Proposal_Information Title: Black holes in kinematically decoupled cores: a study of IC 1459 Proposal_Category: GO Scientific_Category: GALAXIES & CLUSTERS Cycle: 6 Investigators PI_Name: P. Tim de Zeeuw PI_Institution: Sterrewacht Leiden CoI_Name: Roeland P. van der Marel CoI_Institution: Institute for Advanced Study, Princeton Contact: N CoI_Name: C. Marcella Carollo CoI_Institution: Johns Hopkins University, Baltimore Contact: Y CoI_Name: Marijn Franx CoI_Institution: Kapteyn Laboratorium, Groningen Contact: N Abstract: IC 1459 is a luminous active E3 elliptical galaxy which has been studied extensively using ground-based spectroscopy and WFPC2 broad-band imaging, because of its remarkable kinematic properties. The stars in the central 10 arcsec counter-rotate with respect to the gas, and with respect to the stars at larger radii. This and other evidence suggest that a strong accretion event has occurred in the history of this galaxy. Models for the ground-based stellar kinematics and HST broad-band photometry indicate the possible presence of a 3 * 10^9 solar mass black hole (BH). WFPC2 broad-band images show a blue nuclear point source, probably due to non-thermal continuum. Ground-based imaging and spectroscopy of the ionized gas indicates that it resides in a disk at an inclination of approximately 60 degrees. These properties are very similar to those of M87, for which HST has unambiguously demonstrated the presence of a BH, but which presumably had a very different formation history. Establishing the presence of a BH in IC 1459 is important for understanding the relevance of mergers and interactions for the growth of nuclear BHs. We will obtain a WFPC2 H_alpha+[NII] narrow-band image (to be constructed from one on-band and one off-band image) to study the nuclear morphology of the gas disk of IC 1459, and FOS spectra to determine the rotation of the gas close to the nucleus. This will allow the identification of any BH more massive than 10^8 solar masses. Questions Observing_Description: This project consists of two visits. In visit 1, 2 orbits of WFPC2 data will be taken. In visit 2, 6 orbits of FOS/RD data will taken. The first orbit of the WFPC2 visit will be used to obtain exposures with the LRF at 6611 Angstrom. The second orbit will be used to obtain exposures with the narrow F631N filter. The former is an `on-band' image which transmits the H_alpha + [NII] emission lines. The LRF wavelength of 6611 Angstrom with the FR680P15 LRF configuration places the target on the PC CCD with 0.046 x 0.046 arcsec pixels, hence maximizing the spatial resolution. The latter is an emission free image (the contribution of the redshifted [OI]6300 line of the galaxy in F631N will be negligible). The target will be placed at the same positions on the PC CCD as for the LRF exposures in the first orbit (to facilitate the analysis). The F631N image will be combined with PC CCD broad-band images in F555W and F814W that were obtained by us in Cycle 4, to construct a suitable `off-band' image that will be used for the on-minus-off-band subtraction. The final result will be an H_alpha + [NII] image of the ionized gas in the nuclear region of IC 1459. The limited field-of-view for the LRF is no problem, as we are interested mainly in the nuclear (< few arcsec) morphology and flux distribution of the ionized gas. There is no narrow-band FxxxN filter available that could be used instead of the LRF filter. F658N is not suited as on-band image, because [NII]6583 falls exactly on the long-wavelength edge of this filter. Rotation of the gas in IC 1459 will shift this line either just inside or outside the filter, hence producing a gradient in the count-rate of a factor 10 along the major axis, where the gas rotation varies roughly from -250 km/s to +250 km/s. For each filter we obtain three exposures so as to allow accurate cosmic ray subtraction. Two of the exposures are obtained with the target at the same position on the CCD, while the third is obtained with the target shifted by (2,2) pixels, so as to allow identification of hot pixels and CCD defects. There are several things to be noted in this context: (i) we do not require sub-pixel dithering to improve the PSF sampling. (ii) There is no need to adopt a shift of (11,11) PC pixels = (5,5) WF pixels as is often done. With the LRFs there is useful data on only one of the CCD chips. Hence, there is no need to adopt a target shift that corresponds to an integer pixel shift on all CCDs. (iii) There is no need to obtain all three exposures with the target at a different position, as would be done by one of the standard WFPC2 dithering strategies. By obtaining two of the three exposures at the same position, several minutes of overhead time are saved. The count-rates expected for the images are listed in the comments to the individual exposures. We are confident that the resulting S/N allows a detailed study of the ionized gas morphology near the nucleus. The position of the nucleus of IC 1459 was determined using three methods: (i) ellipse fitting to the galaxy isophotes on the relevant DSS plate (plate-ID listed in the target definition); (ii) measurement from our Cycle 4 WFPC2 broad-band images; and (iii) measurement from pre-refurbishment WFPC broad-band images from the HST Archive. The different results agreed to within approx. 1 arcsec, which is sufficient for our purposes. For the FOS target acquisition we will use a sequence of ACQ/PEAK stages on the nucleus of the galaxy, which is bright and point-like. We adopt a slightly non-standard 5-stage peakup. It is a combination of the strategies used in Cycle 5 for our projects GO-5847 and GO-5848 which studied other elliptical galaxies. The suitability of this sequence for the extended surface brightness distribution of IC 1459 was verified using the Monte-Carlo FOS acquisition testing software developed by one of us (RvdM) and which is available on the internet (contact M.~Rosa). The acquisition sequence centers the target in the square 0.25-PAIR (upper) aperture with a mean positioning error of 0.032 arcsec. In the first stage we adopt a 2x5 pattern with the 4.3 aperture, rather than the standard 1x3 pattern. The accuracy of our knowledge of the target coordinates is not sufficient for the latter pattern. The first ACQ/PEAK stage will be done with the G570H grating, to make sure that the FOS will not safe. The subsequent stages will be done with the MIRROR, which provides slightly higher S/N. After acquisition of the target, we will obtain spectra at six positions: with the square 0.25-PAIR (upper) aperture on the nucleus, and at +/- 0.2" along the major axis of the galaxy; and with the square 0.1-PAIR (upper) aperture on the nucleus, and at +/- 0.1" along the major axis of the galaxy. The main goal is to determine the rotation velocity of the gas from the H_alpha + [NII] emission lines, to constrain the nuclear mass distribution and the possible presence of a black hole. We will use the G570H grating on the red detector of the FOS. The wavelength range is then 4569-6818 Angstrom, with a scale of 4.37 Angstrom/diode. At the end of FOS visit we will obtain an ACQ image, so as to allow post-hoc verification of the target positioning. Revised version, Oct 96: The continuum and emission lines fluxes near the nucleus of IC 1459 were determined from the results of visit #1. These were used to calculate the count rates expected for the FOS observations in visit #2. The results are listed in the comments to the individual exposures. The S/N is sufficient to determine the ionized gas kinematics. The dark count rate and sky count rate are negligible. Real_Time_Justification: No real time requirements. Calibration_Justification: Accurate wavelength calibration is essential for the success of our FOS observations. We therefore obtain wavelength calibration spectra in each orbit of the FOS visit. This can be done during earth occultation, and hence does not decrease the time available for observations of the target. Additional_Comments: The POS TARG special requirement in exposure 130 indicates a shift with respect to the default position for the given LRF wavelength. It DOES NOT indicate an absolute position on the CCD. Please ensure that this is correctly implemented when the observations are scheduled. The exposures 210-230 should use the same target positions on the PC CCD as do exposures 110-130, as indicated by the `SAME POS AS' special requirements. ! All keywords with multiple entries are comma delimited except the ! Visit_Requirements and Special_Requirements keywords which can be ! delimited with carriage returns or semi-colons, but not commas Fixed_Targets Target_Number: 1 Target_Name: IC1459 Alternate_Names: PKS2254-367, IRAS22544-3643 Description: GALAXY, ELLIPTICAL, RADIO GALAXY, NUCLEUS, DUST LANE, NLR Position: RA = 22H 57M 10.471S +/- 0.5", DEC = -36D 27' 44.53" +/- 0.5", PLATE-ID = 05XU Equinox: J2000.0 RV_or_Z: V = 1691 RA_PM: 0.0 Dec_PM: 0.0 Epoch: Annual_Parallax: 0.0 Flux: SURF(V) = 14.5 +/- 0.5 B-V = 0.98 +/- 0.1 V-R = 0.85 +/- 0.1 F-LINE(6565) = 5.5 +/- 2.0 e-14 Comments: Coordinates determined as described above. V-band surface brightness is average in central (0.1 arcsec)^2. Line flux is total H_alpha+[NII] flux in central arcsec^2. Target_Number: 2 Target_Name: IC1459-NUC Alternate_Names: Description: GALAXY, ELLIPTICAL, RADIO GALAXY, NUCLEUS, DUST LANE, NLR Position: RA = 22H 57M 10.471S +/- 0.5", DEC = -36D 27' 44.53" +/- 0.5", PLATE-ID = 05XU Equinox: J2000.0 RV_or_Z: V = 1691 RA_PM: 0.0 Dec_PM: 0.0 Epoch: Annual_Parallax: 0.0 Flux: SURF(V) = 14.5 +/- 0.5 B-V = 0.98 +/- 0.1 V-R = 0.85 +/- 0.1 F-LINE(6565) = 5.5 +/- 2.0 e-14 Comments: See comments to target #1. Target_Number: 3 Target_Name: IC1459-MAJ1 Alternate_Names: Description: GALAXY, ELLIPTICAL, RADIO GALAXY, NUCLEUS, DUST LANE, NLR Position: R = 0.2", PA = 30D, FROM 2 Equinox: J2000.0 RV_or_Z: V = 1691 RA_PM: 0.0 Dec_PM: 0.0 Epoch: Annual_Parallax: 0.0 Flux: SURF(V) = 15.1 +/- 0.5 B-V = 0.98 +/- 0.01 V-R = 0.85 +/- 0.1 F-LINE(6565) = 5.5 +/- 2.0 e-14 Comments: Offset from target #2 is along major axis. V-band surface brightness pertains to this position. Line flux is total H_alpha+[NII] flux in central arcsec^2. Target_Number: 4 Target_Name: IC1459-MAJ2 Alternate_Names: Description: GALAXY, ELLIPTICAL, RADIO GALAXY, NUCLEUS, DUST LANE, NLR Position: R = 0.2", PA = 210D, FROM 2 Equinox: J2000.0 RV_or_Z: V = 1691 RA_PM: 0.0 Dec_PM: 0.0 Epoch: Annual_Parallax: 0.0 Flux: SURF(V) = 15.1 +/- 0.5 B-V = 0.98 +/- 0.01 V-R = 0.85 +/- 0.1 F-LINE(6565) = 5.5 +/- 2.0 e-14 Comments: See comments to target #3. Target_Number: 5 Target_Name: IC1459-MAJ3 Alternate_Names: Description: GALAXY, ELLIPTICAL, RADIO GALAXY, NUCLEUS, DUST LANE, NLR Position: R = 0.1", PA = 30D, FROM 2 Equinox: J2000.0 RV_or_Z: V = 1691 RA_PM: 0.0 Dec_PM: 0.0 Epoch: Annual_Parallax: 0.0 Flux: SURF(V) = 14.9 +/- 0.5 B-V = 0.98 +/- 0.01 V-R = 0.85 +/- 0.1 F-LINE(6565) = 1.9 +/- 0.5 e-13 Comments: Offset from target #2 is along major axis. V-band surface brightness pertains to this position. Line flux is total H_alpha+[NII] flux in central arcsec^2. Target_Number: 6 Target_Name: IC1459-MAJ4 Alternate_Names: Description: GALAXY, ELLIPTICAL, RADIO GALAXY, NUCLEUS, DUST LANE, NLR Position: R = 0.1", PA = 210D, FROM 2 Equinox: J2000.0 RV_or_Z: V = 1691 RA_PM: 0.0 Dec_PM: 0.0 Epoch: Annual_Parallax: 0.0 Flux: SURF(V) = 14.9 +/- 0.5 B-V = 0.98 +/- 0.01 V-R = 0.85 +/- 0.1 F-LINE(6565) = 1.9 +/- 0.5 e-13 Comments: See comments to target #5. Visits Visit_Number: 1 Visit_Requirements: On_Hold_Comments: Visit_Comments: Exposure_Number: 110 Target_Name: IC1459 Config: WFPC2 Opmode: IMAGE Aperture: LRF Sp_Element: LRF Wavelength: 6611.0 Optional_Parameters: CR-SPLIT=NO ATD-GAIN=7 Number_of_Iterations: 1 Time_Per_Exposure: 700S Special_Requirements: SEQ 110-130 NON-INT Comments: Expected average emission line count rate in central arcsec^2 of galaxy: 0.16 electrons/sec/pix. Continuum: 0.71 electrons/sec/pix. Sky: 0.001 electrons/sec/pix. Target will fall on PC CCD. Exposure_Number: 120 Target_Name: IC1459 Config: WFPC2 Opmode: IMAGE Aperture: LRF Sp_Element: LRF Wavelength: 6611.0 Optional_Parameters: CR-SPLIT=NO ATD-GAIN=7 Number_of_Iterations: 1 Time_Per_Exposure: 700S Special_Requirements: SAME POS AS 110 Comments: Expected count rates as for exp.110. Exposure_Number: 130 Target_Name: IC1459 Config: WFPC2 Opmode: IMAGE Aperture: LRF Sp_Element: LRF Wavelength: 6611.0 Optional_Parameters: CR-SPLIT=NO ATD-GAIN=7 Number_of_Iterations: 1 Time_Per_Exposure: 700S Special_Requirements: POS TARG 0.0911,0.0911 END ORBIT EXPAND MIN DUR 50% MAX DUR 300% Comments: Last exposure in orbit #1. Expected count rates as for exp.110. The `POS TARG' shifts the target by (2,2) PC pixels w.r.t. the position for exp.110, to allow identification of CCD defects and hot pixels. Exposure_Number: 210 Target_Name: IC1459 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F631N Wavelength: Optional_Parameters: CR-SPLIT=NO ATD-GAIN=7 Number_of_Iterations: 1 Time_Per_Exposure: 700S Special_Requirements: SAME POS AS 110 SEQ 210-230 NON-INT Comments: Expected average continuum count rate in central arcsec^2 of galaxy: 0.70 electrons/sec/pix. Sky: 0.001 electrons/sec/pix. Exposure_Number: 220 Target_Name: IC1459 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F631N Wavelength: Optional_Parameters: CR-SPLIT=NO ATD-GAIN=7 Number_of_Iterations: 1 Time_Per_Exposure: 700S Special_Requirements: SAME POS AS 110 Comments: Expected count rates as for exp.210. Exposure_Number: 230 Target_Name: IC1459 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F631N Wavelength: Optional_Parameters: CR-SPLIT=NO ATD-GAIN=7 Number_of_Iterations: 1 Time_Per_Exposure: 900S Special_Requirements: SAME POS AS 130 END ORBIT EXPAND MIN DUR 50% MAX DUR 300% Comments: Last exposure in orbit #2. Expected count rates as for exp.210. Visit_Number: 2 Visit_Requirements: On_Hold_Comments: Visit_Comments: Exposure_Number: 310 Target_Name: IC1459-NUC Config: FOS/RD Opmode: ACQ/PEAK Aperture: 4.3 Sp_Element: G570H Wavelength: Optional_Parameters: SCAN-STEP-X = 2.36, SCAN-STEP-Y = 0.80, SEARCH-SIZE-X = 2, SEARCH-SIZE-Y = 5, TYPE = UP Number_of_Iterations: 1 Time_Per_Exposure: 1.0S Special_Requirements: ONBOARD ACQ FOR 320 NO SPLIT SEQ 310-340 NON-INT Comments: Estimated V magnitude within aperture = 14.17. Yields approx. 3600 counts on galaxy nucleus. Exp. 310-340 must be completed in first orbit of visit. Exposure_Number: 320 Target_Name: IC1459-NUC Config: FOS/RD Opmode: ACQ/PEAK Aperture: 1.0-PAIR Sp_Element: MIRROR Wavelength: Optional_Parameters: SCAN-STEP-X = 0.740, SCAN-STEP-Y = 0.6495, SEARCH-SIZE-X = 5, SEARCH-SIZE-Y = 2, TYPE = UP Number_of_Iterations: 1 Time_Per_Exposure: 2.0S Special_Requirements: ONBOARD ACQ FOR 330 NO SPLIT Comments: Estimated V magnitude within aperture = 15.66. Yields approx. 2700 counts on galaxy nucleus. Exposure_Number: 330 Target_Name: IC1459-NUC Config: FOS/RD Opmode: ACQ/PEAK Aperture: 0.5-PAIR Sp_Element: MIRROR Wavelength: Optional_Parameters: SCAN-STEP-X = 0.2867, SCAN-STEP-Y = 0.2867, SEARCH-SIZE-X = 3, SEARCH-SIZE-Y = 3, TYPE = UP Number_of_Iterations: 1 Time_Per_Exposure: 4.0S Special_Requirements: ONBOARD ACQ FOR 340 NO SPLIT Comments: Estimated V magnitude within aperture = 16.93. Yields approx. 1700 counts on galaxy nucleus. Exposure_Number: 340 Target_Name: IC1459-NUC Config: FOS/RD Opmode: ACQ/PEAK Aperture: 0.25-PAIR Sp_Element: MIRROR Wavelength: Optional_Parameters: SCAN-STEP-X = 0.1433, SCAN-STEP-Y = 0.1433, SEARCH-SIZE-X = 3, SEARCH-SIZE-Y = 3, TYPE = UP Number_of_Iterations: 1 Time_Per_Exposure: 8.0S Special_Requirements: ONBOARD ACQ FOR 350 NO SPLIT Comments: Estimated V magnitude within aperture = 18.32. Yields approx. 940 counts on galaxy nucleus. Exposure_Number: 350 Target_Name: IC1459-NUC Config: FOS/RD Opmode: ACQ/PEAK Aperture: 0.25-PAIR Sp_Element: MIRROR Wavelength: Optional_Parameters: SCAN-STEP-X = 0.043, SCAN-STEP-Y = 0.043, SEARCH-SIZE-X = 5, SEARCH-SIZE-Y = 5, TYPE = UP Number_of_Iterations: 1 Time_Per_Exposure: 35.0S Special_Requirements: ONBOARD ACQ FOR 360-720 NO SPLIT SEQ 350-372 NON-INT Comments: Estimated V magnitude within aperture = 18.32. Yields approx. 4100 counts on galaxy nucleus. Exp. 350-372 must be completed in 2nd orbit of visit. Exposure_Number: 360 Target_Name: IC1459-NUC Config: FOS/RD Opmode: ACCUM Aperture: 0.25-PAIR Sp_Element: G570H Wavelength: Optional_Parameters: STEP-PATT = SINGLE Number_of_Iterations: 1 Time_Per_Exposure: 600S Special_Requirements: MAX DUR 200% MIN DUR 50% NO SPLIT Comments: Expected count rates at the wavelength of the [NII]6583 line: 1.45 counts/sec/diode in emission, and 0.16 counts/sec/diode in continuum. Exposure_Number: 370 Target_Name: WAVE Config: FOS/RD Opmode: ACCUM Aperture: 0.25-PAIR Sp_Element: G570H Wavelength: Optional_Parameters: STEP-PATT = SINGLE Number_of_Iterations: 1 Time_Per_Exposure: DEF Special_Requirements: NO SPLIT Comments: Wave-cal can be done during occultation. Exposure_Number: 372 Target_Name: WAVE Config: FOS/RD Opmode: ACCUM Aperture: 0.1-PAIR Sp_Element: G570H Wavelength: Optional_Parameters: STEP-PATT = SINGLE Number_of_Iterations: 1 Time_Per_Exposure: DEF Special_Requirements: NO SPLIT Comments: Wave-cal can be done during occultation. Exposure_Number: 410 Target_Name: IC1459-MAJ3 Config: FOS/RD Opmode: ACCUM Aperture: 0.1-PAIR Sp_Element: G570H Wavelength: Optional_Parameters: STEP-PATT = SINGLE Number_of_Iterations: 1 Time_Per_Exposure: 2480S Special_Requirements: MAX DUR 150% MIN DUR 85% NO SPLIT SEQ 410-420 NON-INT Comments: Expected count rates at the wavelength of the [NII]6583 line: 0.21 counts/sec/diode in emission, and 0.02 counts/sec/diode in continuum. Exp. 410-420 must be completed in 3rd orbit of visit. Exposure_Number: 420 Target_Name: WAVE Config: FOS/RD Opmode: ACCUM Aperture: 0.1-PAIR Sp_Element: G570H Wavelength: Optional_Parameters: STEP-PATT = SINGLE Number_of_Iterations: 1 Time_Per_Exposure: DEF Special_Requirements: NO SPLIT Comments: Wave-cal can be done during occultation. Exposure_Number: 510 Target_Name: IC1459-MAJ4 Config: FOS/RD Opmode: ACCUM Aperture: 0.1-PAIR Sp_Element: G570H Wavelength: Optional_Parameters: STEP-PATT = SINGLE Number_of_Iterations: 1 Time_Per_Exposure: 2480S Special_Requirements: MAX DUR 150% MIN DUR 85% NO SPLIT SEQ 510-522 NON-INT Comments: Expected count rates as for exp.410. Exp. 510-522 must be completed in 4th orbit of visit. Exposure_Number: 520 Target_Name: WAVE Config: FOS/RD Opmode: ACCUM Aperture: 0.1-PAIR Sp_Element: G570H Wavelength: Optional_Parameters: STEP-PATT = SINGLE Number_of_Iterations: 1 Time_Per_Exposure: DEF Special_Requirements: NO SPLIT Comments: Wave-cal can be done during occultation. Exposure_Number: 522 Target_Name: WAVE Config: FOS/RD Opmode: ACCUM Aperture: 0.25-PAIR Sp_Element: G570H Wavelength: Optional_Parameters: STEP-PATT = SINGLE Number_of_Iterations: 1 Time_Per_Exposure: DEF Special_Requirements: NO SPLIT Comments: Wave-cal can be done during occultation. Exposure_Number: 610 Target_Name: IC1459-MAJ1 Config: FOS/RD Opmode: ACCUM Aperture: 0.25-PAIR Sp_Element: G570H Wavelength: Optional_Parameters: STEP-PATT = SINGLE Number_of_Iterations: 1 Time_Per_Exposure: 1130S Special_Requirements: NO SPLIT SEQ 610-632 NON-INT Comments: Expected count rates at the wavelength of the [NII]6583 line: 0.36 counts/sec/diode in emission, and 0.09 counts/sec/diode in continuum. Exp. 610-632 must be completed in 5th orbit of visit. Exposure_Number: 620 Target_Name: IC1459-MAJ2 Config: FOS/RD Opmode: ACCUM Aperture: 0.25-PAIR Sp_Element: G570H Wavelength: Optional_Parameters: STEP-PATT = SINGLE Number_of_Iterations: 1 Time_Per_Exposure: 1130S Special_Requirements: MAX DUR 150% MIN DUR 85% NO SPLIT Comments: Expected count rates as for exp.610. Exposure_Number: 630 Target_Name: WAVE Config: FOS/RD Opmode: ACCUM Aperture: 0.25-PAIR Sp_Element: G570H Wavelength: Optional_Parameters: STEP-PATT = SINGLE Number_of_Iterations: 1 Time_Per_Exposure: DEF Special_Requirements: NO SPLIT Comments: Wave-cal can be done during occultation. Exposure_Number: 632 Target_Name: WAVE Config: FOS/RD Opmode: ACCUM Aperture: 0.1-PAIR Sp_Element: G570H Wavelength: Optional_Parameters: STEP-PATT = SINGLE Number_of_Iterations: 1 Time_Per_Exposure: DEF Special_Requirements: NO SPLIT Comments: Wave-cal can be done during occultation. Exposure_Number: 710 Target_Name: IC1459-NUC Config: FOS/RD Opmode: ACCUM Aperture: 0.1-PAIR Sp_Element: G570H Wavelength: Optional_Parameters: STEP-PATT = SINGLE Number_of_Iterations: 1 Time_Per_Exposure: 1620S Special_Requirements: MAX DUR 200% MIN DUR 50% EXPAND NO SPLIT SEQ 710-720 NON-INT Comments: Expected count rates at the wavelength of the [NII]6583 line: 0.52 counts/sec/diode in emission, and 0.02 counts/sec/diode in continuum. Exp. 710-720 must be completed in 6th and final orbit of visit. Exposure_Number: 720 Target_Name: IC1459-NUC Config: FOS/RD Opmode: ACQ Aperture: 4.3 Sp_Element: MIRROR Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 500S Special_Requirements: MAX DUR 150% MIN DUR 85% NO SPLIT Comments: Total magnitude in 0.3x1.3 arcsec diode on the nucleus = 16.38. Expected counts in diode on nucleus: approx. 1500. Data_Distribution Medium: 8MM Blocking_Factor: 10 Ship_To: C. Marcella Carollo Johns Hopkins University Department of Physics & Astronomy Baltimore, MD 21218, USA Ship_Via: UPS Recipient_Email: marci@pha.jhu.edu