! Hubble Space Telescope Cycle 5 (1995) Phase II Proposal Template ! $Id: 6084,v 27.1 1995/11/22 19:44:15 pepsa Exp $ ! ! Refer to the HST Phase II Proposal Instructions to fill this out ! ! Anything after a "!" is ignored, and may be deleted ! ! All keywords with multiple entries are comma delimited except the ! Visit_Requirements and Special_Requirements keywords which can be ! delimited with carriage returns or semi-colons, but not commas ! ! For help call your Program Coordinator: Dustin Manning ! Phone: 410 338-4456 , E-mail: manning@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. ! Date generated: Sun Dec 18 19:21:55 EST 1994 ! Proposal_Information ! Section 4 Title: The Rotation, Masses and Chemical Abundances of the White Dwarfs in WZ Sagittae and VW Hydri Proposal_Category: GO Scientific_Category: Hot Stars Cycle: 5 Investigators PI_name: Dr.Edward Sion PI_Institution: Villanova University CoI_Name: Dr. Min Huang CoI_Institution: Villanova University Contact: ! Y or N (designate at most one contact) CoI_Name: Dr. Paula Szkody CoI_Institution: University of Washington CoI_Name: Dr. Ivan Hubeny CoI_Institution: NASA GSFC Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) The central accreting object in compact binaries and other accreting systems is usually hidden from direct observation, enshrouded by optically thick accretion disks which are opaque to the radiation emitted by the central object as it accretes matter. In the dwarf novae WZ Sagittae and VW Hydri the underlying white dwarf accreter is clearly exposed in the far UV during quiescence. Orbital phase-resolved GHRS spectra near the quadratures (0.25 and 0.75) of their orbits during quiescence will deliver the following fundamental information: (1) the white dwarf rotation rates, yielding critical information on the boundary layer temperature/structure and spinup of the white dwarfs by accretion; (2) the orbital velocity semi-amplitudes and hence white dwarf masses, independent of disk emission line velocities; (3) delineation by profile shape and velocity,of lower temperature line formation regions associated with the rotating photosphere of the white dwarf from line formation region(s) of higher temperature ion species associated with a boundary layer/accretion belt (or putative hot corona?) still present surrounding the white dwarf; (4) detection of weak metal line profiles and variations versus phase in WZ Sagittae to test accretion versus dredgeup for the origin of carbon, and test physical mechanisms that control the flow of accreted elements and hence abundance changes (diffusion, mixing, dilution, dredeup and ongoing accretion during quiescence). Questions ! Free format text (please update) Observing_Description: For WZ Sagittae we need high quality far UV spectra of absorption line features with accurate velocities, orbital phase-resolved and detailed profiles for modelling line shapes, determining the rotational velocity and obtaining GHRS observations centered near orbital phases 0.25 and 0.75 to determine the radial velocity amplitude of the white dwarf by standard cross-correlation techniques of the spectra against each other. Therefore we will use the GHRS side 1 with G140L in (1237-1567 Angstrom), two sets of observations centered at orbital phases 0. 25 and 0.75. From IUE, the flux at 1400Angstrom for WZ Sge is 3* 10^-14. With the G140L disperser we get 0.57Angstrom/diode and can centroid the lines to 0.1 of 0.57Angstrom or 0.06Angstrom. In 8 minutes (giving a phase resolution of 0.1 orbit) we expect 115 c/s/diode and a S/N = 10. We will use the still reliable (Patterson 1994) eclipse ephemeris of Robinson, Nather and Patterson (1978); viz., T = JD2437547.72845+ 0.0566878455E For VW Hyi (a CVZ target!) we will obtain high quality far UV spectra of the line region encompassing the strongest ion absorption features, detected for the first time with our FOS observation of cycle 2. In order to obtain the fully- resolved line profiles, the radial velocity amplitude of the white dwarf, determine the rotational velocity of the white dwarf and delineate different line forming regions, we will use the G160M disperser in the ACCUM operating mode to observe VW Hyi near phases 0.25 and 0.75. Our detailed line profile fitting with TLUSTY and SYNSPEC (Hubeny 1988) utilizes a grid of theoretical profiles broadened by values of vsin i from 0 to several thousand km/s, including composite profiles produced by combining the model fluxes due to a hot differentially rotating accretion belt of adjustable width with synthetic profiles from cooler more slowly rotating higher latitudes of the white dwarf. For VW Hyi during quiescence: Our GHRS, G160M (LSA 1235-1270Angstrom) exposures have count rates of 0.084 cts/sec/diode for VW Hyi requiring 44.5 minutes to reach S/N = 15/diode =60/Angstrom resolution = 0.07 Angstrom/diode (covering high and low temperature species and strongest features (Si II 1260, 1264) in the FOS spectrum; N V (1238, 1242); C III 1247; red wing (turnover) of Lyman Alpha; We will split exposures to obtain a spectrum every 9 minutes. Essentially the same instrumental setup and procedure was used for our successful determination of the velocity amplitude (mass= 0.82 M_\odot) and rotation rate (V_rot = 150 km/s) of the white dwarf in U Gem (Sion et al. 1994). Real_Time_Justification: We need time critical observations for VW Hyi in the sense of obtaining spectra during its quiescence between outbursts (duration 25~50 days) and normal outbursts of 2$~3 days duration. An observation has a 90\ unlikely event of a spectrum during an outburst, it is still of great interest to us. The count rate would not be too large for the GHRS and G160M. The outbursts are statistically very well- characterized by AAVSO and normally quite predictable. The AAVSO and its Director Dr. Janet Mattei have cooperated closely and enthusiastically with us during cycles 2, 3 and 4. Janet Mattei will provide us with VW Hyi normal and superoutburst predictions as she accurately did for cycle 2. Indeed through a scheduling error due to STScI, SPSS operations, one of our FOS spectra was mistakenly rescheduled during a superoutburst avoidance interval, which had been predicted by Dr. Mattei, and specified as a scheduling avoidance interval in our phase II proposal. As a result, the STScI Director approved a cycle 4 carryover to obtain another FOS spectrum of VW Hyi in quiescence. Calibration_Justification: ! Move appropriate text from Real_Time_Justification Additional_Comments: Fixed_Targets ! Section 5.1 Target_Number: 1 Target_Name: WZ-SGE Alternate_Names: Description: STAR, DWARF NOVA, INTERACTING BINARY Position: RA=20H 7M 36.416S +/- 0.15S, ! Most common specification format is DEC=+17D 42' 15.39" +/- 0.20",! RA=0H 0M 0.00S +/- 0S, ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: 2000.0 RV_or_Z: RA_PM: ! Units are seconds of time per year Dec_PM: ! Units are seconds of arc per year Epoch: Annual_Parallax: Flux: V=15.0 +/- 0.1, B-V=+0.1+/-0.05, E(B-V)=0.0+/-0.1 ,F-CONT(1400) = 1.5 +/- 1 E-14 ! Include at least V and B-V Comments: Fixed_Targets ! Section 5.1 Target_Number: 2 Target_Name: VW-HYI Alternate_Names: Description: STAR, DWARF NOVA, INTERACTING BINARY Position: RA=04H 09M 11.300S +/- 0.15S, DEC=-71D 17' 42.00" +/- 0.15", Equinox: 2000.0 RV_or_Z: RA_PM: ! Units are seconds of time per year Dec_PM: ! Units are seconds of arc per year Epoch: Annual_Parallax: Flux: V=13.6+/-0.1, B-V=+0.0+/-0.1, E(B-V)=0.0+/-0.1 ,F-CONT(1400) = 8.0 +/- 1 E-14 ! Include at least V and B-V Comments: Visits ! Section 6 Visit_Number: 1 Visit_Requirements: PERIOD 1.36H AND ZERO-PHASE JD2437547.72845 On_Hold_Comments: Visit_Comments: CENTER EXPOSURES ON PHASES 0.25 AND 0.75 Exposure_Number: 1 ! Section 6.5 Target_Name: WZ-SGE Config: HRS Opmode: ACQ Aperture: 2.0 Sp_Element: MIRROR-N2 Wavelength: Optional_Parameters: BRIGHT=RETURN, SEARCH-SIZE=5 Number_of_Iterations: 1 Time_Per_Exposure: 25S Special_Requirements: ONBOARD ACQ FOR 2 ! Section 7.2 Exposure_Number: 2 ! Section 6.5 Target_Name: WZ-SGE Config: HRS Opmode: RAPID Aperture: 2.0 Sp_Element: G160M Wavelength: 1465 Optional_Parameters: SAMPLE-TIME=1.0 Number_of_Iterations: 1 Time_Per_Exposure: 25M Special_Requirements: Comments: ! Exposure_Number: 3 ! Section 6.5 Target_Name: WZ-SGE Config: HRS Opmode: RAPID Aperture: 2.0 Sp_Element: G140L Wavelength: 1381 Optional_Parameters: SAMPLE-TIME=1.0 Number_of_Iterations: 1 Time_Per_Exposure: 2600S Special_Requirements: PHASE 0.18 TO 0.21 Comments: PHASE CHOOSEN TO INCLUDE BOTH 0.25 AND 0.75 IN EXPOSURE Visits ! Section 6 Visit_Number: 2 Visit_Requirements: CVZ ! PERIOD 1.78H AND ZERO-PHASE JD2440128.02407 On_Hold_Comments: Visit_Comments: BETWEEN 24-JUN-95 AND 17-DEC-95 BETWEEN 15-JAN-96 AND 8-JUL-96 SCHEDULE ONLY BETWEEN ABOVE DATES TO AVOID SUPERMAXIMA Exposure_Number: 4 ! Section 6.5 Target_Name: VW-HYI Config: HRS Opmode: ACQ Aperture: 2.0 Sp_Element: MIRROR-N2 Wavelength: Optional_Parameters: BRIGHT=RETURN, SEARCH-SIZE=5 Number_of_Iterations: 1 Time_Per_Exposure: 25S Special_Requirements: ONBOARD ACQ FOR 5; ! Section 7.2 Exposure_Number: 5 ! Section 6.5 Target_Name: VW-HYI Config: HRS Opmode: RAPID Aperture: 2.0 Sp_Element: G160M Wavelength: 1253 Optional_Parameters: SAMPLE-TIME=1.0 Number_of_Iterations: 1 Time_Per_Exposure: 9800S Comments: ! Exposure_Number: 6 ! Section 6.5 ! Target_Name: VW-HYI ! Config: HRS ! Opmode: RAPID ! Aperture: 2.0 ! Sp_Element: G160M ! Wavelength: 1253 ! Optional_Parameters: !Number_of_Iterations: 1 ! Time_Per_Exposure: 15M !Special_Requirements: ! Comments: Center Exposure on Phase 0.8 ! ! Exposure_Number: 7 ! Section 6.5 ! Target_Name: VW-HYI ! Config: HRS ! Opmode: RAPID ! Aperture: 2.0 ! Sp_Element: G160M ! Wavelength: 1253 ! Optional_Parameters: !Number_of_Iterations: 1 ! Time_Per_Exposure: 15M !Special_Requirements: ! Comments: Center Exposure on Phase 0.02 ! ! Exposure_Number: 8 ! Section 6.5 ! Target_Name: VW-HYI ! Config: HRS ! Opmode: RAPID ! Aperture: 2.0 ! Sp_Element: G160M ! Wavelength: 1253 ! Optional_Parameters: !Number_of_Iterations: 1 ! Time_Per_Exposure: 15M !Special_Requirements: ! Comments: Center Exposure on Phase 0.8 Data_Distribution ! Defaults indicated; change if desired Medium: 8MM ! 8MM or 6250BPI or 1600BPI Blocking_Factor: 10 ! 10 or 1 ! Only astronomers with very old 9- ! track tape drives should consider ! a blocking factor of 1 Ship_To: PI_address ! ! Ship_Via: UPS ! UPS (2-day) or OVERNIGHT ! Overnight shipping done at PI expense Recipient_Email: !emsion@ucis.vill.edu ! Needed if Ship_To: is not PI_Address ! ! 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