8238( 11) - 08/03/99 09:07 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8238 Version: 11 Check-in Date: 03-Aug-1999 09:06:24 1.Proposal Title: Collimated Jets and Low Velocity Forbidden Emission from T Tauri Stars ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 8 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Patrick Hartigan Rice University CoI: Dr. Suzan Edwards Smith College N ------------------------------------------------------------------------------------ 5. Abstract We propose a program of slitless spectroscopy with STIS to image both the low velocity component (LVC) and high velocity component (HVC) of forbidden line emission in single and binary low mass stars undergoing disk accretion. Recent observations suggest that forbidden emission lines trace two distinct outflows from classical T Tauri stars, both associated with disk accretion, but with distinctive kinematic signatures and physical properties. The HVC arises in a stellar jet, with a mass loss rate proportional to the disk accretion rate, while the LVC has a much lower velocity than the jet and becomes the dominant source of forbidden line emission in sources with modest disk accretion rates. The spatial distribution of the LVC will be traced by images of O ILambda5577, which emits only in the LVC. Several arguments suggest that the LVC arises in a slow wind that emerges from the disk at radii out to tens of AU. The proposed observations will provide a decisive test of this hypothesis. Images of other lines such as N II Lambda6583 that emit only HVC gas will define the morphology of the jet as it emerges from the star. These images will quantify how close to the star the jets become collimated. Our targets, which include one single star and four binaries of separation ranging from 0.03 AU -- 465 AU, will allow us to determine how binarity affects disk winds and jet collimation. ------------------------------------------------------------------------------------ 8238( 11) - 08/03/99 09:07 - [ 2] Observations Description ------------------------ Our goal is to obtain emission line images from the slitless spectroscopy both in lines that only have a low-velocity component ( e.g. O I Lambda5577), those that have only a high velocity component, ( e.g. N II Lambda6583), and those that show emission from both components ( e.g. O I Lambda6300; S II Lambda6716; S II Lambda6731). That is, we have used ground-based echelle spectra to determine which lines have only LVC or only HVC emission, and now propose to image these lines with the spatial resolution of STIS. As shown in Fig. 2, emission from a jet is easiest to see against the continuum of the star in a slitless spectrum when the dispersion direction lies along the disk, while emission from the disk is easiest to see when the dispersion direction lies along the jet. For this reason we propose two ORIENTs for each star, one that lies along a well-defined outflow direction or along the axis of the binary, and another in a direction roughly perpendicular to this orientation. Our plan will be to define the stellar PSF from regions of the spectrum between the lines, and subtract this stellar component to leave only an image of the emission line of interest (as one does with a long-slit spectrum; e.g. reference 12). We will dither the spectra to obtain the maximum possible spatial resolution, and perform standard CR- splits. By observing with different ORIENTs we will ensure that our emission line images are reliable. We chose the five objects in Table 1 because each has bright LVC O I Lambda5577 emission, and each shows HVC emission in the O I Lambda6300 line with a known outflow direction or binary orientation. Our exposure times are tied to the O I Lambda5577 flux, which traces the LVC. According to reference 11, the O I Lambda5577 line reaches a maximum of about 50\ the stellar continuum in our objects. For a 14th magnitude star at V, this specific flux corresponds to 4.3* 10^-15 erg, cm^-2s^-1Angstrom^-1. The LVC emits at this level over about 30 km, s^-1, or about 0.1 of a spectral resolution element. Hence, the signal expected per resolution element from the O I Lambda5577 line is the same as that from a continuum source with flux 4.3* 10^-16 erg, cm^-2s^-1Angstrom^-1, or V = 17.2. If we assume that the flux is distributed in a 0.2^ diameter area, the effective surface brightness at V will be 13.4 mag arcsec^-2. According to the STIS exposure time calculator, we achieve S/N = 25 per resolution element in 45 minutes. In actuality O I Lambda5577 photons will need to be extracted from the overlying stellar continuum, so the actual S/N will be about a factor of two lower, but should still provide good emission line images in one orbit per star for each orientation. Choosing a gain of 4e^- will ensure that the stellar continuum will not saturate during the exposures. Real Time Justification ----------------------- None None Calibration Justification ------------------------- Real_Time_Justification Additional Comments ------------------- ------------------------------------------------------------------------------------ 8238( 11) - 08/03/99 09:07 - [ 3] Data Distribution Paper Products: NO Media: ELECTRONIC Blocking Factor: 10 Ship To: Dept of Space Physics and Astronomy, 6100 S. Main, Houston TX 77005-1892 Ship Via: Email: hartigan@sparky.rice.edu ------------------------------------------------------------------------------------ 8238( 11) - 08/03/99 09:07 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 CW-TAU Star, T Tauri Star RA=4H 14M 16.99S +/- 0.03S, J2000 V = 12.3 DEC=28D 10' 58.5" +/- 0.3", B-V = 1.23 PLATE-ID=00DG 2 DD-TAU Star, T Tauri Star RA=4H 18M 31.22S +/- 0.03S, J2000 V = 13.5 DEC=28D 16' 29.5" +/- 0.3", B-V = 0.92 PLATE-ID=0051 3 DF-TAU Star, T Tauri Star RA=4H 27M 2.80S +/- 0.02S, J2000 V = 11.9 DEC=25D 42' 23.1" +/- 0.2", B-V = 0.89 PLATE-ID=000L Comments: BINARY 4 UZ-TAUE Star, T Tauri Star RA=4H 32M 42.96S +/- 0.03S, J2000 V = 11.9 DEC=25D 52' 31.8" +/- 0.3", B-V = 1.19 PLATE-ID=000L 5 HN-TAU Star, T Tauri Star RA=4H 33M 39.35S +/- 0.02S, J2000 V = 13.7 DEC=17D 51' 52.6" +/- 0.2", B-V = 1.06 PLATE-ID=000P 8238( 11) - 08/03/99 09:07 - [ 5] Visit: 01 Visit Priority: Visit Requirements: ORIENT 50.D TO 60.0D ORIENT 230.0D TO 240.0D On Hold Comments: Additional Comments: ORIENT = PA + 45; want PA=160, ORIENT=25. Can't get. Take ORIENT=55 instead Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 CW-TAU STIS/C ACCUM 50CCD MIRROR GAIN=4,WAVECAL=NO 1 0.6 S GS ACQ SCENARIO SINGLE CD ------------------------------------------------------------------------------------------------------------------------------------ 2 CW-TAU STIS/C ACCUM 50CCD G750L 7751 CR-SPLIT=3,NUM-POS=2, 1 1200 S MAX DUR CD PATTERN=ALONG-SLIT,STEP-SIZE=0.2, GAIN=4 ------------------------------------------------------------------------------------------------------------------------------------ 3 CCDFLAT STIS/C ACCUM 52X0.1 G750L 7751 2 DEF CD Comments: Fringe Flat ------------------------------------------------------------------------------------------------------------------------------------ 8238( 11) - 08/03/99 09:07 - [ 6] Visit: 02 Visit Priority: Visit Requirements: ORIENT 50.0D TO 60.0D ORIENT 230.0D TO 240.0D On Hold Comments: Additional Comments: PA=8, ORIENT=53 Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DD-TAU STIS/C ACCUM 50CCD MIRROR GAIN=4,WAVECAL=NO 1 1.4 S CD ------------------------------------------------------------------------------------------------------------------------------------ 2 DD-TAU STIS/C ACCUM 50CCD G750L 7751 CR-SPLIT=2,NUM-POS=2, 1 1230 S MAX DUR CD PATTERN=ALONG-SLIT,STEP-SIZE=0.25 ,GAIN=4 ------------------------------------------------------------------------------------------------------------------------------------ 3 CCDFLAT STIS/C ACCUM 52X0.1 G750L 7751 2 DEF CD Comments: Fringe Flat ------------------------------------------------------------------------------------------------------------------------------------ 8238( 11) - 08/03/99 09:07 - [ 7] Visit: 03 Visit Priority: Visit Requirements: ORIENT 160.0D TO 170.0D ORIENT 340.0D TO 350.0D SCHED 100% On Hold Comments: Additional Comments: PA = 121, ORIENT=166 Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DF-TAU STIS/C ACCUM 50CCD MIRROR GAIN=4,WAVECAL=NO 1 0.4 S CD ------------------------------------------------------------------------------------------------------------------------------------ 2 DF-TAU STIS/C ACCUM 50CCD G750L 7751 CR-SPLIT=3,NUM-POS=2, 1 1110 S MAX DUR CD PATTERN=ALONG-SLIT,STEP-SIZE=0.25 ,GAIN=4 ------------------------------------------------------------------------------------------------------------------------------------ 3 CCDFLAT STIS/C ACCUM 52X0.1 G750L 7751 2 DEF CD Comments: Fringe Flat ------------------------------------------------------------------------------------------------------------------------------------ 8238( 11) - 08/03/99 09:07 - [ 8] Visit: 04 Visit Priority: Visit Requirements: ORIENT 60.0D TO 70.0D ORIENT 240.0D TO 250.0D On Hold Comments: Additional Comments: PA = 19, ORIENT=64 Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 UZ-TAUE STIS/C ACCUM 50CCD MIRROR GAIN=4,WAVECAL=NO 1 0.4 S GS ACQ SCENARIO SINGLE CD ------------------------------------------------------------------------------------------------------------------------------------ 2 UZ-TAUE STIS/C ACCUM 50CCD G750L 7751 CR-SPLIT=3,NUM-POS=2, 1 1200 S MAX DUR CD PATTERN=ALONG-SLIT,STEP-SIZE=0.25 ,GAIN=4 ------------------------------------------------------------------------------------------------------------------------------------ 3 CCDFLAT STIS/C ACCUM 52X0.1 G750L 7751 2 DEF CD Comments: Fringe Flat ------------------------------------------------------------------------------------------------------------------------------------ 8238( 11) - 08/03/99 09:07 - [ 9] Visit: 05 Visit Priority: Visit Requirements: ORIENT 30.0D TO 40.0D ORIENT 210.0D TO 220.0D SCHED 100% On Hold Comments: Additional Comments: PA = 170, ORIENT=35 Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HN-TAU STIS/C ACCUM 50CCD MIRROR GAIN=4,WAVECAL=NO 1 1.6 S CD ------------------------------------------------------------------------------------------------------------------------------------ 2 HN-TAU STIS/C ACCUM 50CCD G750L 7751 CR-SPLIT=2,NUM-POS=2, 1 1120 S MAX DUR CD PATTERN=ALONG-SLIT,STEP-SIZE=0.25 ,GAIN=4 ------------------------------------------------------------------------------------------------------------------------------------ 3 CCDFLAT STIS/C ACCUM 52X0.1 G750L 7751 2 DEF CD Comments: Fringe Flat ------------------------------------------------------------------------------------------------------------------------------------ 8238( 11) - 08/03/99 09:07 - [ 10] Visit: 06 Visit Priority: Visit Requirements: ORIENT 320D TO 330D ORIENT 140D TO 150D VISIBILITY INTERVAL 51 M On Hold Comments: Additional Comments: perp-PA=70, perp-ORIENT=115 Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 CW-TAU STIS/C ACCUM 50CCD MIRROR GAIN=4,WAVECAL=NO 1 0.6 S CD ------------------------------------------------------------------------------------------------------------------------------------ 2 CW-TAU STIS/C ACCUM 50CCD G750L 7751 CR-SPLIT=2,NUM-POS=2, 1 18.5 M MAX DUR CD PATTERN=ALONG-SLIT,STEP-SIZE=0.25 ,GAIN=4 ------------------------------------------------------------------------------------------------------------------------------------ 3 CCDFLAT STIS/C ACCUM 52X0.1 G750L 7751 2 DEF CD Comments: Fringe Flat ------------------------------------------------------------------------------------------------------------------------------------ 8238( 11) - 08/03/99 09:07 - [ 11] Visit: 07 Visit Priority: Visit Requirements: ORIENT 100.0D TO 110.0D ORIENT 280.0D TO 290.0D ORIENT 174D TO 185D On Hold Comments: Additional Comments: wanted perp-PA=98, perp-ORIENT=143, settle for ORIENT=105, not critical here Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DD-TAU STIS/C ACCUM 50CCD MIRROR GAIN=4,WAVECAL=NO 1 1.4 S GS ACQ SCENARIO SINGLE CD ------------------------------------------------------------------------------------------------------------------------------------ 2 DD-TAU STIS/C ACCUM 50CCD G750L 7751 CR-SPLIT=2,NUM-POS=2, 1 1230 S MAX DUR CD PATTERN=ALONG-SLIT,STEP-SIZE=0.25 ,GAIN=4 ------------------------------------------------------------------------------------------------------------------------------------ 3 CCDFLAT STIS/C ACCUM 52X0.1 G750L 7751 2 DEF CD Comments: Fringe Flat ------------------------------------------------------------------------------------------------------------------------------------ 8238( 11) - 08/03/99 09:07 - [ 12] Visit: 08 Visit Priority: Visit Requirements: ORIENT 70.0D TO 80.0D ORIENT 250.0D TO 260.0D On Hold Comments: Additional Comments: perp-PA=31, perp-ORIENT=76 Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DF-TAU STIS/C ACCUM 50CCD MIRROR GAIN=4,WAVECAL=NO 1 0.4 S CD ------------------------------------------------------------------------------------------------------------------------------------ 2 DF-TAU STIS/C ACCUM 50CCD G750L 7751 CR-SPLIT=2,NUM-POS=2, 1 1260 S MAX DUR CD PATTERN=ALONG-SLIT,STEP-SIZE=0.25 ,GAIN=4 ------------------------------------------------------------------------------------------------------------------------------------ 3 CCDFLAT STIS/C ACCUM 52X0.1 G750L 7751 2 DEF CD Comments: Fringe Flat ------------------------------------------------------------------------------------------------------------------------------------ 8238( 11) - 08/03/99 09:07 - [ 13] Visit: 09 Visit Priority: Visit Requirements: ORIENT 150.0D TO 160.0D ORIENT 330.0D TO 340.0D SCHED 100% On Hold Comments: Additional Comments: perp-PA = 109, perp-ORIENT=154 Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 UZ-TAUE STIS/C ACCUM 50CCD MIRROR GAIN=4,WAVECAL=NO 1 0.4 S GS ACQ SCENARIO SINGLE CD ------------------------------------------------------------------------------------------------------------------------------------ 2 UZ-TAUE STIS/C ACCUM 50CCD G750L 7751 CR-SPLIT=2,NUM-POS=2, 1 1120 S MAX DUR CD PATTERN=ALONG-SLIT,STEP-SIZE=0.25 ,GAIN=4 ------------------------------------------------------------------------------------------------------------------------------------ 3 CCDFLAT STIS/C ACCUM 52X0.1 G750L 7751 2 DEF CD Comments: Fringe Flat ------------------------------------------------------------------------------------------------------------------------------------ 8238( 11) - 08/03/99 09:07 - [ 14] Visit: 10 Visit Priority: Visit Requirements: ORIENT 100.0D TO 110.0D ORIENT 280.0D TO 290.0D On Hold Comments: Additional Comments: want perp-PA=80, perp-ORIENT=125; settle for perp-PA=60, perp-ORIENT=105 Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HN-TAU STIS/C ACCUM 50CCD MIRROR GAIN=4,WAVECAL=NO 1 1.6 S CD ------------------------------------------------------------------------------------------------------------------------------------ 2 HN-TAU STIS/C ACCUM 50CCD G750L 7751 CR-SPLIT=2,NUM-POS=2, 1 1230 S MAX DUR CD PATTERN=ALONG-SLIT,STEP-SIZE=0.25 ,GAIN=4 ------------------------------------------------------------------------------------------------------------------------------------ 3 CCDFLAT STIS/C ACCUM 52X0.1 G750L 7751 2 DEF CD Comments: Fringe Flat ------------------------------------------------------------------------------------------------------------------------------------ 8238( 11) - 08/03/99 09:07 - [ 15] Summary Form for Proposal 8238 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 50CCD 52X0.1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters GAIN=4 WAVECAL=NO STEP-SIZE=0.2 STEP-SIZE=0.25 PATTERN=ALONG-SLIT NUM-POS=2 CR-SPLIT=2 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 50.D TO 60.0D ORIENT 230.0D TO 240.0D GS ACQ SCENARIO SINGLE MAX DUR ORIENT 50.0D TO 60.0D ORIENT 230.0D TO 240.0D ORIENT 160.0D TO 170.0D ORIENT 340.0D TO 350.0D SCHED 100% ORIENT 60.0D TO 70.0D ORIENT 240.0D TO 250.0D ORIENT 30.0D TO 40.0D ORIENT 210.0D TO 220.0D SCHED 100% ORIENT 320D TO 330D ORIENT 140D TO 150D VISIBILITY INTERVAL 51 M ORIENT 100.0D TO 110.0D ORIENT 280.0D TO 290.0D ORIENT 174D TO 185D ORIENT 70.0D TO 80.0D ORIENT 250.0D TO 260.0D ORIENT 150.0D TO 160.0D ORIENT 330.0D TO 340.0D SCHED 100% ORIENT 100.0D TO 110.0D ORIENT 280.0D TO 290.0D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G750L ------------------------------------------------------------------------------------------------------------------------------------ Target Names CW-TAU CCDFLAT DD-TAU DF-TAU UZ-TAUE HN-TAU ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 7751 ------------------------------------------------------------------------------------------------------------------------------------