----- Submission 1 (Fri Oct 07 19:25:16 GMT 2005) ----- Chandra joint proposal Assigned ID: 1016 ----- Submission 1 (Mon Aug 15 22:04:38 GMT 2005) ----- Phase I Proposal 1016 (cyc14) successfully submitted. Chandra joint proposal We propose joint Chandra and HST observations of the Guitar Nebula, an extraordinary bow-shock nebula produced by a very high-velocity but otherwise ordinary pulsar. Prior HST observations show epoch dependent changes in shock structure that signify changing ISM conditions. An enigmatic jet or filament is seen in a Chandra ACIS image (year 2000), unlike jets from the Crab or other young pulsars. New Chandra observations will reveal the relative motion of the jet and the pulsar (which has moved by 0.9 arcsec) and thus determine if self confinement or special structure in the ISM plays a dominant role in shaping the jet, and will constrain the particle acceleration mechanism. We request joint high-resolution HST observations to contemporaneously determine the ISM density profile.

The Guitar Nebula is an extended bow shock nebula, approximately 85 arcsec long and 40 arcsec wide, at a position angle of 50 degrees E of N. The key region of interest is the tip of the bow shock, where the high velocity pulsar B2224+65 probes the changing interstellar medium density. We have described our target as a circular region 85 arcsec in diameter, centered at (RA=22:25:47.745, Dec=+65:35:08.84, J2000) but it is critically important that the tip, located at (RA=22:25:52.5, Dec=+65:35:34.3, J2000), is imaged on the WFC chip, away from the chip gap and the edges. Instead of specifying an ORIENT constraint, we have centered the nebula at WFC1-FIX, which accomodates the entire nebula on WFC1. We use a 12-point dither pattern and the F658N narrow band filter to image the H-alpha nebula, resulting in individual exposures of 1225 sec, spanning 3 CVZ orbits. ISM AND CIRCUMSTELLAR MATTER 12 false 50 0.0 false false false false false SUPPORTED ISM EMISSION LINE NEBULA Prior HST observations used DGESTAR = '0427600582F2' (2001) DGESTAR = '0427600550F2' (1994). F-LINE(6563)=2E-15 NEB-222552+653531 J2000 22 25 52.3600 +65 35 33.80 J2000 ACS/WFC Imaging No No F658N POS-TARG DITHER DITHER 4 3.011 ACS-WFC-DITHER-BOX true 69.05 true 0.187 0.265 3 85.28 POS-TARG ACS-WFC-DITHER-LINE 20.67 1 true /data/kelpie/shami/hst/guitar.cyc14/phase2/OP-cache/10763-Ha-v01.xml 1128712689099 (Tic-Visit :proposal-id 10763 :visit-id "01" :proposal-version -1 :trans-version "20050717" :date "07-Oct-2005 15:18:08.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 3410688 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10763 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :cvz T :proposal-id 10763 :visit-id "01" :orbit-number 1 :pcs-time 367 :si-vis-utilization 16630 :al-overhead-at-end 0 :internal-dur-at-end 349 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 0 :low-sky "N" :pcs-visibility 0 :pcs-gap 0 ) true 3 0