Assigned ID: 310 ----- Attempting Submission 1 (Fri Feb 25 08:26:22 GMT 2011) ----- ----- Attempting Submission 1 (Fri Jul 08 22:19:44 GMT 2011) ----- HST Phase II Proposal 12571 (cycle19_phase2_12571.apt) successfully submitted. ----- Attempting Submission 2 (Fri Jul 08 22:20:23 GMT 2011) ----- 1. Instead of FPPOS=ALL, we chose to use three FPPOS offsets (2, 3, and 4) to make a more efficient observing program. Discussions with our Contact Scientist confirmed that this was a sensible decision. The multiple offsets chosen will be adequate to correct for fixed pattern noise, wire grid shadows and other effects that could compromise the quality of the final spectrum. 2. The coordinates of the Crab Pulsar is extremely well known, and a ACQ/SEARCH is not needed. The Crab Halo The Crab Nebula, along with its central pulsar and its explosive origin in SN 1054, plays a crucial role in our understanding of the link between supernovae and pulsar formation and activity. Yet, there are fundamental uncertainties in the nature of the event that have not been settled in more than two decades of investigation. The observed mass in the nebula and pulsar is nearly half of the expected initial stellar mass and the observed energy (much of which may come from the central pulsar) is only a few percent of the typical supernova energy. An attractive solution to this ``missing mass'' problem is that this mass is in a high velocity envelope around the observed Crab Nebula. The envelope would have most of the energy of the explosion (roughly 10^{51} ergs), bringing the energy up to that typical of a Type II supernova. The fact that the Crab filaments have a measured acceleration and show no deceleration at the outer edge is consistent with this hypothesis. The lack of an interaction region created by the fast shell can be attributed to a very low density around the supernova. We propose to search for the fast shell by taking a COS spectrum of the Crab pulsar in the region of the C IV 1550 line. We have carried out time-dependent ionization calculations that show that this line should produce a detectable broad, blueshifted absorption if the shell is present.
The Crab Nebula, along with its central pulsar and its explosive origin in SN 1054, plays a crucial role in our understanding of the link between supernovae and pulsar formation and activity. Yet, the observed mass in the nebula and pulsar is nearly half of the expected initial stellar mass and the observed energy (much of which may come from the central pulsar) is only a few percent of the typical supernova energy. This observing program searches for the fast, outer shell of the Crab Nebula by taking a COS G160M spectrum of the Crab pulsar in the region of the C IV 1550 line. The 1623 setting of G160M is used to increase the spectral coverage in the continuum on the red side of the C IV 1550 feature. The observation is being executed as two 3-orbit visits to maximize schedulability. In order to maximize exposure time while maintaining good data quality, each 3-orbit visit is executed as three exposures of 2546 sec, one each at FPPOS=2, 3, and 4. ISM AND CIRCUMSTELLAR MATTER 12 false 0.0 0.0 false false false false SUPPORTED STAR PULSATING VARIABLE This object was generated by the targetselector and retrieved from the SIMBAD database.This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 COS/FUV Spectroscopic No No G160M 1600 /Volumes/Apps_and_Docs/gsonnebo/NASA/HST/Cycle19/OP-cache/cycle19_phase2_12571-v01.xml The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. (Tic-Visit :proposal-id 12571 :visit-id "01" :proposal-version -1 :trans-version "20110509" :date "01-Jul-2011 15:11:33.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "31" :si-bright-earth-limb-angle 20.0 :data-volume 113280 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12571 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12571 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2916 :al-overhead-at-end 0 :internal-dur-at-end 59 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12571 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3027 :al-overhead-at-end 0 :internal-dur-at-end 69 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12571 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3027 :al-overhead-at-end 0 :internal-dur-at-end 381 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) true 3 0 /Volumes/Apps_and_Docs/gsonnebo/NASA/HST/Cycle19/OP-cache/cycle19_phase2_12571-v02.xml (Tic-Visit :proposal-id 12571 :visit-id "02" :proposal-version -1 :trans-version "20110509" :date "01-Jul-2011 15:10:27.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "31" :si-bright-earth-limb-angle 20.0 :data-volume 113280 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12571 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12571 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2916 :al-overhead-at-end 0 :internal-dur-at-end 59 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12571 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3027 :al-overhead-at-end 0 :internal-dur-at-end 69 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12571 :visit-id "02" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3027 :al-overhead-at-end 0 :internal-dur-at-end 381 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) true 3 0