6608( 4) - 10/26/98 11:14 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6608 Version: 4 Check-in Date: 26-Oct-1998 11:13:30 1.Proposal Title: DETAILED STUDIES OF TWO Z > 3.5 RADIO GALAXIES ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 6 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Wil Van Breugel Institute of Geophysics & Planetary Physics CoI: Huub Roettgering Leiden Observatory N CoI: George Miley Leiden Observatory N CoI: Hyron Spinrad University of California, Berkeley N ------------------------------------------------------------------------------------ 5. Abstract A moderately deep image (6 hrs, F702W+WFPC2) of one of the highest redshift radio galaxies (4C41.17 at z = 3.80) has shown that the rest-frame UV continuum has 1) numerous bright knots along the inner radio source axis, and 2) a clumpy companion system. Both components appear embedded in a common halo of diffuse emission. These observations suggest that we may be witnessing, for the first time, the formation of a galaxy due to the merging of (star forming?) subclumps, as predicted in dissipative galaxy formation scenarios, and of the effects of a young (quasar like ?) AGN on this environment. We propose to obtain a deep HST rest-frame UV (F702W) image of one other z > 3.5 radio galaxy which we have discovered in our ongoing groundbased surveys: 4C 0512+60 at z = 3.790. Combined with extensive groundbased (Keck) observations and future HST NICMOS near-IR imaging and STIS longslit spectroscopy these data will provide crucial new information about key factors which shape young HZRGs (galaxy, AGN, environment, redshift), and will allow us to explore the possible connection between galaxy formation and the origin of AGN, and to test certain attributes of radio galaxy / quasar `unification' models. ------------------------------------------------------------------------------------ 6608( 4) - 10/26/98 11:14 - [ 2] Observations Description ------------------------ Our aims for the current proposal are to explore whether the rest-frame UV and Ly-alpha morphologies such as seen 4C41.17 (clumpy structure, aligned component, nearby companion, and diffuse halo) are a common property of very HZRGs. Our groundbased, 0.5 " seeing data of 4C 0512+60 (z = 3.790) shows good reason to suspect that this is the case, but the high spatial resolution of HST is essential for imaging their morphologies in detail. Perhaps the most surprising new result from the 4C41.17 observations has been the discovery of its clumpy, amorphous companion system. Its diffuse halo and morphological connection to 4C41.17 itself was not seen in the pre-Costar HST images (Miley Etal 1992, ApJ. 401 L69), nor could it have been detected in post-Costar images with the 4 times shorter exposure times used in the cycle 5 and the (proposed) cycle 6 'mini-survey' of HZRG structures. Indeed, even deeper observations of 4C41.17 itself would have been helpful since much of the diffuse F702W continuum emission is only visible at the 2 -- 3 Sigma, or 25.2 mag/(sq.arcsec) level. The faintest clumps in the 4C41.17 field are 26.7 mag. We will examine the usefulness of an ultradeep image, like the 32 orbit exposure of 3C324 by Dickinson Etal, of one of the z > 3.5 radio galaxies when we have high quality data on a number of them. 4C 0512+60 (m_R ~ 23.5) is 0.3 mag fainter than 4C41.17. It is unclear whether this means that the individual clumps will be also fainter, whether there will be fewer of them, or whether the low surface brightness emission will be lower. Since this target is at nearly the same redshift as 4C41.17 we choose to image this object to the same depth (10 orbits) allowing us to evaluate the morphological similarities/differences between these HZRGs at the same sensitivity levels. Real Time Justification ----------------------- None. Calibration Justification ------------------------- None. Additional Comments ------------------- Since only 10 orbits (out of 25 requested) have been allocated we will image only one target, in one filter (F702W), and we will not use the LRF. ------------------------------------------------------------------------------------ Data Distribution Paper Products: Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 6608( 4) - 10/26/98 11:14 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-0512+60 GALAXY, RADIO GALAXY RA=5H 12M 54.81S +/- 0.010S, J2000 Z = V = 24.5 DEC=60D 30' 51.9" +/- 0.1" 3.790 B-V = 1.2 SURF(R) = 29.0 SIZE=0.1+/-0.05 Comments: FAINT, EXTENDED GALAXY 15'' NWW OF BRIGHT DOUBLE STAR A. MUST BE SURE STAR A DOES NOT HAVE SPIKE THROUGH TARGET ON PC1; PA STAR - TARGET = 297; ASSUMING PC1 BLOOM DIRECTION IS AT PA(U3) + 45, AND THAT I WANT BLOOM AT LEAST 45 DEG AWAY FROM TARGET I MUST HAVE ORIENT = PA(U3) IN THE RANGE 130 - 210 DEG 6608( 4) - 10/26/98 11:14 - [ 4] Visit: 01 Visit Priority: Visit Requirements: ORIENT 130.0D TO 210.0D 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 GAL-0512+60 WFPC2 IMAGE PC1-FIX F702W CR-SPLIT=NO 1 2900 S POS TARG 0.0, 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 20 GAL-0512+60 WFPC2 IMAGE PC1-FIX F702W CR-SPLIT=NO 1 2900 S POS TARG 0.0, 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 30 GAL-0512+60 WFPC2 IMAGE PC1-FIX F702W CR-SPLIT=NO 1 2900 S POS TARG 0.0, 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 40 GAL-0512+60 WFPC2 IMAGE PC1-FIX F702W CR-SPLIT=NO 1 2900 S POS TARG 0.0, 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 50 GAL-0512+60 WFPC2 IMAGE PC1-FIX F702W CR-SPLIT=NO 1 2900 S POS TARG 0.0, 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 6608( 4) - 10/26/98 11:14 - [ 5] Visit: 02 Visit Priority: Visit Requirements: SAME ORIENT AS 01 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 GAL-0512+60 WFPC2 IMAGE PC1-FIX F702W CR-SPLIT=NO 1 2900 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 20 GAL-0512+60 WFPC2 IMAGE PC1-FIX F702W CR-SPLIT=NO 1 2900 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 30 GAL-0512+60 WFPC2 IMAGE PC1-FIX F702W CR-SPLIT=NO 1 2900 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 40 GAL-0512+60 WFPC2 IMAGE PC1-FIX F702W CR-SPLIT=NO 1 2900 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 50 GAL-0512+60 WFPC2 IMAGE PC1-FIX F702W CR-SPLIT=NO 1 2900 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 6608( 4) - 10/26/98 11:14 - [ 6] Summary Form for Proposal 6608 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PC1-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 130.0D TO 210.0D POS TARG 0.0, 0.0 SAME ORIENT AS 01 POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F702W ------------------------------------------------------------------------------------------------------------------------------------ Target Names GAL-0512+60 ------------------------------------------------------------------------------------------------------------------------------------