9510( 6) - 08/22/02 08:46 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9510 Version: 6 Check-in Date: 22-Aug-2002 08:45:58 1.Proposal Title: AG Dra -- a high density plasma laboratory ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 11 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Peter Young CLRC, Rutherford Appleton Laboratory CoI: Dr Brian Espey Space Telescope Science Institute N CoI: Dr Andrea Dupree Smithsonian Astrophysical Observatory N CoI: Dr Scott Kenyon Smithsonian Astrophysical Observatory N ------------------------------------------------------------------------------------ 5. Abstract A STIS observation of the symbiotic star AG Draconis yielding spectra in the range 1150--10 000 Angstrom\ is requested. AG Dra is a non-eclipsing binary that shows strong, narrow nebular emission lines that originate in the wind of a K giant, photoionized by a hot white dwarf. The density of the nebula is around 10^10 electrons/cm^3 and is the perfect laboratory for testing the plasma modeling codes cloudy and xstar at high densities. These codes are used for a wide range of astrophysical objects including stellar winds, accretion disks, active galactic nuclei and Seyfert galaxies, and calibrating them against high signal-to-noise spectra from comparatively simple systems is essential. AG Dra is the perfect high density laboratory for this work. In addition, many previously undetected emission lines will be found through the high sensitivity of STIS, which will allow new plasma diagnostics to be tested. These twin objectives are particularly pertinent as the high sensitivity of emphHST/COS will will permit similar high resolution spectroscopy to be applied to a whole new regime of extragalactic objects. By combining far-UV data from \fuse\ with complementary data from STIS, we will determine ratios of emission lines from the same ion, or ions of similar ionization level. These will permit a more complete set of diagnostics than are obtainable from one instrument alone. ------------------------------------------------------------------------------------ 9510( 6) - 08/22/02 08:46 - [ 2] Observations Description ------------------------ High signal-to-noise spectra for AG Dra are required for the complete wavelength range from 1150 to 10 000 Angstrom\ in order to maximise the diagnostic potential and provide constraints for the theoretical modeling. Although the spectral resolution of the CCD spectra will be lower than for the MAMA spectra, the superb flux calibration of STIS is essential to calibrate ground-based optical echelle spectra that will be taken. A key requirement of the STIS observations will be to measure weak lines in the AG Dra spectrum that were beyond the limits of IUE. The detection of weak lines is constrained by the signal-to-noise (S/N) level in the continuum. Our aim is to achieve S/N=10 throughout the 1150--10 000 Angstrom\ range. The AG Dra continuum is assumed to be uniform at a level of 2* 10^-13 \ecsa\ up to a wavelength of 4000 Angstrom. The continuum then rises to a level of around 7* 10^-13 \ecsa\ at 7000 Angstrom. We assume this level applies for wavelengths up to 10 000 Angstrom. References for the continuum level are Mikolajewska et al. (1995) and Gonzalez- Riestra et al. (1999). The E140M and E240M gratings will be used for the MAMA echelle data, which will yield a spectral resolution comparable to \fuse. For maximum throughput, the 0.2* 0.2 is requested. For the CCD spectra, the G430M and G750M gratings will be used, together with the 51* 0.2 slit. All of the MAMA data will be obtained in one visit of 3 orbits. 3 of the CCD exposures can also be obtained without violating the 30min CCD/MAMA restriction. The second visit of 2 orbits will obtain the remaining CCD spectra. AG Dra has a visibility of 57 mins. For the MAMA observations, 68mins are required for the FUV science exposure, 31mins for NUV with the 1978 grating position, and 5mins for NUV with the 2707 grating position. The first orbit will consist of guide star acquisition (6mins), peak-up (6mins), MAMA set-up (8mins) and 32mins of the FUV-MAMA exposure. The second orbit requires 5mins for guide star re- acquisition and 36mins to complete the FUV-MAMA exposure. Changing the grating to E240M for the NUV-MAMA (2707) exposure requires 9mins. The necessary exposure time is 5mins. For orbit 3, 5mins is required for guide star re- acquisition, and 31mins for the NUV-MAMA (1978) science exposure. The remaining time of the 3rd orbit allows three CCD spectra to be taken: G430M (4706 and 5471 positions) and G750M (6768). These grating positions obtain strong lines in the spectra, namely ionHe2 <~m4686, <~m5412, ionH1 H\al\ and ionO6 <~m6860. 5mins overhead for each exposure are needed, together with 1min for the move of the aperture wheel. Exposure times are 1.8secs, 1.2secs and 0.24secs for G430M(4706), G430M(5471) and G750M(6768), respectively. The second visit to AG Dra will take the remaining CCD spectra. 16 short exposures (8 for G430M, 8 for G750M) are needed, with total on-target time of less than 1 minute. Two orbits are required. The first orbit requires 6mins for guide star acquistion, 6mins for a peak-up and 5mins for the first science exposure. There follows 8 science exposures: G430M(3165), G430M(3423), G430M(3680), G430M(3936), G430M(4194), G430M(4451), G430M(4961) and G430M(5216). The exposure times are: 10.1secs, 8.7secs, 6.3secs, 4.2secs, 2.8secs, 2.3secs, 1.5secs, 1.2secs. Seven overheads of 5mins are required for the grating moves. One overhead of 3mins is required for data management. Total time is 56mins for the first orbit. The second orbit requires 5mins of guide star re-acquisition. There are 8 science exposures: G750M(5734), G750M(6252), G750M(7283), G750M(7795), G750M(8311), G750M(8825), G750M(9336) and G750M(9851). Exposure times are: 0.49secs, 0.34secs, 0.30secs, 0.38secs, 0.37secs, 0.43secs and 0.73secs. Eight overheads of 5mins are required for the grating moves. One overhead of 3mins is required for data management. Total time is 49mins for the first orbit. It is to be noted that AG Dra is a potential CVZ target. We do not request a CVZ observation on account of the time constraints (see `Special Requirements'). If it is possible to observe within the CVZ and satisfy the time constraints, the first visit (MAMA+CCD) can be obtained in 2 orbits (Acq 6; Peak-up 6; MAMA overhead 8; 9510( 6) - 08/22/02 08:46 - [ 3] E140M 68; MAMA overhead 8; E230M 4; E230M 31; CCD overheads 16; CCD exposures 1; total=148mins). The second visit can be obtained in 1 orbit (Acq 6; Peak-up 6; 16 exposures 1; 16 overheads 80; grating change 1; total 94mins). For each grating position, the STIS exposure time calculator (ETC) was used to derive the exposure time required to give average S/N's of 10 for the input continuum levels. Real Time Justification ----------------------- A time-critical observation is requested. The AG Dra observation should be performed during a four month period from 1-Jan-2003 to 1-May-2003. This window is suggested for two reasons. The AG Dra emission line fluxes and continuum level vary with the orbital phase of the system (e.g., Gonzalez-Riestra et al. 1999) by up to a factor of 2. The expected time of maximum will be 1-March- 2003. Observations obtained close to this date will maximise the S/N in the spectra. The observing window is also requested because it will ensure that a \fuse\ observation can be obtained either simultaneously or close in time to the STIS observation (\fuse\ Cycle 4 is expected to begin on 1-Dec-2002). The CCD and MAMA spectra will be obtained in separate visits. We request that the two observations be performed within 15 days of each other. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 9510( 6) - 08/22/02 08:46 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 AG-DRACONIS STAR, SYMBIOTIC STAR RA=16H 1M 41.02S +/- 0.3S, J2000 V = - F(6563)=5.0+/-1.0e-11 DEC=66D 48' 10.5" +/- 0.3", 137.6 F(1640)=40+/-10e-12 PLATE-ID=01FX F-CONT-BKG(7000)=7.0+/-2.0e-13 V = 9.47+/-0.40 Coordinate Source: GUIDE_STAR_CATALOG 9510( 6) - 08/22/02 08:46 - [ 5] Visit: 01 Visit Priority: Visit Requirements: GROUP 01, 02 WITHIN 30D BETWEEN 01-MAR-2003 AND 01-MAY-2003 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 AG-DRACONIS STIS/C ACQ F25ND3 MIRROR ACQTYPE=POINT 1 5 S CD ------------------------------------------------------------------------------------------------------------------------------------ 20 AG-DRACONIS STIS/F ACCUM 0.2X0.2 E140M 1425 1 2600 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 30 AG-DRACONIS STIS/F ACCUM 0.2X0.2 E140M 1425 1 1837 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 40 AG-DRACONIS STIS/N ACCUM 0.2X0.2 E230M 2707 1 374 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 50 AG-DRACONIS STIS/N ACCUM 0.2X0.2 E230M 1978 1 241 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 60 AG-DRACONIS STIS/N ACCUM 0.2X0.2 E230M 1978 1 1560 S UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 70 AG-DRACONIS STIS/C ACCUM 52X0.2 G430M 4706 1 10 S CD ------------------------------------------------------------------------------------------------------------------------------------ 80 AG-DRACONIS STIS/C ACCUM 52X0.2 G430M 5471 1 10 S CD ------------------------------------------------------------------------------------------------------------------------------------ 90 AG-DRACONIS STIS/C ACCUM 52X0.2 G750M 6768 1 10 S CD ------------------------------------------------------------------------------------------------------------------------------------ 9510( 6) - 08/22/02 08:46 - [ 6] Visit: 02 Visit Priority: 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 AG-DRACONIS STIS/C ACQ F25ND3 MIRROR ACQTYPE=POINT 1 5 S CD ------------------------------------------------------------------------------------------------------------------------------------ 20 AG-DRACONIS STIS/C ACCUM 52X0.2 G430M 4194 1 10 S CD ------------------------------------------------------------------------------------------------------------------------------------ 30 AG-DRACONIS STIS/C ACCUM 52X0.2 G430M 4451 1 10 S CD ------------------------------------------------------------------------------------------------------------------------------------ 40 AG-DRACONIS STIS/C ACCUM 52X0.2 G430M 5216 1 10 S CD ------------------------------------------------------------------------------------------------------------------------------------ 50 AG-DRACONIS STIS/C ACCUM 52X0.2 G430M 3423 1 15 S CD ------------------------------------------------------------------------------------------------------------------------------------ 60 AG-DRACONIS STIS/C ACCUM 52X0.2 G430M 3680 1 10 S CD ------------------------------------------------------------------------------------------------------------------------------------ 70 AG-DRACONIS STIS/C ACCUM 52X0.2 G430M 3936 1 10 S CD ------------------------------------------------------------------------------------------------------------------------------------ 80 AG-DRACONIS STIS/C ACCUM 52X0.2 G750M 7795 1 10 S CD ------------------------------------------------------------------------------------------------------------------------------------ 90 CCDFLAT STIS/C ACCUM 0.3X0.0 G750M 7795 2 DEF CD 9 ------------------------------------------------------------------------------------------------------------------------------------ 100 CCDFLAT STIS/C ACCUM 0.3X0.0 G750M 8311 2 DEF CD 9 ------------------------------------------------------------------------------------------------------------------------------------ 110 AG-DRACONIS STIS/C ACCUM 52X0.2 G750M 8311 1 10 S CD ------------------------------------------------------------------------------------------------------------------------------------ 120 CCDFLAT STIS/C ACCUM 0.3X0.0 G750M 8825 2 DEF CD 9 ------------------------------------------------------------------------------------------------------------------------------------ 130 AG-DRACONIS STIS/C ACCUM 52X0.2 G750M 8825 1 10 S CD ------------------------------------------------------------------------------------------------------------------------------------ 140 AG-DRACONIS STIS/C ACCUM 52X0.2 G750M 7283 1 10 S CD ------------------------------------------------------------------------------------------------------------------------------------ 150 AG-DRACONIS STIS/C ACCUM 52X0.2 G750M 6252 1 10 S CD ------------------------------------------------------------------------------------------------------------------------------------ 9510( 6) - 08/22/02 08:46 - [ 7] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 160 AG-DRACONIS STIS/C ACCUM 52X0.2 G750M 5734 1 10 S CD ------------------------------------------------------------------------------------------------------------------------------------ 170 AG-DRACONIS STIS/C ACCUM 52X0.2 G430M 4961 1 10 S CD ------------------------------------------------------------------------------------------------------------------------------------ 180 AG-DRACONIS STIS/C ACCUM 52X0.2 G430M 3165 1 20 S CD ------------------------------------------------------------------------------------------------------------------------------------ 190 AG-DRACONIS STIS/C ACCUM 52X0.2 G750M 9336 1 10 S CD ------------------------------------------------------------------------------------------------------------------------------------ 200 CCDFLAT STIS/C ACCUM 0.3X0.0 G750M 9336 2 DEF CD 9 ------------------------------------------------------------------------------------------------------------------------------------ 9510( 6) - 08/22/02 08:46 - [ 8] Summary Form for Proposal 9510 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F25ND3 0.2X0.2 52X0.2 0.3X0.09 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/FUV-MAMA STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GROUP 01, 02 WITHIN 30D BETWEEN 01-MAR-2003 AND 01-MAY-2003 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR E140M E230M G430M G750M ------------------------------------------------------------------------------------------------------------------------------------ Target Names AG-DRACONIS CCDFLAT ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 1425 2707 1978 4706 5471 6768 4194 4451 5216 3423 3680 3936 7795 8311 8825 7283 6252 5734 4961 3165 9336 ------------------------------------------------------------------------------------------------------------------------------------