6657( 4) - 04/29/97 14:37 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6657 Version: 4 Check-in Date: 29-Apr-1997 14:34:36 1.Proposal Title: Resolving the Shocks in Powerful Radio Galaxies ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle AGN GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: CLIVE TADHUNTER UNIVERSITY OF SHEFFIELD CoI: Dave Axon Space Telescope Science Institute N CoI: Neil Clark University of Sheffield N CoI: Stefi Baum Space Telescope Science Institute N CoI: Chris O'Dea Space Telescope Science Institute N CoI: Andy Robinson University of Hertfordshire N CoI: Raffaella Morganti CNR, Bologna N CoI: Bob Fosbury ST-ECF N ------------------------------------------------------------------------------------ 6. Abstract It is clear that jet/cloud interactions play an important role in defining the morphology, kinematics and ionization of the extended gas in active galaxies, we are still far from understanding the physical mechanisms involved. Recent long-slit observations of powerful radio galaxies show clear evidence for shocks in the extended emission line regions, with complex, broad emission line profiles, and an anti-correlation between line width and ionization state. These observations provide the first indication that we have resolved the jet shocks kinematically. In order to model the jet/cloud interactions in depth it is now essential to resolve the shock structures spatially. Therefore, we apply for narrow-band imaging observations with WFPC2 on the HST to map the ionization structures in a small sample of objects in detail. The observations will be used to measure the cooling length of the shocked gas, and to investigate the spatial relationships between different kinematic components and the radio structure. In this way we will make the first stringent test of the idea that the properties of the warm emission line gas along the radio jets are determined more by jet/cloud interactions than by AGN illumination. As well as being fundamental to our general understanding of the emission line physics of active galaxies, these are key observations for understanding the alignment effect in ------------------------------------------------------------------------------------ 6657( 4) - 04/29/97 14:37 - [ 2] Observations Description ------------------------ We will observe each object with WFPC2 using ramp filters centred on the redshifted OII3727 and OIII5007 emission lines, and also using standard, intermediate-band filters centred on the continuum band between these emission lines (for continuum subtraction). We are aiming for a S/N > 4 per WF pixel in the brighter parts of the filamentary structures for both the emission line and the continuum observations. Individual EELR in our sample objects have typical emission line fluxes of ~ 1 * 10^-14 erg cm^-2 s^-1 for OII and ~ 5 * 10^-15 erg cm^-2 s^-1 for OIII. For these fluxes we estimate that we will detect a total of 6 * 10^3 photons in the OII filter and 1.2 * 10^4 photons in the OIII filter for respective exposure times of 2000s and 1000s respectively. Two of the sources have been observed in the HST SNAPshot survey of 3C radio galaxies, using broad-band filters which include the redshifted OIII or HAlpha+NII emission lines. Examination of the images in the HST archive shows that the EELR filaments cover typical projected areas of 0.1 --- 0.5 sq.arcseconds. However, given that there may be more diffuse structures which are not seen in these images (because of low S/N), we assume in our calculations that the filaments cover a projected area of ~1 sq.arcsec (100 WF pixels). With this assumption we estimate that we will detect 60 photons per pixel in OII and 120 photons per pixel in OIII, leading to S/N of ~4.7 (OII) and ~9.2 (OIII) for the same exposure times as above. The sensitivity of these observations is such that we will also be able to search for fainter, more diffuse structures. We emphasise that these numbers are likely to represent a lower limit on S/N in the brighter parts of the EELR, since we have been conservative about the areas covered by the filaments. The typical continuum brightness in the EELR is 1- 2*10^-17 erg cm^-2 AA^-1. Using the sensitivity values for the F547M filter given in Table 6.2 of the instrument handbook, and assuming a similar projected area for the continuum-emitting regions, we estimate that we will detect ~100 photons per pixel in the continuum in 1000s. This will give a S/N in the continuum images similar to that emission line observations. To summarise: the total integration times per object are ~2000s in OII, ~1000s in OIII and ~1000s in the continuum. Including overheads, this will require 2 orbits per object, and 8 orbits to observe all four objects. In the lowest redshift object (4C29.30) the structure is more extended than the 13 arcsecond limit set by the ramp filters. In this case we will centre the filters on the brightest emission line region. Real Time Justification ----------------------- We have been allocated time on the VLA to map PKS2250-41 at high frequency (this source already has extensive ATCA data). We have also been allocated ROSAT time to make deep X-ray images of PKS2250-41, 3C171 and 4C29.30. Deep, pointed Einstein data already exist for 3C277.3. These data will add to an already extensive set of high resolution long-slit spectra and radio maps for the sources. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 6657( 4) - 04/29/97 14:37 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 6657( 4) - 04/29/97 14:37 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 3C171 GALAXY,RADIO RA=6H 55M 14.72S +/- J2000 Z=0.2381 V = 19.1+/-0.1 GALAXY,EMISSION LINE 0.1S,DEC=54D 8' 57.8" +/- B-V = 0.86+/-0.1 NEBULA 1",PLATE-ID=01JX E(B-V) = 0.06+/-0.02 SURF-LINE(5007)=5+/-2e-15 SURF-LINE(3727)=10+/-3e-15 SURF-CONT(4500)=2+/-1e-17 Comments: The magnitudes are for the galaxies as a whole, while the fluxes are the surface brightnesses of the extended regions of interest. The position corresponds to the optical nucleus of the galaxy and has been found from the original GASP images. 2 PKS2250-41 GALAXY,RADIO RA=22H 53M 2.84S +/- 0.1S,DEC=- J2000 Z=0.308 V = 20.5+/-0.2 GALAXY,EMISSION LINE 40D 57' 47.2" +/- 1.0",PLATE- B-V = 1.1+/-0.3 NEBULA ID=047W E(B-V) = 0.06+/-0.02 SURF-LINE(5007)=5+/-2e-15 SURF-LINE(3727)=10+/-3e-15 SURF-CONT(4500)=2+/-1e-17 Comments: The magnitudes are for the galaxies as a whole, while the fluxes are the surface brightnesses of the extended regions of interest. The position corresponds to half way between the nucleus and the western extended emission line arc and has been calculated using optical ground-based astrometry. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1983 0.0 0.0 0.0 3 3C277.3 GALAXY,RADIO RA=12H 54M 12.1065S +/- J2000 Z=0.0857 V = 15.94+/-0.1 GALAXY,EMISSION LINE 0.3",DEC=27D 37' 30.125" +/- 9 B-V = 0.85+/-0.3 NEBULA 0.3",PLATE-ID=002K SURF-LINE(5007)=5+/-2e-15 SURF-LINE(3727)=10+/-3e-15 SURF-CONT(4500)=2+/-1e-17 Comments: The magnitudes are for the galaxies as a whole, while the fluxes are the surface brightnesses of the extended regions of interest. The position corresponds to half way between the nucleus and the southern radio knot, and has been calculated using a position for the core of the galaxy in the GSC reference frame and an offset calculated from a WFPC2 image taken as part of the 3C SNAPshot survey. 4 4C29.30 GALAXY,RADIO RA=08H 40M 2.606S +/- J2000 Z=0.0647 V = 15.7+/-0.2 GALAXY,EMISSION LINE 0.1S,DEC=29D 49' 13.74" +/- 1.0" B-V = 1.0+/-0.3 NEBULA SURF-LINE(5007)=5+/-2e-15 SURF-LINE(3727)=10+/-3e-15 SURF-CONT(4500)=2+/-1e-17 Comments: The magnitudes are for the galaxies as a whole, while the fluxes are the approximate surface brightnesses of the extended regions of interest. The position corresponds to the northern hotspot of the extended radio/optical structure and has been calculated using a radio map of the source. 6657( 4) - 04/29/97 14:37 - [ 5] Visit: 01 Visit Requirements: ORIENT 87D TO 177D On Hold Comments: Additional Comments: The orientation is required: (a) to avoid vignetting at the edge of the CCD/pyramid, and (b) because there is a large velocity gradient across the extended structure, and alignment of the structure in the direction in which the LRF wavelength changes would lead to difficulties in interpretation. The orientation has been calculated by assuming that FR680N filter is in the +15 degree orientation (see Figure 3.5 of WFPC2 Instrument Handbook v3.0). NOTE THAT ORIENT 267D TO 357D WOULD ALSO BE ACCEPTABLE. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 3C171 WFPC2 IMAGE LRF LRF 4615 CR-TOLERANCE=0.05 2 1100 S Comments: This is the [OII] image. ------------------------------------------------------------------------------------------------------------------------------------ 2 3C171 WFPC2 IMAGE LRF LRF 6195 CR-TOLERANCE=0.05 1 1100 S Comments: This is the [OIII] image. Close to vignetted region at edge of CCD. ------------------------------------------------------------------------------------------------------------------------------------ 3 3C171 WFPC2 IMAGE WF2 F547M CR-TOLERANCE=0.05 1 1000 S Comments: This is the continuum image. ------------------------------------------------------------------------------------------------------------------------------------ 6657( 4) - 04/29/97 14:37 - [ 6] Visit: 02 Visit Requirements: ORIENT 270D TO 360D On Hold Comments: Additional Comments: The orientation is required: (a) to avoid vignetting at the edge of the CCD/prism (exposure 1), and (b) because there is a large velocity gradient across the extended structure, and large wavelength shifts in the filter bandpass are undesirable (alignment of the structure in the direction in which the LRF wavelength changes would lead to difficulties in interpretation). The orientation has been calculated by assuming that FR680N filter is in the 0 degree orientation (see Figure 3.5 of WFPC2 Instrument Handbook v3.0). NOTE THAT ORIENT 90D TO 180D WOULD ALSO BE ACCEPTABLE. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 PKS2250-41 WFPC2 IMAGE LRF LRF 4862 CR-TOLERANCE=0.05 2 1100 S Comments: This is the [OII] image. Close to vignetted region at edge of CCD. ------------------------------------------------------------------------------------------------------------------------------------ 2 PKS2250-41 WFPC2 IMAGE LRF LRF 6550 CR-TOLERANCE=0.05 1 1000 S Comments: This is the [OIII] image ------------------------------------------------------------------------------------------------------------------------------------ 3 PKS2250-41 WFPC2 IMAGE WF2 F547M CR-TOLERANCE=0.05 1 1100 S Comments: This is the continuum image. ------------------------------------------------------------------------------------------------------------------------------------ 6657( 4) - 04/29/97 14:37 - [ 7] Visit: 03 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 3C277.3 WFPC2 IMAGE LRF LRF 4044 CR-TOLERANCE=0.05 2 1100 S Comments: This is the [OII] image. ------------------------------------------------------------------------------------------------------------------------------------ 2 3C277.3 WFPC2 IMAGE LRF LRF 5431 CR-TOLERANCE=0.05 1 1000 S Comments: This is the [OIII] image. ------------------------------------------------------------------------------------------------------------------------------------ 3 3C277.3 WFPC2 IMAGE WF3 F467M CR-TOLERANCE=0.05 1 1100 S Comments: This is the continuum image. ------------------------------------------------------------------------------------------------------------------------------------ 6657( 4) - 04/29/97 14:37 - [ 8] Visit: 04 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 4C29.30 WFPC2 IMAGE LRF LRF 3968 CR-TOLERANCE=0.05 2 1100 S Comments: This is the [OII] image. ------------------------------------------------------------------------------------------------------------------------------------ 2 4C29.30 WFPC2 IMAGE LRF LRF 5336 CR-TOLERANCE=0.05 1 1000 S Comments: This is the [OIII] image. ------------------------------------------------------------------------------------------------------------------------------------ 3 4C29.30 WFPC2 IMAGE WF4 F467M CR-TOLERANCE=0.05 1 1100 S Comments: This is the continuum image. ------------------------------------------------------------------------------------------------------------------------------------ 6657( 4) - 04/29/97 14:37 - [ 9] Summary Form for Proposal 6657 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-TOLERANCE=0.05 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category AGN ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 87D TO 177D ORIENT 270D TO 360D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements LRF F547M F467M ------------------------------------------------------------------------------------------------------------------------------------ Target Names 3C171 PKS2250-41 3C277.3 4C29.30 ------------------------------------------------------------------------------------------------------------------------------------