! File: 3600C.PROP ! Database: PEPDB ! Date: 19-FEB-1994:13:25:21 coverpage: title_1: OSCILLATIONS, FLARES, AND TOMOGRAPHY OF AE AQUARII sci_cat: STELLAR ASTROPHYSICS sci_subcat: ERUPTIVE BINARIES proposal_for: GO pi_fname: KEITH pi_lname: HORNE pi_inst: STSCI pi_country: USA pi_phone: 301-338-4964 hours_pri: 5.00 num_pri: 1 fos: Y realtime: N time_crit: N funds_amount: 124701 funds_length: 12 funds_date: OCT-92 off_fname: HERVEY off_mi: S. off_lname: STOCKMAN off_title: DEPUTY DIRECTOR off_inst: STSCI off_addr_1: 3700 SAN MARTIN DRIVE off_city: BALTIMORE off_state: MD off_zip: 21218 off_country: USA off_phone: 301-338-4730 ! end of coverpage abstract: line_1: AE Aquarii is the most rapidly spinning of the magnetic cataclysmic variables. line_2: Its 16.5 and 33s oscillations and large aperiodic flaring have been studied at line_3: radio, optical, x-ray, and TeV gamma-ray energies but never before in the UV. line_4: Accretion onto the magnetic poles of the white dwarf is thought to produce line_5: rotating x-ray searchlight beams that irradiate the surrounding accretion flow. line_6: The impressive flares may represent accretion rate fluctuations gated by line_7: magnetic reconnection near the co-rotation radius, where disk material enters line_8: the magnetosphere. The source of relativistic electrons producing the highly line_9: variable spectrum of unpolarized radio emission is uncertain. line_11: We propose FOS,G160L observations in RAPID (1s) readout mode for 7 consecutive line_12: HST orbits covering one 9.88h binary period to measure the oscillations and line_13: flares as a function of wavelength and binary phase, and to investigate line_14: relationships between the oscillations and flares. We predict 1-20 percent line_15: oscillations in the UV, making this the only spectral region in which the line_16: oscillations can be studied with good S/N. HST has sufficient sensitivity and line_17: time resolution to make this an easy experiment. Besides clarifying the nature line_18: of the oscillations and flares, we will perform doppler and time-delay line_19: tomography of the UV emission-line regions in the system. ! ! end of abstract general_form_proposers: lname: HORNE fname: KEITH title: PI inst: STSCI country: USA ! lname: MARSH fname: THOMAS mi: R inst: OXFORD UNIVERSITY country: UK esa: Y ! lname: ROBINSON fname: EDWARD mi: L inst: UNIVERSITY OF TEXAS AT AUSTIN country: USA esa: N ! lname: WOOD fname: JANET mi: H inst: UNIVERSITY OF TEXAS AT AUSTIN country: USA esa: N ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: We will use the FOS with Blue digicon and G160L grating in RAPID readout mode line_2: to obtain a time resolution of 1s covering with 6.5A/pixel the spectral region line_3: 1150-2300 Angstroms. The order 0 spectrum also available in this mode will line_4: provide a simultaneous record of optical variations along with the UV spectral line_5: variations. A short sequence with FOS/BLUE PRISM will also be obtained line_6: to see if MgII oscillates or flares. line_7: We need to observe AE Aqr for one complete 9.88 hour binary orbit period in line_8: order to determine the pulse-timing orbit of the UV oscillations, and to line_9: perform the tomographic mapping of the emission-line regions. This will require line_10: 7 HST orbits. A total on-target exposure time of 5 hours will be accumulated line_11: given that the earth will occult AE Aqr roughly half the time, permitting line_12: 35-45m observing per HST orbit. Because the spectral resolution is quite low line_13: (600 km/s/pixel) compared to the line widths (3000 km/s), the gaps in phase line_14: coverage will not greatly hamper the doppler tomography experiment. The 35-45 line_15: minute continuous observing window in each HST orbit is long enough to give a line_16: fair sample of the the oscillation and flaring behavior at that binary phase; line_17: the flares last typically 10 minutes. ! question: 4 section: 1 line_1: HST is needed to provide UV sensitivity and time resolution sufficient to line_2: detect the 33 and 16.5s oscillations, and the flares. IUE has been used to line_3: define the time-averaged spectrum of AE Aqr (see figure), but it is useless for line_4: the high time-resolution observartions we need here. Ground-based studies have line_5: been important in establishing the basic nature of the AE Aqr system, the line_6: existence of flares and oscillations, the binary orbit and white dwarf spin line_7: period, and have raised the questions that are being addressed in this HST line_8: experiment. ! question: 5 section: 1 line_1: We need observations on 7 consecutive HST orbits to cover the full 9.88 hour line_2: binary orbit period. We considered a series of shorter exposures with line_3: time-critical requirements designed to hit specific binary phases, but the line_4: overheads involved with target acquisition makes that approach far less line_5: efficient than acquiring AE Aqr once and observing for 7 consecutive HST line_6: orbits. ! question: 6 section: 1 line_1: None. ! question: 7 section: 1 line_1: The spectra will be reduced using the standard pipeline software using line_2: workstations at STScI. The co-investigators will take copies of the reduced line_3: data to their home institutions for analysis. We will display the data as line_4: trailed spectrograms, as power spectra vs wavelength, and as power spectra vs line_5: time. We will decompose the spectra into mean, rms, and oscillation components, line_6: and fit models to each of these. We have already developed software for doppler line_7: tomography and echo mapping, and will be modifying the echo-mapping code to line_8: exploit rotation of the binary system to construct 2-d maps. Photoionization line_9: codes will be run for comparison of the mean and variable components of the line_10: emission-line spectra. ! question: 8 section: 1 line_1: We will attempt to obtain simultaneous coverage with ground-based telescopes, line_2: but this should not affect the success of the HST observations, which form a line_3: self-contained experiment. ! question: 9 section: 1 line_1: GO-2380 "Instabilities in Accretion Disks and the Outbursts of Dwarf Novae" line_2: Horne and Marsh - data under analysis. line_3: GO-2334 "Ultraviolet Spectroscopy of the Black Hole A0620-00" line_4: McClintock, Remillard, and Horne - data under analysis. line_5: GO-3232 "Observations of X-Ray Nova Muscae 1991" line_6: Panagia, Lund, Gilmozzi, Horne, Paresce, Valle, and Schrader. line_7: - paper submitted to Ap.J. line_8: (None of these is closely related to this proposal.) ! question: 10 section: 1 line_1: Salary and basic computer facilities are being provided for the P.I. ! !end of general form text general_form_address: lname: HORNE fname: KEITH category: PI inst: STSCI addr_1: 3700 SAN MARTIN DRIVE city: BALTIMORE state: MD zip: 21218 country: USA phone: 410-338-4964 ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: AE-AQR descr_1: A,151,154,161 pos_1: PLATE-ID = 02C4, pos_2: RA = 20H 40M 9.02S +/- 0.5", pos_3: DEC = -0D 52' 15.5" +/- 0.5" equinox: J2000 pm_or_par: N pos_epoch_bj: B pos_epoch_yr: 1980.55 comment_1: VARIABLE STAR, comment_2: UV MAY VARY BY 1MAG IN 10MIN. fluxnum_1: 1 fluxval_1: V = 10.8 +/- 1.1 fluxnum_2: 1 fluxval_2: B-V = 0.8 fluxnum_3: 2 fluxval_3: F-CONT(1500) = 3 +/- 1 E-13 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 sequence_1: DEFINE sequence_2: AEAQR targname: AE-AQR config: FOS/BL opmode: ACQ/PEAK aperture: 4.3 sp_element: G160L num_exp: 1 time_per_exp: 10S fluxnum_1: 1 priority: 1 req_1: ONBOARD ACQ FOR 1.5; req_2: GROUP 1-3 NO GAP; req_3: SPATIAL SCAN; comment_1: BRIGHT VARIABLE STAR. comment_2: UV MAY VARY BY 1MAG IN 10MIN. comment_3: 0.26S GIVES 300 X 11 COUNTS. ! linenum: 1.500 sequence_1: DEFINE sequence_2: AEAQR targname: AE-AQR config: FOS/BL opmode: ACQ/PEAK aperture: 1.0 sp_element: G160L num_exp: 1 time_per_exp: 10S fluxnum_1: 1 priority: 1 req_1: ONBOARD ACQ FOR 2-3; req_2: SPATIAL SCAN; ! linenum: 2.000 sequence_1: DEFINE sequence_2: AEAQR targname: AE-AQR config: FOS/BL opmode: RAPID aperture: 4.3 sp_element: G160L num_exp: 1 time_per_exp: 20M priority: 1 param_1: READ-TIME=3.2, param_2: SUB-STEP=2 comment_1: 9.88 HR BINARY PERIOD TAKES 7 OR MORE comment_2: CONSECUTIVE HST ORBITS. 5H EXPOSURE comment_3: ASSUMES 45M PER HST ORBIT. 4S READOUTS comment_4: FOR FLARES, AND 16.5S OSCILLATIONS. ! linenum: 2.500 sequence_1: DEFINE sequence_2: AEAQR targname: AE-AQR config: FOS/BL opmode: RAPID aperture: 4.3 sp_element: G160L num_exp: 7 time_per_exp: 40M priority: 1 param_1: READ-TIME=3.2, param_2: SUB-STEP=2 ! linenum: 3.000 sequence_1: DEFINE sequence_2: AEAQR targname: AE-AQR config: FOS/BL opmode: RAPID aperture: 4.3 sp_element: PRISM num_exp: 1 time_per_exp: 40M priority: 1 param_1: READ-TIME=3.2, param_2: SUB-STEP=2 comment_1: RAPID READOUT REQUIRED FOR FLARES, comment_2: AND 16.5 AND 33 SEC OSCILLATIONS. ! linenum: 4.000 sequence_1: USE sequence_2: AEAQR req_1: CYCLE 2 / 1-4 ; req_2: AT 30-AUG-1992 +/- 70D ; comment_1: RELAX TIMING CONSTRAINT IF REQUIRED comment_2: FOR SCHEDULING. PI HAS COORDINATED comment_3: OBSERVATIONS PLANNED. ! ! end of exposure logsheet scan_data: line_list: 1 fgs_scan: cont_dwell: D dwell_pnts: 3 dwell_secs: 1.00 scan_width: 0.0000 scan_length: 2.8000 sides_angle: 90.0000 number_lines: 1 scan_rate: 0.0000 first_line_pa: 0.0000 scan_frame: S/C len_offset: 1.4 wid_offset: 0.0 ! line_list: 1.5 fgs_scan: cont_dwell: D dwell_pnts: 6 dwell_secs: 1.00 scan_width: 0.7000 scan_length: 3.5000 sides_angle: 90.0000 number_lines: 2 scan_rate: 0.0000 first_line_pa: 90.0000 scan_frame: S/C len_offset: 1.75 wid_offset: 0.35 ! ! end of scan data