8215( 22) - 01/27/00 09:32 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8215 Version: 22 Check-in Date: 27-Jan-2000 09:32:19 1.Proposal Title: New clues to the ejection process in young stars:, Forbidden line imaging of T Tauri micro-jets ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 8 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Catherine Dougados Observatoire de Grenoble CoI: Dr. Sylvie Cabrit DEMIRM, Observatoire de Paris N CoI: Pr. Alejandro Raga UNAM, Mexico N CoI: Claudia Lavalley LAOG, Observatoire de Grenoble N CoI: Dr. Jonathan Ferreira LAOG, Observatoire de Grenoble N ------------------------------------------------------------------------------------ 5. Abstract Bipolar outflows play a fundamental role in star formation. However, the ejection and collimation mechanisms are still not identified. Classical T Tauri stars (CTTS) offer a unique opportunity to progress on this problem, as their optical forbidden line emission allows to trace collimated winds very close to the central star (d <= 100 AU). Determining the exact flow geometry and the line excitation mechanism is essential to obtain new clues to the mass-loss process in young stars. Our team has recently obtained at CFHT the first sub-arcsecond resolution (FWHM=0.15") images of micro-jets around 3 T Tauri stars: DG Tau, CW Tau, RW Aur. They reveal unprecedented details about the morphology of these jets, strongly suggesting ejection and velocity variability. However, such ground-based studies are limited to high- accretion sources. We propose here to use the unique HST resolution capabilities to image for the first time the innermost regions of jets associated with 4 CTTs wi t h R band magnitudes > 13. Extending our sample to less extreme stars is crucial if we want to derive meaningful constraints on the mass-loss process in CTTS. Images in the 3 narrow-band filters SII, NII and OI will be obtained. We will thus have access both to the jet excitation conditions and intrinsic morphology, and compare them with theoretical predictions from MHD models. ------------------------------------------------------------------------------------ 8215( 22) - 01/27/00 09:32 - [ 2] Observations Description ------------------------ Choice of instrument and filters: We will use the Wide Field Camera which offers the best sensitivity to extended emission. To study the jet inside 0.5" of the star, we will perform high-accuracy continuum subtraction and PSF deconvolution, making use of the available psf library and synthetic psfs computed by the Tiny Tim sofware. It is also crucial that we image the jet with narrow-band emission line filters: this will increase the jet/star contrast ratio by a very large factor of ~eq 900Angstrom/30Angstrom = 30 and will therefore considerably reduce the PSF removal artefacts that otherwise prevent reliable jet imaging within ~eq 0.2" of the star (see e.g. Stapelfeldt et al. 1997). We will perform continuum observations in the F547M filter in order to avoid all major emission lines., Integration times: We have estimated the expected jet surface brightnesses at 1" from the star for our targets by combining forbidden line ground-based photometry (HEG95; see Table 1) and spat i a l extensions published by Hirth et al. (1997), assuming the same jet widths and intensity fall off along the jet as in DG Tau. Surface brightnesses in the OI line range from 5 * 10^-15 to a few 10^-14 erg s^-1 cm^-2 arcsec^-2. Hence, with 3600s on-source integration time with the WFC camera and F631N filter, we get a signal to noise ratio per pixel > 6. Similar integration times of 3600s will be used for all 3 lines, which have comparable brightnesses at such distances (cf. DG Tau and O I/[S II] ratios). Each integration will be split into 3 exposures of 1200sec each to allow for cosmic rays correction. We will also acquire 2 short 30sec exposures both in each filter to obtain an unsaturated image of the central source and get information on the jet closer to the source. In the case of DO Tau and DP Tau we will also acquire a set of 2x150s exposures in each filter in order to probe the very inner regions of the jets. The visibility of our sources is 52 min per orbit. Inc lu di ng overheads, a maximum of 2 1200s exposure per orbit will be obtained per orbit. We will spend 5 orbits on DP Tau (mapping in OI, SII and NII), 4 on DO Tau (OI and SII) and one on HN Tau (mapping in SII). Real Time Justification ----------------------- None Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Paper Products: NO Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 8215( 22) - 01/27/00 09:32 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 DPTAU STAR, T TAURI STAR, RA=04H 42M 37.68S +/- 0.1S, J2000 V = 14.2+/-0.1 EMISSION LINE STAR, DEC=25D 15' 38.0" +/- 1.0" R = 13.1+/-0.1 ISM, JET W-LINE(6716)=2.1 W-LINE(6300)=3.55 W-LINE(6583)=0.6 Comments: VARIABLE CONTINUUM STAR, JET AT PA=221D 2 DOTAU STAR, T TAURI STAR, RA=04H 38M 28.57S +/- 0.1S, J2000 V = 13.8+/-0.5 EMISSION LINE STAR, DEC=26D 10' 49.4" +/- 0.5", R = 12.6+/-0.5 ISM, JET PLATE-ID=000L W-LINE(6731)=0.87+/-0.3 W-LINE(6300)=4.4+/-1. W-LINE(6716)=0.35+/-0.05 Comments: VARIABLE CONTINUUM STAR, JET AT PA=250D 3 HNTAU STAR, T TAURI STAR, RA=04H 33M 39.35S +/- 0.02S, J2000 V = 13.95+/-0.4 EMISSION LINE STAR, DEC=17D 51' 52.6" +/- 0.2", R = 12.67+/-0.4 ISM, JET PLATE-ID=000P W-LINE(6300)=9.85+/-2 W-LINE(6716)=0.85+/-0.1 W-LINE(6731)=2.2+/-0.4 W-LINE(6584)=0.83+/-0.3 Comments: VARIABLE CONTINUUM STAR, BLUESHIFTED JET AT PA=350D 8215( 22) - 01/27/00 09:32 - [ 4] Visit: 01 Visit Priority: Visit Requirements: ORIENT 70D TO 100D On Hold Comments: Additional Comments: WANT JET PA=221D ALONG X-AXIS Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 DPTAU WFPC2 IMAGE WF3 F673N ATD-GAIN=15,CR-SPLIT=NO 1 1100 S GS ACQ SCENARIO SINGLE Comments: STAR WILL BE SATURATED ------------------------------------------------------------------------------------------------------------------------------------ 20 DPTAU WFPC2 IMAGE WF3 F673N ATD-GAIN=15,CR-SPLIT=NO 1 1200 S Comments: STAR WILL BE SATURATED ------------------------------------------------------------------------------------------------------------------------------------ 30 DPTAU WFPC2 IMAGE WF3 F673N ATD-GAIN=15,CR-SPLIT=NO 1 1200 S Comments: STAR WILL BE SATURATED ------------------------------------------------------------------------------------------------------------------------------------ 40 DPTAU WFPC2 IMAGE WF3 F658N ATD-GAIN=15,CR-SPLIT=NO 1 1200 S Comments: STAR WILL BE SATURATED ------------------------------------------------------------------------------------------------------------------------------------ 50 DPTAU WFPC2 IMAGE WF3 F658N ATD-GAIN=15,CR-SPLIT=NO 1 17 M NEW OBSET FULL ACQ GS ACQ SCENARIO SINGLE MAX DUR Comments: STAR WILL BE SATURATED ------------------------------------------------------------------------------------------------------------------------------------ 60 DPTAU WFPC2 IMAGE WF3 F658N ATD-GAIN=15,CR-SPLIT=NO 1 17 M MAX DUR Comments: STAR WILL BE SATURATED ------------------------------------------------------------------------------------------------------------------------------------ 70 DPTAU WFPC2 IMAGE WF3 F631N ATD-GAIN=15,CR-SPLIT=NO 1 1200 S Comments: STAR WILL BE SATURATED ------------------------------------------------------------------------------------------------------------------------------------ 80 DPTAU WFPC2 IMAGE WF3 F631N ATD-GAIN=15,CR-SPLIT=NO 1 1200 S Comments: STAR WILL BE SATURATED ------------------------------------------------------------------------------------------------------------------------------------ 90 DPTAU WFPC2 IMAGE WF3 F631N ATD-GAIN=15,CR-SPLIT=NO 1 1200 S EXPAND MIN DUR 1100 S MAX DUR 1500 S Comments: STAR WILL BE SATURATED ------------------------------------------------------------------------------------------------------------------------------------ 100 DPTAU WFPC2 IMAGE WF3 F631N ATD-GAIN=15,CR-SPLIT=NO 2 30 S MAX DUR 30 S ------------------------------------------------------------------------------------------------------------------------------------ 110 DPTAU WFPC2 IMAGE WF3 F658N ATD-GAIN=15,CR-SPLIT=NO 2 30 S MAX DUR 30 S ------------------------------------------------------------------------------------------------------------------------------------ 120 DPTAU WFPC2 IMAGE WF3 F673N ATD-GAIN=15,CR-SPLIT=NO 2 30 S MAX DUR 30 S ------------------------------------------------------------------------------------------------------------------------------------ 130 DPTAU WFPC2 IMAGE WF3 F547M ATD-GAIN=15,CR-SPLIT=NO 1 5 S MAX DUR 5 S ------------------------------------------------------------------------------------------------------------------------------------ 140 DPTAU WFPC2 IMAGE WF3 F547M ATD-GAIN=15,CR-SPLIT=NO 1 100 S ------------------------------------------------------------------------------------------------------------------------------------ 8215( 22) - 01/27/00 09:32 - [ 5] Visit: 02 Visit Priority: Visit Requirements: ORIENT 265D TO 325D ORIENT 100D TO 130D ORIENT 132.5D TO 142.5D ORIENT 177.5D TO 187.5D On Hold Comments: Additional Comments: WANT JET PA=250D ALONG POSITIVE X-AXIS Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 DOTAU WFPC2 IMAGE WF3 F673N ATD-GAIN=15,CR-SPLIT=NO 1 1100 S GS ACQ SCENARIO SINGLE Comments: STAR WILL BE SATURATED ------------------------------------------------------------------------------------------------------------------------------------ 20 DOTAU WFPC2 IMAGE WF3 F673N ATD-GAIN=15,CR-SPLIT=NO 1 1200 S Comments: STAR WILL BE SATURATED ------------------------------------------------------------------------------------------------------------------------------------ 30 DOTAU WFPC2 IMAGE WF3 F673N ATD-GAIN=15,CR-SPLIT=NO 1 1200 S Comments: STAR WILL BE SATURATED ------------------------------------------------------------------------------------------------------------------------------------ 40 DOTAU WFPC2 IMAGE WF3 F673N ATD-GAIN=15,CR-SPLIT=NO 1 1200 S Comments: STAR WILL BE SATURATED ------------------------------------------------------------------------------------------------------------------------------------ 50 DOTAU WFPC2 IMAGE WF3 F673N ATD-GAIN=15,CR-SPLIT=NO 1 1200 S Comments: STAR WILL BE SATURATED ------------------------------------------------------------------------------------------------------------------------------------ 60 DOTAU WFPC2 IMAGE WF3 F673N ATD-GAIN=15,CR-SPLIT=NO 1 1200 S Comments: STAR WILL BE SATURATED ------------------------------------------------------------------------------------------------------------------------------------ 70 DOTAU WFPC2 IMAGE WF3 F631N ATD-GAIN=15,CR-SPLIT=NO 2 30 S MAX DUR 30 S ------------------------------------------------------------------------------------------------------------------------------------ 80 DOTAU WFPC2 IMAGE WF3 F631N ATD-GAIN=15,CR-SPLIT=NO 3 140 S ------------------------------------------------------------------------------------------------------------------------------------ 90 DOTAU WFPC2 IMAGE WF3 F673N ATD-GAIN=15,CR-SPLIT=NO 2 30 S MAX DUR 30 S ------------------------------------------------------------------------------------------------------------------------------------ 100 DOTAU WFPC2 IMAGE WF3 F673N ATD-GAIN=15,CR-SPLIT=NO 3 140 S ------------------------------------------------------------------------------------------------------------------------------------ 110 DOTAU WFPC2 IMAGE WF3 F547M ATD-GAIN=15,CR-SPLIT=NO 2 5 S MAX DUR 5 S ------------------------------------------------------------------------------------------------------------------------------------ 120 DOTAU WFPC2 IMAGE WF3 F547M ATD-GAIN=15,CR-SPLIT=NO 2 100 S ------------------------------------------------------------------------------------------------------------------------------------ 8215( 22) - 01/27/00 09:32 - [ 6] Visit: 03 Visit Priority: Visit Requirements: ORIENT 20D TO 50D ORIENT 200D TO 230D On Hold Comments: Additional Comments: JET AT PA=350D ALONG X AXIS Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 HNTAU WFPC2 IMAGE WF3 F673N ATD-GAIN=15,CR-SPLIT=NO 1 900 S EXPAND MAX DUR 1200 S MIN DUR 900 S Comments: STAR WILL BE SATURATED ------------------------------------------------------------------------------------------------------------------------------------ 20 HNTAU WFPC2 IMAGE WF3 F673N ATD-GAIN=15,CR-SPLIT=NO 1 900 S EXPAND MAX DUR 1200 S MIN DUR 900 S Comments: STAR WILL BE SATURATED ------------------------------------------------------------------------------------------------------------------------------------ 30 HNTAU WFPC2 IMAGE WF3 F673N ATD-GAIN=15,CR-SPLIT=NO 2 30 S MAX DUR 30 S ------------------------------------------------------------------------------------------------------------------------------------ 8215( 22) - 01/27/00 09:32 - [ 7] Summary Form for Proposal 8215 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WF3 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ATD-GAIN=15 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 70D TO 100D GS ACQ SCENARIO SINGLE NEW OBSET FULL ACQ GS ACQ SCENARIO SINGLE MAX DUR MAX DUR EXPAND MIN DUR 1100 S MAX DUR 1500 S MAX DUR 30 S MAX DUR 5 S ORIENT 265D TO 325D ORIENT 100D TO 130D ORIENT 132.5D TO 142.5D ORIENT 177.5D TO 187.5D ORIENT 20D TO 50D ORIENT 200D TO 230D EXPAND MAX DUR 1200 S MIN DUR 900 S ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F673N F658N F631N F547M ------------------------------------------------------------------------------------------------------------------------------------ Target Names DPTAU DOTAU HNTAU ------------------------------------------------------------------------------------------------------------------------------------