Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 1219c Report Date: 09-May-96:16:20 Version: ********** Check-in Date: ********** 1.Proposal Title: POLARIZATION MAPPING OF THE INNER STRUCTURE OF THE SEYFERT GALAXY NGC 1068 TO SEARCH FOR A NON-THERMAL SOURCE ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID QUASARS, AGN GTO/FOC Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Alec Boksenberg ROYAL GREENWICH OBSERVATORY UNITED KIN 0223 374000 PROFESSOR ------------------------------------------------------------------------------------ 7. Abstract Several Seyfert galaxies, including NGC 1068, are known to be intrinsically polarized. The source of this polarization may be synchrotron emission from a jet or electron scattering from an accretion disk or dust scattering from an extended aggregate of clouds surrounding the nucleus. Images with the Space Telescope at a resolution of 0.02" should resolve structure down to a scale of ~1 parsec in NGC 1068. High signal-to-noise images in polarized light should then enable one to discriminate between bright (unpolarized) HII regions, extended polarizing dust clouds and a compact polarized non-thermal source. In the UV, where residual galaxy dilution is weakest, polarizations of ~15% can be expected. The combination of UV sensitivity and high spatial resolution make the FOC well suited to this experiment. This proposal to use the FOC follows naturally from our extensive programme of ground-based observations and modelling of Seyfert nuclei. ------------------------------------------------------------------------------------ 8. Scientific Key Words: POLARIMETRY, NUCLEUS, SEYFERT GALAXY NGC1068 ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 6.00 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 1219c PI: Alec Boksenberg Proposal Title: POLARIZATION MAPPING OF THE INNER STRUCTURE OF THE SEYFERT GALAXY NGC 1068 TO SEARCH FOR A NON-THERMAL SOURCE ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ M. Ward OXFORD UNIVERSITY UNITED KING X D. J. Axon MANCHESTER, UNIVERSITY OF UNITED KING X Ian S. Mclean ROYAL OBSERVATORY, EDINBURGH UNITED KING X Alec Boksenberg ROYAL GREENWICH OBSERVATORY UNITED KING X S. R. Heathcote NOAO, CERRO TOLOLO INTERAMERICAN UNITED KING X OBSERVATORY ------------------------------------------------------------------------------------ 3. Description of proposed observations. At the distance of NGC 1068 (~16 Mpc assuming Ho = 75 km s-1 Mps-1), 2pc~= 0.03" and this should be within the capabilities of ST. The FOC in the f/96 mode would yield 0.022 arcsec/pixel and a format of 512 x 512 would give 11.2" x 11.2" or 860 x 860 pc. Since the effective magnitude of the unresolved central source will be ~ 16-17, the central pixels will saturate but the wings and all other sources, such as jets, will be below saturation. A second set of observations using the f/288 mode on the unresolved central source should enable its polarization to be determined accurately. 3.2 Errors For pixel receiving flux at near the maximum counting rate of 0.6 count/s/ pixel then an integration time of 2 hours per Rochon polarizer (0d, 60d, 120d) will yield errors ~ 1%. If the count rate is ten times smaller then the polarization error will be ~ 3%. The latter will still be a 5SIGMA result (per pixel) if te expected polarization of 15% is indeed present. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. ST Justification Because we are searching for compact, polarized sources in the innermost regions of the Seyfert nucleus then high spatial (angular) resolution is essential. The ST resolution is clearly beyond the bounds of any ground-based technique except perhaps speckle. But the speckle techniques are difficult and in any case, polarization images are the main requirements here. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. Roll orientation must be known for polarimetry ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. Reduction and Analysis of Data The required software for analysis of polarization images already exists at the Royal Observatory, Edinburgh on the STARLINK VAX 11/780 system. All that is required is that the ST FOC data be available in FITS format on a magnetic tape. A description of our polarimetry package (IMPOL) has been supplied to STScI and to the FOC team (Dr C Blades); it could probably be transferred to the ECF VAX computer system. A detailed functional specification for the reduction of polarization data under SDAS has been prepared by Dr Olivia Lupie (STScI) and this would appear to embody all the basic requirements (including display) and many additional features. It would, however, be very useful to receive TEST DATA (e.g. polarized flat fields through each Rochon prism) on magnetic tape at an early date to test for compatibility of the existing softwsre with the type of data produced by the FOC. ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). Resources Supplied These would mainly be in the form of data analysis capabilities and travel support. Page 3 ------------------------------------------------------------------------------------ 13. High angular resolution polarization images of NGC1068 to search for spatially extended and/or compact sources of polarixation within the nucleus of this Seyfert galaxy. ------------------------------------------------------------------------------------ 11. Address Information Name: IAN S. MCLEAN Category: CON Institution: ROYAL OBSERVATORY Address: BLACKFORD HILL City: EDINBURGH State: Zip Code: Country: UNITED KINGDOM Telephone: 031 668 8100 Telex (or e-mail): 72383 ------------------------------------------------------------------------------------ Name: ALEC BOKSENBERG Category: PI Institution: ROYAL GREENWICH OBSERVATORY Address: MADINGLEY ROAD CB3 0EZ City: CAMBRIDGE State: Zip Code: Country: UNITED KINGDOM Telephone: 44 223 374000 Telex (or e-mail): 817235 ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 1219c [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial |Acqui|FLX| Flux data No | Name | Description | Position |Eqnx | Vel. |Prblm|REF| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC1068-NUC SEYFERT GALAXY NUCLEUS RA = 2H 40M 7.06S +/- 0.1S, 1950 Z=0.0037 EXT 1 SURF(V)=13.0 DEC = -0D 13' 31.46" +/- 0.05" Comments: UNRESOLVED POINT SOURCE SHOULD BE APPROXIMATELY V=16.0 REF TO PLATE_REQ/PLATE_AVAIL DELETED TO GET A VALIDATION NOT GASP. TOO BRIGHT ------------------------------------------------------------------------------------------------------------------------------------ 2 HD16970- CALIBRATION RA = 2H 40M 42.060S +/- 1950 1 V = 3.46, TYPE = A3V, E(B-V) = CALIB 0.1S, 2 0.01 DEC = +03D 01' 29.14" +/- F-CONT(1965) = 1.35 +/- 0.14E-10 0.5" Comments: GASP MEASURE THIS IS A HIGH PROPER STAR. DOUBLE, 3 & 6.8 MAG SEPARATION 3" Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) B 1950.00 -0.0094 +/- 0.0013 -0.1470 +/- 0.0200 0.0480 +/- 0.0100 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 1219c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DEF FOC NGC1068-NUC FOC/96 IMAGE 512X512 F307M, 3080 1 1800S 1 # GROUP 1-3 WITHIN -POL-1 POL0 1D SAME ORIENT FOR 2- 3 AS 1 CYCLE 2 /1-14 GUID TOL 0.020" / 1-14 COND IF TAC OK / 1 -14 ------------------------------------------------------------------------------------------------------------------------------------ 2 DEF FOC NGC1068-NUC FOC/96 IMAGE 512X512 F307M, 3080 1 1800S 1 # -POL-1 POL60 ------------------------------------------------------------------------------------------------------------------------------------ 3 DEF FOC NGC1068-NUC FOC/96 IMAGE 512X512 F307M, 3080 1 1800S 1 # -POL-1 POL120 Comments: SIGMA(P)~2% FOR 4 HOURS. ------------------------------------------------------------------------------------------------------------------------------------ 4 USE FOC 1 -POL-1 ------------------------------------------------------------------------------------------------------------------------------------ 5 USE FOC 1 SAME ORIENT FOR 5 -POL-1 AS 4 ------------------------------------------------------------------------------------------------------------------------------------ 6 DEF FOC NGC1068-NUC FOC/ IMAGE 512X512 F307M, 3080 1 1300S 1 # GROUP 6-8 WITHIN -POL-2 288 POL0 1D SAME ORIENT FOR 7- 8 AS 6 Comments: REMOVED GROUP TO GET A VERIFY ------------------------------------------------------------------------------------------------------------------------------------ 7 DEF FOC NGC1068-NUC FOC/ IMAGE 512X512 F307M, 3080 1 1300S 1 # -POL-2 288 F1ND, POL60 ------------------------------------------------------------------------------------------------------------------------------------ 8 DEF FOC NGC1068-NUC FOC/ IMAGE 512X512 F307M, 3080 1 1300S 1 # -POL-2 288 POL120 Comments: SIGMA(P)~3% FOR 1.5 HOURS. ------------------------------------------------------------------------------------------------------------------------------------ 9 USE FOC 2 SAME ORIENT FOR 9 -POL-2 AS 4 ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC1068-NUC FOC/96 IMAGE 256X256 F190M 1975 1 500S 1 ORIENT 220D +/- 10D GROUP 11-13 WITHIN 1D Comments: ORIENT 40D +/- 10D IS EQUALLY GOOD. ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC1068-NUC FOC/96 IMAGE 256X256 F190M 1975 1 500S 1 ORIENT 260D +/- 10D Comments: ORIENT 80D +/- 10D IS EQUALLY GOOD. ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 1219c [ 6] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 13 NGC1068-NUC FOC/96 IMAGE 256X256 F190M 1975 1 500S 1 ORIENT 300D +/- 10D Comments: ORIENT 120D +/- 10D IS EQUALLY GOOD. ------------------------------------------------------------------------------------------------------------------------------------ 14 HD16970- FOC/ IMAGE 512X512 F190M, 1975 300S 2 1 CALIB FOR 13 CALIB 288 F8ND SEQ 11-14 NO GAP SAME ORIENT FOR 14 AS 13 Comments: NOTE HIGH PROPER MOTION STAR WHICH IS CLOSE DOUBLE. ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 1219c [ 7] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOC/96 FOC/288 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GTO/FOC ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 6.00 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category QUASARS, AGN ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GROUP 1-3 WITHIN 1D; SAME ORIENT FOR 2-3 AS 1; CYCLE 2 /1-14; GUID TOL 0.020" / 1-14; COND IF TAC OK / 1-14; SAME ORIENT FOR 5 AS 4; GROUP 6-8 WITHIN 1D; SAME ORIENT FOR 7-8 AS 6; SAME ORIENT FOR 9 AS 4 ORIENT 220D +/- 10D; GROUP 11-13 WITHIN 1D; ORIENT 260D +/- 10D; ORIENT 300D +/- 10D; CALIB FOR 13; SEQ 11-14 NO GAP; SAME ORIENT FOR 14 AS 13; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F307M,POL0 F307M,POL60 F307M,POL120 F307M,F1ND,POL60 F190M F190M, F8ND ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC1068-NUC HD16970-CALIB ------------------------------------------------------------------------------------------------------------------------------------