5931( 0) - 07/18/95 18:43 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 5931 Version: ********** Check-in Date: ********** 1.Proposal Title: Location of Particle Acceleration in Radio Hot Spots. ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle AGN GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Dr. Klaus Meisenheimer Max-Planck-Institut fuer Astronomie CoI: Dr. Hermann-Josef Roeser Max-Planck-Institut fuer Astronomie Y CoI: Dr. Richard A. Perley National Radio Astronomy Observatory N ------------------------------------------------------------------------------------ 6. Abstract A wide variety of AGN phenomena -- e.g. the powerful double radio sources, the superluminal jets in quasars, and last but not least the unexpected powerful Gamma - ray emission of many blazars -- cannot be explained without the presence of ultrarelativistic particles (electrons, protons and perhaps positrons). But it is still a mystery how the underlying cosmic particle accelerators work. Since the most efficient acceleration processes take place in hot spots of extended radio sources (reaching E_max > 10^5 m_ec^2) and these hot spots are relatively large (> 1 kpc) they are the prime target in order to study the acceleration process and its spatial structure in detail. For the nearest hot spots the required spatial resolution of 100 pc corresponds to about 0sec point 1 which is reached by the VLA at high radio frequencies and with the HST at optical frequencies. We propose to obtain high S/N images of the nearest two optically detected hot spots in 3C 111 and Pictor A in two bandpaths with WFPC2. They will allow us to derive maps of the radio-optical and optical spectral index with a resolution of 1/10 of the hot spot diameter. Such spectral index maps are the crucial observational input for the decision between competing models of the acceleration mechanisms and should lead to a quantitative description of the underlying physics. ------------------------------------------------------------------------------------ 5931( 0) - 07/18/95 18:43 - [ 2] Observations Description ------------------------ We propose to observe the western hot spot of Pictor A in 2 wavebands, seperated by a large wavelength ratio in order to derive an accurate optical spectral index alpha_opt. Optimum WFPC2 filters are F300W and F622W. We aim to reach a alpha_opt accuracy Sigma (Alpha ) <= 0.07 in order to detect the expected variations (DeltaAlpha_opt = 0.2 ... 0.7). This requires a S/N ratio of ~eq 30 (per resolution element, in the following: ``beam'') in each filter. From the optical spectrum we derive a total hot spot flux of 40 muJy (at 300 nm) and 125 muJy (at 620 nm), respectively. With an angular extend of 1sec point 2 * 0sec point 5 and using a circular beam of 0sec point 11 (FWHM) one gets a mean surface brightness of sigma_300 = 0.95 muJy/beam and sigma_620 = 2.98 MuJy/beam, respectively. In order to get a S/N ratio of 30 (per beam) in F300W we need 3 exposures a 1100 sec (calculated according SNR = N_obj / sqrtN_obj + N_sky + beam*RON^2 with \int QT from table 6.2). This would fill ~ 1.5 orbits. Thus we chose the integration time in F622W such that a 2-orbit visit is fully used: t_int = 3 * 350 sec. This results in a comfortable S/N ratio = 74 (per beam) which will allow us to study the morphology in great detail. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ COMMENT on the ACTUAL PHASE II proposal: The dithering of the telescope pointing by 0.5" (11 PC pixel) or 1.0" (22 pix) currently causes a superfluous "telescope alignment overhead" of 2min. Therefore we had to reduce the integration times of our exposures to: 1100,1000 (orb-1) and 900,300,300,300 (orb-2). ---------------------------------------------------------------- For the eastern hot spot of 3C 111, we propose to obtain a high S/N map (>= 30) with one filter, F791W, only. With a total flux at 800 nm of 2.6 muJy and an extend of 0sec point 8 * 1sec point 5 we get a mean surface brightness of 0.15 muJy per 0.22arcsec beam (FWHM). This beam width is perfectly matched to the resolution of VLA maps at 3.6 cm which we are analysing currently. We calculate that 13 exposures a 2500 sec are sufficient to reach the attempted S/N ratio = 30. Thus 2 visits with in total 13 orbits are needed for this object. In fact, the experience with RPS2 showed that most one-orbit exposure can be extended to 2700S. for positional reference we included three exposures of 100s to get a unsaturated image of a nearby field star. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 5931( 0) - 07/18/95 18:43 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 PICTOR-A- GALAXY, Radio Galaxy, RA=05H 18M 00.05S +/-0.01S, DEC= 1950 Z = SURF-CONT(3000)= 2.8+/-0.3 E-16 WEST Hotspot -45.8146D +/- 0.0001D 0.0350 SURF-CONT(6200)= 2.1+/-0.2 E-16 2 3C111-EAST GALAXY, Radio Galaxy, RA=04H 15M 09.75S +/- 0.05S, 1950 Z = SURF-CONT(7900)= 1.3+/-0.3 E-18 Hotspot DEC=+37D 55' 15.0" +/- 0.3" 0.0485 SURF-CONT(6500)= 1.0+/-0.2 E-18 5931( 0) - 07/18/95 18:43 - [ 4] Visit: 01 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 PICTOR-A- WFPC2 IMAGE PC1 F300W CR-SPLIT=NO 1 1100S POS TARG 0.0,-1.001 WEST ------------------------------------------------------------------------------------------------------------------------------------ 2 PICTOR-A- WFPC2 IMAGE PC1 F300W CR-SPLIT=NO 1 1000S POS TARG 1.001,0.000 EXPAND MIN DUR 1000s WEST MAX DUR 1200s END ORBIT Comments: exposure time could be expanded to 1100S if slewing overhead is removed ------------------------------------------------------------------------------------------------------------------------------------ 3 PICTOR-A- WFPC2 IMAGE PC1 F300W CR-SPLIT=NO 1 900S POS TARG -0.500,0.500 EXPAND MIN DUR 900s WEST MAX DUR 1200s Comments: exposure time could be expanded to 1100S if slewing overhead is removed ------------------------------------------------------------------------------------------------------------------------------------ 4 PICTOR-A- WFPC2 IMAGE PC1 F622W CR-SPLIT=NO 1 300S SAME POS AS 3 EXPAND MIN DUR 300s MAX DUR WEST 400s Comments: exposure time could be expanded to 350S if slewing overhead is removed ------------------------------------------------------------------------------------------------------------------------------------ 5 PICTOR-A- WFPC2 IMAGE PC1 F622W CR-SPLIT=NO 1 300S POS TARG 1.001,0.000 EXPAND MIN DUR 300s WEST MAX DUR 400s Comments: exposure time could be expanded to 350S if slewing overhead is removed ------------------------------------------------------------------------------------------------------------------------------------ 6 PICTOR-A- WFPC2 IMAGE PC1 F622W CR-SPLIT=NO 1 300S POS TARG 0.000,-1.001 EXPAND MIN DUR 300s WEST MAX DUR 400s END ORBIT Comments: exposure time could be expanded to 350S if slewing overhead is removed ------------------------------------------------------------------------------------------------------------------------------------ 5931( 0) - 07/18/95 18:43 - [ 5] Visit: 02 Visit Requirements: ORIENT 87D TO 87D GROUP 2-3 WITHIN 56D On Hold Comments: Additional Comments: Constraints to avoid blooming and diffraction spikes of star at P.A. = 192D, ORIENT + 180 Degrees = -155D TO -91D is also possible. Original ORIENT was a range from 25D to 89D ( and that range +180D as above ), but it has been set to 87D as a fixed value based on flight database prep work such as determined by GS availability, etc. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 3C111-EAST WFPC2 IMAGE PC1 F791W CR-SPLIT=NO 1 2400S POS TARG 0.,-1.001 END ORBIT ------------------------------------------------------------------------------------------------------------------------------------ 2 3C111-EAST WFPC2 IMAGE PC1 F791W CR-SPLIT=NO 1 100S POS TARG 1.001,0.000 ------------------------------------------------------------------------------------------------------------------------------------ 3 3C111-EAST WFPC2 IMAGE PC1 F791W CR-SPLIT=NO 1 2500S SAME POS AS 2 EXPAND MIN DUR 2300s MAX DUR 2700s END ORBIT ------------------------------------------------------------------------------------------------------------------------------------ 4 3C111-EAST WFPC2 IMAGE PC1 F791W CR-SPLIT=NO 1 2700S POS TARG -0.500,0.500 END ORBIT ------------------------------------------------------------------------------------------------------------------------------------ 5 3C111-EAST WFPC2 IMAGE PC1 F791W CR-SPLIT=NO 1 2700S POS TARG -1.001,-0.500 END ORBIT ------------------------------------------------------------------------------------------------------------------------------------ 6 3C111-EAST WFPC2 IMAGE PC1 F791W CR-SPLIT=NO 1 100S POS TARG 0.061,-0.880 ------------------------------------------------------------------------------------------------------------------------------------ 7 3C111-EAST WFPC2 IMAGE PC1 F791W CR-SPLIT=NO 1 2500S SAME POS AS 6 EXPAND MIN DUR 2300s MAX DUR 2700s END ORBIT ------------------------------------------------------------------------------------------------------------------------------------ 8 3C111-EAST WFPC2 IMAGE PC1 F791W CR-SPLIT=NO 1 2700S POS TARG -0.940,0.121 END ORBIT ------------------------------------------------------------------------------------------------------------------------------------ 9 3C111-EAST WFPC2 IMAGE PC1 F791W CR-SPLIT=NO 1 2700S POS TARG 0.561,0.621 END ORBIT ------------------------------------------------------------------------------------------------------------------------------------ 10 3C111-EAST WFPC2 IMAGE PC1 F791W CR-SPLIT=NO 1 2700S POS TARG 1.061,-0.379 END ORBIT ------------------------------------------------------------------------------------------------------------------------------------ 5931( 0) - 07/18/95 18:43 - [ 6] Visit: 03 Visit Requirements: SAME ORIENT AS 2 ORIENT 87D TO 87D On Hold Comments: Additional Comments: SAME GUIDE STARS AS visit 2 preferrable. ORIENT has been set to 87D to exactly match that of SU 02. SAME ORIENT AS 2 is an absolute requirement. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 11 3C111-EAST WFPC2 IMAGE PC1 F791W CR-SPLIT=NO 1 2400S POS TARG 0.121,1.062 END ORBIT ------------------------------------------------------------------------------------------------------------------------------------ 12 3C111-EAST WFPC2 IMAGE PC1 F791W CR-SPLIT=NO 1 2700S POS TARG 1.122,0.061 END ORBIT ------------------------------------------------------------------------------------------------------------------------------------ 13 3C111-EAST WFPC2 IMAGE PC1 F791W CR-SPLIT=NO 1 100S POS TARG -0.379,-0.439 ------------------------------------------------------------------------------------------------------------------------------------ 14 3C111-EAST WFPC2 IMAGE PC1 F791W CR-SPLIT=NO 1 2500S SAME POS AS 13 EXPAND MIN DUR 2300s MAX DUR 2600s END ORBIT ------------------------------------------------------------------------------------------------------------------------------------ 15 3C111-EAST WFPC2 IMAGE PC1 F791W CR-SPLIT=NO 1 2700S POS TARG -0.880,0.561 END ORBIT ------------------------------------------------------------------------------------------------------------------------------------ 16 3C111-EAST WFPC2 IMAGE PC1 F791W CR-SPLIT=NO 1 2700S POS TARG 0.621,0.939 END ORBIT ------------------------------------------------------------------------------------------------------------------------------------ 5931( 0) - 07/18/95 18:43 - [ 7] Summary Form for Proposal 5931 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category AGN ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements POS TARG 0.0,-1.001 POS TARG 1.001,0.000 EXPAND MIN DUR 1000s MAX DUR 1200s END ORBIT POS TARG -0.500,0.500 EXPAND MIN DUR 900s MAX DUR 1200s SAME POS AS 3 EXPAND MIN DUR 300s MAX DUR 400s POS TARG 1.001,0.000 EXPAND MIN DUR 300s MAX DUR 400s POS TARG 0.000,-1.001 EXPAND MIN DUR 300s MAX DUR 400s END ORBIT ORIENT 87D TO 87D GROUP 2-3 WITHIN 56D POS TARG 0.,-1.001 END ORBIT POS TARG 1.001,0.000 SAME POS AS 2 EXPAND MIN DUR 2300s MAX DUR 2700s END ORBIT POS TARG -0.500,0.500 END ORBIT POS TARG -1.001,-0.500 END ORBIT POS TARG 0.061,-0.880 SAME POS AS 6 EXPAND MIN DUR 2300s MAX DUR 2700s END ORBIT POS TARG -0.940,0.121 END ORBIT POS TARG 0.561,0.621 END ORBIT POS TARG 1.061,-0.379 END ORBIT SAME ORIENT AS 2 ORIENT 87D TO 87D POS TARG 0.121,1.062 END ORBIT POS TARG 1.122,0.061 END ORBIT POS TARG -0.379,-0.439 SAME POS AS 13 EXPAND MIN DUR 2300s MAX DUR 2600s END ORBIT POS TARG -0.880,0.561 END ORBIT POS TARG 0.621,0.939 END ORBIT ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F300W F622W F791W ------------------------------------------------------------------------------------------------------------------------------------ Target Names PICTOR-A-WEST 3C111-EAST ------------------------------------------------------------------------------------------------------------------------------------