----- Submission 1 (Mon Apr 14 18:14:03 GMT 2003) ----- The Distance to M83 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.
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. 12 false false false false false SUPPORTED GALAXY HALO J2000 00 00 0.00 +00 00 0.00 J2000 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. (Tic-Visit :proposal-id 9864 :visit-id "01" :proposal-version -1 :trans-version "20030408" :date "14-Apr-2003 10:46:50.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 1210560 :tdrss-contact-duration 0 ) (Tic-Obset :proposal-id 9864 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 9864 :visit-id "01" :orbit-number 1 :pcs-time 365 :si-vis-utilization 2809 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3207 :pcs-gap 0 ) (Tic-Orbit :proposal-id 9864 :visit-id "01" :orbit-number 2 :pcs-time 300 :si-vis-utilization 2827 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3207 :pcs-gap 0 ) false