10715( 4) - 11/15/05 06:30 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 10715 Version: 4 Check-in Time: 15-Nov-2005 11:30:01 Title CSL-1: a peculiar gravitational lens and possible cosmic string ------------------------------------------------------------------------------------ Type Cycle Parallel Pointing Tolerance GO/DD 14 ------------------------------------------------------------------------------------ Investigators Contact? PI: Prof. Massimo Capaccioli Osservatorio Astronomico di Capodimonte (OAC) CoI: Prof. Mikhail V. Sazhin Sternberg State Astronomical Institute N CoI: Dr. Maurizio Paolillo Universita' degli Studi di Napoli N CoI: Prof. Giuseppe Longo Universita' degli Studi di Napoli N CoI: Dr. Ethan J. Schreier Associated Universities, Inc. N CoI: Dr. Olga S. Khovanskaya Sternberg State Astronomical Institute N CoI: Dr. Giovanni Covone Observatoire de Marseille N CoI: Dr. Ester Piedipalumbo Universita' degli Studi di Napoli N CoI: Dr. Norman Grogin The Johns Hopkins University N ------------------------------------------------------------------------------------ Abstract 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. ------------------------------------------------------------------------------------ 10715( 4) - 11/15/05 06:30 - [ 2] Observations Description ------------------------ 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. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- 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. ------------------------------------------------------------------------------------ 10715( 4) - 11/15/05 06:30 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 CSL-1 GALAXY, ELLIPTICAL, RA=12H23M30.6000S +/- 0.3", J2000 Z = 0.46 V = 21.0+/-0.13 GRAVITATIONAL LENS, DEC=-12D38'56.70" +/- 0.3", INTERACTING GALAXY PLATE-ID=015J Coordinate Source: IMAGE_TIED_TO_GSC_FRAME 10715( 4) - 11/15/05 06:30 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type ACS-WFC-DITHER-LINE ACS-WFC-DITHER-LINE Pattern_Purpose DITHER DITHER Number_Of_Points 2 3 Point_Spacing 0.134 0.172 Line_Spacing Coordinate_Frame POS-TARG POS-TARG Pattern_Orient 132.58 47.23 Angle_Between_Sides Center_Pattern NO NO ------------------------------------------------------------------------------------------------------------------------------------ 10715( 4) - 11/15/05 06:30 - [ 5] Visit: 01 Visit Priority: Visit Requirements: PCS MODE FINE On Hold Comments: Additional Comments: Orbits 1, 2 and 3 of our program Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 CSL-1 ACS/WFC ACCUM WFC F814W CR-SPLIT=NO 1 1250 S POS TARG -13, 10; PATTERN see below 1 1 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ CSL-1 1 ACS/WFC ACCUM WFC F814W 1 1 none none 1 1215.0 S CSL-1 1 ACS/WFC ACCUM WFC F814W 1 2 none none 1 1215.0 S CSL-1 1 ACS/WFC ACCUM WFC F814W 1 3 none none 2 1256.0 S CSL-1 1 ACS/WFC ACCUM WFC F814W 2 1 none none 2 1256.0 S CSL-1 1 ACS/WFC ACCUM WFC F814W 2 2 none none 3 1266.0 S CSL-1 1 ACS/WFC ACCUM WFC F814W 2 3 none none 3 1266.0 S 10715( 4) - 11/15/05 06:30 - [ 6] Visit: 02 Visit Priority: Visit Requirements: PCS MODE FINE; SCHED 30%; SAME ORIENT AS 01 On Hold Comments: Additional Comments: Orbits 4, 5 and 6 of our program Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 CSL-1 ACS/WFC ACCUM WFC F814W CR-SPLIT=NO 1 1300 S POS TARG -13.296, 13.581; see below PATTERN 1 1 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ CSL-1 1 ACS/WFC ACCUM WFC F814W 1 1 none none 1 1215.0 S CSL-1 1 ACS/WFC ACCUM WFC F814W 1 2 none none 1 1215.0 S CSL-1 1 ACS/WFC ACCUM WFC F814W 1 3 none none 2 1256.0 S CSL-1 1 ACS/WFC ACCUM WFC F814W 2 1 none none 2 1256.0 S CSL-1 1 ACS/WFC ACCUM WFC F814W 2 2 none none 3 1266.0 S CSL-1 1 ACS/WFC ACCUM WFC F814W 2 3 none none 3 1266.0 S 10715( 4) - 11/15/05 06:30 - [ 7] Summary Form for Proposal 10715 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE FINE; POS TARG -13, 10; PATTERN 1 1; SCHED 30%; SAME ORIENT AS 01; POS TARG -13.296, 13.581; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names CSL-1 ------------------------------------------------------------------------------------------------------------------------------------