! $Id: 5364,v 5.1 1994/07/27 17:07:31 pepsa Exp $ coverpage: title_1: THE UV SPECTRAL COMPONENTS IN RE1938-461, THE BRIGHTEST ROSAT title_2: WFC DISCOVERED POLAR WITH A HIGH EUV/OPTICAL RATIO: CYCLE4 MEDIUM. sci_cat: HOT STARS sci_subcat: ERUPTIVE BINARIES proposal_for: GO pi_fname: SIMON pi_lname: ROSEN pi_inst: UNIVERSITY OF LEICESTER pi_country: U.K. hours_pri: 4.43 num_pri: 1 fos: Y time_crit: N off_fname: KEN off_lname: POUNDS off_title: HEAD OF DEPT. off_inst: 8042 off_addr_1: DEPT. OF PHYSICS off_addr_2: UNIVERSITY OF LEICESTER off_addr_3: UNIVERSITY RD. off_city: LEICESTER off_country: U.K. off_phone: UK-533-523509 ! end of coverpage abstract: line_1: Eight new magnetic cataclysmic variables were discovered during the ROSAT WFC line_2: survey. Seven of these have been identified with polar (or AM Her) systems. line_3: A striking result that has emerged is that the new polars appear to populate a line_4: region of high EUV/optical flux ratio when compared to that measured for the line_5: previously known systems that were also detected in the WFC survey. It is line_6: highly likely that these new polars also possess large soft/hard X-ray flux line_7: ratios. In this case, the WFC result suggests that a) polars with large soft line_8: excesses are more common than previously believed and b) that the mode of line_9: accretion in these particular systems is likely to be via the direct penetration line_10: of the white dwarf's surface by blobs of accreting material rather than by the line_11: formation of a hard X-ray emitting column above the surface. The new polars line_12: will have a direct bearing on the division between the two different modes of line_13: accretion. They also provide the means to probe the detailed nature of the line_14: processes occurring in the accretion region. We are proposing low resolution line_15: HST FOS observations of the brightest of these EUV luminous polars discovered line_16: in the WFC survey to a) search for the tail of the emission component from the line_17: heated region around the accreting pole to constrain the luminosity, size and line_18: temperature of this constituent and b) to perform an initial study of the UV line_19: emission lines, measuring their flux and radial velocity motion to constrain line_20: the dynamics and physical (ionization) structure within the accretion flow. ! ! end of abstract general_form_proposers: lname: ROSEN fname: SIMON title: PI mi: R inst: UNIVERSITY OF LEICESTER country: UNITED KINGDOM esa: Y ! lname: WATSON fname: MIKE inst: UNIVERSITY OF LEICESTER country: UNITED KINGDOM esa: Y ! lname: OSBORNE fname: JULIAN inst: UNIVERSITY OF LEICESTER country: UNITED KINGDOM esa: Y ! lname: KING fname: ANDREW inst: UNIVERSITY OF LEICESTER country: UNITED KINGDOM esa: Y ! lname: MASON fname: KEITH inst: MULLARD SPACE SCIENCE LABORATORY country: UNITED KINGDOM esa: Y ! lname: BUCKLEY fname: DAVID inst: UNIVERSITY OF CAPE TOWN country: SOUTH AFRICA esa: N ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: We propose to obtain the first UV spectra of the recently line_2: discovered polar, RE1938-461, allowing us to measure phase- line_3: dependent variability in the UV continuum and emission lines. line_4: We will exploit the temporally resolved spectra to search for line_5: the tail of the emission from the white dwarf's heated line_6: accretion region. Potential phase differences between this line_7: component and orbitally modulated flux from the accretion flow line_8: should allow us to separate their contributions. We can then line_9: perform spectral model fits (e.g. different temperature black- line_10: body components) to constrain the temperature, luminosity and line_11: size of the emission sites. Radial velocity and flux line_12: variability in the UV emission lines will probe physical and line_13: dynamical structure in the accretion flow. line_15: We will use the FOS with the 0.9" aperture and the G160L line_16: grating to provide coverage of the 1150A-2500A\ range with a line_17: resolution of around 7A/pix. Coverage down to the shortest UV line_18: wavelengths is essential if we are to be able to search for line_19: the steep component from the heated accretion region in the line_20: far UV. We will use the FOS in RAPID mode, recording 20s line_21: exposures. This will permit us to test for any large-scale line_22: spectral changes during the transition from the faint to line_23: the bright phase. ! question: 3 section: 2 line_1: We request coverage of one orbital cycle in this initial line_2: investigation. ! question: 4 section: 1 line_1: The accretion flow within 10 stellar radii of the white dwarf line_2: should be hot (10000330, line_10: 590, 630, 1680 and 5400 counts/diode at the same wavelengths, line_11: permitting changes in the continuum level to be detectable line_12: at levels of less than 6% at all wavelengths in each diode. line_13: Spectra will be binned in wavelength, where necessary, to line_14: enhance the S/N. for example, by combining data over a 100 line_15: range, we might expect to improve the sensitivity to line_16: variations by a factor of 4. line_17: For this first acquisition of UV data from RE1938-461, we line_18: seek coverage of one complete orbital cycle. We request 3 line_19: hours of on-source data which will require 5 HST orbits line_20: (assuming ~32 minutes of data per HST orbit). This will line_21: provide near complete phase coverage of the orbital cycle line_22: and will yield sufficient S/N to identify and quantify the line_23: spectral components we expect to be present. ! question: 5 section: 1 line_1: We do not request any special scheduling requirements. line_2: However, contiguous orbits will provide excellent phase coverage line_3: of the 2.33~hr orbital cycle and will maximize observing line_4: efficiency by reducing the overheads from acquisitions (i.e. line_5: we would require only one primary acquisition). ! question: 6 section: 1 line_1: Routine FOS calibration data will be sufficient for our purposes. ! ! question: 8 section: 1 line_1: It is extremely advantageous to acquire simultaneous multi- line_2: wavelength data for variable objects like polars since only line_3: then we can be confident that the spectra represent the same line_4: state of the system. We will be endeavouring to obtain line_5: simultaneous or near simultaneous optical spectroscopy of line_6: RE1938-461 with the HST observations in order to compare the line_7: behaviour of the UV and optical continuum and lines at the line_8: same epoch. However, we stress that we will be seeking to line_9: arrange suitable optical observations that fit in with the line_10: HST schedule, rather than requiring HST observations to be line_11: dependent on optical scheduling. One of our collaborators line_12: (DB) has been particularly successful in arranging line_13: contemporaneous optical coverage from the South African line_14: Astronomical Observatory during satellite observations of line_15: cataclysmic variables over the years. He will apply for time line_16: on the 1.9m telescope to secure simultaneous or quasi- line_17: simultaneous optical coverage of RE1938-461. We expect line_18: that such observations can be arranged at relatively short line_19: notice (1-2 months). Nevertheless, we point out that the line_20: optimum optical observing season is between July and September. ! question: 9 section: 1 line_1: GO-3578 Line eclipse mapping of an accretion disk wind. line_2: (KOM,JED). Preliminary results presented at UK National line_3: Astronomy meeting in March 1993. line_4: GO-3579 The UV orbital lightcurve of the X-ray binary line_5: X1822-371. (KOM). Not done line_6: GO-4661 UV eclipse mapping of the Accretion flow in the line_7: eclipseing Intermediate Polar, EX Hya (SRR,KOM). Failed due to line_8: satellite/instrument problems unrelated to that observation. line_9: GO-4659 A time-resolved UV study of the wind outflow in the line_10: enigmatic cataclycmic variable, V795 Her. Supplemental time line_11: awarded. Obs not yet performed. line_12: GO-4449 Occultation studies of RE1149+28: An object with line_13: an extreme EUV/optical ratio. (KOM,SRR). Scheduled for late 93. line_14: Proposal GO-4449, whilst looking at another high EUV/optical line_15: ratio polar, is primarily aimed at searching for a UV counter- line_16: part to an occultation effect seen in the optical emission line_17: lines. Moreover, it will be using the G130H grating so that a line_18: search for the differing components that contribute to its line_19: UV continuum flux is not viable (due to the narrow range line_20: covered). RE1149+28 is also a factor of six fainter than line_21: RE1938-461. ! question: 10 section: 1 line_1: The analysis of our HST data will be undertaken by the PI line_2: and the Co-I's. All proposers have access to DEC Vax line_3: machines or SUN stations which are dedicated to astronomical line_4: research. ! !end of general form text general_form_address: lname: ROSEN fname: SIMON mi: R category: PI inst: University of Leicester addr_1: Dept. of Physics, addr_3: University Rd., city: Leicester country: UNITED KINGDOM phone: 0533 552077 ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: STAR-193835-461256 descr_1: A, 153 pos_1: RA = 19H 38M 35.75S +/- 1.0", pos_2: DEC = -46D 12' 55.99" +/- 1.0", pos_3: PLATE-ID = 04FS equinox: J2000 comment_1: UV FLUXES ARE PREDICTIONS BASED comment_2: ON UV DATA FROM V834 CEN, A POLAR comment_3: OF SIMILAR OPTICAL MAGNITUDE. comment_4: SYSTEM CAN FADE BY 2 MAGNITUDUES comment_5: ON TIMESCALES OF WEEKS. TARGET comment_6: POSN QUOTED TO ME AS GOOD TO 1" fluxnum_1: 1 fluxval_1: V= 15.5 +/- 0.5 fluxnum_2: 2 fluxval_2: B-V = 0.0 +/- 0.3 fluxnum_3: 3 fluxval_3: E(B-V) = 0.0 +/- 0.1 fluxnum_4: 4 fluxval_4: F-CONT(1250) = 2.0 +/- 1.0 E-14 fluxnum_5: 5 fluxval_5: F-CONT(1450) = 1.5 +/- 0.8 E-14 fluxnum_6: 6 fluxval_6: F-CONT(1750) = 1.0 +/- 0.5 E-14 fluxnum_7: 7 fluxval_7: F-CONT(2500) = 0.5 +/- 0.2 E-14 fluxnum_8: 8 fluxval_8: F-LINE(1550) = 10. +/- 5. E-14 fluxnum_9: 9 fluxval_9: W-LINE(1550) = 10 +/- 3 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: STAR-193835-461256 config: FOS/BL opmode: ACQ/PEAK aperture: 4.3 sp_element: G400H num_exp: 1 time_per_exp: 10S fluxnum_1: 1 fluxnum_2: 3 priority: 1 param_1: SCAN-STEP-Y=1.204, param_2: SEARCH-SIZE-X=1, param_3: SEARCH-SIZE-Y=3, req_1: ONBOARD ACQ FOR 1.5; req_2: CYCLE 4; comment_1: STAR VARIES BY UPTO 0.5 MAGS ABOUT comment_2: ITS MEAN OF V=15.5. IF IN A LOW comment_3: STATE, IT COULD BE FAINTER BY 2 comment_4: MAGS. OPTIMUM STRATEGY SHOULD USE comment_5: ACQUISITION+CONTIGUOUS HST ORBITS ! linenum: 1.500 targname: STAR-193835-461256 config: FOS/BL opmode: ACQ/PEAK aperture: 1.0 sp_element: G400H num_exp: 1 time_per_exp: 10S fluxnum_1: 1 fluxnum_2: 3 priority: 1 param_1: SCAN-STEP-X=0.602, param_2: SCAN-STEP-Y=0.602 param_3: SEARCH-SIZE-X=6, param_4: SEARCH-SIZE-Y=2, req_1: ONBOARD ACQ FOR 1.7; req_2: CYCLE 4; ! linenum: 1.700 targname: STAR-193835-461256 config: FOS/BL opmode: ACQ/PEAK aperture: 0.5 sp_element: G400H num_exp: 1 time_per_exp: 10S fluxnum_1: 1 fluxnum_2: 3 priority: 1 param_1: SCAN-STEP-X=0.3, param_2: SCAN-STEP-Y=0.3, param_3: SEARCH-SIZE-X=3, param_4: SEARCH-SIZE-Y=3, req_1: ONBOARD ACQ FOR 2-6; req_2: CYCLE 4; ! linenum: 2.000 targname: STAR-193835-461256 config: FOS/BL opmode: RAPID aperture: 1.0 sp_element: G160L wavelength: 1830 num_exp: 1 time_per_exp: 31.5M s_to_n: 25 s_to_n_time: 420S fluxnum_1: 5 priority: 1 param_1: COMB=YES param_2: READ-TIME=20 req_1: CYCLE 4 comment_1: SPECTRA WILL BE PHASE FOLDED TO comment_2: ACHIEVE DESIRED S/N comment_3: OPTIMUM STRATEGY SHOULD USE comment_4: ACQUISITION+CONTIGUOUS HST ORBITS ! linenum: 3.000 targname: STAR-193835-461256 config: FOS/BL opmode: RAPID aperture: 1.0 sp_element: G160L wavelength: 1830 num_exp: 1 time_per_exp: 1880S s_to_n: 25 s_to_n_time: 420S fluxnum_1: 5 priority: 1 param_1: COMB=YES param_2: READ-TIME=20 req_1: CYCLE 4 ! linenum: 4.000 targname: STAR-193835-461256 config: FOS/BL opmode: RAPID aperture: 1.0 sp_element: G160L wavelength: 1830 num_exp: 1 time_per_exp: 1880S s_to_n: 25 s_to_n_time: 420S fluxnum_1: 5 priority: 1 param_1: COMB=YES param_2: READ-TIME=20 req_1: CYCLE 4 ! linenum: 5.000 targname: STAR-193835-461256 config: FOS/BL opmode: RAPID aperture: 1.0 sp_element: G160L wavelength: 1830 num_exp: 1 time_per_exp: 1880S s_to_n: 25 s_to_n_time: 420S fluxnum_1: 5 priority: 1 param_1: COMB=YES param_2: READ-TIME=20 req_1: CYCLE 4 ! linenum: 6.000 targname: STAR-193835-461256 config: FOS/BL opmode: RAPID aperture: 1.0 sp_element: G160L wavelength: 1830 num_exp: 1 time_per_exp: 1880S s_to_n: 25 s_to_n_time: 420S fluxnum_1: 5 priority: 1 param_1: COMB=YES param_2: READ-TIME=20 req_1: CYCLE 4 ! ! end of exposure logsheet ! No scan data records found