9387( 5) - 02/13/03 13:05 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9387 Version: 5 Check-in Date: 13-Feb-2003 13:04:17 1.Proposal Title: The Natural Occulting Disk and Host Galaxy of the Red BAL Quasar FIRST J1556+3517 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 11 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Michael Brotherton University of Wyoming CoI: Prof. Robert Becker UC Davis/LLNL N CoI: Dr. Dean Hines Univ. of Arizona N CoI: Dr. Hien Tran The Johns Hopkins University N CoI: Dr. Mark Lacy UC Davis/LLNL N CoI: Dr. Michael Gregg UC Davis/LLNL N CoI: Dr. Gabriela Canalizo Lawrence Livermore National Laboratory N CoI: Dr. Richard White Space Telescope Science Institute N ------------------------------------------------------------------------------------ 5. Abstract We propose an innovative imaging observation of the host galaxy of the red, broad absorption line (BAL) quasar FIRST J1556+3517. This object is already noteworthy as being the first radio-loud BAL quasar, and moreover a member of the very rare class of ``Fe-LoBAL'' quasars. FIRST J1556+3517 also has the unique property (out of some 60+ BALQSOs) of having unpolarized BAL troughs wider than the bandpass of the linear ramp filter of ACS. This unpolarized trough light most likely arises from stars comprising the host galaxy of FIRST J1556+3517. In this special quasar exists a natural occulting disk -- the BAL outflow -- and the opportunity to image a quasar host galaxy at high redshift without the complications of separating out the quasar. Red low-ionization BAL quasars like FIRST J1556+3517 have been hypothesized to be young merger products with high accretion rates and active star formation, perhaps representing a key evolutionary state in the lifetime of massive galaxies. ------------------------------------------------------------------------------------ 9387( 5) - 02/13/03 13:05 - [ 2] Observations Description ------------------------ We propose ACS ramp filter imaging of an unpolarized trough bottom in FIRST J1556+3517. The broadest unpolarized trough is Fe II* Lambda2380 approximately centered at an observed wavelength of 5853 Angstrom. The only filter that will fully fit inside this trough is the FR601N filter, using the WFC1 detector (the only available choice for the wavelength range required). See Figure 3. Our high signal-to-noise ratio optical spectrum of FIRST J1556+3517 (Fig. 1) was obtained through a slit one arcsecond in width, and shows a trough flux level of 8.5 * 10^-18 \ergsAcm\ (the flux calibration is believed to be accurate to within 20\ surface brightness by assuming this flux is emitted over a square arcsecond; more likely there is a non-uniform distribution. Using the on- line ACS exposure time calculator (ETC), a SNR = 10 per 2 * 2 pixel resolution element requires just over 11 ksec. Given the declination of FIRST J1556+3517, there are 54 minutes available per orbit. Initial guide star acquisition requires 6 minutes (with 5 minutes re-acquisition on subsequent orbits). Using the WFC, the initial exposure requires 4 minutes overhead, with 2.5 minutes on subsequent exposures. With these overheads we can achieve an 11, 010 second exposure in four orbits. We request five orbits (which can be done in a singe visit) for a total of 13, 800 seconds, since we would like to go as deep as feasible, the input flux level is somewhat uncertain, and the stellar distribution is unknown. beginfigure vspace*-0.6cm beginminipaget10.cm psfigfile=troughplot.eps, angle=0, height=7.0cm, width=8.5cm endminipage beginminipageb7.5cm vspace-8.0cm caption Closeup of the Fe II* Lambda2380 trough (solid line), and the proposed ramp filter FR601N bandpass centered on 5853Angstrom\ (dashed line). The left axis shows the total flux, while the right axis shows the filter transmission. The Fe II* Lambda2380 trough is the broadest in FIRST J1556+3517 and is unpolarized over the range of the filter bandpass. labelbpfig endminipage vspace-0.2cm endfigure Real Time Justification ----------------------- None. None. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 9387( 5) - 02/13/03 13:05 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 FIRST- GALAXY, QUASAR RA=15H 56M 33.8S +/- 0.1", J2000 Z = F(5850)=1+/-0.2e-17 J1556+3517 DEC=35D 17' 58" +/- 0.1" 1.500 Coordinate Source: Other_Source: FIRST-APM match, Becker et al. 1997, ApJL, 479, 93 9387( 5) - 02/13/03 13:05 - [ 4] Visit: 01 Visit Priority: 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 FIRST-J1556 ACS/WF ACCUM WFC FR601N 5853 CR-SPLIT=2 1 2550 S POS TARG 0.0, 0.0 +3517 C ------------------------------------------------------------------------------------------------------------------------------------ 2 FIRST-J1556 ACS/WF ACCUM WFC FR601N 5853 CR-SPLIT=2 1 2700 S POS TARG 0.0984, 0.1070 +3517 C ------------------------------------------------------------------------------------------------------------------------------------ 3 FIRST-J1556 ACS/WF ACCUM WFC FR601N 5853 CR-SPLIT=2 1 2700 S POS TARG -0.0984, 0.1070 +3517 C ------------------------------------------------------------------------------------------------------------------------------------ 4 FIRST-J1556 ACS/WF ACCUM WFC FR601N 5853 CR-SPLIT=2 1 2700 S POS TARG -0.0984,-0.1070 +3517 C ------------------------------------------------------------------------------------------------------------------------------------ 5 FIRST-J1556 ACS/WF ACCUM WFC FR601N 5853 CR-SPLIT=2 1 2700 S POS TARG 0.0984,-0.1070 +3517 C ------------------------------------------------------------------------------------------------------------------------------------ 9387( 5) - 02/13/03 13:05 - [ 5] Visit: 51 Visit Priority: 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 FIRST-J1556 ACS/WF ACCUM WFC FR601N 5853 CR-SPLIT=2 1 2550 S POS TARG 0.0, 0.0 +3517 C ------------------------------------------------------------------------------------------------------------------------------------ 2 FIRST-J1556 ACS/WF ACCUM WFC FR601N 5853 CR-SPLIT=2 1 2700 S POS TARG 0.0984, 0.1070 +3517 C ------------------------------------------------------------------------------------------------------------------------------------ 3 FIRST-J1556 ACS/WF ACCUM WFC FR601N 5853 CR-SPLIT=2 1 2700 S POS TARG -0.0984, 0.1070 +3517 C ------------------------------------------------------------------------------------------------------------------------------------ 4 FIRST-J1556 ACS/WF ACCUM WFC FR601N 5853 CR-SPLIT=2 1 2700 S POS TARG -0.0984,-0.1070 +3517 C ------------------------------------------------------------------------------------------------------------------------------------ 5 FIRST-J1556 ACS/WF ACCUM WFC FR601N 5853 CR-SPLIT=2 1 2700 S POS TARG 0.0984,-0.1070 +3517 C ------------------------------------------------------------------------------------------------------------------------------------ 9387( 5) - 02/13/03 13:05 - [ 6] Summary Form for Proposal 9387 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=2 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements POS TARG 0.0, 0.0 POS TARG 0.0984, 0.1070 POS TARG -0.0984, 0.1070 POS TARG -0.0984,-0.1070 POS TARG 0.0984,-0.1070 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements FR601N ------------------------------------------------------------------------------------------------------------------------------------ Target Names FIRST-J1556+3517 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 5853 ------------------------------------------------------------------------------------------------------------------------------------