9272( 4) - 03/26/02 15:16 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9272 Version: 4 Check-in Date: 26-Mar-2002 15:15:56 1.Proposal Title: Revealing the Nature of the X-ray Absorption in NGC 4151 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 10 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Steven Kraemer Catholic University of America CoI: D. Michael Crenshaw Georgia State University Y ------------------------------------------------------------------------------------ 5. Abstract Determining the nature of the soft X-ray absorption in the Seyfert galaxy NGC 4151 has proved elusive. Currently, the strong downturn below 3 keV is thought to be a blend of absorption edges from highly ionized species in an unusually large column of gas. However, it has been impossible to test this explanation or constrain physical models of the gas due to the inability of previous X-ray missions to resolve the expected absorption lines. We propose simultaneous Chandra and HST/STIS observations of NGC 4151 to detect the X-ray absorption lines, determine the ionization state, column, and kinematics of the X-ray absorbers, and determine the connection to the UV absorbers. ------------------------------------------------------------------------------------ Observations Description ------------------------ We will obtain E140m and E230M spectra of the nucleus, simultaneous with Chandra. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 9272( 4) - 03/26/02 15:16 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4151 GALAXY, SEYFERT RA=12H 10M 32.52S +/- 0.02S, J2000 V = 12.5 DEC=39D 24' 20.76" +/- 0.2", PLATE-ID=01QY Coordinate Source: GUIDE_STAR_CATALOG 9272( 4) - 03/26/02 15:16 - [ 3] Visit: 01 Visit Priority: Visit Requirements: SCHED 100% On Hold Comments: Additional Comments: To be scheduled simultaneously with Chandra observations. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC4151 STIS/C ACQ F28X50L MIRROR 1 0.1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC4151 STIS/F ACCUM 0.2X0.2 E140M 1425 1 2200 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 30 NGC4151 STIS/F ACCUM 0.2X0.2 E140M 1425 1 2700 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 40 NGC4151 STIS/F ACCUM 0.2X0.2 E140M 1425 1 2700 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 50 NGC4151 STIS/N ACCUM 0.2X0.2 E230M 2707 1 2700 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 60 NGC4151 STIS/N ACCUM 0.2X0.2 E230M 1978 1 2700 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9272( 4) - 03/26/02 15:16 - [ 4] Summary Form for Proposal 9272 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 0.2X0.2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/FUV-MAMA STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SCHED 100% ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR E140M E230M ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC4151 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 1425 2707 1978 ------------------------------------------------------------------------------------------------------------------------------------