12904( 3) - 14-Aug-2012 16:26:37 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 12904 Version: 3 Check-in Time: 14-Aug-2012 16:26:37 STScI Edit Number: 0 Title The Galactic Fountain Meets The Accreting Halo ------------------------------------------------------------------------------------ Type Cycle GO 20 ------------------------------------------------------------------------------------ Investigators Contact? PI: Prof. Joel N. Bregman University of Michigan Y CoI: Dr. Eric D. Miller Massachusetts Institute of Technology N ------------------------------------------------------------------------------------ Abstract Galaxies grow by accretion of gas in addition to mergers, but the current accretion rate onto a typical spiral is uncertain by at least an order of magnitude. Gas can accrete hot and we observe X-ray emitting gas extending several kpc above the plane around spirals. This may be a hot accretion mode, a galactic fountain, or a combination. These phenomena are best studied around edge-on galaxies, where there is unambiguous height information. A unique set of conditions exist around the nearby edge-on galaxy NGC 891, which not only has an HI map and X-ray halo extending 10 kpc from the disk, it has a bright background AGN projected 5 kpc above the disk. Metal halo absorption lines of Fe II and Mg II are seen against the AGN continuum, offering the promise of using metallicities to differentiate between fountain gas, with near-solar metallicities, and accreted gas with 0.1-0.3 solar metallicities. We cannot achieve those goals with these low resolution NUV STIS spectra, but the proposed COS observation will permit us to determine metallicities as a function of velocity through the rotating halo. Depletions onto grains will be inferred from elemental column density ratios. These observations will determine the relative importance of fountain vs accretion and will provide the most complete picture for the properties of a gaseous halo around a normal spiral galaxy. ------------------------------------------------------------------------------------ Observations Description ------------------------ This program is designed to obtain spectra of an AGN projected behind the halo of an edge-on galaxy, NGC 891 for the purpose of characterizing the metallicity distribution in multiple elements. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 12904( 3) - 14-Aug-2012 16:26:37 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC891AGN GALAXY, HALO, QSO, RA=02H22M24.4600S +/- 0.1", J2000 V = 17.5 +/- .5 SPIRAL DEC=+42D21'38.20" +/- 0.1" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 12904( 3) - 14-Aug-2012 16:26:37 - [ 3] Visit: 01 Visit Requirements: SCHED 100% On Hold Comments: Additional Comments: NUV Acquistion Image Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC891AGN COS/NUV ACQ/IMA PSA MIRRORA 1 14 S GE ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC891AGN COS/NUV TIME-TA PSA G230L 3360 BUFFER-TIME=2500, EXTENDED=NO, 1 3030 S G FP-POS=ALL, FLASH=YES see below ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC891AGN COS/NUV TIME-TA PSA G230L 3360 BUFFER-TIME=2500, EXTENDED=NO, 1 3030 S G FP-POS=ALL, FLASH=YES see below ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC891AGN 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A GE NGC891AGN 2 COS/NUV TIME-TA PSA G230L 3360 none none none 1 1 1137.0 S G NGC891AGN 2 COS/NUV TIME-TA PSA G230L 3360 none none none 2 1 1137.0 S G NGC891AGN 2 COS/NUV TIME-TA PSA G230L 3360 none none none 3 2 1324.0 S G NGC891AGN 2 COS/NUV TIME-TA PSA G230L 3360 none none none 4 2 1324.0 S G NGC891AGN 3 COS/NUV TIME-TA PSA G230L 3360 none none none 1 3 1327.0 S G NGC891AGN 3 COS/NUV TIME-TA PSA G230L 3360 none none none 2 3 1327.0 S G NGC891AGN 3 COS/NUV TIME-TA PSA G230L 3360 none none none 3 4 1324.0 S G NGC891AGN 3 COS/NUV TIME-TA PSA G230L 3360 none none none 4 4 1324.0 S G 12904( 3) - 14-Aug-2012 16:26:37 - [ 4] Visit: 02 Visit Requirements: SCHED 100% 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 NGC891AGN COS/NUV ACQ/IMA PSA MIRRORA 1 14 S GE ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC891AGN COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=6100, EXTENDED=NO, 1 3030 S G FP-POS=ALL, FLASH=YES see below ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC891AGN 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A GE NGC891AGN 2 COS/FUV TIME-TA PSA G130M 1291 none none none 1 1 2312.0 S G NGC891AGN 2 COS/FUV TIME-TA PSA G130M 1291 none none none 2 2 2724.0 S G NGC891AGN 2 COS/FUV TIME-TA PSA G130M 1291 none none none 3 3 2724.0 S G NGC891AGN 2 COS/FUV TIME-TA PSA G130M 1291 none none none 4 4 2724.0 S G 12904( 3) - 14-Aug-2012 16:26:37 - [ 5] Visit: 03 Visit Requirements: SCHED 100% 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 NGC891AGN COS/NUV ACQ/IMA PSA MIRRORA 1 14 S GE ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC891AGN COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=6100, EXTENDED=NO, 1 3030 S G FP-POS=ALL, FLASH=YES see below ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC891AGN COS/FUV TIME-TA PSA G130M 1291 BUFFER-TIME=6100, EXTENDED=NO, 1 3030 S G FP-POS=3, FLASH=YES see below ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC891AGN 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A GE NGC891AGN 2 COS/FUV TIME-TA PSA G130M 1291 none none none 1 1 2312.0 S G NGC891AGN 2 COS/FUV TIME-TA PSA G130M 1291 none none none 2 2 2724.0 S G NGC891AGN 2 COS/FUV TIME-TA PSA G130M 1291 none none none 3 3 2724.0 S G NGC891AGN 2 COS/FUV TIME-TA PSA G130M 1291 none none none 4 4 2724.0 S G NGC891AGN 3 COS/FUV TIME-TA PSA G130M 1291 none none none none 5 2724.0 S G 12904( 3) - 14-Aug-2012 16:26:37 - [ 6] Summary Form for Proposal 12904 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/IMAGE, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=2500, BUFFER-TIME=6100, EXTENDED=NO, FLASH=YES, FP-POS=3, FP-POS=ALL ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SCHED 100% ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G130M, G230L, MIRRORA ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC891AGN ------------------------------------------------------------------------------------------------------------------------------------