! Proposal 6700, submission 1 ! PI: Dr. Edward Sion ! Received Fri Feb 16 10:22:00 EST 1996 ! From: jason@hrssun.gsfc.nasa.gov ! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! $Id: 6700,v 5.1 1996/12/13 14:45:12 pepsa Exp $ ! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! $Id: 6700,v 5.1 1996/12/13 14:45:12 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: Manning ! Phone: 410-338-4456 , E-mail: manning@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. ! Name of Phase I Proposal: archive-0795.sion.prop ! Date generated: Fri Dec 22 16:55:44 EST 1995 ! Proposal_Information ! Section 4 Title: GHRS SPECTROSCOPY OF THE EXPOSED WHITE DWARF IN THE HIGH ACCRETION RATE DWARF NOVA RX AND Proposal_Category: GO Scientific_Category: BINARIES AND STAR FORMATION Cycle: 6 Investigators PI_name: Dr. Edward Sion PI_Institution: Department of Astronomy and Astrophysics, Villanova University CoI_Name: Dr. Paula Szkody CoI_Institution: University of Washington at Seattle Contact: ! Y or N (designate at most one contact) CoI_Name: Dr. Ivan Hubeny CoI_Institution: Goddard Space Flight Center Contact: ! Y or N (designate at most one contact) CoI_Name: Dr. Min Huang CoI_Institution: Villanova University Contact: ! Y or N (designate at most one contact) CoI_Name: Dr. Al Holm CoI_Institution: Space Telescope Science Institute Contact: ! Y or N (designate at most one contact) CoI_Name: Dr. Fuhua Cheng CoI_Institution: University of Maryland Contact: ! Y or N (designate at most one contact) CoI_Name: Dr. Janet Mattei CoI_Institution: American Association of Variable Star Observers Contact: ! Y or N (designate at most one contact) CoI_Name: Dr. Constanze la Dous CoI_Institution: VILSPA Contact: ! Y or N (designate at most one contact) CoI_Name: Dr. Barbara Hassall CoI_Institution: Oxford University Contact: ! Y or N (designate at most one contact) CoI_Name: Dr. Emmi Meyer-Hofmeister CoI_Institution: Max-Planck Institute, Garching Contact: ! Y or N (designate at most one contact) CoI_Name: Dr. Fritz Myer CoI_Institution: Max-Planck Institute, Garching Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) Out of the six dwarf novae with exposed white dwarfs studied with Hubble during quiescence, only one, U Gem, lies above the period gap where mass transfer rates are generally higher and where the white dwarfs appear to be hotter (younger?) in CV systems with quite possibly shorter evolutionary histories. RX And and its exposed white dwarf fills an absolutely critical need for another system above the gap. Orbital Phase-resolved GHRS G140L observations near the quadratures of its orbit during quiescence will deliver the following fundamental information: (1) the white dwarf rotation rate; (2) the T_eff , log g and chemical abundances of the white dwarf; (3) the orbital velocity semi-amplitudes and hence a white dwarf mass independent of disk emission line velocities; (4) delineation by profile structure, line formation regions associated with a cooler more slowly rotating white dwarf photosphere versus formation regions of higher temperature ion species associated with a boundary layer/accretion belt (or putative hot corona?) still present surrounding the white dwarf; (5) the cooling response of the white dwarf to compressional and irradiative heating by the dwarf nova event (does it explain the UV flux decline, a problem for disk instability models?); (6) tests of physical mechanisms that control the flow of accreted elements and hence abundance changes (diffusion, mixing/dilution dredgeup and ongoing accretion during quiescence). Questions ! Free format text (please update) Observing_Description: We propose to obtain three observations of RX And with the GHRS G140L grating (with the added scientific benefit of high time resolution) in order to secure spectra with a resolution of 1750 at Lyman Alpha, covering the wavelength interval 1150 -1430A. The three observations will be separated by 9.5 days over a 19 day interval. For RX And the continuum flux at 1300A is 5E-14, which we expect to yield 1400 cts/diode during a 25 minute exposure. Our GHRS spectra will be carried out in the ACCUM mode. We will use the best available orbital period, determined by Kaitchuk (1989, PASP, 101, 1129) who gives the following orbital ephemeris: 2447041.932 +/- 0.2098930 E +/- 0.002. Although we emphasize white dwarf studies during dwarf nova quiescence, if RX And goes into outburst, we would welcome and most surely deliver new science by analyzing the data thoroughly and modelling it with disk, belt, white dwarf combinations (as we did with the superoutburst FOS spectrum of VW Hydri (see Huang et al. 1996) while fully characterizing the parameters of the wind outflow which very likely arises from the inner disk/boundary layer (or the metal-laden hot white dwarf atmosphere itself.) Obtaining spectra in decline or rise to outburst would allow us to model the onset or gradual spindown and cooling of the inner disk/accretion belt. Our analysis will bring to bear the effects of (1) an absorbing curtain above the disk plane (cf. Sion et al. 1995, Horne et al. 1994), the effect of the H2 quasi-molecular absorption, the effect of an accretion belt, a full steady state accretion disk, a non-steady state disk and nearly completed optically thin disk models with vertical structure, being developed by our co-I Dr. Ivan Hubeny. In addition the temperature of the white dwarf in response to the outburst will be simulated with Sion's quasi- static stellar evolution code with time variable accretion and the effects of compressional heating and boundary layer irradiation (e.g. Sion 1995). In addition we will have 1D and 2D hydrodynamic simulations with shear mixing of angular momentum of the accreted material (e.g. Sparks, Sion, Starrfield, Austin 1993) Real_Time_Justification: The outbursts of RX And range from 3-10 days while its quiescence ranges from 5 to 20 days (Ritter, CV catalog). The short timing of the cycle prohibits any target of opportunity status with HST. If we define a cycle length as one outburst + one quiescence, then the shortest cycle length is 8 days and the longest cycle length is 30 days, yielding an average cycle length of 19 days. Hence, if we obtain three spectra, with the second spectrum following the first by 9.5 days and the third spectrum spaced from the second by 9.5 days, we estimate, from long term AAVSO data, that there is a 34\% probability that the first observation will take place in outburst while there is a 66\% probability that the first spectrum will be in quiescence. Thus any random observation has about a 66\% chance of being in quiescence. Hence, we are confident that over any 19 day interval (the average cycle length), three equally spaced observations will yield quiescent spectra. The probability that two of the three spectra are in outburst is 34\% while the probability that one of the three is in outburst is 34\% and the probability that all three are in quiescence is 34\%. Thus there is almost a 70\% probability that at least two of our proposed spectra will be in quiescence. The three observations should each be separated by 9.5 days; the first observation should be centered at 0.25 phase, the second observaton centered at 0.25 phase, and the third observation at 0.75 phase in order to sample the quadratures for the K1 velocity semi-amplitude and hence the white dwarf mass determination. Calibration_Justification: ! Move appropriate text from Real_Time_Justification Additional_Comments: Fixed_Targets ! Section 5.1 Target_Number: 1 Target_Name: RX-AND Alternate_Names: Description: STAR,DWARF NOVA,INTERACTING BINARY Position: RA=01H 04M 35.6S +/- 0.5S, ! Most common specification format is DEC=+41D 17' 58.50" +/- 0.50", ! RA=0H 0M 0.00S +/- 0S, ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: J2000 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=14.9 +/- 0.1, B-V=+0.1+/-0.05, E(B-V)=0.0+/-0.1, ! Include at least V and B-V F-CONT(1400) = 5.0 +/- 1 E-14 Comments: PERIOD 5.03H AND ZERO-PHASE JD2447041.932 ! This is a template for a single visit containing a single exposure ! Repeat exposure and visit blocks as needed Visits ! Section 6 Visit_Number: 1 Visit_Requirements: PERIOD 5.03H AND ZERO-PHASE JD2447041.932 ! Section 7.1 On_Hold_Comments: Visit_Comments: CENTER EXPOSURE ON PHASE 0.25 Exposure_Number: 1 ! Section 6.5 Target_Name: RX-AND Config: HRS Opmode: ACQ Aperture: 2.0 Sp_Element: MIRROR-N1 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: RX-AND Config: HRS Opmode: ACCUM Aperture: 2.0 Sp_Element: G140L Wavelength: 1290 Optional_Parameters: Number_of_Iterations: 26 Time_Per_Exposure: 54.4S Special_Requirements: PHASE 0.20 TO 0.30 Comments: CENTER ON ORBITAL PHASE 0.25 +/- 0.05 PHASE 0.0 OCCURS AT JD2447041.932 Visits ! Section 6 Visit_Number: 2 Visit_Requirements: PERIOD 5.03H AND ZERO-PHASE JD2447041.932 On_Hold_Comments: Visit_Comments: CENTER EXPOSURE ON PHASE 0.25 Exposure_Number: 3 ! Section 6.5 Target_Name: RX-AND Config: HRS Opmode: ACQ Aperture: 2.0 Sp_Element: MIRROR-N1 Wavelength: Optional_Parameters: BRIGHT=RETURN, SEARCH-SIZE=5 Number_of_Iterations: 1 Time_Per_Exposure: 25S Special_Requirements: ONBOARD ACQ FOR 4 ! Section 7.2 Exposure_Number: 4 ! Section 6.5 Target_Name: RX-AND Config: HRS Opmode: ACCUM Aperture: 2.0 Sp_Element: G140L Wavelength: 1290 Optional_Parameters: Number_of_Iterations: 21 Time_Per_Exposure: 54.4S Special_Requirements: PHASE 0.20 TO 0.30 NON-INT Comments: CENTER ON ORBITAL PHASE 0.25 +/- 0.05 PHASE 0.0 OCCURS AT JD2444071.932 Visits ! Section 6 Visit_Number: 3 Visit_Requirements: PERIOD 5.03H AND ZERO-PHASE JD2447041.932 On_Hold_Comments: Visit_Comments: CENTER EXPOSURE ON PHASE 0.75 Exposure_Number: 5 ! Section 6.5 Target_Name: RX-AND Config: HRS Opmode: ACQ Aperture: 2.0 Sp_Element: MIRROR-N1 Wavelength: Optional_Parameters: BRIGHT=RETURN, SEARCH-SIZE=5 Number_of_Iterations: 1 Time_Per_Exposure: 25S Special_Requirements: ONBOARD ACQ FOR 6 ! Section 7.2 Exposure_Number: 6 ! Section 6.5 Target_Name: RX-AND Config: HRS Opmode: ACCUM Aperture: 2.0 Sp_Element: G140L Wavelength: 1290 Optional_Parameters: Number_of_Iterations: 21 Time_Per_Exposure: 54.4S Special_Requirements: PHASE 0.70 TO 0.80 NON-INT Comments: CENTER ON ORBITAL PHASE 0.75 +/- 0.05 PHASE 0.0 OCCURS AT JD=2447041.932 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: Dr. E.M. Sion Department of Astronomy and Astrophysics ! PI Address from Phase I is: Villanova University 800 Lancaster Avenue Villanova, PA 19085 ! ! Ship_Via: UPS ! UPS (2-day) or OVERNIGHT ! Overnight shipping done at PI expense Recipient_Email: ! Needed if Ship_To: is not PI_Address ! ! Let us know what you think of this template and software! ! Please send a list of your likes and dislikes to your Program Coordinator