----- Attempting Submission 4 (Thu Jun 25 22:10:38 GMT 2009) ----- A Deep Exploration of Classes of Long Period Variable Stars in M31 We propose a thrifty but information-packed investigation with WFC3/IR F160W and F110W providing crucial information about Long Period Variables in M31, at a level of detail that has recently allowed the discovery of new variable star classes in the Magellanic Clouds, a very different stellar population. These observations are buttressed by an extensive map of the same fields with ACS and WFPC2 exposures in F555W and F814W, and a massive ground-based imaging patrol producing well-sampled light curves for more than 400,000 variable stars. Our primary goal is to collect sufficient NIR data in order to analyze and classify the huge number of long-period variables in our catalog (see below) through Period-Luminosity (P/L) diagrams. We will produce accurate P/L diagrams for both the bulge and a progression of locations throughout the disk of M31. These diagrams will be similar in quality to those currently in the Magellanic Clouds, with their lower metallicity, radically different star formation history, and larger spread in distance to the variables. M31 offers an excellent chance to study more typical disk populations, in a manner which might be extended to more distant galaxies where such variables are still visible, probing a much more evenly spread progenitor age distribution than cepheids (and perhaps useful as a distance scale alternative or cross-check). Our data will also provide a massive and unique color-magnitude dataset; we expect that this study will produce several important results, among them a better understanding of P/L and P/L-color relations for pulsating variables which are essential to the extragalactic distance ladder. We will view these variables at a common distance over a range of metallicities (eliminating the distance-error vs. metallicity ambiguity between the LMC and SMC), allow further insight into possible faint-variable mass-loss for higher metallicities, and in general produce a sample more typical of giant disk galaxies predominant in many studies.
There are two variants of the observing strategy depending on the density of stars in the WFC3 IR field. For Visits 1, 2, 7 & 8 of one orbit apiece, there is only one pointing per orbit, and for each field a primary NSAMP=14 or 15, STEP200 IR exposure is made in each of F110W and F160W, respectively. Meanwhile a parallel ACS/WFC CR-SPLIT=2 exposure of 1083s or 1283s is made in each of F555W and F814W, respectively. Each of these four Visits is paired with another visit for which the IR exposure is positioned within the ACS field of the paired visit, and vice versa (with ORIENT angles 180 degrees apart between the two visits). For Visits 3, 4, 5 & 6 of one orbit apiece, there are two fields like the one described above, but with shorter exposures in both WFC3/IR and ACS/WFC . These are taken within the same orbit by first taking a short pair of WFC3/IR exposures half-way in between, and then making small (less than 2 arcmin) Pointing Manuevers from this central pointing, meaning that a second Guide Star Acqusition is not needed. For these Visits 3, 4, 5 & 6, Exposures 1 & 2 are useful for photometrically tying together the fields in the later pointings in these Visits, and for increasing the counts of bright stars. For these Visits 3, 4, 5 & 6, some of the WFC3/IR and ACS/WFC fields overlap in the same manner as with Visits 1, 2, 7 & 8. JUSTIFICATION FOR VISIT TIMING REQUIREMENTS: We have selected Visits 1 and 6 as examples of each of the two basic observational strategies for a one-orbit visit, and we are requsting that these be executed in calendar year 2009 to make absolutely sure that the observational strategy produces suitable results. While we are confident that both observational strategies will work, but they are challenging. We feel that the "Before" conditions on Visits 1 and 6 are prudent and justified. RESOLVED STELLAR POPULATIONS 12 false 0.0 0.0 false false false false false SUPPORTED GALAXY BULGE DISK J2000 00 43 10.5400 +41 17 47.80 J2000 GALAXY BULGE DISK J2000 00 43 11.9500 +41 17 43.60 J2000 GALAXY BULGE DISK J2000 00 43 15.7600 +41 20 52.20 J2000 GALAXY BULGE DISK J2000 00 43 4.0800 +41 26 25.60 J2000 GALAXY BULGE DISK J2000 00 44 48.9500 +41 22 59.30 J2000 GALAXY BULGE DISK J2000 00 44 50.9700 +41 24 42.40 J2000 GALAXY BULGE DISK J2000 00 44 20.8900 +41 28 44.60 J2000 GALAXY BULGE DISK J2000 00 43 24.5300 +41 37 50.40 J2000 GALAXY BULGE DISK J2000 00 43 24.5300 +41 37 50.40 J2000 GALAXY BULGE DISK J2000 00 43 24.5300 +41 37 50.40 J2000 GALAXY BULGE DISK J2000 00 43 24.5300 +41 37 50.40 J2000 GALAXY BULGE DISK J2000 00 43 24.5300 +41 37 50.40 J2000 GALAXY BULGE DISK J2000 00 43 24.5300 +41 37 50.40 J2000 GALAXY BULGE DISK J2000 00 43 24.5300 +41 37 50.40 J2000 GALAXY BULGE DISK J2000 00 43 24.5300 +41 37 50.40 J2000 GALAXY BULGE DISK J2000 00 43 24.5300 +41 37 50.40 J2000 WFC3/IR Imaging No No F110W WFC3/IR Imaging No No F160W ACS/WFC Imaging No No F555W ACS/WFC Imaging No No F814W WFC3/IR Imaging No No F110W WFC3/IR Imaging No No F160W ACS/WFC Imaging No No F555W ACS/WFC Imaging No No F814W WFC3/IR Imaging No No F110W WFC3/IR Imaging No No F160W ACS/WFC Imaging No No F555W ACS/WFC Imaging No No F814W WFC3/IR Imaging No No F110W WFC3/IR Imaging No No F160W ACS/WFC Imaging No No F555W ACS/WFC Imaging No No F814W WFC3/IR Imaging No No F110W WFC3/IR Imaging No No F160W ACS/WFC Imaging No No F555W ACS/WFC Imaging No No F814W WFC3/IR Imaging No No F110W WFC3/IR Imaging No No F160W ACS/WFC Imaging No No F555W ACS/WFC Imaging No No F814W WFC3/IR Imaging No No F110W WFC3/IR Imaging No No F160W ACS/WFC Imaging No No F555W ACS/WFC Imaging No No F814W WFC3/IR Imaging No No F110W WFC3/IR Imaging No No F160W ACS/WFC Imaging No No F555W ACS/WFC Imaging No No F814W The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11647 :visit-id "01" :proposal-version -1 :trans-version "20090130" :date "25-Jun-2009 14:34:38.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1659152 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11647 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11647 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3017 :al-overhead-at-end 0 :internal-dur-at-end 998 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3351 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11647 :visit-id "02" :proposal-version -1 :trans-version "20090130" :date "25-Jun-2009 14:35:14.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1659152 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11647 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11647 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3017 :al-overhead-at-end 0 :internal-dur-at-end 998 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3351 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11647 :visit-id "03" :proposal-version -1 :trans-version "20090130" :date "25-Jun-2009 15:08:25.0" :trans-errors '(:WARNINGS 2 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 2198832 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11647 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 11647 :visit-id "03" :obset-id "A3" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11647 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3011 :al-overhead-at-end 0 :internal-dur-at-end 979 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3351 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11647 :visit-id "04" :proposal-version -1 :trans-version "20090130" :date "25-Jun-2009 15:10:56.0" :trans-errors '(:WARNINGS 2 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 2198832 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11647 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 11647 :visit-id "04" :obset-id "A4" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11647 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3011 :al-overhead-at-end 0 :internal-dur-at-end 979 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3351 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11647 :visit-id "05" :proposal-version -1 :trans-version "20090130" :date "25-Jun-2009 14:35:59.0" :trans-errors '(:WARNINGS 2 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 2198832 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11647 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 11647 :visit-id "05" :obset-id "A5" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11647 :visit-id "05" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3010 :al-overhead-at-end 0 :internal-dur-at-end 979 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3351 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11647 :visit-id "06" :proposal-version -1 :trans-version "20090130" :date "25-Jun-2009 14:36:10.0" :trans-errors '(:WARNINGS 2 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 2198832 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11647 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 11647 :visit-id "06" :obset-id "A6" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11647 :visit-id "06" :orbit-number 1 :pcs-time 241 :si-vis-utilization 3011 :al-overhead-at-end 0 :internal-dur-at-end 979 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3351 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11647 :visit-id "07" :proposal-version -1 :trans-version "20090130" :date "25-Jun-2009 15:11:13.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1659152 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11647 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11647 :visit-id "07" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3017 :al-overhead-at-end 0 :internal-dur-at-end 998 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3351 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 17.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 11647 :visit-id "08" :proposal-version -1 :trans-version "20090130" :date "25-Jun-2009 15:11:30.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1659152 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11647 :visit-id "08" :obset-id "08" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11647 :visit-id "08" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3017 :al-overhead-at-end 0 :internal-dur-at-end 998 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3351 :pcs-gap 0 ) true 1 0