6490( 6) - 09/11/96 15:37 - [ 0] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6490 Version: 6 Check-in Date: 11-Sep-1996 15:29:25 1.Proposal Title: Deep Imaging of Extended Optical Structure around the Quasar 4C37.43 ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle AGN GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: ALAN STOCKTON UNIVERSITY OF HAWAII CoI: John MacKenty Space Telescope Science Institute N ------------------------------------------------------------------------------------ 6. Abstract Essentially all imaging of low-redshift QSO host galaxies in Cycle 4 and Cycle 5 programs has been of a survey nature, with relatively short exposures on a large number of objects. Particularly in view of the uncertainties and questions that have arisen as a result of these survey programs, we feel that it is essential to carry out deep imaging of a few critical fields in bandpasses matched to the objects' spectral properties. We propose here such observations of 4C37.43 Specifically, we will obtain (1) deep WFC images in a continuum band between [O III] Lambda5007 and HAlpha, (2) PC images, in the same band, with exposures calculated to avoid saturation on the quasar, to give good resolution of the immediate nuclear environment, and (3) deep narrow-band (linear ramp filter) images, centered on O III Lambda5007. 4C37.43 has the most luminous extended emission region of any low- redshift QSO. ------------------------------------------------------------------------------------ Observations Description ------------------------ We plan the following observations: (1) deep WFC imaging through F814W, (2) shorter PC image exposures to obtain higher resolution in the nucleus, and (3) narrow-band imaging with the linear ramp filters on the [O III] Lambda5007 line. For the continuum observations, the faintest features for which we would need to obtain a S/N ~ 3 (per pixel) have an average surface brightness of m_AB(8000) = 24.2 arcsec^-2 (determined from our ground-based observations). We have determined that for the WFC observations, exposures around 600 s give the best compromise placement of the available dynamic range: typically 5 to 9 pixels at the peak of the quasars will saturate, and the sky background will be comparable to the square of the readout noise. Using the filter and system throughput information in the WFPC2 manual, we find that for a 600 s exposure, we obtain 6 e^- pixel^-2 from the source, 26 e^- pixel^-2 from the sky, and 5 e^- pixel^-2 dark signal (assuming the device is run at -83 ^degreesC). With a readout noise of 5.2 e^-, we find a S/N of 0.75 for the 600 s exposure. Therefore, 16 exposures combined would give a S/N of 3.0. For the PC images, we will aim to keep the peak pixel just below saturation, since these images are intended to explore structure very close to the nucleus. Saturation is not a significant problem for the linear ramp filter images; our exposure times will be limited instead by cosmic-ray hit density. In estimating the total exposure we need, we have used the average surface brightness (over a 3" diameter region) of the [O III] Lambda5007 line in the bright region 4" E of 4C37.43 as our fiducial, with a target S/N of 5 per pixel. In a 2700 s exposure, we would average 17 e^- pixel^- 2 from the [O III] emission, 7 e^- pixel^-2 from the sky, and 22 e^- pixel^-2 from dark background. With the readout noise of 5.2 e^ -, we obtain a S/N of 2.4 per pixel. Four such exposures would give a S/N of 4.8. These exposures admittedly require a substantial amount of HST time. The main point is that, if one ends up having to bin the data to obtain the required S/N on a low-surface-brightness feature, one has voided one of the principal reasons for going to the HST in the first place. We firmly believe that a focussed effort at obtaining deep continuum and line images of a few QSOs will ultimately prove to be essential to the scientific goal of understanding QSO environments and an important complement to the currently- popular ``survey mode,'' in which relatively shallow images of many QSOs are obtained through standard filters. We have optimized the exposures to fill orbits as closely as possible. Leftover bits of time in individual orbits on 4C37.43 are used to obtain PSF calibration observations on bright stars within 2' of the quasar, so the same guide stars can be used. Because we require 10 orbits for 4C37.43, two visits are necessary. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6490( 6) - 09/11/96 15:37 - [ 1] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 B2-1512+37 GALAXY,QUASAR RA=15H 14M 43.05S +/- 0.02S, 2000 Z=0.3708 V = 16.27 DEC=36D 50' 50.36" +/- 0.2", B-V = -0.02 PLATE-ID=01R7 Comments: Flux given is that of the quasar. The actual target is the surrounding host galaxy, and the WFC observations are intended to obtain S/N=2 per pixel on a surface brightness of m_AB(8000A) = 24.2 arcsec^-2. WFC exposures are intended to barely saturate on the quasar peak; PC exposures are not to saturate. 2 B2-1512+37- Calibration, Point RA=15H 14M 37.99S +/- 0.05S, 2000 V = 12.77 PSF-CALIB Spread Function DEC=36D 51' 06.3" +/- 0.5", PLATE-ID=01R7 6490( 6) - 09/11/96 15:37 - [ 2] Visit: 01 Visit Requirements: BETWEEN 20-JAN-97 AND 20-JUL-97 On Hold Comments: Additional Comments: Alternate time period, equally suitable: BETWEEN 20-JAN-97 AND 20-JUL-97 Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 B2-1512+37 WFPC2 IMAGE WF3 F814W CR-TOLERANCE=0 2 800 S ------------------------------------------------------------------------------------------------------------------------------------ 2 B2-1512+37- WFPC2 IMAGE WF3 F814W CR-TOLERANCE=0 3 10 S SEQ 1-2 NON-INT PSF-CALIB ------------------------------------------------------------------------------------------------------------------------------------ 3 B2-1512+37 WFPC2 IMAGE WF3 F814W CR-TOLERANCE=0 2 800 S POS TARG +0.50,+0.25 ------------------------------------------------------------------------------------------------------------------------------------ 4 B2-1512+37- WFPC2 IMAGE WF3 F814W CR-TOLERANCE=0 4 10 S POS TARG +0.50,+0.25 PSF-CALIB ------------------------------------------------------------------------------------------------------------------------------------ 5 B2-1512+37 WFPC2 IMAGE WF3 F814W CR-TOLERANCE=0 2 800 S POS TARG +0.75,+0.75 ------------------------------------------------------------------------------------------------------------------------------------ 6 B2-1512+37- WFPC2 IMAGE WF3 F814W CR-TOLERANCE=0 4 10 S POS TARG +0.75,+0.75 PSF-CALIB ------------------------------------------------------------------------------------------------------------------------------------ 7 B2-1512+37 WFPC2 IMAGE WF3 F814W CR-TOLERANCE=0 2 800 S POS TARG +0.25,+0.50 ------------------------------------------------------------------------------------------------------------------------------------ 8 B2-1512+37- WFPC2 IMAGE WF3 F814W CR-TOLERANCE=0 4 10 S POS TARG +0.25,+0.50 PSF-CALIB ------------------------------------------------------------------------------------------------------------------------------------ 6490( 6) - 09/11/96 15:37 - [ 3] Visit: 02 Visit Requirements: SAME ORIENT AS 1 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 ------------------------------------------------------------------------------------------------------------------------------------ 9 B2-1512+37 WFPC2 IMAGE PC1 F814W 8 160 S ------------------------------------------------------------------------------------------------------------------------------------ 10 B2-1512+37- WFPC2 IMAGE PC1 F814W 5 4 S SEQ 9-10 NON-INT PSF-CALIB ------------------------------------------------------------------------------------------------------------------------------------ 11 B2-1512+37 WFPC2 IMAGE PC1 F814W 8 160 S POS TARG +0.75,+0.75 ------------------------------------------------------------------------------------------------------------------------------------ 12 B2-1512+37- WFPC2 IMAGE PC1 F814W 6 4 S POS TARG +0.75,+0.75 PSF-CALIB ------------------------------------------------------------------------------------------------------------------------------------ 13 B2-1512+37 WFPC2 IMAGE LRF LRF 6864 CR-SPLIT=NO 1 2700 S ------------------------------------------------------------------------------------------------------------------------------------ 14 B2-1512+37 WFPC2 IMAGE LRF LRF 6864 CR-SPLIT=NO 1 2000 S ------------------------------------------------------------------------------------------------------------------------------------ 15 B2-1512+37- WFPC2 IMAGE LRF LRF 6864 2 100 S PSF-CALIB ------------------------------------------------------------------------------------------------------------------------------------ 16 B2-1512+37 WFPC2 IMAGE LRF LRF 6864 CR-SPLIT=NO 1 2700 S POS TARG +0.75,+0.75 ------------------------------------------------------------------------------------------------------------------------------------ 17 B2-1512+37 WFPC2 IMAGE LRF LRF 6864 CR-SPLIT=NO 1 2000 S POS TARG +0.75,+0.75 ------------------------------------------------------------------------------------------------------------------------------------ 18 B2-1512+37- WFPC2 IMAGE LRF LRF 6864 2 100 S POS TARG +0.75,+0.75 PSF-CALIB ------------------------------------------------------------------------------------------------------------------------------------ 6490( 6) - 09/11/96 15:37 - [ 4] Summary Form for Proposal 6490 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-TOLERANCE=0 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category AGN ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 20-JAN-97 AND 20-JUL-97 SEQ 1-2 NON-INT POS TARG +0.50,+0.25 POS TARG +0.75,+0.75 POS TARG +0.25,+0.50 SAME ORIENT AS 1 SEQ 9-10 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F814W LRF ------------------------------------------------------------------------------------------------------------------------------------ Target Names B2-1512+37 B2-1512+37-PSF-CALIB ------------------------------------------------------------------------------------------------------------------------------------