! File: 4271C.PROP ! Database: PEPDB ! Date: 20-FEB-1994:19:49:04 coverpage: title_1: TESTING THE STAR-DISK CONNECTION: CIV AND MGII MAPS OF ACCRETION DISKS title_2: CYC3-MED sci_cat: HOT STARS sci_subcat: ERUPTIVE BINARIES proposal_for: GO pi_fname: KEITH pi_lname: HORNE pi_inst: STSCI pi_country: USA pi_phone: 410-338-4964 hours_pri: 3.47 num_pri: 1 hrs: Y realtime: N time_crit: N funds_length: 12 off_fname: HERVEY S. off_lname: STOCKMAN off_title: DEPUTY DIRECTOR off_inst: 3470 off_addr_1: 3700 SAN MARTIN DRIVE off_city: BALTIMORE, MD off_zip: 21218 off_country: USA off_phone: 301-338-4730 ! end of coverpage abstract: line_1: Empirical scaling laws among magnetic activity indicators are well established line_2: for the sun and other cool stars. Ground-based studies of Balmer and CaII line_3: emission suggest that similar relationships may hold for the accretion disks line_4: and tidally-locked secondary stars in cataclysmic variables. We propose to test line_5: this star-disk connection by using HST to make Doppler maps of MgII and CIV line_6: emission in three quiescent dwarf novae. These lines sensitive to chromospheric line_7: and transition region temperature regimes are predicted to scale as radius to line_8: the -3/2 and -3 respectively in the Keplerian accretion disk. Our experiment line_9: tests the hypothesis that dynamo action powers emission lines from accretion line_10: disk chromospheres. The disk and secondary star rotate much faster than the line_11: stars for which magnetic activity relations have been previously determined. By line_12: expanding the study of magnetic activity to higher rotation rates and different line_13: geometries, we expect to gain insights into the basic physics that will advance line_14: our understanding of dynamos and magnetic activity in a broad context. line_15: NOTE: THE TAC CUT THIS PROPOSAL FROM 3 TO 1 OBJECT. ! ! end of abstract general_form_proposers: lname: HORNE fname: KEITH title: PI inst: STSCI country: USA esa: N ! lname: MARSH fname: THOMAS mi: R inst: UNIVERSITY OF OXFORD country: UNITED KINGDOM esa: Y ! lname: RUTTEN fname: RENE' inst: UNIVERSITEIT VAN AMSTERDAM country: NETHERLANDS esa: Y ! lname: SAAR fname: STEVEN mi: H inst: CENTER FOR ASTROPHYSICS country: USA esa: N ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: We will use the GHRS with the G270M grating to observe MgII 2800A emission line line_2: profiles out to +/- 2300 km/s with a resolution of 11 km/s, and with the G160M line_3: grating to observe CIV 1550A profiles out to +/- 3300 km/s with a resolution of line_4: 16 km/s. These modes are nearly ideal for our experiment. The spectral line_5: resolution provides 8-12 resolution elements across the width of the line_6: rotationally-broadened lines of the late-type secondary stars, which have a V line_7: sin(i) of about 128 km/s. This will permit Doppler imaging of individual active line_8: regions should they be present. The velocity range covered is also sufficient line_9: to embrace the extended wings of the emission lines from the Keplerian line_10: accretion disk. line_12: We will perform the Doppler imaging study on three dwarf novae, T Leo,(P=1.4h), line_13: IP Peg (P=3.8h), and U Gem (P=4.2h). These dwarf novae have strong cleanly line_14: double-peaked Balmer emission lines to ensure that the dominant emission line line_15: region is the accretion disk chromosphere and that there is not appreciable line_16: contamination of CIV emission from a wind. line_17: NOTE: THE TAC CUT OUR STUDY DOWN TO 1 OBJECT. ! question: 3 section: 2 line_1: We need phase-resolved spectra covering a range of binary phases in order to line_2: use the Doppler mapping technique to separate the disk emission from the line_3: late-type star emission. We can achieve this while making efficient use of line_4: spacecraft time by taking 8-10 minute exposures alternating between the two line_5: gratings (it takes about 1 minute to switch gratings). Since this gives 2 line_6: exposures per grating during the visibility window of each HST orbit, 4 HST line_7: orbits will provide coverage around 8 different binary phases, adequate for the line_8: Doppler mapping studies. The elapsed time between the first and last line_9: observations will be 5.6 hours, so we will sample all phases of the 1.41, 3.79 line_10: and 4.25 hour binary periods. line_12: The gaps in binary phase coverage caused by earth occultations will introduce line_13: some ambiguities in our Doppler maps, but we feel they will not be too line_14: detrimental to our science goals. In principle the Doppler tomogram of a disk line_15: is completely determined by spectra covering only half of the the binary cycle. line_16: This is because the disk is flat, so that every element on the disk surface is line_17: visible at all binary phases, thus the line profiles in the second half of the line_18: cycle are just mirror images of those in the first half. Despite the phase gaps line_19: we are confident we can use the data to determine the radial profile of the line_20: disk emission lines, and the contribution from several faces of the secondary line_21: star. ! question: 4 section: 1 line_1: From the ground we have obtained phase-resolved spectra for Balmer emission line_2: lines and have used them to construct Doppler maps (Marsh and Horne 1990; line_3: Marsh, et al. 1990) and we have extended those Doppler mapping studies to line_4: include Ca II K (Fig 2). We must now go into the UV to confirm whether the MgII line_5: and CIV emission follow the relationships predicted by the star-disk line_6: connection. MgII should vary as R**-3/2, while CIV should vary as R**-3. line_8: We need the high UV sensitivity of the HST and high spectral resolution of the line_9: GHRS to observe the velocity profiles of MgII and CIV emission lines with line_10: enough time resolution to follow the changes in the line velocity profiles as line_11: the binary system rotates. The time resolution required by the sampling theorem line_12: for Doppler tomography is of order DT = P * DV / V, where DT is the time line_13: resolution, P is the binary period, DV is the resolution of the map, and V is line_14: the maximum velocity in the Doppler map. For DV=20 km/s, V=2000km/s, we need line_15: 100 time samples around the binary period, and P=1.5-4.25h that means from 1 to line_16: 3 minutes between spectra. We cannot use IUE because not only is its line_17: sensitivity too low, but also IUE's time resolution is insufficient because it line_18: takes 20 minutes or so to read out its cameras. ! question: 5 section: 1 line_1: The observations of each object must occur on consecutive HST orbits in order line_2: to provide samples at different binary phases around the binary orbit. We could line_3: alternatively schedule time-critical observations aimed to hit specific binary line_4: phases, but the scheduling problems and overheads associated with finding guide line_5: stars make that alternative far less efficient than finding the target once and line_6: sitting there for consecutive HST orbits. line_7: T Leo's binary period is 85m, compared with HST's 96m orbit. Thus line_8: 4 HST orbits equals approx. 4.5 T Leo periods. line_9: We therefore observe HST orbits 1 and 2 at CIV and MgII, line_10: then skip orbits 3 and 4, then repeat CIV and MgII in orbits 5 and 6. line_11: This covers the binary phase pretty uniformly. ! question: 6 section: 1 line_1: None ! question: 7 section: 1 line_1: Initial data reduction and calibration will use the standard pipelined software line_2: at STScI. We will first make plots of spectral and temporal slices through the line_3: data and display the data as trailed spectrograms to check for obvious line_4: problems. We will then apply our maximum entropy software which will make line_5: Doppler maps of the emission-line regions. We have used this software and line_6: published results of analyses of ground-based data on IP Peg and U Gem. line_8: By examining the Doppler maps we can see directly the kinematics of the line_9: emission line regions, and from that infer what parts of the system emit the line_10: lines. For example, disk emission appears as a ring on the Doppler map, while line_11: emission from the late-type star appears as a sharp component displaced upward line_12: from the center as in Figure 2. We will determine the radial profile of the line_13: disk component of the emission by averaging in azimuth around the center of the line_14: ring on the map. Then we will subtract the disk component from the data and line_15: examine the trailed spectrogram to see if the residual appears to be consistent line_16: with emission from the late-type secondary star. We may find that there are line_17: active regions on the companion star, in which case we will modify our mapping line_18: code to solve for the distribution of flux on the Roche lobe surface of the line_19: late-type star as well as on the plane of the accretion disk. ! question: 8 section: 1 line_1: The exposure times planned for this experiment are NOT dictated by line_2: signal-to-noise ratio requirements, but rather are required to record velocity line_3: profiles at 8 representative phases around full binary cycles. line_5: We will attempt to acquire coordinated earth-based observations. ! question: 9 section: 1 line_1: Cycle 1: line_2: GO-2334 "Ultraviolet Spectroscopy of the Black Hole AO620-00" line_3: McClintock, Remillard, and Horne line_4: GO-2380 "Instabilities in Accretion Disks and the Outbursts of Dwarf Novae" line_5: Horne and Marsh line_6: GO-3232 "Observations of X-Ray Nova Muscae 1991" line_7: Panagia, Lund, Gilmozzi, Horne, Paresce, Valle, and Schrader line_8: Cycle 2: line_9: GO-3578 "Line Eclipse Mapping of an Accretion Disk Wind" line_10: Mason, Drew, Marsh, Horne, Cordova, Mauche, Raymond line_11: GO-3600 "Oscillations, Flares, and Tomography of AE Aquarii" line_12: Horne, Marsh, Robinson, Wood. line_13: GO-3683 "Accretion Disk Mapping in Eclipsing Cataclysmic Variables" line_14: Horne, Barwig, Long, Marsh, Polidan, Raymond, Robinson, Rutten, line_15: Shafter, Szkody, Wade, Wood, and Zhang line_16: GO-3824 "A Search for Silicon and Carbon in GO Com" line_17: Wood, Marsh, Lambert, and Horne line_18: GO-3836 "Spectroscpic Observations of the Exposed line_19: WDs in the Dwarf Novae U Gem, WZ Sge, and VW Hyi" line_20: Sion, Szkody, Gilland, Long, Pringle, Horne, Wood ! 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: STSCI addr_2: 3700 SAN MARTIN DRIVE city: BALTIMORE, MD zip: 21218 country: USA phone: 410-338-4964 ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: T-LEO descr_1: A,149,161 pos_1: RA = 11H 38M 26.954S +/- 0.07S, pos_2: DEC = +03D 22' 08.05" +/- 1", pos_3: PLATE-ID=0592 equinox: J2000 pm_or_par: N comment_1: V=10 IN RARE DWARF NOVA OUTBURSTS fluxnum_1: 1 fluxval_1: V=15.5 +/- 0.5 fluxnum_2: 2 fluxval_2: F-CONT(1550) = 12 +/- 3 E-15 fluxnum_3: 3 fluxval_3: F-CONT(2800) = 8 +/- 3 E-15 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: T-LEO config: HRS opmode: ACQ aperture: 2.0 sp_element: MIRROR-N2 num_exp: 1 time_per_exp: 90S fluxnum_1: 2 param_1: SEARCH-SIZE=3 param_2: BRIGHT=RETURN req_1: CYCLE 3 / 1-6 ; req_2: ONBOARD ACQ FOR 2-3 ; req_3: SEQ 1-3 NO GAP ; comment_1: EXPECT 700-1000 C/S, comment_2: THUS USE STEP-TIME = 10S. comment_3: TO PERMIT COORDINATED OBSERVATIONS, comment_4: PLEASE NOTIFY P.I. WHEN DATES ARE comment_5: SCHEDULED OR CHANGED. ! linenum: 2.000 targname: T-LEO config: HRS opmode: ACCUM aperture: 2.0 sp_element: G160M wavelength: 1549 num_exp: 38 time_per_exp: 54.4S param_1: STEP-PATT = 5 param_2: COMB = FOUR req_1: NON-INT ; comment_1: FOR TIME-RESOLVED SPECTROSCOPY, comment_2: NEED SMALL DEADTIME. CHANGE TO comment_3: COMB=TWO, OR STEP-PATT=3, OR DOUBLE comment_4: TIME_PER_EXP TO KEEP DEADTIME BELOW 20 comment_5: PERCENT. THEN SET NUMBER OF EXPOSURES comment_6: TO FILL AVAILABLE TIME IN HST ORBIT. ! linenum: 3.000 targname: T-LEO config: HRS opmode: ACCUM aperture: 2.0 sp_element: G270M wavelength: 2800 num_exp: 38 time_per_exp: 54.4S param_1: STEP-PATT = 5 param_2: COMB = FOUR req_1: NON-INT ; comment_1: FOR TIME-RESOLVED SPECTROSCOPY, comment_2: NEED SMALL DEADTIME. CHANGE TO comment_3: COMB=TWO, OR STEP-PATT=3, OR DOUBLE comment_4: TIME_PER_EXP TO KEEP DEADTIME BELOW 20 comment_5: PERCENT. THEN SET NUMBER OF EXPOSURES comment_6: TO FILL AVAILABLE TIME IN HST ORBIT. ! linenum: 4.000 targname: T-LEO config: HRS opmode: ACQ aperture: 2.0 sp_element: MIRROR-N2 num_exp: 1 time_per_exp: 90S fluxnum_1: 2 param_1: SEARCH-SIZE=3 param_2: BRIGHT=RETURN req_1: ONBOARD ACQ FOR 5-6 ; req_2: SEQ 4-6 NO GAP ; req_3: AFTER 1 BY 384M +/- 10M; comment_1: 384M = 4 HST ORBITS, comment_2: 384M = 4.5 T-LEO PERIODS. comment_3: THIS DELAY ENSURES COVERAGE OF comment_4: OPPOSITE HALF OF T-LEO ORBIT. comment_5: EXPECT 700-1000 C/S, comment_6: THUS USE STEP-TIME = 10S. ! linenum: 5.000 targname: T-LEO config: HRS opmode: ACCUM aperture: 2.0 sp_element: G160M wavelength: 1549 num_exp: 38 time_per_exp: 54.4S param_1: STEP-PATT = 5 param_2: COMB = FOUR req_1: NON-INT ; comment_1: FOR TIME-RESOLVED SPECTROSCOPY, comment_2: NEED SMALL DEADTIME. CHANGE TO comment_3: COMB=TWO, OR STEP-PATT=3, OR DOUBLE comment_4: TIME_PER_EXP TO KEEP DEADTIME BELOW 20 comment_5: PERCENT. THEN SET NUMBER OF EXPOSURES comment_6: TO FILL AVAILABLE TIME IN HST ORBIT. ! linenum: 6.000 targname: T-LEO config: HRS opmode: ACCUM aperture: 2.0 sp_element: G270M wavelength: 2800 num_exp: 38 time_per_exp: 54.4S param_1: STEP-PATT = 5 param_2: COMB = FOUR req_1: NON-INT ; comment_1: FOR TIME-RESOLVED SPECTROSCOPY, comment_2: NEED SMALL DEADTIME. CHANGE TO comment_3: COMB=TWO, OR STEP-PATT=3, OR DOUBLE comment_4: TIME_PER_EXP TO KEEP DEADTIME BELOW 20 comment_5: PERCENT. THEN SET NUMBER OF EXPOSURES comment_6: TO FILL AVAILABLE TIME IN HST ORBIT. ! ! end of exposure logsheet ! No scan data records found