6132( 15) - 11/21/95 17:36 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6132 Version: 15 Check-in Date: ********** 1.Proposal Title: Envelopes and jets of young stellar objects ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Interstellar Medium GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Scott J. Kenyon Smithsonian Astrophysical Observatory CoI: Lee Hartmann Smithsonian Astrophysical Observatory N CoI: Barbara Whitney Smithsonian Astrophysical Observatory N CoI: Stephen Strom Five College Astronomy Department N CoI: Suzan Edwards Five College Astronomy Department N CoI: Nuria Calvet Centro de Investigaciones de Astronomia N CoI: Deborah Padgett Infrared Processing and Analysis Center N ------------------------------------------------------------------------------------ 6. Abstract We propose an imaging program to constrain the initial angular momentum of protostellar cloud cores, the radii of circumstellar disks, and the interaction between the highly- collimated jets and protostellar envelopes of young stellar objects. Our sample spans a range of evolutionary states, from the youngest stars still enshrouded in their parent clouds to older systems where infall has nearly ceased. PC images in an I-band continuum filter will constrain the structure of dusty envelopes outlined in scattered light; S II images will determine the location of the jet relative to the infalling envelope. Our scattering models for ground- based images suggest that optically thick protostellar envelopes have bipolar cavities that allow light from the central star to illuminate a large reflection nebula. HST images will enable us to measure the size and shape of this cavity close to the central star and its surrounding disk. By comparing the degree of jet collimation and the shape of the scattered light cavity on 0sec point1--0sec point2 scales, we will also explore the possibility that jets create the cavities, shape the scattered light nebulae, reverse the infall, and set the final mass of the star. Theoretical models predict that scattered light can be enhanced in a rotating ring, where material from the envelope lands on the outer disk. Detection of these rings in the least-reddened sources of our sample would provide direct measurements of the disk radius and indirect measurements of the initial angular momentum per unit mass in the parent clouds. ------------------------------------------------------------------------------------ 6132( 15) - 11/21/95 17:36 - [ 2] Observations Description ------------------------ We request PC observations of 4 embedded protostars and 6 T Tauri stars (TTS) in the Taurus dark cloud. The protostars are the brightest and bluest known. We have previously modeled their SEDs and near-IR images; some have strong S II emission (Kenyon Etal 1993a, b; see Figures 1--2). The TTS are also bright and have K--N colors intermediate between those of pure disk sources and protostars. Our plan is to acquire 1100 sec exposures of each protostar with the F814W (2 images) and F673N filters (2 images). The F814W filter is the one of the longest wavelength filters available on HST and gives us the best S/N for very red sources. We predict S/N ~ 15--20 per resolution element per 1100 sec continuum exposure for a monochromatic source with an I magnitude equal to that of a typical protostar with an angular size of 15". We detected S II emission in several protostars at count rates of 0.05 counts per sec per pixel with a 48" telescope. If this emission is confined to an unresolved jet with a length of several arcsec, we expect S/N ~ 7--10 per resolution element per 1100 sec exposure in the jet. Most TTS have F(O I) ~ 2--3F(S II). We chose S II for this program, because the differential reddening between O I and S II for a typical protostar is at least 1.5 mag. This portion of our program requires 8 orbits. We also plan observations of 6 TTS with the same filter set. The TTS exposure times are short: 0.1--5 sec at I and 10--300 sec at S II will saturate the central pixel. Our first goal is to acquire three I-band exposures that almost saturate the central pixel and a fourth image overexposed by a factor of ~ 10. We will subtract a normalized PSF from a coadd of the three short exposures and analyze the residual flux. Simulations indicate that any flux from a flared disk or envelope will be ~ 5--10 times brighter than the stellar PSF at 0sec point5. This flux level corresponds to S/N ~ 10 per resolution element per exposure above the read noise. Our second goal is to acquire S II images that just saturate the central pixel. The program TTS have EW(S II) = 0.2--2 Angstrom, which implies S/N ~ 5--15 per resolution element per exposure for an unresolved jet 1" in length. We expect to acquire 4--8 S II images per source, depending on the integration time, and can bin the data to increase S/N for weak sources. This portion of our program requires 6 orbits. We plan to devote one orbit to measuring the PSF of a single main sequence star in the S II silter to make sure we have the best possible PSF to subtract from our program S II images. Real Time Justification ----------------------- We will acquire several types of supporting observations. 1. Near-IR imaging polarimetry of protostars and TTS with COB at the KPNO 1.3-m telescope (Dec 1994). Imaging polarimetry with 1" resolution will constrain the shape and orientation of the outflow cavity on 5--15" scales. 2. Narrow-band optical imaging of protostars with the SAO 48 telescope (Nov -Dec 1994). These images will constrain frequency of S II emission in protostars. 3. VRI optical imaging of protostars and TTS with the SAO 48 telescope (Nov-Dec 1994). These images will constrain the shape of the outflow cavity on 5-- 15" scales. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 6132( 15) - 11/21/95 17:36 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6132( 15) - 11/21/95 17:36 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 IRAS04016+26 STAR, T Tauri Star, RA=04H 04M 43.09S +/- 2.0S, J2000.0 V=20.5 10 Protoplanetary Disk, DEC=26D 18' 58.0" +/- 2.0" Jet 2 IRAS04248+26 STAR, T Tauri Star, RA=04H 27M 57.69S +/- 2.0S, J2000.0 V=22.0 12 Protoplanetary Disk, DEC=26D 19' 19.0" +/- 2.0" Jet 3 IRAS04303+22 STAR, T Tauri Star, RA=04H 33M 16.20S +/- 2.0S, J2000.0 V=22.5 47 Protoplanetary Disk, DEC=22D 53' 20.4" +/- 2.0" Jet 4 CW-TAU STAR, T Tauri Star, RA=04H 14M 17.77S +/- 1.0S, J2000.0 V=13.3 Protoplanetary Disk, DEC=28D 10' 29.0" +/- 1.0" Jet 6132( 15) - 11/21/95 17:36 - [ 5] Visit: 01 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 ------------------------------------------------------------------------------------------------------------------------------------ 11 IRAS04016+2 WFPC2 IMAGE WF3 F814W CR-SPLIT=0.5,CR 1 1000S 610 -TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 12 IRAS04016+2 WFPC2 IMAGE WF3 F814W CR-SPLIT=0.5,CR 1 1000S POS TARG 0.15,0.15 END ORBIT 610 -TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 13 IRAS04016+2 WFPC2 IMAGE WF3 F673N CR-SPLIT=0.5,CR 1 1100S SAME POS AS 12 610 -TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 14 IRAS04016+2 WFPC2 IMAGE WF3 F673N CR-SPLIT=0.5,CR 1 1100S SAME POS AS 11 610 -TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 6132( 15) - 11/21/95 17:36 - [ 6] Visit: 02 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 ------------------------------------------------------------------------------------------------------------------------------------ 21 IRAS04248+2 WFPC2 IMAGE WF3 F814W CR-SPLIT=0.5,CR 1 1000S 612 -TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 22 IRAS04248+2 WFPC2 IMAGE WF3 F814W CR-SPLIT=0.5,CR 1 1000S POS TARG 0.15,0.15 END ORBIT 612 -TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 23 IRAS04248+2 WFPC2 IMAGE WF3 F814W CR-SPLIT=0.5,CR 1 1100S POS TARG 0.3,0.3 612 -TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 24 IRAS04248+2 WFPC2 IMAGE WF3 F673N CR-SPLIT=0.5,CR 1 1100S SAME POS AS 23 END ORBIT 612 -TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 25 IRAS04248+2 WFPC2 IMAGE WF3 F673N CR-SPLIT=0.5,CR 1 1100S SAME POS AS 22 612 -TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 26 IRAS04248+2 WFPC2 IMAGE WF3 F673N CR-SPLIT=0.5,CR 1 1100S SAME POS AS 21 612 -TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 6132( 15) - 11/21/95 17:36 - [ 7] Visit: 03 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 ------------------------------------------------------------------------------------------------------------------------------------ 31 IRAS04303+2 WFPC2 IMAGE WF3 F814W CR-SPLIT=0.5, 1 1000S MAX DUR 247 ATD-GAIN=7,CR- TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 32 IRAS04303+2 WFPC2 IMAGE WF3 F814W CR-SPLIT=0.5, 1 1000S POS TARG 0.15,0.15 MAX DUR 247 ATD-GAIN=7, CR- TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 6132( 15) - 11/21/95 17:36 - [ 8] Visit: 04 Visit Requirements: ORIENT 220D TO 230D 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 ------------------------------------------------------------------------------------------------------------------------------------ 41 CW-TAU WFPC2 IMAGE PC1-FIX F814W 1 2S POS TARG 12.282,-12.282 ------------------------------------------------------------------------------------------------------------------------------------ 42 CW-TAU WFPC2 IMAGE PC1-FIX F814W 1 2S POS TARG 12.213,-12.213 ------------------------------------------------------------------------------------------------------------------------------------ 43 CW-TAU WFPC2 IMAGE PC1-FIX F814W 1 20S SAME POS AS 42 ------------------------------------------------------------------------------------------------------------------------------------ 44 CW-TAU WFPC2 IMAGE PC1-FIX F814W 1 20S SAME POS AS 41 ------------------------------------------------------------------------------------------------------------------------------------ 45 CW-TAU WFPC2 IMAGE PC1-FIX F673N CR-SPLIT=NO 1 150S SAME POS AS 41 ------------------------------------------------------------------------------------------------------------------------------------ 46 CW-TAU WFPC2 IMAGE PC1-FIX F673N CR-SPLIT=NO 2 150S SAME POS AS 42 ------------------------------------------------------------------------------------------------------------------------------------ 47 CW-TAU WFPC2 IMAGE PC1-FIX F673N CR-SPLIT=0.5 1 500S SAME POS AS 42 ------------------------------------------------------------------------------------------------------------------------------------ 6132( 15) - 11/21/95 17:36 - [ 9] Summary Form for Proposal 6132 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=0.5 CR-TOLERANCE=0.0 ATD-GAIN=7 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Interstellar Medium ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements POS TARG 0.15,0.15 END ORBIT SAME POS AS 12 SAME POS AS 11 POS TARG 0.3,0.3 SAME POS AS 23 END ORBIT SAME POS AS 22 SAME POS AS 21 MAX DUR POS TARG 0.15,0.15 MAX DUR ORIENT 220D TO 230D POS TARG 12.282,-12.282 POS TARG 12.213,-12.213 SAME POS AS 42 SAME POS AS 41 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F814W F673N ------------------------------------------------------------------------------------------------------------------------------------ Target Names IRAS04016+2610 IRAS04248+2612 IRAS04303+2247 CW-TAU ------------------------------------------------------------------------------------------------------------------------------------