12614( 2) - 11-Jul-2011 13:11:35 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 12614 Version: 2 Check-in Time: 11-Jul-2011 13:11:35 STScI Edit Number: 0 Title Are the Ultra-Compact High-Velocity Clouds Minihalos? Constraints from Quasar Absorption Lines ------------------------------------------------------------------------------------ Type Cycle GO 19 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Orly Gnat California Institute of Technology CoI: Mr. Jacob Faerman Tel Aviv University - Wise Observatory N CoI: Prof. Amiel Sternberg Tel Aviv University - Wise Observatory N CoI: Prof. Christopher F. McKee University of California - Berkeley N CoI: Dr. Eran O. Ofek California Institute of Technology N CoI: Ms. Elizabeth Adams Cornell University N CoI: Prof. Riccardo Giovanelli Cornell University N CoI: Prof. Martha Haynes Cornell University N ------------------------------------------------------------------------------------ Abstract We propose spectroscopic metal absorption-line observations (C II 1334.5A, Si III 1260.4A, and Si III 1206.5A) of two ultra-compact 21cm H I Arecibo sources, toward two closely aligned (4 and 10 arcmin) and suitably bright (41 and 291 microJy in the FUV) background SDSS quasars that we have identified for this purpose. These ultra-compact H I clouds have been proposed as possible 21cm-selected minihalos in the Local Group. COS measurements will constrain the metallicity and thermal pressures in these possibly multiphased clouds, and will provide a test of the minihalo hypothesis. We request 23 orbits. ------------------------------------------------------------------------------------ Observations Description ------------------------ we require COS observations toward two quasars that are positioned close to and behind the ultra-compact 21cm H I Arecibo sources AGC258242 and AGC268069. We have identified two FUV-bright (> 40 ?Jy) SDSS quasars that are suitable for this purpose. Our goal is to detect the CII 1334.5A, SiII 1260.4A, and SiIII 1206.5A absorption lines in the UCHVCs, and to infer the ion column densities. For the spectroscopy we will the COS FUV G130M grating, with a central wavelength of 1327A, (R~20, 000-24, 000). Our minihalo models predict that CII, SiII, SiIII should be readily observable, but that other ions are too underabundant to detect easily. Spectral observations with G130M could also reveal the existence of OI 1302.2A, SII 1259.5A, SiIV 1393.8A, and NV 1238.8A. Detecting any of these species will provide significant clues regarding the nature and location of the UCHVCs, in addition to testing the minihalo hypothesis. AGC258242 ? An SDSS quasar is located at an angular distance of 4 arcmin from the center of AGC258242. This quasar is at a redshift z = 0.2851, and has a mean GALEX FUV specific flux of 41 micro-Jy (FUV AB mag = 19.86). Given the H I column density and the radial extent of this UCHVC, we predict the following metal-line column-densities for this cloud: For CII 1334.5A, N_CII~1.6e14 12614( 2) - 11-Jul-2011 13:11:35 - [ 2] cm^?2; For SiII 1260.4A, N_SiII~1.4e13 cm^?2; And for SiIII 1206.5A, 1e12 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSS-J15095 COS/NUV ACQ/IMA PSA MIRRORA 1 27.3 S 2.19+111047 GE .0 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSS-J15095 COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=2959, FP-POS=ALL 1 2959 S 2.19+111047 G see below .0 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSS-J150952.19+111 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A 047.0 GE SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 1 1 2548.0 S 047.0 G SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 2 2 N/A 047.0 G SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 3 3 N/A 047.0 G SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 4 4 N/A 047.0 G 12614( 2) - 11-Jul-2011 13:11:35 - [ 5] Visit: 02 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSS-J15095 COS/NUV ACQ/IMA PSA MIRRORA 1 27.3 S 2.19+111047 GE .0 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSS-J15095 COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=2959, FP-POS=ALL 1 2959 S 2.19+111047 G see below .0 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSS-J150952.19+111 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A 047.0 GE SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 1 1 2548.0 S 047.0 G SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 2 2 N/A 047.0 G SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 3 3 N/A 047.0 G SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 4 4 N/A 047.0 G 12614( 2) - 11-Jul-2011 13:11:35 - [ 6] Visit: 03 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSS-J15095 COS/NUV ACQ/IMA PSA MIRRORA 1 27.3 S 2.19+111047 GE .0 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSS-J15095 COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=2959, FP-POS=ALL 1 2959 S 2.19+111047 G see below .0 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSS-J150952.19+111 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A 047.0 GE SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 1 1 2548.0 S 047.0 G SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 2 2 N/A 047.0 G SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 3 3 N/A 047.0 G SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 4 4 N/A 047.0 G 12614( 2) - 11-Jul-2011 13:11:35 - [ 7] Visit: 04 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSS-J15095 COS/NUV ACQ/IMA PSA MIRRORA 1 27.3 S 2.19+111047 GE .0 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSS-J15095 COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=2959, FP-POS=ALL 1 2959 S 2.19+111047 G see below .0 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSS-J150952.19+111 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A 047.0 GE SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 1 1 2548.0 S 047.0 G SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 2 2 N/A 047.0 G SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 3 3 N/A 047.0 G SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 4 4 N/A 047.0 G 12614( 2) - 11-Jul-2011 13:11:35 - [ 8] Visit: 05 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSS-J15095 COS/NUV ACQ/IMA PSA MIRRORA 1 27.3 S 2.19+111047 GE .0 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSS-J15095 COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=2959, FP-POS=ALL 1 2959 S 2.19+111047 G see below .0 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSS-J150952.19+111 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A 047.0 GE SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 1 1 2548.0 S 047.0 G SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 2 2 N/A 047.0 G SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 3 3 N/A 047.0 G SDSS-J150952.19+111 2 COS/FUV TIME-TA PSA G130M 1291 none none none 4 4 N/A 047.0 G 12614( 2) - 11-Jul-2011 13:11:35 - [ 9] Visit: 06 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSS-J16051 COS/NUV ACQ/IMA PSA MIRRORB 1 60 S 9.70+144852 GE .2 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSS-J16051 COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=2268, FP-POS=1 1 2268 S 9.70+144852 G see below .2 ------------------------------------------------------------------------------------------------------------------------------------ 3 SDSS-J16051 COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=2959, FP-POS=2 1 2959 S 9.70+144852 G .2 ------------------------------------------------------------------------------------------------------------------------------------ 4 SDSS-J16051 COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=2959, FP-POS=3 1 2959 S 9.70+144852 G .2 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSS-J160519.70+144 1 COS/NUV ACQ/IMA PSA MIRRORB none none none none 1 N/A 852.2 GE SDSS-J160519.70+144 2 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 2455.0 S 852.2 G SDSS-J160519.70+144 3 COS/FUV TIME-TA PSA G130M 1291 none none none none 2 N/A 852.2 G SDSS-J160519.70+144 4 COS/FUV TIME-TA PSA G130M 1291 none none none none 3 N/A 852.2 G 12614( 2) - 11-Jul-2011 13:11:35 - [ 10] Summary Form for Proposal 12614 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/IMAGE, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=2268, BUFFER-TIME=2959, FP-POS=1, FP-POS=2, FP-POS=3, FP-POS=ALL ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G130M, MIRRORA, MIRRORB ------------------------------------------------------------------------------------------------------------------------------------ Target Names SDSS-J150952.19+111047.0, SDSS-J160519.70+144852.2 ------------------------------------------------------------------------------------------------------------------------------------