Submission failed communicating with the submission server: java.rmi.ConnectException: Connection refused to host: 130.167.201.116; nested exception is: java.net.ConnectException: Connection timed out Assigned ID: 744 ----- Attempting Submission 1 (Fri Feb 24 21:43:57 GMT 2012) ----- HST Phase I Proposal 744 (bhb_2orb.apt) successfully submitted. ----- Attempting Submission 2 (Sat Feb 25 00:25:19 GMT 2012) ----- ----- Attempting Submission 1 (Tue Jul 10 03:45:14 GMT 2012) ----- We propose ACS and WFC3 F475W and F814W imaging in two fields between 5 and 10 kpc along the minor axis of M31. These locations sample the transition between the bulge/disk-dominated and halo-dominated regions. The images would cover a total of 19 square arcminutes and would be used to characterize the complete blue horizontal branch (BHB) populations within the halo/bulge transition zone. The observations will test model predictions of the density of BHB stars and the ratio of BHB to red giant branch stars at these radii. Our present halo model is based on HST measurements of BHB stars from 2 to 35 kpc, but has a large gap in coverage from 5 kpc to 10 kpc. The proposed observations will result in the first reliable M31 halo profile covering such a large radial baseline, breaking degeneracies in current attempts to decompose M31 into bulge, disk, and halo components. Furthermore, this test will validate the use of the BHB to measure halo profiles in other systems, potentially making it possible to characterize galaxy halo populations with photometry that reaches only the horizontal branch. Our proposed observations will bridge the current gap between the large amounts of HST data available in the M31 halo and the excellent HST coverage of the M31 disk. Ultimately, these data will complete the most reliable profile ever measured of the inner regions of the M31 stellar halo, which yields an accurate total stellar halo mass and represents an historical record of how the halo formed. We are performing ACS/WFC and WFC3/UVIS observations in parallel, orienting the telescope so that the fields are aligned with the M31 minor axis. Both cameras will observe for one orbit through the F475W filter and one orbit through the F814W filter. UNRESOLVED STELLAR POPULATIONS AND GALAXY STRUCTURE 12 false 0.0 0.0 false false false false SUPPORTED GALAXY HALO J2000 J2000 GALAXY HALO J2000 J2000 ACS/WFC Imaging No No F475W ACS/WFC Imaging No No F814W WFC3/UVIS Imaging No No F475W WFC3/UVIS Imaging No No F814W 1341534499316 /private/var/folders/Xi/Xi6N6P9IG9ecfGILbBKqIU+++TI/-Tmp-/OPVisit1797073915855697674.xml The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 12997 :visit-id "01" :proposal-version -1 :trans-version "20120604" :date "05-Jul-2012 17:28:19.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 4583744 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12997 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12997 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2674 :al-overhead-at-end 40 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3010 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12997 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2787 :al-overhead-at-end 1 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3010 :pcs-gap 0 ) true 2 0