5980( 0) - 07/18/95 19:02 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 5980 Version: ********** Check-in Date: ********** 1.Proposal Title: The jet of 3C 273: its morphology and the nature of the local particle acceleration mechanism(s) ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle AGN GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Hermann-Josef Roeser Max-Planck-Institut fuer Astronomie CoI: Klaus Meisenheimer Max-Planck-Institut fuer Astronomie N CoI: Robin G. Conway Jodrell Bank N CoI: Richard J. Davis Jodrell Bank N ------------------------------------------------------------------------------------ 6. Abstract Ground and space based observations of the 3C273 jet have revealed a complex structure. The optically faint compact radio hot spot, the optically quiet radio lobe/halo and the low brightness level in the inner part of the jet are morphological features not understood within our standard picture of extragalactic radio sources. Most puzzling we have to invoke particle acceleration all over the jet and not only in the strong hot spot or compact knots. This is due to the short life time of optically radiating relativistic particles. Highly resolved radio maps reveal structure with angular scales down to the 0.1" level. As it is the high- frequency information which gives the most stringent constraints on the physics at work, a detailed analysis thus has to rely on HST. We propose to obtain deep images in two filters to construct an optical spectral index map at 0.1" resolution. This map will allow a detailed radio/optical comparison to trace places of particle acceleration. As we know from ground based observations the synchrotron spectra exhibit a cutoff, which happens to lie in the IR-optical regime. Thus the optical spectral index is a sensitive indicator for changes in this cutoff frequency, which in turn maps changes in the maximum energy of the relativistic particles i.e. the acceleration efficiency. By comparison with total intensity and polarization maps we should get hints at the basic acceleration mechanism at work. ------------------------------------------------------------------------------------ 5980( 0) - 07/18/95 19:02 - [ 2] Observations Description ------------------------ An accuracy for the spectral index on the order of 0.1 is needed to allow meaningful interpretation. With two filters selected at 300 and at 622 nm for DQE reasons a signal-to- noise ratio (S/N) of 30 per resolution element is thus needed. We have calculated the necessary exposure times to achieve that for the hot spot in the F622W, which is roughly equivalent in surface brightness to the inter-knot region. It is, however, not feasible to reach a S/N of 30 per resolution element in F300W for the hot spot. In that filter, we have timed the integration time to achieve our goal on average over the main body of the jet. The individual exposure times have been set to make use of the full visibility period in each orbit. The table quotes the signal- to-noise ratio per resolution element in the resulting summed frame for the various features in the jet. The calculations include photon noise in the object, the background and the read-out-noise of the detector. filter F300W feature area flux Deltat frames S/N_of_sum microJy sec number per_beam knot A .5" x .5" 3.2 2580 14 39 knot D .5" x .8" 2.5 2580 14 22 hot spot .5" x .5" 0.6 2580 14 9 filter F622W feature area flux Deltat frames S/N_of_sum microJy sec number per_beam knot A .5" x .5" 5.7 2400 4 75 knot D .5" x .8" 8.4 2400 4 71 hot spot .5" x .5" 1.6 2400 4 31 The resolution element was assumed to be 0.11". For astrometric purposes we will also obtain a short exposure in each filter (not to saturate the quasar nucleus and the astrometric reference stars in the field). These exposures require a total of 18 orbits which could be acquired in two separate visits. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: __Diagnostic-Sum-Section__ Software-Version (Contro, ------------------------------------------------------------------------------------ 5980( 0) - 07/18/95 19:02 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 3C273-jet GALAXY,Quasar,Jet RA = 12H 26M 32.530S +/- 0.007S, 1950 Z = SURF-CONT(5370)=2.6 +/- 0.3E-17 SURF- DEC = +2D 19' 31.2" +/- 0.1" 0.158 CONT(2590)=4.2 +/- 0.4E-17 SIZE = 2.3 +/ - 0.3 Comments: Bright object (Quasar core) with V=13mag 20" from jet. Position (jet) is relative to 3C273 core, as given in Guide-Star-Catalogue, i.e. coordiantes are in GSC- frame. 5980( 0) - 07/18/95 19:02 - [ 4] Visit: 01 Visit Requirements: PCS MODE F ORIENT 108d TO 110d On Hold Comments: Additional Comments: Orientation constraint by CCD blooming and diffraction spikes. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 3C273-jet WFPC2 IMAGE PC1-FIX F622W CLOCKS=YES,CR- 1 2300S POS TARG 0.0,0.0 SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 2 3C273-jet WFPC2 IMAGE PC1-FIX F622W CLOCKS=YES,CR- 1 2500S POS TARG -0.501,0. SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 3 3C273-jet WFPC2 IMAGE PC1-FIX F622W CLOCKS=NO,CR- 1 2S SAME POS AS 2 SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 4 3C273-jet WFPC2 IMAGE PC1-FIX F622W CLOCKS=YES,CR- 1 2600S POS TARG 0.,+0.501 SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 5 3C273-jet WFPC2 IMAGE PC1-FIX F622W CLOCKS=YES,CR- 1 2600S POS TARG +0.501,0. SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 6 3C273-jet WFPC2 IMAGE PC1-FIX F300W CLOCKS=YES,CR- 1 2600S POS TARG 0.,0. SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 7 3C273-jet WFPC2 IMAGE PC1-FIX F300W CLOCKS=YES,CR- 1 2600S POS TARG -0.501,0. SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 8 3C273-jet WFPC2 IMAGE PC1-FIX F300W CLOCKS=YES,CR- 1 2500S POS TARG -1.002,+0.501 SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 9 3C273-jet WFPC2 IMAGE PC1-FIX F300W CLOCKS=NO,CR- 1 8S SAME POS AS 8 SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 10 3C273-jet WFPC2 IMAGE PC1-FIX F300W CLOCKS=YES,CR- 1 2600S POS TARG +0.501,-0.501 SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 5980( 0) - 07/18/95 19:02 - [ 5] Visit: 02 Visit Requirements: PCS MODE F SAME ORIENT AS 1 On Hold Comments: Additional Comments: Orientation constraint by CCD blooming and diffraction spikes. Use same guide-stars as in visit 1. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 11 3C273-jet WFPC2 IMAGE PC1-FIX F300W CLOCKS=YES,CR- 1 2300S POS TARG +0.334,-0.334 SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 12 3C273-jet WFPC2 IMAGE PC1-FIX F300W CLOCKS=YES,CR- 1 2600S POS TARG +0.835,+0.167 SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 13 3C273-jet WFPC2 IMAGE PC1-FIX F300W CLOCKS=YES,CR- 1 2500S POS TARG -0.668,-0.334 SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 14 3C273-jet WFPC2 IMAGE PC1-FIX F300W CLOCKS=NO,CR- 1 8S SAME POS AS 13 SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 15 3C273-jet WFPC2 IMAGE PC1-FIX F300W CLOCKS=YES,CR- 1 2600S POS TARG -0.167,+0.668 SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 16 3C273-jet WFPC2 IMAGE PC1-FIX F300W CLOCKS=YES,CR- 1 2600S POS TARG +1.336,+0.668 SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 5980( 0) - 07/18/95 19:02 - [ 6] Visit: 03 Visit Requirements: PCS MODE F SAME ORIENT AS 1 On Hold Comments: Additional Comments: Orientation constraint by CCD blooming and diffraction spikes. Use same guide-stars as in visit 1. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 17 3C273-jet WFPC2 IMAGE PC1-FIX F300W CLOCKS=YES,CR- 1 2300S POS TARG +0.668,+0.835 SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 18 3C273-jet WFPC2 IMAGE PC1-FIX F300W CLOCKS=YES,CR- 1 2500S POS TARG -0.835,+0.334 SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 19 3C273-jet WFPC2 IMAGE PC1-FIX F300W CLOCKS=NO,CR- 1 8S SAME POS AS 18 SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 20 3C273-jet WFPC2 IMAGE PC1-FIX F300W CLOCKS=YES,CR- 1 2600S POS TARG -0.334,-0.167 SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 21 3C273-jet WFPC2 IMAGE PC1-FIX F300W CLOCKS=YES,CR- 1 2600S POS TARG +0.167,+0.835 SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 22 3C273-jet WFPC2 IMAGE PC1-FIX F300W CLOCKS=YES,CR- 1 2600S POS TARG +1.169,-0.167 SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ 5980( 0) - 07/18/95 19:02 - [ 7] Summary Form for Proposal 5980 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CLOCKS=YES CR-SPLIT=NO CLOCKS=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category AGN ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE F ORIENT 108d TO 110d POS TARG 0.0,0.0 POS TARG -0.501,0. SAME POS AS 2 POS TARG 0.,+0.501 POS TARG +0.501,0. POS TARG 0.,0. POS TARG -1.002,+0.501 SAME POS AS 8 POS TARG +0.501,-0.501 PCS MODE F SAME ORIENT AS 1 POS TARG +0.334,-0.334 POS TARG +0.835,+0.167 POS TARG -0.668,-0.334 SAME POS AS 13 POS TARG -0.167,+0.668 POS TARG +1.336,+0.668 POS TARG +0.668,+0.835 POS TARG -0.835,+0.334 SAME POS AS 18 POS TARG -0.334,-0.167 POS TARG +0.167,+0.835 POS TARG +1.169,-0.167 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F622W F300W ------------------------------------------------------------------------------------------------------------------------------------ Target Names 3C273-jet ------------------------------------------------------------------------------------------------------------------------------------