7351( 6) - 04/07/99 11:54 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7351 Version: 6 Check-in Date: 16-Feb-1998 12:12:30 1.Proposal Title: Kinematics of the Halpha Nuclear Disk in M81: A Search for a MBH in the Nearest LINER ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Holland Ford The Johns Hopkins University CoI: Nick Devereux New Mexico State University N CoI: George Jacoby Kitt Peak National Observatory N CoI: Zlatko Tsvetanov Johns Hopkins University Y ------------------------------------------------------------------------------------ 5. Abstract As the nearest example of an AGN with a directly observable nucleus, M81 is important and merits intense scrutiny. Because HST's exquisite angular resolution is fixed, the minimum detectable mass of a massive black hole (M_BH) and the minimum detectable radius of influence of the M_BH scale with distance. Consequently, M81, with a minimum detectable M_BH ~ 10^6 M_sun, and M31 are our best bests for pinning down the lower end of the M_BH mass function in luminous galaxies. And, if we can show unambiguously that M81 hosts a M_BH, as appears will be the case in the Milky Way, M31, and M32, we will have evidence that M_BHs are commonly, and perhaps always, found in nucleated galaxies. Our WFPC2 Halpha images show that there is a small (r ~ 70 pc) disk of ionized gas in the center of M81. The disk has nearly the same size as the nuclear disks in M87 and NGC 4261, and shows many of the same morphological features (eg spiral arms and eccentricity). We propose to take STIS 0.1" long-slit spectra with the G750M grating to measure the kinematics in the nuclear disk. Our goals are: 1) Measure and characterize the kinematics and turbulence in the disk, and investigate the variability of the broad line region. 2)Use the kinematics and our HST images to measure the central mass-to-light ratio and the mass of the unresolved (r <= 0.8 pc) Seyfert-like nucleus. This ``knocking on the door'' of M81 for the M_BH census will yield an important datum in the new field of black hole demographics. ------------------------------------------------------------------------------------ 7351( 6) - 04/07/99 11:54 - [ 2] Observations Description ------------------------ To measure the gas kinematics in the Halpha disk we will use the STIS G750M grating centered at 6581 A with the 0.1" slit. We have estimated the exposure times required to achieve a SNR~5-10 in the peaks of the brightest lines, Halpha and [N ii] 6583, at a distance ~1" from nucleus. For this purpose we used the STIS WWW ETC by supplying our own FOS spectrum of a galaxy with similar emission lines parameters. The scaling factor was determined in such a way that our spectrum reproduces the average Halpha surface brightness measured in our HST image at several positions in the nuclear disk. We then scaled the spectrum by the appropriate factor. In these simulations we have assumed that the lines are unbroadened 1" from nucleus. Close to the nucleus they likely will be broadened, but the surface brightness increases fast enough toward the center to insure that the SNR will be higher in the center. Our calculations show that we can achieve the above described S/N ratio in about a 1000-1500 s exposure. The 0.1" slit is essential, so that we do not loose spatial resolution. To confidently model the kinematics of the gaseous disk, more than one slit position is essential. To accomplish this we will place 7 slit positions parallel to each other across the nucleus and oriented roughly along the apparent major axis of the disk. This will insure that we do not miss the nucleus due to some small pointing error. All this can be done in 3 orbits. In Fig. 1 (right panel) we give a sketch of the STIS slit positions. Orbit 1 will take the GS acquisition, the STIS target acquisition and peak up sequence, plus the first two slit positions. Positions 3 to 7 will be taken during the second and third orbit. wavelength range covered includes [O i] 6300+64, [N ii] 6548+83, Halpha, and [S ii] 6716+31. This will allow us to obtain some important additional information, such as radial variations in the excitation and gas density. Real Time Justification ----------------------- We do not have special requirements. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Paper Products: Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 7351( 6) - 04/07/99 11:54 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC3031-NUC GALAXY, SPIRAL, LINER, RA=9H 55M 33.38S +/- 0.01S, J2000 V=-35 V = +15.35 NUCLEUS DEC=69D 3' 55.16" +/- 0.01", F(4800)=2.1+/-0.2e-15 PLATE-ID=00M9 Comments: continuum estimated from WFPC2 image and FOS spectrum 7351( 6) - 04/07/99 11:54 - [ 4] Visit: 01 Visit Priority: Visit Requirements: ORIENT 20D TO 50D On Hold Comments: Additional Comments: Slit orientation +/-15D relative to best PA. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC3031-NUC STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 2.0 S ONBOARD ACQ FOR 2 CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC3031-NUC STIS/C ACQ/PEA 52X0.1 MIRROR 1 3.5 S ONBOARD ACQ FOR 10 CD K ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC3031-NUC STIS/C ACCUM 52X0.1 G750M 6581 CR-SPLIT=2 1 1000 S PAR 11 WITH 10 POS TARG 0 CD , 0 ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC3031-NUC WFPC2 IMAGE WFALL-F F439W CR-SPLIT=NO 1 800 S IX Comments: PAR 11 WITH 10 ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC3031-NUC STIS/C ACCUM 52X0.1 G750M 6581 CR-SPLIT=2 1 1000 S PAR 21 WITH 20 POS TARG CD -0.1, 0 Comments: Slit -X1 ------------------------------------------------------------------------------------------------------------------------------------ 21 NGC3031-NUC WFPC2 IMAGE WFALL-F F439W CR-SPLIT=NO 1 700 S IX Comments: PAR 21 WITH 20 ------------------------------------------------------------------------------------------------------------------------------------ 30 NGC3031-NUC STIS/C ACCUM 52X0.1 G750M 6581 CR-SPLIT=2 1 1000 S PAR 31 WITH 30 POS TARG CD 0.1, 0 Comments: Slit +X1 ------------------------------------------------------------------------------------------------------------------------------------ 31 NGC3031-NUC WFPC2 IMAGE WFALL-F F439W CR-SPLIT=NO 1 700 S IX Comments: PAR 31 WITH 30 ------------------------------------------------------------------------------------------------------------------------------------ 40 NGC3031-NUC STIS/C ACCUM 52X0.1 G750M 6581 CR-SPLIT=2 1 1100 S PAR 41 WITH 40 POS TARG CD -0.2, 0 Comments: Slit -X2 ------------------------------------------------------------------------------------------------------------------------------------ 41 NGC3031-NUC WFPC2 IMAGE WFALL-F F555W CR-SPLIT=NO 1 700 S IX Comments: PAR 41 WITH 40 ------------------------------------------------------------------------------------------------------------------------------------ 50 NGC3031-NUC STIS/C ACCUM 52X0.1 G750M 6581 CR-SPLIT=NO 1 600 S PAR 51 WITH 50 POS TARG CD -0.3, 0 Comments: Slit -X3 ------------------------------------------------------------------------------------------------------------------------------------ 51 NGC3031-NUC WFPC2 IMAGE WFALL-F F555W CR-SPLIT=NO 1 300 S IX Comments: PAR 51 WITH 50 ------------------------------------------------------------------------------------------------------------------------------------ 7351( 6) - 04/07/99 11:54 - [ 5] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 55 NGC3031-NUC STIS/C ACCUM 52X0.1 G750M 6581 CR-SPLIT=NO 1 610 S PAR 56 WITH 55 POS TARG CD -0.3, 0 Comments: Slit -X3 ------------------------------------------------------------------------------------------------------------------------------------ 56 NGC3031-NUC WFPC2 IMAGE WFALL-F F555W CR-SPLIT=NO 1 300 S IX Comments: PAR 55, 56 WITH 50 ------------------------------------------------------------------------------------------------------------------------------------ 60 NGC3031-NUC STIS/C ACCUM 52X0.1 G750M 6581 CR-SPLIT=2 1 1000 S PAR 61 WITH 60 POS TARG CD 0.2, 0 Comments: Slit +X2 ------------------------------------------------------------------------------------------------------------------------------------ 61 NGC3031-NUC WFPC2 IMAGE WFALL-F F814W CR-SPLIT=NO 1 700 S IX Comments: PAR 61 WITH 60 ------------------------------------------------------------------------------------------------------------------------------------ 70 NGC3031-NUC STIS/C ACCUM 52X0.1 G750M 6581 CR-SPLIT=2 1 1050 S PAR 71, 72 WITH 70 POS CD TARG 0.3, 0 Comments: Slit +X3 ------------------------------------------------------------------------------------------------------------------------------------ 71 NGC3031-NUC WFPC2 IMAGE WFALL-F F814W CR-SPLIT=NO 1 300 S IX Comments: PAR 71, 72 WITH 70 ------------------------------------------------------------------------------------------------------------------------------------ 72 NGC3031-NUC WFPC2 IMAGE WFALL-F F814W CR-SPLIT=NO 1 300 S IX Comments: PAR 71, 72 WITH 70 ------------------------------------------------------------------------------------------------------------------------------------ 7351( 6) - 04/07/99 11:54 - [ 6] Summary Form for Proposal 7351 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 52X0.1 WFALL-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACQ/PEAK ACCUM IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT CR-SPLIT=2 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 20D TO 50D ONBOARD ACQ FOR 2 ONBOARD ACQ FOR 10 PAR 11 WITH 10 POS TARG 0, 0 PAR 21 WITH 20 POS TARG -0.1, 0 PAR 31 WITH 30 POS TARG 0.1, 0 PAR 41 WITH 40 POS TARG -0.2, 0 PAR 51 WITH 50 POS TARG -0.3, 0 PAR 56 WITH 55 POS TARG -0.3, 0 PAR 61 WITH 60 POS TARG 0.2, 0 PAR 71, 72 WITH 70 POS TARG 0.3, 0 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G750M F439W F555W F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC3031-NUC ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 6581 ------------------------------------------------------------------------------------------------------------------------------------