8639( 6) - 07/21/00 08:31 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8639 Version: 6 Check-in Date: 21-Jul-2000 08:30:27 1.Proposal Title: The Origin of Gaseous Outflows in Active Galaxies ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 9 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Andrew Wilson University of Maryland CoI: Patrick Shopbell University of Maryland N ------------------------------------------------------------------------------------ 5. Abstract We have recently obtained HST PC images of the ionized gas in the Circinus galaxy, a nearby (distance 4 Mpc) Seyfert 2. The images reveal that the nuclear (i.e. the inner 2^ = 40 pc) high excitation gas is ``V-shaped'' and represents the inner part of the ``ionization cone'' seen previously on much larger scales in ground-based observations. At 10 - 15^ = 190 - 280 pc from the nucleus, there is an elliptical ring of high excitation gas, which we infer to be the end of the intrinsically circular cone viewed at its known orientation. The images thus suggest that the observed emission lies along the boundary of a conical structure, a situation which has probably originated through mass entrainment of dense gas in the galaxy disk along the edges of a low density outflow. We wish to obtain long slit observations of this structure. Our goals are: 1) to confirm or reject this picture kinematically; 2) investigate how gas is entrained into the outflow from the dense ism in the galaxy disk in the inner (< 40 pc) region of the outflow at unprecedented spatial resolution for a Seyfert galaxy (our resolution of 1 pc is comparable to or smaller than the expected radius of the inner edge of the putative blocking ``torus''); 3) distinguish between collimation of ionization photons or of gaseous outflow as the origin of the ``ionization cone''; 4) attempt to measure the mass of the nuclear black hole using a long slit spectrum of the disk HII regions. ------------------------------------------------------------------------------------ 8639( 6) - 07/21/00 08:31 - [ 2] Observations Description ------------------------ A) Visit 1 After acquiring the galaxy, we shall obtain a slitless spectrum with grating G430M. The dispersion direction will be perpendicular to the cone axis and the radially elongated filaments (i.e. it will be along the direction of minimum spatial extent of the ionized gas). Although we believe that such a spectrum will confuse spatial and spectral information in a Seyfert galaxy, we think it is nevertheless worthwhile obtaining one. The time required is relatively short and the combination of slitless and slitted exposures is a powerful one. We shall then use the 0.2^ slit with grating G430M to obtain a spectrum through the bright nuclear feature with the slit in p.a. 110^degrees (see Fig. 2 top). Then we shall step across the bright inner 2^ region, obtaining a total of 6 slit positions with the slit in p.a. 110^degrees. This particular choice of p.a. not only minimises the number of slits required to cover the bright region (Fig. 1 bottom), but also allows inclusion of the region of fainter filaments on the SW side of the elliptical ring some 15^ NW of the nucleus (Fig. 1 top, Fig. 2 top). We shall then offset the slit to the NE to cover the filaments in the N part of the elliptical ring some 15^ from the nucleus (Fig. 2 top). For these latter observations, we request a further 6 slit positions (for a total of 12 at this p.a.), one of which will be down the important axis of the cone, where faint line emission is present. As may be seen from the ground-based OIIILambda5007 image (Fig. 2 top right), our choice of slit p.a. also permits us to cover much of the fainter emission along the outflow direction, which is off the edge of the PC (Fig. 2 top left). S/N calculation Our exposure times are governed by the need to obtain adequate S/N in OIIILambda5007 (for line profile and kinematic measurements) of the faint emission 10 - 15^ NW of the nucleus (Figs 1 top, 2 top). The typical OIIILambda5007 brightness here is 1 * 10^-17 erg cm^-2 s^-1 (PC pixel)^-1. Combining with the sensitivity of the G430M system near 5014 Angstrom\ for a diffuse source and a 0.2^ slit (p274, STIS Users Manual) and assuming a line width of 200 km s^-1 (from ground-based spectra), we obtain a count rate of 5.3 * 10^-3 counts s^-1 pix_lambda^-1 pix_s^-1. For a S/N of 3 pix_lambda^-1 pix_s^ -1, we require an exposure time of ~eq 28 mins (or 22 mins using the ETC). These considerations also demonstrate that we will see this fainter emission with the slitless exposure to be obtained in Orbit 1. Therefore, we can obtain 2 slit positions per 57 min (non- CVZ) orbit. At least some of the even fainter emission beyond 15^ revealed by the ground-based image (Fig. 2 top right) will be seen by appropriate spatial or spectral binning. For the required 12 slit positions, we thus request 6 orbits, plus the first orbit during which we shall obtain the slitless spectrum, for a total of 7 orbits with G430M. Details of Observations Orbit 1 will be broken up as follow: GS Acq. 6 mins; Target Acq 6 mins; Acq Peakup 6 mins (we don't need the Acq Peakup for the slitless exposure, but might as well do it now rather than in Orbit 2); first spectroscopic exposure overhead 5 mins; slitless spectrum with G430M 2 * 15 mins (crsplit = 2 for all science exposures) + readout 74 secs. Each subsequent orbit (orbits 2 - 7) will be broken up as follows: GS Reacq 5 mins; spectra at first slit location through 0.2^ slit 2 * 12.5 mins; readout time 74 secs; offset to new target position 20 secs; spectra at second slit location through 0.2^ slit 2 * 12.5 mins; readout time 74 secs. \medskip B) Visit 2 We shall obtain a single long slit spectrum with G750M along the major axis of the galaxy disk (p.a. ~eq 30^degrees) to measure the rotation curve of the HII regions, as described in the Scientific Justification. The faintest regions along the slit in HAlpha + NII (from our PC image) in the inner ~eq 2.5^ have brightness ~eq 5 * 10^-18 erg cm^-2 s^-1 (PC pixel)^-1. Combining with the sensitivity of the G750M system near 6570 Angstrom\ for a diffuse source and a 0.2^ slit (p268, STIS Users Manual) and assuming a line width of 100 km s^-1 (for the HII regions), we obtain a count rate of 1.2 * 10^-2 counts s^-1 pix_lambda^-1 pix_s^-1. For a S/N of 5 pix_lambda^-1 pix_s^-1, we require an exposure time of ~eq 32 mins. The single orbit will be broken up as follow: GS Acq. 6 mins; Target Acq 6 mins; Acq Peakup 6 mins; spectroscopic exposure overhead 5 mins; slit spectrum along galaxy disk axis with G750M 2 * 16 mins + readout 74 secs. Real Time Justification ----------------------- Circinus is in the `heart' of the CVZ. At the declination of Circinus, the total duration of all CVZ opportunities is 251 orbits and there are 7 CVZ opportunities, according to the www tables for cycle 9. Unfortunately, we cannot request the CVZ because of our two preferred orientations. However, the project would greatly benefit from the longer duration of the CVZ (we could perform the G430M observations in fewer orbits) and we ask that STScI keep an eye open for whether either of our requested orientations will fit within a CVZ. Circinus is known from our unpublished ROSAT HRI imaging to have extended X-ray emission, both along and perpendicular to its disk. The X-ray emission out of the disk (to the NW, along the ``ionization cone'') is believed to be thermal emission from the hot component of the wind. We are obtaining imaging spectroscopy of Circinus with the ACIS instrument on Chandra as part of Wilson's guaranteed time project. Comparison of the STIS spectroscopy with the Chandra imaging spectroscopy will allow a unique probe of the relationship between the kinematics of the outflow from a galactic nucleus with the accompanying hot gas on an unprecedentedly small linear scale, due to the high resolutions of STIS and Chandra and the proximity (4 Mpc) of Circinus. In particular, it will be interesting to check whether the X-ray-emitting gas fills the interior of the cone, with the optical line-emitting gas on the surface of the cone, as suggesting by our HST imaging. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 8639( 6) - 07/21/00 08:31 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 CIRCINUS- GALAXY, SEYFERT, RA=14H 13M 9.84S +/- 0.5", DEC=- J2000 SURF(8000)=3e-15 NUCLEUS STARBURST 65D 20' 18.9" +/- 0.5", PLATE- V = 12.1 ID=060Y Coordinate Source: GSC_SURVEY_PLATE 8639( 6) - 07/21/00 08:31 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type STIS-PERP-TO-SLIT Pattern_Purpose MOSAIC Number_Of_Points 6 Point_Spacing 0.2 Coordinate_Frame POS-TARG Pattern_Orient 0 Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type STIS-PERP-TO-SLIT Pattern_Purpose MOSAIC Number_Of_Points 2 Point_Spacing 1.2 Coordinate_Frame POS-TARG Pattern_Orient 0 Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 3 Primary_Pattern Secondary_Pattern Pattern_Type STIS-PERP-TO-SLIT Pattern_Purpose MOSAIC Number_Of_Points 4 Point_Spacing 1.2 Coordinate_Frame POS-TARG Pattern_Orient 0 Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ 8639( 6) - 07/21/00 08:31 - [ 5] Visit: 01 Visit Priority: Visit Requirements: ORIENT 151D TO 159D ON HOLD On Hold Comments: Execute either visit 1 or visit 4. Choose whichever is easier to schedule. Additional Comments: This RPS file has been configured for normal orbits, due to our ORIENT constraint. However, the target lies in the heart of the CVZ. We would like to use CVZ orbits if possible, at our desired ORIENT. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 CIRCINUS-NU STIS/C ACQ F28X50L MIRROR DIFFUSE-CENTER=FLUX-CENTROID, 1 60 S CLEUS CD P CHECKBOX=3,ACQTYPE=DIFFUSE ------------------------------------------------------------------------------------------------------------------------------------ 20 CIRCINUS-NU STIS/C ACCUM F28X50L MIRROR CR-SPLIT=NO 1 30 S CLEUS CD P ------------------------------------------------------------------------------------------------------------------------------------ 25 CIRCINUS-NU STIS/C ACCUM F28X50O MIRROR 1 300 S CLEUS CD II ------------------------------------------------------------------------------------------------------------------------------------ 30 NONE STIS/C ACCUM 52X0.2 MIRROR LAMP=TUNGSTEN 1 1 S CD Comments: Continuum lamp exposure to register slit w/ CCD image. ------------------------------------------------------------------------------------------------------------------------------------ 40 WAVE STIS/C ACCUM 52X0.2 G430M 4961 1 DEF CD Comments: GO wavecal exposure. ------------------------------------------------------------------------------------------------------------------------------------ 50 CIRCINUS-NU STIS/C ACCUM 50CCD G430M 4961 CR-SPLIT=2 1 1600 S CLEUS CD Comments: Automatic wavecals have not been switched off , since we want them to occur in orbits 2, 3, 4 of this visit. We will therefore get an automatic wavecal with no slit from this exposure. Is this a problem? ------------------------------------------------------------------------------------------------------------------------------------ 60 CIRCINUS-NU STIS/C ACCUM 52X0.2 G430M 4961 CR-SPLIT=2 1 1400 S PATTERN 1 60 POS TARG CLEUS CD -0.1, 0.0 Comments: POS TARG offset assumes ORIENT = 151D to 159D. ------------------------------------------------------------------------------------------------------------------------------------ 8639( 6) - 07/21/00 08:31 - [ 6] Visit: 02 Visit Priority: Visit Requirements: ORIENT 151D TO 159D ON HOLD On Hold Comments: Execute either visit 2 or visit 5. Choose whichever is easier to schedule. Additional Comments: This RPS file has been configured for normal orbits, due to our ORIENT constraint. However, the target lies in the heart of the CVZ. We would like to use CVZ orbits if possible, at our desired ORIENT. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 CIRCINUS-NU STIS/C ACQ F28X50L MIRROR DIFFUSE-CENTER=FLUX-CENTROID, 1 60 S CLEUS CD P CHECKBOX=3,ACQTYPE=DIFFUSE ------------------------------------------------------------------------------------------------------------------------------------ 20 CIRCINUS-NU STIS/C ACCUM 52X0.2 G430M 4961 CR-SPLIT=2 1 1100 S POS TARG -4.8, 0.0 CLEUS CD PATTERN 2 20 Comments: POS TARG offset assumes ORIENT = 151D to 159D. Use of ORIENT = 331D to 339D would require POS TARG offset of minus 4.8 arcsec. ------------------------------------------------------------------------------------------------------------------------------------ 30 CIRCINUS-NU STIS/C ACCUM 52X0.2 G430M 4961 CR-SPLIT=2 1 1400 S POS TARG -8.4, 0.0 CLEUS CD PATTERN 3 30 Comments: POS TARG offset assumes ORIENT = 151D to 159D. ------------------------------------------------------------------------------------------------------------------------------------ 8639( 6) - 07/21/00 08:31 - [ 7] Visit: 03 Visit Priority: Visit Requirements: ORIENT 70D TO 80D ORIENT 250D TO 260D On Hold Comments: Additional Comments: This RPS file has been configured for normal orbits, due to our ORIENT constraint. However, the target lies in the heart of the CVZ. We would like to use CVZ orbits if possible, at our desired ORIENT. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 CIRCINUS-NU STIS/C ACQ F28X50L MIRROR DIFFUSE-CENTER=FLUX-CENTROID, 1 60 S CLEUS CD P CHECKBOX=3,ACQTYPE=DIFFUSE ------------------------------------------------------------------------------------------------------------------------------------ 20 CIRCINUS-NU STIS/C ACCUM F28X50L MIRROR CR-SPLIT=NO 1 30 S CLEUS CD P ------------------------------------------------------------------------------------------------------------------------------------ 30 CIRCINUS-NU STIS/C ACCUM 52X0.2 G750M 6581 CR-SPLIT=2 1 2000 S CLEUS CD ------------------------------------------------------------------------------------------------------------------------------------ 8639( 6) - 07/21/00 08:31 - [ 8] Visit: 04 Visit Priority: Visit Requirements: ORIENT 331D TO 339D ON HOLD On Hold Comments: Execute either visit 1 of visit 4. Choose whichever is easier to schedule. Additional Comments: This RPS file has been configured for normal orbits, due to our ORIENT constraint. However, the target lies in the heart of the CVZ. We would like to use CVZ orbits if possible, at our desired ORIENT. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 CIRCINUS-NU STIS/C ACQ F28X50L MIRROR DIFFUSE-CENTER=FLUX-CENTROID, 1 60 S CLEUS CD P CHECKBOX=3,ACQTYPE=DIFFUSE ------------------------------------------------------------------------------------------------------------------------------------ 20 CIRCINUS-NU STIS/C ACCUM F28X50L MIRROR CR-SPLIT=NO 1 30 S CLEUS CD P ------------------------------------------------------------------------------------------------------------------------------------ 25 CIRCINUS-NU STIS/C ACCUM F28X50O MIRROR 1 300 S CLEUS CD II ------------------------------------------------------------------------------------------------------------------------------------ 30 NONE STIS/C ACCUM 52X0.2 MIRROR LAMP=TUNGSTEN 1 1 S CD Comments: Continuum lamp exposure to register slit w/ CCD image. ------------------------------------------------------------------------------------------------------------------------------------ 40 WAVE STIS/C ACCUM 52X0.2 G430M 4961 1 DEF CD Comments: GO wavecal exposure. ------------------------------------------------------------------------------------------------------------------------------------ 50 CIRCINUS-NU STIS/C ACCUM 50CCD G430M 4961 CR-SPLIT=2 1 1600 S CLEUS CD Comments: Automatic wavecals have not been switched off , since we want them to occur in orbits 2, 3, 4 of this visit. We will therefore get an automatic wavecal with no slit from this exposure. Is this a problem? ------------------------------------------------------------------------------------------------------------------------------------ 60 CIRCINUS-NU STIS/C ACCUM 52X0.2 G430M 4961 CR-SPLIT=2 1 1400 S PATTERN 1 60 POS TARG 0.1 CLEUS CD , 0.0 Comments: POS TARG offset assumes ORIENT = 331D to 339D. ------------------------------------------------------------------------------------------------------------------------------------ 8639( 6) - 07/21/00 08:31 - [ 9] Visit: 05 Visit Priority: Visit Requirements: ORIENT 331D TO 339D ON HOLD On Hold Comments: Execute either visit 2 or visit 5. Choose whichever is eaiser to schedule. Additional Comments: This RPS file has been configured for normal orbits, due to our ORIENT constraint. However, the target lies in the heart of the CVZ. We would like to use CVZ orbits if possible, at our desired ORIENT. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 CIRCINUS-NU STIS/C ACQ F28X50L MIRROR DIFFUSE-CENTER=FLUX-CENTROID, 1 60 S CLEUS CD P CHECKBOX=3,ACQTYPE=DIFFUSE ------------------------------------------------------------------------------------------------------------------------------------ 20 CIRCINUS-NU STIS/C ACCUM 52X0.2 G430M 4961 CR-SPLIT=2 1 1100 S POS TARG 4.8, 0.0 PATTERN CLEUS CD 2 20 Comments: POS TARG offset assumes ORIENT = 331D to 339D. ------------------------------------------------------------------------------------------------------------------------------------ 30 CIRCINUS-NU STIS/C ACCUM 52X0.2 G430M 4961 CR-SPLIT=2 1 1400 S POS TARG 8.4, 0.0 PATTERN CLEUS CD 3 30 Comments: POS TARG offset assumes ORIENT = 331D to 339D. ------------------------------------------------------------------------------------------------------------------------------------ 8639( 6) - 07/21/00 08:31 - [ 10] Summary Form for Proposal 8639 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP F28X50OII 52X0.2 50CCD ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters DIFFUSE-CENTER=FLUX-CENTROID CHECKBOX=3 ACQTYPE=DIFFUSE CR-SPLIT=NO LAMP=TUNGSTEN CR-SPLIT=2 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 151D TO 159D ON HOLD PATTERN 1 60 POS TARG -0.1, 0.0 POS TARG -4.8, 0.0 PATTERN 2 20 POS TARG -8.4, 0.0 PATTERN 3 30 ORIENT 70D TO 80D ORIENT 250D TO 260D ORIENT 331D TO 339D ON HOLD PATTERN 1 60 POS TARG 0.1, 0.0 POS TARG 4.8, 0.0 PATTERN 2 20 POS TARG 8.4, 0.0 PATTERN 3 30 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G430M G750M ------------------------------------------------------------------------------------------------------------------------------------ Target Names CIRCINUS-NUCLEUS NONE WAVE ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 4961 6581 ------------------------------------------------------------------------------------------------------------------------------------