12554( 2) - 05-Jul-2011 11:44:30 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 12554 Version: 2 Check-in Time: 05-Jul-2011 11:44:30 STScI Edit Number: 0 Title The Origins of Carbon-Enhanced Metal-Poor Stars ------------------------------------------------------------------------------------ Type Cycle GO 19 ------------------------------------------------------------------------------------ Investigators Contact? PI: Prof. Timothy C. Beers Michigan State University CoI: Prof. John Cowan University of Oklahoma Norman Campus N CoI: Dr. Anna Frebel Smithsonian Institution Astrophysical N Observatory CoI: Prof. Inese I. Ivans University of Utah N CoI: Prof. James E. Lawler University of Wisconsin - Madison N CoI: Dr. Ian U. Roederer Carnegie Institution of Washington Y CoI: Prof. Hendrik Schatz Michigan State University N CoI: Prof. Christopher Sneden University of Texas at Austin N CoI: Dr. Jennifer S. Sobeck University of Chicago N ------------------------------------------------------------------------------------ Abstract We propose to measure abundances of light and heavy neutron-capture elements for six of the brightest examples of carbon-enhanced metal-poor (CEMP) stars, in order to provide the data needed to directly test models for the origin of these stars in the early Galaxy. CEMP stars are recognized as important tracers of Galactic chemical evolution at metallicities [Fe/H] < -2.0, where they account for on the order of 20% of all stars, rising to 40% below [Fe/H] = -3.5, and 100% below [Fe/H] = -4.0. Detailed understanding of their astrophysical origin has been limited by the lack of a complete inventory of their neutron-capture elements, which are required to probe the nucleosynthetic processes involved in producing their distinctive abundance patterns. Our targets span the known range of neutron-capture element variations associated with CEMP stars (3 stars with pure s-process enhancements, 2 stars with evidence of both r-process and s-process enhancements, and 1 star with low abundances of neutron-capture elements). Each class may well be associated with different progenitor objects, including the first AGB stars in the Galaxy, "faint supernovae'' undergoing mixing and fallback, or even the winds from massive, rapidly rotating stars with [Fe/H] < -6.0. A more complete set of neutron-capture elements will provide tight constraints on these nucleosynthetic and evolutionary models, including the necessary ingredients for understanding the structure and evolution of the first AGB stars in the Galaxy, and shed light on the transition phase from SNII as major C-producers in the early Universe to AGB stars being the major C-producers at later times. ------------------------------------------------------------------------------------ Observations Description ------------------------ We will use STIS (NUV-MAMA detectors, E230M grating) to observe three carbon enhanced metal-poor (CEMP) stars. These stars are the brightest representatives of the CEMP-s, CEMP-r/s, and CEMP-no classes. All three target stars have been chosen on the basis of abundances derived from high-quality ground-based optical spectra and the stars' relative brightness. 12554( 2) - 05-Jul-2011 11:44:30 - [ 2] The transitions of interest are spaced over a wide wavelength range of the near-UV (2282 to 3058 Angstroms). Our target S/N (~40/1 per resolution element in the continuum near 2833 Angstroms) is based on our line strength predictions for typical features of interest (specifically, Pb I 2833). We have estimated integration times using the current version of the STIS exposure time calculator for our setup based on Kurucz models of the flux distribution for our 3 target stars. We plan an ACQ and ACQ/PEAK image at the beginning of all visits, and another ACQ/PEAK image in the middle of visits lasting longer than 3 orbits. Otherwise, the obseving strategy is straightforward: spend as much time as possible observing these stars in one echelle mode to acquire as much S/N as possible. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- Finding charts checked to confirm that predicted star positions at epoch of DSS image perfectly align with the diffraction spikes. -iur, 30jun2011 (To do this: click on the "Targets", "Fixed Targets", [starname], then "File" --> "Export" --> "Export Target Confirmation Charts") ------------------------------------------------------------------------------------ 12554( 2) - 05-Jul-2011 11:44:30 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 BD+440493 STAR, G III-I RA=02H26M49.7381S +/- 0.1", J2000 V = V = 9.13 +/- 0.05 DEC=+44D57'46.52" +/- 0.1" -151. Reference Frame: ICRS Comments: Coordinates, PM, parallax, and RV taken from SIMBAD using the values from the 2007 Hipparcos re-reduction. -iur, 30jun2011 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.011026560912302594 -0.03312 0.00488 ------------------------------------------------------------------------------------------------------------------------------------ 2 HD196944 STAR, K III-I RA=20H40M46.0857S +/- 0.1", J2000 V = V = 8.41 +/- 0.03 DEC=-06D47'50.65" +/- 0.1" -174. Reference Frame: ICRS Comments: Coordinates, PM, parallax, and RV taken from SIMBAD using the values from the 2007 Hipparcos re-reduction. -iur, 30jun2011 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000.0 0.0028117642441772097 -0.02745 0.00205 ------------------------------------------------------------------------------------------------------------------------------------ 3 HD201626 STAR, K III-I RA=21H09M59.2724S +/- 0.1", J2000 V = V = 8.13 +/- 0.03 DEC=+26D36'54.93" +/- 0.1" -145. Reference Frame: ICRS Comments: Coordinates, PM, parallax, and RV taken from SIMBAD using the values from the 2007 Hipparcos re-reduction. -iur, 30jun2011 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000.0 -0.0030908560033567085 0.03022 0.00442 ------------------------------------------------------------------------------------------------------------------------------------ 12554( 2) - 05-Jul-2011 11:44:30 - [ 4] Visit: 01 Visit Requirements: On Hold Comments: Additional Comments: HD196944 - visit 1 of 1 Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD196944 STIS/CCD ACQ F25ND3 MIRROR 1 1.0 S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD196944 STIS/CCD ACQ/PEA 0.2X0.05N MIRROR 1 1.0 S K D ------------------------------------------------------------------------------------------------------------------------------------ 3 HD196944 STIS/NUV ACCUM 0.2X0.06 E230M 2707 1 2160 S -MAMA see below ------------------------------------------------------------------------------------------------------------------------------------ 4 HD196944 STIS/NUV ACCUM 0.2X0.06 E230M 2707 1 3000 S -MAMA see below ------------------------------------------------------------------------------------------------------------------------------------ 5 HD196944 STIS/NUV ACCUM 0.2X0.06 E230M 2707 1 3000 S -MAMA see below ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ HD196944 1 STIS/CCD ACQ F25ND3 MIRROR none none none none 1 N/A HD196944 2 STIS/CCD ACQ/PEA 0.2X0.05 MIRROR none none none none 1 N/A K ND HD196944 3 STIS/NUV ACCUM 0.2X0.06 E230M 2707 none none none none 1 1852.0 S -MAMA HD196944 4 STIS/NUV ACCUM 0.2X0.06 E230M 2707 none none none none 2 2990.0 S -MAMA HD196944 5 STIS/NUV ACCUM 0.2X0.06 E230M 2707 none none none none 3 2990.0 S -MAMA 12554( 2) - 05-Jul-2011 11:44:30 - [ 5] Visit: 02 Visit Requirements: On Hold Comments: Additional Comments: HD201626 - visit1 of 1 Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD201626 STIS/CCD ACQ F25ND3 MIRROR 1 1.0 S ------------------------------------------------------------------------------------------------------------------------------------ 2 HD201626 STIS/CCD ACQ/PEA 0.2X0.05N MIRROR 1 1.0 S K D ------------------------------------------------------------------------------------------------------------------------------------ 3 HD201626 STIS/NUV ACCUM 0.2X0.06 E230M 2707 1 2160 S -MAMA see below ------------------------------------------------------------------------------------------------------------------------------------ 4 HD201626 STIS/NUV ACCUM 0.2X0.06 E230M 2707 1 3100 S -MAMA see below ------------------------------------------------------------------------------------------------------------------------------------ 5 HD201626 STIS/NUV ACCUM 0.2X0.06 E230M 2707 1 3100 S -MAMA see below ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ HD201626 1 STIS/CCD ACQ F25ND3 MIRROR none none none none 1 N/A HD201626 2 STIS/CCD ACQ/PEA 0.2X0.05 MIRROR none none none none 1 N/A K ND HD201626 3 STIS/NUV ACCUM 0.2X0.06 E230M 2707 none none none none 1 1867.0 S -MAMA HD201626 4 STIS/NUV ACCUM 0.2X0.06 E230M 2707 none none none none 2 3005.0 S -MAMA HD201626 5 STIS/NUV ACCUM 0.2X0.06 E230M 2707 none none none none 3 3005.0 S -MAMA 12554( 2) - 05-Jul-2011 11:44:30 - [ 6] Visit: 03 Visit Requirements: On Hold Comments: Additional Comments: BD+440493 - visit 1 of 2 Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 BD+440493 STIS/CCD ACQ F25ND3 MIRROR 1 1.0 S ------------------------------------------------------------------------------------------------------------------------------------ 2 BD+440493 STIS/CCD ACQ/PEA 0.2X0.05N MIRROR 1 1.0 S K D ------------------------------------------------------------------------------------------------------------------------------------ 3 BD+440493 STIS/NUV ACCUM 0.2X0.06 E230M 2707 1 2160 S -MAMA see below ------------------------------------------------------------------------------------------------------------------------------------ 4 BD+440493 STIS/NUV ACCUM 0.2X0.06 E230M 2707 1 3000 S -MAMA see below ------------------------------------------------------------------------------------------------------------------------------------ 5 BD+440493 STIS/CCD ACQ/PEA 0.2X0.05N MIRROR 1 1.0 S K D ------------------------------------------------------------------------------------------------------------------------------------ 6 BD+440493 STIS/NUV ACCUM 0.2X0.06 E230M 2707 1 2640 S -MAMA see below ------------------------------------------------------------------------------------------------------------------------------------ 7 BD+440493 STIS/NUV ACCUM 0.2X0.06 E230M 2707 1 3000 S -MAMA see below ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ BD+440493 1 STIS/CCD ACQ F25ND3 MIRROR none none none none 1 N/A BD+440493 2 STIS/CCD ACQ/PEA 0.2X0.05 MIRROR none none none none 1 N/A K ND BD+440493 3 STIS/NUV ACCUM 0.2X0.06 E230M 2707 none none none none 1 1951.0 S -MAMA BD+440493 4 STIS/NUV ACCUM 0.2X0.06 E230M 2707 none none none none 2 3089.0 S -MAMA BD+440493 5 STIS/CCD ACQ/PEA 0.2X0.05 MIRROR none none none none 3 N/A K ND BD+440493 6 STIS/NUV ACCUM 0.2X0.06 E230M 2707 none none none none 3 2168.0 S -MAMA BD+440493 7 STIS/NUV ACCUM 0.2X0.06 E230M 2707 none none none none 4 3089.0 S -MAMA 12554( 2) - 05-Jul-2011 11:44:30 - [ 7] Visit: 04 Visit Requirements: On Hold Comments: Additional Comments: BD+440493 - visit 2 of 2 Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 BD+440493 STIS/CCD ACQ F25ND3 MIRROR 1 1.0 S ------------------------------------------------------------------------------------------------------------------------------------ 2 BD+440493 STIS/CCD ACQ/PEA 0.2X0.05N MIRROR 1 1.0 S K D ------------------------------------------------------------------------------------------------------------------------------------ 3 BD+440493 STIS/NUV ACCUM 0.2X0.06 E230M 2707 1 2160 S -MAMA see below ------------------------------------------------------------------------------------------------------------------------------------ 4 BD+440493 STIS/NUV ACCUM 0.2X0.06 E230M 2707 1 3000 S -MAMA see below ------------------------------------------------------------------------------------------------------------------------------------ 5 BD+440493 STIS/CCD ACQ/PEA 0.2X0.05N MIRROR 1 1.0 S K D ------------------------------------------------------------------------------------------------------------------------------------ 6 BD+440493 STIS/NUV ACCUM 0.2X0.06 E230M 2707 1 2640 S -MAMA see below ------------------------------------------------------------------------------------------------------------------------------------ 7 BD+440493 STIS/NUV ACCUM 0.2X0.06 E230M 2707 1 3000 S -MAMA see below ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ BD+440493 1 STIS/CCD ACQ F25ND3 MIRROR none none none none 1 N/A BD+440493 2 STIS/CCD ACQ/PEA 0.2X0.05 MIRROR none none none none 1 N/A K ND BD+440493 3 STIS/NUV ACCUM 0.2X0.06 E230M 2707 none none none none 1 1951.0 S -MAMA BD+440493 4 STIS/NUV ACCUM 0.2X0.06 E230M 2707 none none none none 2 3089.0 S -MAMA BD+440493 5 STIS/CCD ACQ/PEA 0.2X0.05 MIRROR none none none none 3 N/A K ND BD+440493 6 STIS/NUV ACCUM 0.2X0.06 E230M 2707 none none none none 3 2168.0 S -MAMA BD+440493 7 STIS/NUV ACCUM 0.2X0.06 E230M 2707 none none none none 4 3089.0 S -MAMA 12554( 2) - 05-Jul-2011 11:44:30 - [ 8] Summary Form for Proposal 12554 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 0.2X0.05ND, 0.2X0.06, F25ND3 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD, STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ, ACQ/PEAK ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements E230M, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names BD+440493, HD196944, HD201626 ------------------------------------------------------------------------------------------------------------------------------------