9818( 39) - 06/17/04 14:21 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9818 Version: 39 Check-in Date: 17-Jun-2004 18:19:47 1.Proposal Title: Reverberation Mapping of the Least Luminous Seyfert 1 Galaxy NGC 4395 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle 4. Parallel Pointing Tolerance GO 12 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Prof. Ari Laor Technion-Israel Institute of Technology CoI: Prof. Bradley M. Peterson Ohio State University Y CoI: Prof. Dan Maoz Tel Aviv University - Wise Observatory N CoI: Prof. Alex V. Filippenko University of California - Berkeley N CoI: Dr. Luis C. Ho Carnegie Institution of Washington N CoI: Prof. Ed. Moran Wesleyan University N CoI: Prof. Alice Quillen University of Rochester N ------------------------------------------------------------------------------------ 6. Abstract We propose to make a short UV and optical reverberation mapping monitoring of NGC~4395, by far the least luminous Seyfert 1 galaxy known (M_B~ -10), where the Broad Line Region (BLR) is most likely between a fraction of a light hour to a few light hours across. This program will: 1. extend by a factor of ~100 the range of R_BLR probed by RM, 2. allow to test models for AGN continuum emission and BLR structure at very low L and M_BH. 3. provide significantly more reliable estimates of its M_BH than currently available, 4. allow to probe the M_BH-sigma_* relation in AGN at very low M_BH, which cannot be probed by other methods. Existing archival FOS observations indicate significant (up to 30-40%) line and continuum variations within one orbit, suggesting that the proposed RM is likely to succeed. The unusually small R_BLR in NGC 4395 implies that RM can be performed here at only a fraction of the cost required in typical AGN. ------------------------------------------------------------------------------------ 9818( 39) - 06/17/04 14:21 - [ 2] Observations Description ------------------------ {\bf HST:} We propose to monitor NGC~4395 continuously for 5 consecutive orbits in two consecutive visits (one day apart), i.e. a total of 10 orbits, using the STIS/G140L. Each visit is limited to a maximum of 5 orbits by SAA passage. We will use the TIME-TAG mode to obtain suborbital time resolution. A S/N = 7 per resolution element is obtained at 1500~\AA\ in a single 10-min integration through the $52\times 0.5$ slit (using the mean FOS flux of $2.2\times 10^{- 15}$~ergs s$^{-1}$ cm$^{-2}$ \AA$^{-1}$), which equals the S/N in a full orbit of the archival FOS spectra. The continuum will be integrated over $\sim 50$~\AA\ bins, increasing the S/N to $\sim 40$. The C~IV equivalent width is $\sim 50$~\AA, and we thus expect to determine its flux with a S/N of $\sim 40$ per 10 min integration as well. The STIS/G140L covers the Ly$\alpha$ (partly blended with geocoronal), N~V, O~IV]+Si~IV, C~IV, He~II, and O~III] lines, which the archival FOS spectrum shows are prominent (e.g., the C~IV line peak flux density is $\sim 10$ times the continuum level), and this may allow velocity-resolved RM. We request here $2\times 5$ orbits of monitoring in order to increase the chances of observing sharp large-amplitude variability events (e.g., Fig. 2), which help in the lag determinations, and to increase the size of the data set to 38 spectra of 10 min integrations, which is typical of other successful RM campaigns. The factor three drop in flux at 1270~\AA\ within one orbit (96 min), implies a minimum drop of $\sim 13$\% in 10~min, which should be detectable at a level of 5$\sigma$ with the expected S/N of 40. Any power on smaller time scales will increase the expected short-timescale variability amplitude. Real Time Justification ----------------------- We request that the two STIS 5-orbit visits be obtained during March or April, when NGC 4395 is observable throughout the night from the Northern hemisphere. Furthermore, each of the HST visits should be centered in time near midnight US Mountain Time (i.e., UT 09:00) to allow maximum overlap between the ground- based coverage and the 7.5 hours HST visit. Once HST scheduling of the two visits (on consecutive days) is set, we will coordinated our approved NOAO telescope time (two nights on the NOAO 4m and 2.1m telescopes). Given the ground based scheduling constraints, it will be most helpful to have the exact HST schedule as early as possible. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 9818( 39) - 06/17/04 14:21 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4395 GALAXY, AMORPHOUS RA=12H 25M 48.82S +/- 1.4", J2000 V = V = 12.7+/-0.4 IRREGULAR DEC=33D 32' 49.23" +/- 1.4", 360.0 PLATE-ID=00Y2 Coordinate Source: GSC_SURVEY_PLATE 9818( 39) - 06/17/04 14:21 - [ 4] Visit: 01 Visit Priority: Visit Requirements: BETWEEN 10-Apr-2004 AND 11-Apr-2004 PERIOD 24 H AND ZERO-PHASE JD2444000.500000 GROUP 01, 02 WITHIN 26.0 H VISIBILITY INTERVAL 52 M On Hold Comments: Additional Comments: All 5 orbits in this visit should be consecutive. Original BETWEEN was 15- MAR-2004 AND 15-APR-2004 before reducing to specific NOAO night. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4395 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 2 S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4395 STIS/FUV TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=950 1 30 M PHASE 0.12 TO 0.23 -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC4395 STIS/FUV TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=1000 1 46.5 M -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC4395 STIS/FUV TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=1000 1 45.5 M -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC4395 STIS/FUV TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=1000 1 45.5 M -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC4395 STIS/FUV TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=1000 1 45.5 M -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 01 1 none none none none 1 tbd 01 2 none none none none 1 tbd 01 3 none none none none 2 tbd 01 4 none none none none 3 tbd 01 5 none none none none 4 tbd 01 6 none none none none 5 tbd 9818( 39) - 06/17/04 14:21 - [ 5] Visit: 02 Visit Priority: Visit Requirements: PERIOD 24 H AND ZERO-PHASE JD2444000.500000 BETWEEN 11-Apr-2004:02:30:00.0 AND 12-Apr-2004 VISIBILITY INTERVAL 52 M On Hold Comments: Additional Comments: All 5 orbits should be consecutive. BETWEEN is for simultaneous NOAO observing. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4395 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 2 S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4395 STIS/FUV TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=950 1 30 M PHASE 0.12 TO 0.3 -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC4395 STIS/FUV TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=1000 1 46 M -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC4395 STIS/FUV TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=1000 1 45.5 M -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC4395 STIS/FUV TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=1000 1 45.5 M -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC4395 STIS/FUV TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=1000 1 45.5 M -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 02 1 none none none none 1 tbd 02 2 none none none none 1 tbd 02 3 none none none none 2 tbd 02 4 none none none none 3 tbd 02 5 none none none none 4 tbd 02 6 none none none none 5 tbd 9818( 39) - 06/17/04 14:21 - [ 6] Visit: 11 Visit Priority: Visit Requirements: BETWEEN 28-Jun-2004 AND 12-Jul-2004 VISIBILITY INTERVAL 52 M On Hold Comments: Additional Comments: All 5 orbits in this visit should be consecutive. Repeat of visit 01. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4395 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=POINT 1 2 S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4395 STIS/FUV TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=950 1 30 M -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC4395 STIS/FUV TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=1000 1 46.5 M -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC4395 STIS/FUV TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=1000 1 45.5 M -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC4395 STIS/FUV TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=1000 1 45.5 M -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC4395 STIS/FUV TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=1000 1 45.5 M -MAMA G ------------------------------------------------------------------------------------------------------------------------------------ 9818( 39) - 06/17/04 14:21 - [ 7] Summary Form for Proposal 9818 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 52X0.5 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/FUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT BUFFER-TIME=950 BUFFER-TIME=1000 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 10-Apr-2004 AND 11-Apr-2004 PERIOD 24 H AND ZERO-PHASE JD2444000.500000 GROUP 01, 02 WITHIN 26.0 H VISIBILITY INTERVAL 52 M PHASE 0.12 TO 0.23 PERIOD 24 H AND ZERO-PHASE JD2444000.500000 BETWEEN 11-Apr-2004 02 30 00.0 AND 12-Apr-2004 VISIBILITY INTERVAL 52 M PHASE 0.12 TO 0.3 BETWEEN 28-Jun-2004 AND 12-Jul-2004 VISIBILITY INTERVAL 52 M ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G140L ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC4395 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 1425 ------------------------------------------------------------------------------------------------------------------------------------