Assigned ID: 562 ----- Attempting Submission 1 (Fri Feb 25 19:46:52 GMT 2011) ----- ----- Attempting Submission 1 (Mon Jul 04 09:32:27 GMT 2011) ----- Stellar Forensics III: A post-explosion view of the progenitors of core-collapse supernovae Recent studies have used high spatial resolution HST observations of supernova (SN) sites to directly identify the progenitors of core-collapse SNe on pre-explosion images. These studies have set constraints about the nature of massive stars and their evolution just prior to their explosion as SNe. Now, at late-times when the SNe have faded sufficiently, it is possible to return to the sites of these core-collapse SNe to search for clues about the nature of their progenitors. We request time to conduct deep, late-time, high-resolution imaging with ACS/WFC of the sites of two core-collapse SNe 2009kr and 2009md. We aim to: 1) Confirm our original identifications, made in pre-explosion images, by confirming that the progenitors are now missing; 2) Apply image subtraction techniques for this late-time imaging with our pre-explosion images to determine accurate photometry of the progenitors to constrain their temperatures and luminosities; and 3) study the stellar populations in the immediate vicinities of these SNe, previously obscured by the progenitor and the SN, to provide a measure of the progenitor's age, as well. HST provides the unique combination of high-resolution optical/IR imaging at very faint magnitudes that will facilitate this study.
We require 3 color imaging of the sites of 2 SNe (2009kr and 2009md) using ACS WFC. In order to reduce time spent on reading out, we will use the WFC 1k subarray. For each SN we will use 2 orbits to acquire deep F435W, F555W and F814W imaging (to reach magnitude limits indicated below). For each filter, we will adopt a four-point, box dither pattern for the removal of hot-pixels and cosmic rays. Tests of arranging the observations with only 4 pointing maneuvers (rather than the 16 we use) showed this pattern to be less efficient, hence we adopt 16 separate pointing maneuvers. As stated in the Phase I, the SNe need to be faint (or completely absent) in these observations - hence we require them to be scheduled in the second half of Cycle 19 (which we take to be after 1 Apr 2012). 2009kr - Visit 1 - 2 orbits I - 4x384s - I ~26 at 5sig B - 4x270s - B ~26 at 3sig V - 4x425s - V ~ 27 at 5sig 2009md - Visit 2 - 2 orbits I - 4x384s - I ~26 at 5sig B - 4x268s - B ~26 at 3sig V - 4x425s - V ~ 27 at 5sig HOT STARS 12 false 0.0 0.0 false false false false SUPPORTED EXT-STAR SUPERNOVA TYPE II This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 EXT-STAR SUPERNOVA TYPE II This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 ACS/WFC Imaging No No F435W ACS/WFC Imaging No No F555W ACS/WFC Imaging No No F814W ACS/WFC Imaging No No F435W ACS/WFC Imaging No No F555W ACS/WFC Imaging No No F814W POS-TARG DITHER 0.265 LINE 0.187 false false 69.05 4 20.67 ACS-WFC-DITHER-BOX 1 false /Users/justyn/Documents/text/proposals/hst_cycle19/go/OP-cache/cycle19-v01.xml The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. Visit for SN 2009kr (Tic-Visit :proposal-id 12559 :visit-id "01" :proposal-version -1 :trans-version "20110509" :date "02-Jul-2011 14:21:58.0" :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 213328 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12559 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12559 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2915 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12559 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3024 :al-overhead-at-end 0 :internal-dur-at-end 272 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) true 2 0 /Users/justyn/Documents/text/proposals/hst_cycle19/go/OP-cache/cycle19-v02.xml The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. Visit for SN 2009md (Tic-Visit :proposal-id 12559 :visit-id "02" :proposal-version -1 :trans-version "20110509" :date "02-Jul-2011 14:29:16.0" :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 213328 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12559 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12559 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2911 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3245 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12559 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3020 :al-overhead-at-end 0 :internal-dur-at-end 272 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3245 :pcs-gap 0 ) true 2 0