9439( 5) - 05/07/03 14:08 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9439 Version: 5 Check-in Date: 07-May-2003 14:07:21 1.Proposal Title: The Size Scales of Line-Emitting Regions in the Cloverleaf QSO ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 11 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Dr. David A. Turnshek University of Pittsburgh CoI: Dr. Sandhya M. Rao University of Pittsburgh N CoI: Dr. Kyu-Hyun Chae University of Pittsburgh N ------------------------------------------------------------------------------------ 5. Abstract The Cloverleaf QSO is a four-component gravitationally-lensed broad absorption line (BAL) QSO. Models of the Cloverleaf lens indicate that, if a sufficiently extended emitting region surrounds the central source, an Einstein ring or partial ring will be seen in emission. However, the compact continuum should appear as four unresolved components, as is verified in existing broad-band images. These predictions are very robust. We propose here to determine or place limits on the size-scale of several of the emitting regions in the Cloverleaf using this effect. This will be done using the ACS-WFC RAMP filters to take images in LyAlpha, NV, and the nearby continuum. Narrow-band observations with NICMOS will image OIII and the nearby continuum. An observation of each of these emitting regions will allow us to explore a different aspect of the QSO's physical environment. Regardless of the findings, these results will improve our understanding of the size-scales of the line-emitting regions in BAL QSOs and in QSOs in general. ------------------------------------------------------------------------------------ 9439( 5) - 05/07/03 14:08 - [ 2] Observations Description ------------------------ We propose 5 orbits of imaging with the ACS-WFC (3 orbits) and NICMOS-NIC2 (2 orbits). Dithering will be used during some of the observations. The individual exposures in ACS-WFC will be with the FR432N RAMP filter to cover both 4290 Angstrom\ (LyAlpha emission) and 4402 Angstrom\ (NV emission), and with the FR462N RAMP filter to cover 4615 Angstrom\ (1300 Angstrom\ rest frame continuum). Since we cannot be sure what to expect, approximately an equal amount of time will be spent on these filters. A short broad-band F435W exposure will also be taken to determine if the Cloverleaf varied since it was last observed with HST. The LyAlpha emission is about 0.3 times the strength of the NV emission, but the LyAlpha emission is isolated in the NV BAL trough, so there will be little continuum to subtract off. The strength of the NV emission in the RAMP filter will be comparable to the continuum. There are various scenarios for computing the S/N depending on the extent (or lack thereof) of any emission. If the emission is extended and the continuum source is easily subtracted, there should be no problem reaching a S/N ~ 20-30 per resolution element (2x2 pixels), where a full Einstein ring has ~ 70 resolution elements. The individual exposures in NIC2-F160W (continuum) and NIC2-F180M (OIII) will be limited as necessary to avoid saturation. The flux in the OIII line is f_OIII ~ 1.4times10^-14 ergs s^-1 cm^-2 (Hill et al. 1993). If this is distributed over the area of the Einstein ring (Figure 1), a S/N ~8 per pixel will be reached. However, if it is less extended (e.g. <100 pc) there will (again) be confusion with the compact central source. We will use the procedure describe in Hamilton, Casertano & Turnshek (2001) and Hamilton (2001) to subtract the 4 unresolved components from the images before searching for evidence for any faint Einstein ring. Since we have a robust model of where the ring should be as a function of the size-scale of the extended region, this will form the basis for designing a software filter to perform a very sensitive search. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 9439( 5) - 05/07/03 14:08 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 Q1413+1143 GALAXY, QSO, RA=14H15M46.25S +/- 1.0", J2000 Z = 2.54 V = 17.0+/-0.0 GRAVITATIONAL LENS, DEC=+11D29'43.99" +/- 1.0", EINSTEIN RING PLATE-ID=01US Coordinate Source: GSC_SURVEY_PLATE 9439( 5) - 05/07/03 14:08 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type ACS-WFC-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.265 Coordinate_Frame POS-TARG Pattern_Orient 20.67 Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type NIC-SQUARE-WAVE-DITH Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 4.9875 Coordinate_Frame POS-TARG Pattern_Orient 90.0 Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 3 Primary_Pattern Secondary_Pattern Pattern_Type LINE Pattern_Purpose OTHER Number_Of_Points 1 Point_Spacing 0.0 Coordinate_Frame POS-TARG Pattern_Orient 0.0 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 9439( 5) - 05/07/03 14:08 - [ 5] Visit: 01 Visit Priority: Visit Requirements: SCHED 40% 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 Q1413+1143 ACS/WF ACCUM WFC1 F435W CR-SPLIT=NO 1 20 S PATTERN 3 1 C ------------------------------------------------------------------------------------------------------------------------------------ 2 Q1413+1143 ACS/WF ACCUM WFC FR423N 4290 CR-SPLIT=NO 1 470 S PATTERN 1 2 C ------------------------------------------------------------------------------------------------------------------------------------ 3 Q1413+1143 ACS/WF ACCUM WFC1 F435W CR-SPLIT=NO 1 20 S PATTERN 3 3 C ------------------------------------------------------------------------------------------------------------------------------------ 4 Q1413+1143 ACS/WF ACCUM WFC FR423N 4402 CR-SPLIT=NO 1 500 S PATTERN 1 4 C ------------------------------------------------------------------------------------------------------------------------------------ 5 Q1413+1143 ACS/WF ACCUM WFC2 F435W CR-SPLIT=NO 1 20 S POS TARG 50, 0 PATTERN 3 C 5 ------------------------------------------------------------------------------------------------------------------------------------ 6 Q1413+1143 ACS/WF ACCUM WFC FR462N 4615 CR-SPLIT=NO 1 474 S PATTERN 1 6 C ------------------------------------------------------------------------------------------------------------------------------------ 7 Q1413+1143 NIC2 MULTIAC NIC2 F180M SAMP-SEQ=STEP64,NSAMP=17 1 DEF LOW-SKY PATTERN 2 7 CUM ------------------------------------------------------------------------------------------------------------------------------------ 8 Q1413+1143 NIC2 MULTIAC NIC2 F180M SAMP-SEQ=STEP64,NSAMP=15 1 DEF LOW-SKY PATTERN 2 8 CUM ------------------------------------------------------------------------------------------------------------------------------------ 9 Q1413+1143 NIC2 MULTIAC NIC2 F160W SAMP-SEQ=STEP64,NSAMP=9 1 DEF LOW-SKY PATTERN 2 9 CUM ------------------------------------------------------------------------------------------------------------------------------------ 9439( 5) - 05/07/03 14:08 - [ 6] Summary Form for Proposal 9439 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC1 WFC WFC2 NIC2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC NIC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO NSAMP=17 NSAMP=15 NSAMP=9 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SCHED 40% PATTERN 3 1 PATTERN 1 2 PATTERN 3 3 PATTERN 1 4 POS TARG 50, 0 PATTERN 3 5 PATTERN 1 6 LOW-SKY PATTERN 2 7 LOW-SKY PATTERN 2 8 LOW-SKY PATTERN 2 9 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F435W FR423N FR462N F180M F160W ------------------------------------------------------------------------------------------------------------------------------------ Target Names Q1413+1143 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 4290 4402 4615 ------------------------------------------------------------------------------------------------------------------------------------