9864( 8) - 06/30/04 10:00 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9864 Version: 8 Check-in Date: 30-Jun-2004 13:59:14 1.Proposal Title: The Distance to M83 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle 4. Parallel Pointing Tolerance GO 12 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Dr. Barry F. Madore Carnegie Institution of Washington CoI: Dr. Wendy L. Freedman Carnegie Institution of Washington N CoI: Ms. Olga Pevunova California Institute of Technology N ------------------------------------------------------------------------------------ 6. Abstract M83 is a spiral galaxy at a distance of 4-5 Mpc. It is almost face-on, and it has been measured to support one of the largest chemical-composition, radial metallicity gradients in the local sample of high-luminosity spiral galaxies. It also has one of the highest absolute levels of mean metallicity in its inner regions. As such M83 is a chemical laboratory, within which we can probe (in both a differential and in an absolute way) the zero point, the variation and the sensitivity of the Cepheid PL relation as a function of metallicity. ------------------------------------------------------------------------------------ Observations Description ------------------------ Pair of V and I exposures are to be obtained so as to detect the tip of the red giant branch (TRGB) in the halo of M83. Color-magnitude diagrams will be used to discriminate agianst foreground objects, AGB stars and background galaxies. The tip will be measured using special-purpose edge-detection software. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 9864( 8) - 06/30/04 10:00 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 M83-HALO GALAXY, HALO RA=13H37M1.7S +/- 0.1", DEC=- J2000 V = 25.0 29D43'52.0" +/- 0.1" Coordinate Source: Other_Source: OTHER 9864( 8) - 06/30/04 10:00 - [ 3] Visit: 01 Visit Priority: Visit Requirements: PCS MODE FINE; BEFORE 06-SEP-2004:00:00:00 On Hold Comments: Additional Comments: In order to proceed with a follow-up proposal in the next Cycle it is essential that we have the ACS data for M83 in hand this year. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 M83-HALO ACS/WFC ACCUM WFC F606W CR-SPLIT=NO,GAIN=2 1 900 S ------------------------------------------------------------------------------------------------------------------------------------ 2 M83-HALO ACS/WFC ACCUM WFC F814W CR-SPLIT=NO,GAIN=2 1 1500 S ------------------------------------------------------------------------------------------------------------------------------------ 3 M83-HALO ACS/WFC ACCUM WFC F814W CR-SPLIT=NO,GAIN=2 1 1500 S ------------------------------------------------------------------------------------------------------------------------------------ 4 M83-HALO ACS/WFC ACCUM WFC F606W CR-SPLIT=NO,GAIN=2 1 1000 S ------------------------------------------------------------------------------------------------------------------------------------ 9864( 8) - 06/30/04 10:00 - [ 4] Summary Form for Proposal 9864 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO GAIN=2 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE FINE; BEFORE 06-SEP-2004 00 00 00 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F606W F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names M83-HALO ------------------------------------------------------------------------------------------------------------------------------------