8628( 3) - 04/05/00 13:36 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8628 Version: 3 Check-in Date: 05-Apr-2000 13:35:57 1.Proposal Title: High Density (~ 10^9 cm^-3) gas in the jet formation region of T Tauri stars ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 9 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Ana Gomez De Castro ESA, VILSPA, Infrared Space Observatory CoI: Dr. Eva Verdugo ISO Data Centre N ------------------------------------------------------------------------------------ 5. Abstract Outflow is ubiquotous during star formation however the mechanism which drives it, is still uknown. The key observational information about how outflow is initiated is contained within a region of angular size smaller than 0.1 arcsec (for the nearest stars) which is not accessible to direct imaging. It has been shown that the jet density increases towards the source but the commonly used optical forbidden lines cannot probe densities higher than ~ 10^6 cm^- 3. An analysis of the ultraviolet tracers of shocked material carried out by us and based on data from the HST Archive has shown that jet emission is also detected from the UV semiforbidden lines of CIII](1908 A) and SiIII](1892 A). The infered electronic density of the emitting gas is ~ 1e9 - 1e10 cm-3. Therefore the UV semiforbidden lines provide a unique tool for studying the physics of jet formation within the ``black box'' which is not accessible by other means. This project, however, can only be carried out with: HST+STIS. Given the relevance of studying the base of the jet to understand the physics of outflow (and accretion) in star formation, we apply in this proposal for HST observing time to measure the CIII] and SiIII] lines in a small sample of T Tauri stars. Our objective is to compare the kinematics of the UV line formation region with that of the optical forbidden lines and to determine the physical characteristics of the jet formation region. ------------------------------------------------------------------------------------ 8628( 3) - 04/05/00 13:36 - [ 2] Observations Description ------------------------ We propose to observe the CIII] and SiIII] lines of 7 TTSs with the mid resolution G230M grating of the STIS spectrograph to study the properties of the line formation region and compare them with those of the optical forbidden lines. The sample has been extracted from the IUE Final Archive (see Gomez de Castro & Franqueira 1997). We have selected sources with strong CIII] and SiIII] lines which, in addition, have blueshifted emission in the optical forbidden lines of [OI](6300 A). The exposure times have been calculated with the WWW STIS Exposure Time Calculator and using as input the CIII] line fluxes given in Table 1 from low dispersion IUE spectra to achieve a S/N = 15 at 1900 Angstrom. We have used IUE fluxes since they are available for all the sources in our sample whereas only two stars have been observed with HST. begintableh begincenter captionC iii line fluxes and exposures times for the sample of stars begintabularllcccc Name & HD & F(C iii) 10^-13 erg cm^-2 s^-1 & Texp m & Toverh m & Orbits, DE Tau & & 8.64 & 64.47 & 29 & 2, RY Tau & 283571 & 0.55 & 76.40 & 29 & 2, T Tau & 284419 & 1.40 & 27.65 & 25 & 1, RW Aur & 240764 & 0.95 & 39.57 & 29 & 2, RU Lup & 142560 & 1.50 & 25.72 & 25 & 1, AK Sco & 152404 & 1.60 & 24.03 & 25 & 1, DI Cep & & 0.37 & 120.73 & 38 & 3, endtabular endcenter endtable ORBIT CALCULATION., Science exposures overheads:, Generic: We have allowed 6 min. for the Guide Star Adquisition since V>9 mag for our sample of stars. 5 min. extra per orbit have been included whenever reacquisition was required., Acquisitions and Peakups: 6 min. for the STIS target Adquisition (MODE=ACQ)., Spectroscopy: We have allowed 8 min. for setting the instrument. 4 extra minutes have been allowed for obtaining a wavecal each orbit., , Number of orbits., The visibility time of our targets range between 53 and 56 minutes depending on their declinations. We have computed the number of orbits required accordingly (see Table 1). Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 8628( 3) - 04/05/00 13:36 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 DE-TAU STAR, T TAURI STAR RA=04H 21M 55.68S +/- 0.02S, J2000 V = 13.0+/-0.3 DEC=27D 55' 6.8" +/- 0.3", PLATE B-V = 1.38 -ID=0051 TYPE=M2V F-CONT(1855)=1.9e-15 F-LINE(1908)=0.3e-13 W-LINE(1908)=1.0 2 HD283571 STAR, T TAURI STAR RA=04H 21M 57.44S +/- 0.02S, J2000 V = 10.0+/-0.4 DEC=28D 26' 36" +/- 0.3", PLATE- B-V = 1.03 ID=0051 TYPE=K1V F-CONT(1855)=2.5e-15 F-LINE(1908)=0.55e-13 W-LINE(1908)=1.0 3 HD284419 STAR, T TAURI STAR RA=04H 21M 59.42S +/- 0.01S, J2000 V = 9.9+/-0.4 DEC=19D 32' 6.4" +/- 0.2", PLATE B-V = 1.19 -ID=000P TYPE=K0V F-CONT(1855)=6.1e-15 F-LINE(1908)=1.4e-13 W-LINE(1908)=1.0 4 HD240764 STAR, T TAURI STAR RA=05H 7M 49.51S +/- 0.02S, J2000 V = 10.12+/-0.40 DEC=30D 24' 5.5" +/- 0.3", PLATE B-V = 0.65 -ID=00DH TYPE=K1V F-CONT(1855)=1.6e-14 F-LINE(1908)=0.95e-13 W-LINE(1908)=1.0 5 HD142560 STAR, T TAURI STAR RA=15H 56M 42.26S +/- 0.03S, J2000 V = 10.52+/-0.44 DEC=-37D 49' 15.7" +/- 0.5", B-V = 0.48 PLATE-ID=02F8 TYPE=K F-CONT(1855)=3.4e-14 F-LINE(1892)=2.9e-13 W-LINE(1892)=1.8 6 HD152404 STAR, T TAURI STAR RA=16H 54M 44.75S +/- 0.05S, J2000 V = 9.21+/-0.41 DEC=-36D 53' 18.5" +/- 0.6", B-V = 0.59 PLATE-ID=06Q2 TYPE=F5V F-CONT(1855)=1e-14 F-LINE(1908)=1.6e-13 W-LINE(1908)=1.0 7 DI-CEP STAR, T TAURI STAR RA=22H 56M 12.31S +/- 0S, J2000 V = 11.3+/-0.25 DEC=58D 40' 2.1" +/- 0" B-V = 0.87 TYPE=G8V F-CONT(1855)=4.9e-15 F-LINE(1908)=0.37e-13 W-LINE(1908)=1.0 8628( 3) - 04/05/00 13:36 - [ 4] Visit: 01 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 DE-TAU STIS/C ACQ F28X50L MIRROR 1 0.1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 DE-TAU STIS/N ACCUM 52X0.2 G230M 1884 3 45 M UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8628( 3) - 04/05/00 13:36 - [ 5] 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HD284419 STIS/C ACQ F28X50L MIRROR 1 0.1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 HD284419 STIS/N ACCUM 52X0.2 G230M 1884 3 10 M UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8628( 3) - 04/05/00 13:36 - [ 6] Visit: 03 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HD240764 STIS/C ACQ F28X50L MIRROR 1 0.1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 HD240764 STIS/N ACCUM 52X0.2 G230M 1884 3 13 M UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8628( 3) - 04/05/00 13:36 - [ 7] Visit: 04 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HD142560 STIS/C ACQ F28X50L MIRROR 1 0.1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 HD142560 STIS/N ACCUM 52X0.2 G230M 1884 3 12 M UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8628( 3) - 04/05/00 13:36 - [ 8] Visit: 05 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HD152404 STIS/C ACQ F28X50O MIRROR 1 1 S CD II ------------------------------------------------------------------------------------------------------------------------------------ 2 HD152404 STIS/N ACCUM 52X0.2 G230M 1884 3 9 M UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8628( 3) - 04/05/00 13:36 - [ 9] Visit: 06 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 DI-CEP STIS/C ACQ F28X50L MIRROR 1 0.1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 DI-CEP STIS/N ACCUM 52X0.2 G230M 1884 3 40 M UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8628( 3) - 04/05/00 13:36 - [ 10] Visit: 07 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HD283571 STIS/C ACQ F28X50L MIRROR 1 0.1 S CD P ------------------------------------------------------------------------------------------------------------------------------------ 2 HD283571 STIS/N ACCUM 52X0.2 G230M 1884 3 24 M UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8628( 3) - 04/05/00 13:36 - [ 11] Summary Form for Proposal 8628 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 52X0.2 F28X50OII ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G230M ------------------------------------------------------------------------------------------------------------------------------------ Target Names DE-TAU HD284419 HD240764 HD142560 HD152404 DI-CEP HD283571 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 1884 ------------------------------------------------------------------------------------------------------------------------------------