13043( 6) - 02-Nov-2012 15:15:57 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 13043 Version: 6 Check-in Time: 02-Nov-2012 15:15:57 STScI Edit Number: 3 Title Multiwavelength spectra of the fine structure of the Crab ------------------------------------------------------------------------------------ Type Cycle GO 20 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Oleg Y. Kargaltsev George Washington University Y CoI: Dr. George G. Pavlov The Pennsylvania State University N CoI: Prof. Stephen S. Eikenberry University of Florida N CoI: Dr. Andrei Bykov Ioffe Physical Technical Institute N CoI: Dr. Koji Mori University of Miyazaki N CoI: Dr. Martin Durant University of Florida N CoI: Dr. Gloria Dubner Instituto De Astronomia Y Fisica Del N Espacio CoI: Dr. Sami-Matias Niemi University of Florida N ------------------------------------------------------------------------------------ Abstract The Crab is one of the most famous objects in high-energy astrophysics and an archetypal example of a young pulsar with a pulsar wind nebula (PWN). Observations with HST and Chandra have resolved the remarkable dynamic PWN structure and served as a prolific driver in advancing the theory of relativistic magnetized outflows in general and pulsar winds in particular. Despite the large amount of data collected, there are still important gaps in our knowledge, such as the lack of contemporaneous, multiwavelength spectra of the prominent PWN features. Furthermore, high-resolution, wide-field, high-quality NIR and FUV images have never been obtained. We propose a joint HST-Chandra-EVLA campaign to understand multiwavelength spectral changes across the PWN. Thanks to the brightness of the Crab PWN and superb resolution of all the three observatories, spectral changes can be mapped on ~1 arcsecond scales in a very short time. Therefore, this program is very efficient, highly synergistic, and will also provide a legacy set of contemporaneous, high-resolution images of the Crab PWN (taken across 9 decades in frequency!) that will serve as a reference for years to come. ------------------------------------------------------------------------------------ Observations Description ------------------------ Our goal is to obtain high-resolution NIR, optical, and UV images covering the area surrounding the Crab pulsar. The HST visit will consist of just 2 orbits. During the 1st orbit we will take 4 images with ACS/SBC F140LP covering ~55''x55'' region centered on the pulsar to produce a 4-tile mosaic covering the central part of the PWN which includes the interesting features such as the bright wisps, the base of the jet, and knots. For the brightest PWN region (with the pulsar included) the total count rate in the detector FoV will not exceed 2, 500 cts/s which is significantly below the SBC global count rate limit. We estimate the average source count rate per square arcminute to be ~2.2 cts/s/arcs^2 (see ACS.im.413982) and up to a factor of 5 higher for the 13043( 6) - 02-Nov-2012 15:15:57 - [ 2] brightest PWN features (wisps and knots). For our estimates we used UIT observation results from Hennessy et al. (1992; http://adsabs.harvard.edu/abs/1992ApJ...395L..13H) as well as our own measurments based in WFPC2 F170W images from HST program GO-5354. The above count rates are much higher than the sky and detector dark/glow count rates which therefore will not be of a concern with F140LP. In 688 s exposure for each of the mosaic tiles we will obtain S/N=50-100 for the the brightest PWN features and accurately measure their FUV fluxes and surface brightness distribution. The pulsar count rate will be ~37 cts/s within r=1'' aperture (see ACS.im.413443). This is well below the local SBC limit. There are no bright stars within the region we will observe (as we verified with the APT BOT). . During the 2nd orbit of the same visit we will obtain four images (at 4 dither points using WFC3-IR-DITHER-LINE pattern; total scientific exposure 1, 612 s) with the WFC3/IR F160W filter, which offers 123''x136'' field of view. We will use the SAMPSEQ=SPARS50 with NSAMP=9 to obtain a better dynamic range for the images. We estimate S/N to be in the range 20-100 (depending on the brightness of the PWN features), sufficient for accurate flux measurments. The two images with WFC3/UVIS/F555W (total exposure 774 s) will be obtained at two different positions (using WFC3-UVIS-DITHER-LINE) pattern to remove the artifacts in the post processing. To reduce the CTE loss we will use post-flash LED (with FLASH=12 e/pixel). The PWN features in the F555W image will have even higher S/N and, aside from the multiwavelength spectra, it will be used for comparison with the Crab images that were previously obtain with HST using the same or similar V-band filter. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 13043( 6) - 02-Nov-2012 15:15:57 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 CRAB STAR, A4-A9 V-IV RA=05H34M31.9787S +/- 0.1", J2000 V = 16.5 DEC=+22D00'53.96" +/- 0.1" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 13043( 6) - 02-Nov-2012 15:15:57 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type ACS-SBC-MOSAIC-BOX Pattern_Purpose MOSAIC Number_Of_Points 4 Point_Spacing 24 Line_Spacing 28 Coordinate_Frame POS-TARG Pattern_Orient 90.0 Angle_Between_Sides 264.24 Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.145 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 46.84 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 3 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-IR-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.636 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 41.788 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 13043( 6) - 02-Nov-2012 15:15:57 - [ 5] Visit: 01 Visit Requirements: BETWEEN 26-NOV-2012 AND 03-DEC-2012 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 CRAB ACS/SBC ACCUM SBC F140LP 1 95 S PATTERN 1 1 see below ------------------------------------------------------------------------------------------------------------------------------------ 2 CRAB WFC3/UVI ACCUM UVIS-FIX F555W FLASH=12 1 937 S PATTERN 2 2 S see below ------------------------------------------------------------------------------------------------------------------------------------ 3 CRAB WFC3/IR MULTIAC IR-FIX F160W NSAMP=9, SAMP-SEQ=SPARS50 1 DEF PATTERN 3 3 CUM ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ CRAB 1 ACS/SBC ACCUM SBC F140LP 1 none none none 1 648.0 S CRAB 1 ACS/SBC ACCUM SBC F140LP 2 none none none 1 648.0 S CRAB 1 ACS/SBC ACCUM SBC F140LP 3 none none none 1 648.0 S CRAB 1 ACS/SBC ACCUM SBC F140LP 4 none none none 1 648.0 S CRAB 2 WFC3/UVI ACCUM UVIS-FIX F555W 1 none none none 2 387.0 S S CRAB 2 WFC3/UVI ACCUM UVIS-FIX F555W 2 none none none 2 387.0 S S CRAB 3 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 2 N/A CUM CRAB 3 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 2 N/A CUM CRAB 3 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 2 N/A CUM CRAB 3 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 2 N/A CUM 13043( 6) - 02-Nov-2012 15:15:57 - [ 6] Summary Form for Proposal 13043 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR-FIX, SBC, UVIS-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/SBC, WFC3/IR, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=12, NSAMP=9, SAMP-SEQ=SPARS50 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 26-NOV-2012 AND 03-DEC-2012, PATTERN 1 1, PATTERN 2 2, PATTERN 3 3 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F140LP, F160W, F555W ------------------------------------------------------------------------------------------------------------------------------------ Target Names CRAB ------------------------------------------------------------------------------------------------------------------------------------