9362( 4) - 01/02/03 07:22 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9362 Version: 4 Check-in Date: 02-Jan-2003 07:21:36 1.Proposal Title: STIS Observations of the Intrinsic UV Absorption in the Dwarf Seyfert Nucleus of NGC 4395 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 11 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Steven Kraemer Catholic University of America CoI: Prof. D. Michael Crenshaw Georgia State University Y CoI: Prof. Alexei Filippenko University of California, Berkeley N CoI: Dr. Jack Gabel Catholic University of America N CoI: Dr. Luis Ho Carnegie Observatories N CoI: Prof. Joseph Shields Ohio University N CoI: Dr. T. Jane Turner University of Maryland, Baltimore County N ------------------------------------------------------------------------------------ 5. Abstract The Sd IV dwarf galaxy NGC 4395 is one of the nearest (d ~ 4.2 Mpc) and least luminous (L_bol ~ 10^41 ergs s^-1) examples of Seyfert 1 galaxies. Furthermore, it is the only known example of an active nucleus within a bulgeless, extreme late-type galaxy. This unique object possesses all of the classic Seyfert 1 properties in miniature, including broad and narrow emission lines and highly variable X-ray emission, presumably powered by a small (few x 10^4 M_\odot) black hole. Furthermore, we have discovered evidence for blueshifted, intrinsic absorption lines in the UV (C IV LambdaLambda1548.2, 1550.8), while X-ray spectra show the presence of bound-free edges from O VII and O VIII. We propose HST/STIS echelle observations to determine the properties (ionization states, column densities, velocity coverages, covering factors) of the intrinsic UV absorbers in NGC 4395. Due to the high covering factor of its narrow-line emission, NGC 4395 offers the best case for testing the connection between the absorbers and the narrow-line region (NLR). Furthermore, an empirical comparison of its absorption properties with those in higher luminosity active galactic nuclei (AGN) will provide valuable constraints on dynamical models of the absorbers, which make predictions that are strongly dependent on luminosity and/or central black hole mass. ------------------------------------------------------------------------------------ 9362( 4) - 01/02/03 07:22 - [ 2] Observations Description ------------------------ We propose STIS echelle observations with the E140M grating (1150 -- 1710 Angstrom) and the E230M grating (2280 -- 3100 Angstrom) through the 0.2'' x 0.2'' aperture. This wavelength range gives us access to all the important UV resonance lines, such as N V, Si IV, C IV, Mg II, and Ly- Alpha. Based on the earlier FOS spectra of NGC 4395, the peak fluxes of the C IV LambdaLambda1548.2, 1550.8 and Mg II LambdaLambda2795.5, 2802.7 lines are ~ 1.5 x 10^-14 ergs s^-1 cm^-2 AA^-1 and 2 x 10^-15 ergs s^-1 cm^-2 AA^-1, respectively. We will bin the data to a spectral resolution of Lambda/DeltaLambda ~ 10, 000, corresponding to ~ 30 km s^- 1, which will be sufficient for resolving the individual kinematic components of the absorption. At this resolution, we will achieve a signal-to-noise ratio (S/N) of ~ 8.9 near the peak of C IV with an exposure time of 8100 seconds, or 3 HST orbits. The expected S/N will be ~ 5 near the absorption feature at 1000 km s^-1 blueward of line center; based on our experience, this is sufficient for determining ionic column densities. For Mg II, we will achive a signal-to-noise ratio of ~ 9.6 with an exposure time of 2700 seconds or, 1 orbit. Real Time Justification ----------------------- We have proposed to obtain FUSE Cycle 3 spectra of NGC 4395. Since intrinsic absorbers are typically variable, and the continuum source in NGC 4395 is known to vary on short timescales (Lira, et al. 1999, MNRAS, 305, 109), we request that the FUSE and STIS spectra be obtained within 2 weeks of one another, if possible. Note that much of the science will be retained even if it is not possible to achieve this scheduling. Calibration Justification ------------------------- Additional Comments ------------------- To be coordinated with FUSE observations. ------------------------------------------------------------------------------------ 9362( 4) - 01/02/03 07:22 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4395 GALAXY, SEYFERT RA=12H 25M 48.98S +/- 0.05S, J2000 V = 12.8 DEC=33D 32' 51.0" +/- 0.5", PLATE-ID=00Y2 Coordinate Source: GUIDE_STAR_CATALOG 9362( 4) - 01/02/03 07:22 - [ 4] Visit: 01 Visit Priority: Visit Requirements: SCHED 100% 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC4395 STIS/C ACQ F28X50L MIRROR 1 1.0 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC4395 STIS/N ACCUM 0.2X0.2 E230M 2707 1 2200 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 30 NGC4395 STIS/F ACCUM 0.2X0.2 E140M 1425 1 2700 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 40 NGC4395 STIS/F ACCUM 0.2X0.2 E140M 1425 1 2700 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 50 NGC4395 STIS/F ACCUM 0.2X0.2 E140M 1425 1 2700 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 9362( 4) - 01/02/03 07:22 - [ 5] Summary Form for Proposal 9362 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 0.2X0.2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/NUV-MAMA STIS/FUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SCHED 100% ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR E230M E140M ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC4395 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 2707 1425 ------------------------------------------------------------------------------------------------------------------------------------