8147( 3) - 02/23/99 16:28 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8147 Version: 3 Check-in Date: 08-Feb-1999 10:49:14 1.Proposal Title: Ongoing Mass Transfer in the Galaxy Pair NGC 1409/10 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 8 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: William Keel University of Alabama ------------------------------------------------------------------------------------ 5. Abstract WFPC2 snapshot imaging shows a dust lane connecting the members of the strongly interacting galaxy pair NGC 1409/10, as well as polar dust structure in NGC 1409. This is an excellent case for direct mass transfer during a tidal encounter, and a unique chance to estimate the total mass and deposition rate during such transfer. I propose two-color STIS imagery of this system, which will allow a three-dimensional reconstruction of the dust geometry. The results will show whether these dust structures in fact connect and wrap around the recipient galaxy, making this a genuine instance of mass dumping, for which a mass-flow rate could be estimated from broad dynamical considerations. Two passbands are needed to break the depth/extinction degeneracy that remains from single-passband data. ------------------------------------------------------------------------------------ 8147( 3) - 02/23/99 16:28 - [ 2] Observations Description ------------------------ The observing strategy is dictated by the need for S/N=5 or greater per pixel at the faintest part of the overlapping light between the galaxies where the dust lane crosses, measured from the snapshot PC image at V=22.0 per square arcsecond. At this S/N, the dust lane can be detected even if it goes behind 90% of the light, being about 25 STIS pixels wide. The higher QE and wider passbands of the STIS imaging mode yield better S/N in two passbands than would WFPC2. A blue band will be synthesized by differencing the white-light and long -pass STIS images. The wide-B difference image should have S/N=6 per (smaller STIS) pixel at this point after 2700 seconds in each filter (with the S/N in the redder passband near 20). Since the precise effective wavelengths are not too important here, as long as they can be calculated, the broader passbands and higher DQE of the STIS CCD win. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Paper Products: NO Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 8147( 3) - 02/23/99 16:28 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC-1409 GALAXY, Spiral, RA=03H 41M 10.43S +/-0.1S, DEC=- 2000.0 Z=0.0253 V = 15.4 Seyfert, Interacting 01D 18' 03.0" +/- 1.0", PLATE- 1 B-V = 0.9 Galaxy, Dust Lane ID=021D Comments: Coordinates from WFPC2 snapshot exposure u2e63t01 (plate ID is just for bookkeeping and avoiding warning messages) 8147( 3) - 02/23/99 16:28 - [ 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 NGC-1409 STIS/C ACCUM F28X50L MIRROR CR-SPLIT=2 1 2500 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-1409 STIS/C ACCUM 50CCD MIRROR CR-SPLIT=2 1 2700 S CD ------------------------------------------------------------------------------------------------------------------------------------ 8147( 3) - 02/23/99 16:28 - [ 5] Summary Form for Proposal 8147 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 50CCD ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=2 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC-1409 ------------------------------------------------------------------------------------------------------------------------------------