as the ground-based SBF method is limited to <3,000 km
s^-1. The high spatial resolution of HST allows precise measurement of the SBF
signal at large distances, and allows easy recognition of globular clusters,
background galaxies, and dust clouds in the BCG images that must be removed prior to
SBF detection. The proposing team developed the SBF method, the first BCG Hubble
diagram based on a full-sky, volume-limited BCG sample, played major roles in the
calibration of WFPC and WFPC2, and are conducting observations of local galaxies
that will validate the SBF zeropoint (through GTO programs). This work uses the SBF
method to tie both the Cepheid and Local Group giant-branch distances generated by
HST to the large scale Hubble flow, which is most accurately traced by BCGs.
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Observations Description
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Experience with nearby bright galaxies shows that the apparent fluctuation
magnitude for galaxies with mean color V -I=1.20 will be /line m_I = 31.5 at a
distance of 3,000 km/s. Total integration times must be long enough so that a
``typical star'' of this luminosity contributes at least 5 photons. The need
for this signal level has been established from extensive ground-based work ---
the distance error target of 5\ quickly below this level. For the F814W filter
and WFPC2, we calculate the exposure time to receive 5 photons from a typical
star at distance D as t = 6.00times10^3 sec\; (D/3000, km/s)^2 10^1.6(V-I)-
1.20. The list of BCGs and total integration times are: The individual
exposures will be CR-split. We will request offsets of a few WFC-pixels between
the exposures to improve rejection of any residual hot pixels, as well as to
improve flat-fielding and rejection of any additional CCD defects. Given the
large number of exposures, we expect to obtain excellent rejection of both hot
pixels and CR events. We emphasize, in any case, that the SBF method works by
measuring the amplitude of the PSF power-spectrum, which can be cleanly
separated from noise introduced by any low-level deviant pixels or CR events
that remain. The sample of 5 galaxies is required to 1) reduce the total formal
error below the nominal 5\ provide cross-checks between individual BCG, and 3)
to reduce vulnerability of the calibration to choice of the fundamental rest
frame of the universe. We selected the specific galaxies so that their average
position in the Hubble diagram is insensitive to a number of plausible choices
for the rest frame. We emphasize the strengths of our team for conducting this
program. All five investigators are highly experienced with the reduction and
analysis of CCD images. Tonry defined the SBF method, and with Ajhar, applied
it to an extensive sample of nearby galaxies. The SBF formalism includes full
treatment of both astronomical and detector sources of variance that must be
accounted for before isolating the SBF signal itself. Lauer and Postman
developed the BCG Hubble diagram that will be calibrated by the SBF method.
Lauer, Postman, and Tonry have all worked on large scale velocity flows.
Holtzman, as a member of the WFPC2 and WFPC1 teams, has been the lead for
producing the WFPC2 calibration products, and has developed algorithms for
rejection of CR events and hot pixels specific to the WFPC2 detectors. Lauer,
as a member of the WFPC1 team, was one of the leads for the calibration of that
instrument, and with Holtzman is an experienced HST researcher.
Real Time Justification
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None No coordinated or supporting observations with other facilities are
required. Ground-based B and R images of all targets have already been obtained
by Lauer & Postman at KPNO and CTIO. Tonry & Ajhar have defined the SBF method
and investigated its systematic properties from an extensive set of ground-
based images at KPNO, CTIO, and MDM.
Calibration Justification
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Additional Comments
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Data Distribution
Media: 8MM
Blocking Factor: 10
Ship To: PI_Address
Ship Via: UPS
Email: ,
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TARGET LIST a) Fixed Targets
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Tar| Target | Target | Target |Coord | Radial | Flux data
No | Name | Description | Position |Eqnx | Vel. |
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1 ABELL0262-M1 GALAXY, Elliptical, BCM RA = 01H 52M 46.28S +/- 0.07S, J2000 V = SURF(V) = 21.4 +/- 0.3
DEC = +36D 09' 05.3" +/- 1" 4831
Comments: Brightest Cluster Galaxy in Abell 0262
2 ABELL3560-M1 GALAXY, Elliptical, BCM RA = 13H 31M 53.33S +/- 0.07S, J2000 V = SURF(V) = 21.4 +/- 0.3
DEC = -33D 14' 04.4" +/- 1" 3644
Comments: Brightest Cluster Galaxy in Abell 3560
3 ABELL3565-M1 GALAXY, Elliptical, BCM RA = 13H 36M 39.06S +/- 0.07S, J2000 V = SURF(V) = 21.4 +/- 0.3
DEC = -33D 57' 56.7" +/- 1" 3762
Comments: Brightest Cluster Galaxy in Abell 3565
4 ABELL3742-M1 GALAXY, Elliptical, BCM RA = 21H 07M 52.28S +/- 0.07S, J2000 V = SURF(V) = 21.4 +/- 0.3
DEC = -47D 10' 43.4" +/- 1" 4764
Comments: Brightest Cluster Galaxy in Abell 3742
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Visit: 01
Visit Requirements: <none>
On Hold Comments: <none>
Additional Comments: <none>
Exposures
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Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special
Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements
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101 ABELL0262- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 900S POS TARG 0.00, 0.00
M1
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102 ABELL0262- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1100S POS TARG 0.8969, 0.0946
M1
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103 ABELL0262- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1100S POS TARG 1.0010, 0.8908
M1
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104 ABELL0262- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1300S POS TARG 0.1052, 0.9954
M1
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105 ABELL0262- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1100S POS TARG -0.8903, 1.1006
M1
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106 ABELL0262- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1300S POS TARG -0.9965, -0.0940
M1
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107 ABELL0262- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1100S POS TARG -1.1006, -0.8903
M1
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108 ABELL0262- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1300S POS TARG -0.1052, -0.9954
M1
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109 ABELL0262- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1100S POS TARG 1.0895, -1.1017
M1
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110 ABELL0262- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1300S POS TARG 1.8857, -1.2058
M1
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111 ABELL0262- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1100S POS TARG 1.9931, 0.1881
M1
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112 ABELL0262- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1300S POS TARG 2.0982, 1.1835
M1
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113 ABELL0262- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1100S POS TARG 2.2017, 1.8801
M1
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114 ABELL0262- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1300S POS TARG 1.2063, 1.9853
M1
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Visit: 02
Visit Requirements: <none>
On Hold Comments: <none>
Additional Comments: <none>
Exposures
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Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special
Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements
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201 ABELL3560- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 900S POS TARG 0.00, 0.00
M1
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202 ABELL3560- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1100S POS TARG 0.8969, 0.0946
M1
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203 ABELL3560- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1100S POS TARG 1.0010, 0.8908
M1
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204 ABELL3560- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1300S POS TARG 0.1052, 0.9954
M1
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205 ABELL3560- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1100S POS TARG -0.8903, 1.1006
M1
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206 ABELL3560- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1300S POS TARG -0.9965, -0.0940
M1
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207 ABELL3560- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1100S POS TARG -1.1006, -0.8903
M1
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208 ABELL3560- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1300S POS TARG -0.1052, -0.9954
M1
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Visit: 03
Visit Requirements: <none>
On Hold Comments: <none>
Additional Comments: <none>
Exposures
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Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special
Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements
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301 ABELL3565- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 900S POS TARG 0.00, 0.00
M1
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302 ABELL3565- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1100S POS TARG 0.8969, 0.0946
M1
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303 ABELL3565- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1100S POS TARG 1.0010, 0.8908
M1
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304 ABELL3565- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1300S POS TARG 0.1052, 0.9954
M1
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305 ABELL3565- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1100S POS TARG -0.8903, 1.1006
M1
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306 ABELL3565- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1300S POS TARG -0.9965, -0.0940
M1
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307 ABELL3565- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1100S POS TARG -1.1006, -0.8903
M1
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308 ABELL3565- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1300S POS TARG -0.1052, -0.9954
M1
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309 ABELL3565- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1100S POS TARG 1.0895, -1.1017
M1
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310 ABELL3565- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1300S POS TARG 1.8857, -1.2058
M1
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5910( 0) - 07/18/95 18:35 - [ 8]
Visit: 04
Visit Requirements: <none>
On Hold Comments: <none>
Additional Comments: <none>
Exposures
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Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special
Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements
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401 ABELL3742- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 900S POS TARG 0.00, 0.00
M1
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402 ABELL3742- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1200S POS TARG 0.8969, 0.0946
M1
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403 ABELL3742- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1200S POS TARG 1.0010, 0.8908
M1
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404 ABELL3742- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1200S POS TARG 0.1052, 0.9954
M1
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405 ABELL3742- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1200S POS TARG -0.8903, 1.1006
M1
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406 ABELL3742- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1200S POS TARG -0.9965, -0.0940
M1
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407 ABELL3742- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1200S POS TARG -1.1006, -0.8903
M1
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408 ABELL3742- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1200S POS TARG -0.1052, -0.9954
M1
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409 ABELL3742- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1200S POS TARG 1.0895, -1.1017
M1
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410 ABELL3742- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1200S POS TARG 1.8857, -1.2058
M1
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411 ABELL3742- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1200S POS TARG 1.9931, 0.1881
M1
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412 ABELL3742- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1200S POS TARG 2.0982, 1.1835
M1
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413 ABELL3742- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1200S POS TARG 2.2017, 1.8801
M1
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414 ABELL3742- WFPC2 IMAGE PC1 F814W CR-SPLIT=NO 1 1200S POS TARG 1.2063, 1.9853
M1
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5910( 0) - 07/18/95 18:35 - [ 9]
Summary Form for Proposal 5910
Item Used in this proposal
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Configurations WFPC2
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Opmodes IMAGE
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Optional Parameters CR-SPLIT=NO
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Proposal Category GO
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Scientific Category Galaxies & Clusters
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Special Requirements POS TARG 0.00, 0.00 POS TARG 0.8969, 0.0946 POS TARG 1.0010, 0.8908 POS TARG 0.1052, 0.9954 POS
TARG -0.8903, 1.1006 POS TARG -0.9965, -0.0940 POS TARG -1.1006, -0.8903 POS TARG -0.1052, -0.9954
POS TARG 1.0895, -1.1017 POS TARG 1.8857, -1.2058 POS TARG 1.9931, 0.1881 POS TARG 2.0982, 1.1835
POS TARG 2.2017, 1.8801 POS TARG 1.2063, 1.9853
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Spectral Elements F814W
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Target Names ABELL0262-M1 ABELL3560-M1 ABELL3565-M1 ABELL3742-M1
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