6785( 6) - 09/12/96 14:30 - [ 0] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6785 Version: 6 Check-in Date: 12-Sep-1996 14:25:51 1.Proposal Title: Ionized Gas Disks In Nearby Early Type Galaxies ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle GALAXIES & CLUSTERS GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Matthew Malkan University of California CoI: Wayne Webb University of California N ------------------------------------------------------------------------------------ 6. Abstract We propose WFPC2 H Alpha/N II imaging to search for gas disks in the nuclei of nearby early-type galaxies. Discovering these disks is vital because they allow the most direct spectroscopic measurement of the gravitational effects of the supermassive black holes they orbit. HST has already used the spatially resolved Doppler-shifted emission lines of just such a rotating disk in M 87 to provide the first conclusive dynamical mass estimate of a galactic black hole. We propose to image the nuclei of all 9 remaining nearby early-type galaxies which are also good candidates for having similar nuclear disks of ionzed gas. They have strong nuclear H Alpha/N II emission at a low redshift (z<0.0057) which places it within the WFPC2 ``N II" filter bandpass. The small distances of these galaxies are also essential so that HST can resolve the finest spatial scales (10 parsecs or less), where the gravitational effects of a black hole would be most detectable. Half of the sample galaxies contain compact nuclear radiosources (as does M 87), so that we can see if that makes a systematic difference in the nuclear distribution of ionized gas. We will also search for evidence of bipolar outflows aligned with the radio jets, and for other interesting structures in H Alpha\ such as shock fronts, bubbles, and superwinds. ------------------------------------------------------------------------------------ Observations Description ------------------------ We propose to use the unparalleled resolving power of post- Costar HST to search for nuclear disks in early-type galaxies by imaging emission-line galactic nuclei. All candidates have z<0.0057, so that their H Alpha\\ emission is contained in the passband of the WFPC2 ``N II" filter. Even if the disks we find are no larger in physical extent than those already discovered, they should still be resolvable into at least two elements along the slit. Since we are looking for relatively bright emission lines, any WFPC2 detections are essentially guaranteed to be bright enough for accurate line velocity measurements with FOS. The Table lists the target galaxies in order of decreasing priority, based on emission line flux (Filippenko & Sargent 1985;Silchenko 1989; Dressler and Sandage 1983; Kim 1989; Caldwell 1984;Ho et al. 1995; Phillips et al. 1986 ). For one of the weaker-lined galaxies, the line flux in a small ground-based slit is 1.e-13 erg/sec/cm2, which will produce a total of 65 detected photoelectrons per second through the 658N filter. We will assume somewhat conservatively that this flux is spread uniformly over the central 200 pixels of the PC1. Then our two consecutive 750- second exposures will detect a total of 500 counts per pixel. In the worst case the starlight continuum will also contribute four times this. The extra photon- statistical noise of the continuum photons drops the resulting SNR of the continuum-subtracted emission line image to 10 per pixel. Some modest smoothing over the WFPC2 pixels will yield a comparable SNR per spatial resolution element in the faintest targets. The broadband exposure times are estimated to yield at least a few thousand detected photons per PC1 pixel. This safely avoids saturation, but provides sufficiently high signal to noise in the continuum image, that it will not add significant noise when it is scaled and subtracted from the 658N exposure to yield a pure emission line image. (We will not obtain another broadband expsosure if WFPC2 has already obtained a broad V, R, or I image of the galactic nucleus). Since our exposure times will be longer than those used in the M 87 study, they will compensate for the somewhat lower line fluxes, yielding images of comparable quality. Since our typical target visibilities are 50 minutes per orbit, all of the exposures---including the short broadband image---can be obtained within a single orbit per galaxy. (The one galaxy with less visibility---NGC 5846--- will not need another broadband exposure.) No special calibrations are required. Only HST can provide nearly an order of magnitude improvement in spatial resolution over ground-based optical telescopes. A surprisingly large proportion of HST's pre-COSTAR serendipitous discoveries have shown that very interesting nuclear structures exist on this scale size, which is inaccessible to ground-based optical imaging. Real Time Justification ----------------------- No special scheduling requirements. No special coordination requests. Our own supporting observations need not be simultaneous. We will also obtain deep multicolor ground-based images (at Lick Observatory) and VLA radio maps of those galaxies visible from the Northern hemisphere. We will propose for multicolor CCD imaging of the Southern galaxies from CTIO. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6785( 6) - 09/12/96 14:30 - [ 1] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC2328 Galaxy RA=7H 1M 1.0S +/-0.3S, DEC=-41D 1950 V = SURF(V) = 15+/-1 59' 42.0" +/-2" +1159 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1950 0 0 0 2 NGC2640 Galaxy RA=8H 36M 5.0S +/-0.3S, DEC=-54D 1950 V = SURF(V) = 15+/-1 56' 51.0" +/-2" +1051 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1950 0 0 0 3 NGC4036 Galaxy RA=11H 58M 53.6S +/-0.3S, 1950 V = SURF(V) = 15+/-1 DEC=62D 10' 23.0" +/-2" +1397 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1950 0 0 0 4 NGC3718 Galaxy RA=11H 29M 50.7S +/-0.3S, 1950 V = SURF(V) = 15+/-1 DEC=53D 20' 33.0" +/-2" +1031 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1950 0 0 0 5 NGC4111 Galaxy RA=12H 4M 31.0S +/-0.3S, DEC=43D 1950 V = +815 SURF(V) = 15+/-1 20' 37.0" +/-2" Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1950 0 0 0 6 NGC5084 Galaxy RA=13H 17M 34.0S +/-0.3S, DEC=- 1950 V = SURF(V) = 15+/-1 21D 33' 54.0" +/-2" +1700 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1950 0 0 0 7 NGC2787 Galaxy RA=9H 14M 49.7S +/-0.3S, DEC=69D 1950 V = +649 SURF(V) = 15+/-1 24' 50.0" +/-2" Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1950 0 0 0 8 NGC2768 Galaxy RA=9H 7M 45.2S +/-0.3S, DEC=60D 1950 V = SURF(V) = 15+/-1 14' 40.0" +/-2" +1335 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1950 0 0 0 9 NGC5846 GALAXY RA=15H 3M 56.9S +/-0.3S, DEC=1D 1950 V = SURF(V) = 15+/-1 47' 53.0" +/-2" +1680 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1950 0 0 0 6785( 6) - 09/12/96 14:30 - [ 2] Visit: 01 Visit Requirements: 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 ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC2328 WFPC2 IMAGE PC1 F658N DITHER-TYPE=LINE,CR-SPLIT=NO 1 1100 S ------------------------------------------------------------------------------------------------------------------------------------ 6785( 6) - 09/12/96 14:30 - [ 3] Visit: 02 Visit Requirements: CVZ 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 ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC2640 WFPC2 IMAGE PC1 F702W DITHER-TYPE=LINE 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 21 NGC2640 WFPC2 IMAGE PC1 F658N DITHER-TYPE=LINE 1 1400 S ------------------------------------------------------------------------------------------------------------------------------------ 6785( 6) - 09/12/96 14:30 - [ 4] Visit: 03 Visit Requirements: CVZ 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 ------------------------------------------------------------------------------------------------------------------------------------ 30 NGC4036 WFPC2 IMAGE PC1 F702W DITHER-TYPE=LINE 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 31 NGC4036 WFPC2 IMAGE PC1 F658N DITHER-TYPE=LINE 1 1400 S ------------------------------------------------------------------------------------------------------------------------------------ 6785( 6) - 09/12/96 14:30 - [ 5] Visit: 04 Visit Requirements: 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 ------------------------------------------------------------------------------------------------------------------------------------ 40 NGC3718 WFPC2 IMAGE PC1 F702W 1 400 S SEQ 40-41 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 41 NGC3718 WFPC2 IMAGE PC1 F658N DITHER-TYPE=LINE,CR-SPLIT=NO 1 800 S ------------------------------------------------------------------------------------------------------------------------------------ 6785( 6) - 09/12/96 14:30 - [ 6] Visit: 05 Visit Requirements: 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 ------------------------------------------------------------------------------------------------------------------------------------ 50 NGC4111 WFPC2 IMAGE PC1 F702W 1 600 S SEQ 50-51 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 51 NGC4111 WFPC2 IMAGE PC1 F658N DITHER-TYPE=LINE 1 600 S ------------------------------------------------------------------------------------------------------------------------------------ 6785( 6) - 09/12/96 14:30 - [ 7] Visit: 06 Visit Requirements: 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 ------------------------------------------------------------------------------------------------------------------------------------ 60 NGC5084 WFPC2 IMAGE PC1 F702W 1 500 S SEQ 60-61 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 61 NGC5084 WFPC2 IMAGE PC1 F658N DITHER-TYPE=LINE 1 600 S ------------------------------------------------------------------------------------------------------------------------------------ 6785( 6) - 09/12/96 14:30 - [ 8] Visit: 07 Visit Requirements: CVZ 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 ------------------------------------------------------------------------------------------------------------------------------------ 70 NGC2787 WFPC2 IMAGE PC1 F702W DITHER-TYPE=LINE 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 71 NGC2787 WFPC2 IMAGE PC1 F658N DITHER-TYPE=LINE 1 1400 S ------------------------------------------------------------------------------------------------------------------------------------ 6785( 6) - 09/12/96 14:30 - [ 9] Visit: 08 Visit Requirements: CVZ 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 ------------------------------------------------------------------------------------------------------------------------------------ 80 NGC2768 WFPC2 IMAGE PC1 F702W DITHER-TYPE=LINE 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 81 NGC2768 WFPC2 IMAGE PC1 F658N DITHER-TYPE=LINE 1 1400 S ------------------------------------------------------------------------------------------------------------------------------------ 6785( 6) - 09/12/96 14:30 - [ 10] Visit: 09 Visit Requirements: 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 ------------------------------------------------------------------------------------------------------------------------------------ 91 NGC5846 WFPC2 IMAGE PC1 F658N CR-SPLIT=NO,DITHER-TYPE=LINE 1 1100 S ------------------------------------------------------------------------------------------------------------------------------------ 6785( 6) - 09/12/96 14:30 - [ 11] Summary Form for Proposal 6785 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters DITHER-TYPE=LINE CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category GALAXIES & CLUSTERS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CVZ SEQ 40-41 NON-INT SEQ 50-51 NON-INT SEQ 60-61 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F658N F702W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC2328 NGC2640 NGC4036 NGC3718 NGC4111 NGC5084 NGC2787 NGC2768 NGC5846 ------------------------------------------------------------------------------------------------------------------------------------