This resubmission includes the following changes: 1) the dither between the 2 visits to cover the intra-chip gap has been modified to 6x72 pixels for safety concerns, resulting in a POS-TARG offset between the visits of 0.296x3.58. 2) each orbit has been shortened by 60s to reduce scheduling constraints. A final concern is that, according to the VTT integrated in APT, it seems that variations in the orientation produce a rotation of the FOV centered on the WFC aperture reference point, and not on the offset target, which may result in our target falling in the inter-chip gap or on the amplifiers readout bounduary. This looks as a VTT bug, but we would appreciate if the Contact Scientist could verify that this is the case . ----- Submission 1 (Mon Jun 13 17:18:39 GMT 2005) ----- ----- Submission 2 (Sun Nov 13 23:36:09 GMT 2005) ----- Phase II Proposal 10715 (CSL1_phase2) successfully submitted. ----- Submission 3 (Mon Nov 14 18:55:36 GMT 2005) ----- Proposal resubmission: the previous version was not saved before submission. Assigned ID: 239 ----- Submission 1 (Fri Jan 21 17:12:07 GMT 2005) ----- CSL-1: a peculiar gravitational lens and possible cosmic string Much recent work (see for instance Huterer & Vachaspati 2003; Kibble 2004; Polchinski 2004) has emphasized the importance that the peculiar object CSL-1 could bear on elementary particle physics and cosmology, in the case that its nature as the first observational evidence for lensing of a galaxy by a cosmic string could be confirmed. CSL-1 was discovered by the proponents who also proposed several observational tests to definitively pinpoint its nature (Sazhin et al. 2003, 2004). With this proposal we plan to carry the most important of such tests: id est, to use the ACS/WFC to detect the sharp morphological features produced by a cosmic string and to check whether the other gravitational lens candidates, detected by the authors in the region around CSL-1 on photometric grounds only (Sazhin et al. 2004), present similar peculiar features. Following Kibble (2004) and many others, we wish to stress that, could its link to a cosmic string be confirmed, CSL-1 will provide the first measurement ever of the energy scale of the symmetry breaking and of the energy scale of the Grand Unification Theory (GUT), and will open a new way to investigate fundamental physics using astronomical instruments.
This program is aimed at detecting peculiar morphological features in the image of the candidate gravitational lens named CSL1. The object consists of two early tipe galaxies separated by a projected angular distance of ~2". To successfully complete the program we need to achieve an angular resolution of ~0.1 arcsec and reach a low surface brightness level. We will use the ACS/WFC with the F814W filter, which has a high throughput to minimize the observing time and allows a good sampling of the HST PSF with minimum distortions or backscattering effects. The target will be offset by -13x10 pixels from the WFC reference point to displace it from the amplifier readout bounduary. We will split the observations in 2 visits, each one consisting of 3 orbits. In each visit we will perform dithering adopting a sub-pixel dither pattern, in order to allow pixel subsampling while minimizing the geometric distortions, remove cosmic rays and hot pixels. Each visit consists of 6 exposures (2 per orbit) arranged in two 3pt sub-pixel patterns offset by -2x2 pixels, for a total exposure time of 14948 s. The two visits will be further offset by 6x72 pixels in POS-TARG coordinates in order to cover the inter-chip gap. The dither pattern coordinates do not take into account the changes in the X,Y distortion coefficient due to the off center position of the target from the WFC aperture reference point. We ask the Contact Scientist to contact us in case this effects are believe to seriously affect the 1/3 pixel subsampled image reconstruction in the data reduction phase. COSMOLOGY 3 false 0.0 false false false false false SUPPORTED GALAXY ELLIPTICAL GRAVITATIONAL LENS INTERACTING GALAXY J2000 12 23 31.0000 -12 38 56.70 J2000 ACS/WFC Imaging No No F814W POS-TARG DITHER DITHER 3 0.134 ACS-WFC-DITHER-LINE false false 0.172 2 132.58 POS-TARG ACS-WFC-DITHER-LINE 47.23 1 true C:\Documents and Settings\Maurizio\My Documents\Physics & Astronomy\string_proposal\phase II revised\OP-cache\CSL1_phase2-v01.xml Orbits 1, 2 and 3 of our program (Tic-Visit :proposal-id 10715 :visit-id "01" :proposal-version -1 :trans-version "20050717" :date "14-Nov-2005 18:55:26.0" :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 1705344 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10715 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10715 :visit-id "01" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2824 :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 3251 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10715 :visit-id "01" :orbit-number 2 :pcs-time 367 :si-vis-utilization 2824 :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 3251 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10715 :visit-id "01" :orbit-number 3 :pcs-time 367 :si-vis-utilization 2824 :al-overhead-at-end 0 :internal-dur-at-end 349 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3251 :pcs-gap 0 ) true 3 0 C:\Documents and Settings\Maurizio\My Documents\Physics & Astronomy\string_proposal\New Folder\OP-cache\CSL1_phase2-v01.xml C:\Documents and Settings\Maurizio\My Documents\Physics & Astronomy\string_proposal\phase II revised\OP-cache\CSL1_phase2-v02.xml Orbits 4, 5 and 6 of our program (Tic-Visit :proposal-id 10715 :visit-id "02" :proposal-version -1 :trans-version "20050717" :date "14-Nov-2005 18:56:59.0" :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 1705344 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10715 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10715 :visit-id "02" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2824 :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 3251 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10715 :visit-id "02" :orbit-number 2 :pcs-time 367 :si-vis-utilization 2824 :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 3251 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10715 :visit-id "02" :orbit-number 3 :pcs-time 367 :si-vis-utilization 2824 :al-overhead-at-end 0 :internal-dur-at-end 349 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3251 :pcs-gap 0 ) true 3 0 C:\Documents and Settings\Maurizio\My Documents\Physics & Astronomy\string_proposal\New Folder\OP-cache\CSL1_phase2-v02.xml