7344( 3) - 06/02/97 15:26 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7344 Version: 3 Check-in Date: 02-Jun-1997 15:25:02 1.Proposal Title: Witnessing the Birth of Radio Galaxies: WFPC & NICMOS Observations of CSOs ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle AGN/QUASARS GO 7 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Dr. John Stocke UNIVERSITY OF COLORADO CoI: John Conway Onsala Space Observatory N CoI: Eric Perlman Space Telescope Science Institute N CoI: Mitchell Begelman University of Colorado, Boulder N CoI: Chris Reynolds University of Colorado, Boulder N ------------------------------------------------------------------------------------ 6. Abstract We propose to obtain high resolution optical (B,R) and near-IR (H) images of the cores of bright, nearby galaxies which contain powerful radio sources called ``Compact Symmetric Objects'' (CSOs). There is ample evidence that CSOs are the very young (< 10^4 yrs old) progenitors of the powerful radio galaxies like Cygnus A. But unlike virtually all other radio galaxies, most CSOs have been detected in H I 21cm absorption, indicating an unusual (for a radio galaxy) nucler environment. We propose to use the HST PC and NICMOS to image the nearest examples of CSOs to search for evidence for a recent merger of disk galaxies, creating both the ``baby Cygnus A'' and the overall elliptical morphology seen in virtually all powerful radio galaxies. Only HST can image these galaxies at the same size scale of the CSO itself, also allowing us to search for nuclear structures aligned with the radio source in this formative stage. ------------------------------------------------------------------------------------ 7344( 3) - 06/02/97 15:26 - [ 2] Observations Description ------------------------ We propose to image our CSO targets in F450W and F702W bands with the planetary camera configuration of WF/PC, as well as with NICMOS in F160W. The goal of this program is to investigate the nature of these youngest of AGNs, in an attempt to determine what triggered their "turn-on" and understand their interior structure. To this end, we will need to obtain images not only of the inner regions, but also of any companions which fall within the capabilities of HST during the one orbit allocated to WFPC and NICMOS (each) per target. Obtaining images of companions and evidence of interaction is extremely important to the success of this program given the possibly central role that interactions may play in the formation of radio-loud AGN. Assuming the central surface brightnesses observed for giant elliptical galaxies of ~ 16 mag arcsec^ -2, observations in the two WFPC passbands can be made in one orbit per target. The F450W and F702W integration times (to be carried out within the same orbit) have been calculated to yield similar signal-to-noise ratios per pixel of >50:1 in each image in the brightest regions of the nucleus (for two sources, 1146+59 and 1943+70, even higher signal-to-noise will be achieved because they are in the CVZ, making longer integrations possible within an orbit). These signal-to- noise ratios assume no reddening in the image, which will certainly not be true in the inner nuclear region. The high signal to noise we will achieve, in addition to having two colors, will facilitate interpretation of any morphologies that are observed. Resolutions of <= 50 pc should be achieved on these three targets. For the NICMOS observations, we have chosen to use the NIC1 camera for all three sources, which will yield resolutions comparable to the PC for direct comparison purposes and to search the inner nuclear region beyond the veil of the reddening. While we expect a point source to be present in these objects, since the precise amount of reddening and its distribution across the nuclear region is unknown, we base our integration times only on the observed E galaxy core brightness, which, for our targets will require one orbit integrations to acheive signal-to-noise ratios of 30-50 per pixel in the brightest regions. The high signal-to-noise is critical to these observations given evidence based upon ground-based observations that the nuclear sources in CSOs do not emerge from their shrouds until the near-infrared (J and H band). Given the sizes observed on optical survey plates, two of the targets (1943+70 and 4C31.04) should fit nicely into PC1. The third (1146+59) is at extremely low redshift so that only the inner half will fit into PC1. For two targets, 4C31.04 and 1943+70, we are requesting ORIENTs and POS TARGs. In the case of 4C31.04, the ORIENT and POS TARG requested for the WFPC2 observations will allow the maximum surface brightness sensitivity in the optical to be achieved for a possible tidal "tail" which is visible on the optical survey plates. As a result, a neighboring galaxy 25" away will also fall on the PC. We have also requested an ORIENT for its NICMOS observation in order to image the neighboring galaxy on NIC2. The other target for which we have requested ORIENTs and POS TARGs, 1943+70, has several neighboring galaxies visible on sky survey plates. The ORIENTs and POS TARGs we have requested will allow these neighboring galaxies to fall within the field of view of the WFPC (the galaxies are not well placed to be observed with either NIC2 or NIC3). Real Time Justification ----------------------- B and R band observations are to be carried out sequentially, within the same orbit, followed by the near-IR observations if possible to maximize observing efficiency. High dynamic range VLBA continuum maps exist for all these sources at several frequencies. We (Conway, Perlman, Stocke) are obtaining second epoch maps, if they do not already exist, to set limits on outflow velocities. These sources are being mapped with VLBA in the H I absorption line to determine the details of the H I distribution in the nuclei of these galaxies. None of the planned supporting observations require special scheduling considerations for the HST imaging proposed herein. Calibration Justification ------------------------- Real_Time_Justification Additional Comments ------------------- ------------------------------------------------------------------------------------ 7344( 3) - 06/02/97 15:26 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 7344( 3) - 06/02/97 15:26 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 1146+59 GALAXY,RADIO GALAXY RA=11H 48M 50.34S +/- 1",DEC=59D J2000 V = 12.6+/-0.5 24' 55.93" +/- 1",PLATE-ID=01QZ 2 1943+70 GALAXY,RADIO GALAXY RA=19H 45M 53.57S +/- 1",DEC=70D J2000 V = 16.7+/-0.5 55' 48.87" +/- 1",PLATE-ID=00MA 3 4C31.04 GALAXY,RADIO GALAXY RA=01H 19M 35.05S +/- 1",DEC=32D J2000 V = 16.0+/-0.5 10' 50.28" +/- 1",PLATE-ID=00DV 7344( 3) - 06/02/97 15:26 - [ 5] 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 1146+59 WFPC2 IMAGE PC1 F450W CR-SPLIT=0.5,CR-TOLERANCE=0.0, 1 1600 S CLOCKS=NO ------------------------------------------------------------------------------------------------------------------------------------ 20 1146+59 WFPC2 IMAGE PC1 F702W CR-SPLIT=0.5,CR-TOLERANCE=0.0 1 600 S ------------------------------------------------------------------------------------------------------------------------------------ 7344( 3) - 06/02/97 15:26 - [ 6] Visit: 02 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 1146+59 NIC1 MULTIAC NIC1 F160W SAMP-SEQ=SPARS256,NSAMP=13 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 7344( 3) - 06/02/97 15:26 - [ 7] Visit: 03 Visit Requirements: ORIENT 120D TO 160D On Hold Comments: Additional Comments: ORIENT and POS TARG will allow six neighboring galaxies to fall on various WF chips, allowing a much more complete picture of the environment of this galaxy. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 1943+70 WFPC2 IMAGE PC1 F450W CR-SPLIT=0.5,CR-TOLERANCE=0.0 1 1600 S POS TARG -5,-5 ------------------------------------------------------------------------------------------------------------------------------------ 20 1943+70 WFPC2 IMAGE PC1 F702W CR-SPLIT=0.5,CR-TOLERANCE=0.0 1 700 S POS TARG -5,-5 ------------------------------------------------------------------------------------------------------------------------------------ 7344( 3) - 06/02/97 15:26 - [ 8] Visit: 04 Visit Requirements: On Hold Comments: Additional Comments: Companion galaxies are not well placed to be observed with NICMOS. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 1943+70 NIC1 MULTIAC NIC1 F160W SAMP-SEQ=SPARS256,NSAMP=13 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 7344( 3) - 06/02/97 15:26 - [ 9] Visit: 05 Visit Requirements: ORIENT 110D TO 140D On Hold Comments: Additional Comments: ORIENT and POS TARG requested will allow a tidal tail to fall on WF3, allowing the maximum surface brightness sensitivity to be achieved for this low surface brightness feature. In addition, the galaxy's near-neighbor to the SW, with which it is interacting, will also fall on the PC. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 4C31.04 WFPC2 IMAGE PC1 F450W CR-SPLIT=0.5,CR-TOLERANCE=0.0 1 1600 S POS TARG 8,-6 ------------------------------------------------------------------------------------------------------------------------------------ 20 4C31.04 WFPC2 IMAGE PC1 F702W CR-SPLIT=0.5,CR-TOLERANCE=0.0 1 520 S POS TARG 8,-6 ------------------------------------------------------------------------------------------------------------------------------------ 7344( 3) - 06/02/97 15:26 - [ 10] Visit: 06 Visit Requirements: ORIENT 60D TO 100D On Hold Comments: Additional Comments: The ORIENT requested will allow the tidal tail and near neighbor to fall on NIC1 chip. This will allow a complete, three-band picture of this interacting system. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 4C31.04 NIC1 MULTIAC NIC1 F160W SAMP-SEQ=SPARS256,NSAMP=12 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 7344( 3) - 06/02/97 15:26 - [ 11] Summary Form for Proposal 7344 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 NIC1 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=0.5 CR-TOLERANCE=0.0 CLOCKS=NO NSAMP=13 SAMP-SEQ=SPARS256 NSAMP=12 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category AGN/QUASARS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 120D TO 160D POS TARG -5,-5 ORIENT 110D TO 140D POS TARG 8,-6 ORIENT 60D TO 100D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F450W F702W F160W ------------------------------------------------------------------------------------------------------------------------------------ Target Names 1146+59 1943+70 4C31.04 ------------------------------------------------------------------------------------------------------------------------------------