! File: 2603C.PROP ! Database: PEPDB ! Date: 17-FEB-1994:09:07:09 coverpage: title_1: PARALLEL OBSERVATIONS OF H LY ALPHA EMISSION FROM THE LOCAL ISM sci_cat: INTERSTELLAR MEDIUM proposal_for: GO cont_id: 2603 pi_title: DR. pi_fname: JOHN pi_mi: T. pi_lname: CLARKE pi_inst: MICHIGAN, UNIVERSITY OF pi_country: USA pi_phone: 313-747-3540 keywords_1: INTERPLANETARY MEDIUM, LISM GAS, SOLAR WIND hours_par: 24.00 num_par: 7 hrs: X funds_amount: 41096 funds_length: 12 funds_date: AUG-91 pi_position: DOCTOR off_fname: MARTIN off_mi: H. off_lname: TOBIN off_inst: ASSISTANT DIRECTOR off_addr_1: DIV. OF RESEARCH DEVELOPMENT AND ADMIN. off_addr_2: UNIVERSITY OF MICHIGAN off_addr_3: 245 W. ENG. BLDG, 550 E. UNIVERSITY ST., off_city: ANN ARBOR off_state: MI off_zip: 48109 off_country: USA off_phone: 313-763-1268 off_telex: 432-0815 ! end of coverpage abstract: line_1: We propose to observe the sky background H Ly alpha emission in parallel with line_2: scheduled observations to study the emission generated by local ISM hydrogen line_3: penetrating into the solar system. This component can be observed when the line_4: earth orbital motion Doppler-shifts the geocoronal line from the LISM vector. line_5: By defining the velocity vector of the interstellar wind (ISW) in the solar line_6: system we may identify which of several local clouds in the LISM encompasses line_7: the solar system. By a careful measurement of the ISW line shape we may study line_8: the temperature of the LISM and interaction of the ISW with the heliospheric line_9: bow shock and solar wind. This proposal is solely for parallel observing time. ! ! end of abstract general_form_proposers: lname: CLARKE fname: JOHN title: P.I. mi: T. inst: MICHIGAN, UNIVERSITY OF country: USA ! lname: FAHR fname: HANS inst: BONN UNIVERSITY country: FRG esa: X ! lname: BERTAUX fname: JEAN-LOUP inst: CNRS, DEPARTMENT OF AERONOMY country: FRANCE esa: X ! lname: LALLEMENT fname: ROSINE inst: CNRS, DEPARTMENT OF AERONOMY country: FRANCE esa: X ! lname: PARESCE fname: FRANCESCO inst: STSCI country: USA esa: X ! ! end of general_form_proposers block general_form_text: question: 3 section: 0 line_1: We are proposing for parallel observations only, using the HRS and line_2: Echelle A grating. With the LSA we will obtain 0.10 A resolution and line_3: a count rate of 1.6 cts/sec-kR, whereas the SSA will give .013 A line_4: resolution and .026 cts/sec-kR. The ISW H Ly alpha emission may be line_5: 0.1 - 1.0 kR, depending on the angle of observation to the flow line_6: direction and the solar flux. For a 500 R emission and a 30 min. dark line_7: orbit integration with the LSA, we would get 1400 counts (S/N = 40) line_8: spread over 8 diodes. By centroiding we could measure the line of line_9: sight velocity of the ISW with an accuracy of roughly 1-2 km/sec. Our line_10: first priority is to obtain such measurements of the velocity and line_11: emission brightness over a range of lines of sight. No HST pointing line_12: is required as long as no other emission sources are in the aperture, line_13: since the ISW is diffuse over the sky. A minimum of 6 lines of sight line_14: is initially requested, all in parallel mode. The second priority is line_15: to measure the temperature of the ISW through the line shape determined line_16: from HRS SSA spectra at .013 A resolution. The line width is expected line_17: to be in the range 50-100 mA, so that 13 mA resolution will easily line_18: resolve the line width and shape. In a 30 min. integration we would line_19: only achieve S/N of 5, however, so that longer integrations would be line_20: desired. We propose to use the HRS during the WF/PC UV-flood line_21: operation, when the HST will be pointed at the anti-sun for periods of line_22: 10-20 orbits. Note: due to problems with side 1 of GHRS, we have line_23: changed our mode to GHRS 160M with the SSA - 2/92. ! question: 4 section: 0 line_1: The scientific importance of observing the ISW separately from the line_2: LISM is discussed above. The only emission lines bright enough to be line_3: observed in the ISW are the UV resonance lines of H and He, and we are line_4: proposing to observe the brightest emission of H Ly alpha. The HST is line_5: the only instrument with sufficiently high resolution and UV line_6: sensitivity to study the emission velocity and line profile. Although line_7: the integration times are substantial, the observation requires no line_8: dedicated pointing and can be conducted entirely in parallel mode. The line_9: information derived from this study will complement the HST and ground- line_10: based studies of the LISM through absorption spectra of near-by stars, line_11: which we have pursued in the past (Lallement et al. 1986). ! question: 5 section: 0 line_1: There are no tracking requirements, other than that the HRS aperture line_2: be "empty" except for sky background emission. Our data will be line_3: obtained in parallel during the 40 min. of dark orbit to minimize the line_4: brightness of the geocoronal emission, and as such no serial exposure line_5: time is required. The exposure times necessay to achieve useful S/N line_6: levels are discussed in the observing plan (see question 3). We wish line_7: to have the GHRS continue taking data through the entire orbit (yes, line_8: even while looking at the bright Earth) so that we may model the line_9: variation in the geocoronal emission over the orbit. ! question: 6 section: 0 line_1: We would like observations distributed about the general inflow or line_2: upwind direction ( alpha = 17 hrs, delta = -20 degrees) to determine line_3: the velocity vector and line profile, to be arranged with the HST line_4: schedule as opportunities permit. These opportunities will be line_5: limited to the WF/PC UV-flood's, as determined by the TAC. We line_6: understand that our GHRS observations will be conducted as a line_7: default procedure during all WF/PC UV-flood's after launch and line_8: through the end of the first GO cycle. The GHRS integrations may line_9: be performed in any order, and the SSA spectra stopped when nearing line_10: the end of the UV-flood. At least for the first observation, we line_11: would like the GHRS data-taking to continue through Earth occultation line_12: so that we may model the geocoronal Ly alpha emission background. ! question: 7 section: 0 line_1: The GHRS spectra will be reduced using standard programs obtained from line_2: the ST ScI or GHRS team on facilities at the Univ. Michigan. There are line_3: no special calibrations or techniques required, other than a careful line_4: measurement of the ISW line velocity and the shape/profile of the ISW line_5: line. The analysis of the data will involve determination of the ISW line_6: velocity vector using existing programs, and the analysis of the ISW line_7: Ly alpha line shape by conventional techniques. The analysis of the line_8: local flow components in the LISM has been published by Lallement et line_9: al. (1986), and the analysis of the effects of modification of the flow line_10: at the heliospheric boundary be Fahr and Shizgal (1983). These workers line_11: will take the lead role in the interpretation of the ISW velocity line_12: vector and temperature derived from the HRS spectra. The interpretation line_13: of the ISW line profile will likely involve detailed modeling of different line_14: flow components and their interaction with the heliospheric bow shock. line_15: Although it appears that we will obtain only two spectra per UV-flood, line_16: the separation of the geocoronal emission and modeling of the ISW line line_17: will involve considerable work to interpret the data. ! question: 10 section: 0 line_1: Complete computing facilities are in place and available within the line_2: Space Physics Research Lab. for use on this effort. Two VAX 750's and line_3: VAX 8600 are accessible via a local area network, in addition to the line_4: Michigan network (MERIT) and the SPAN network. A SUN 4/110 workstation line_5: running IDL has been purchased using University of Michigan funds. line_6: In addition to the above resources, three DEC color graphics line_7: workstations, with hard copy capability, are available to provide high line_8: quality output for publications. ! !end of general form text general_form_address: lname: CLARKE fname: JOHN mi: T. title: DR. category: PI inst: UNIVERSITY OF MICHIGAN addr_1: AOSS DEPARTMENT city: ANN ARBOR state: MI zip: 481092143 country: USA ! ! end of general_form_address records ! No fixed target records found ! No solar system records found generic_targets: targnum_1: 1 name_1: ISM descr_1: OTHER: INTERPLANETARY MEDIUM criteria_1: OBSERVE DURING ALL WF/PC criteria_2: UV-FLOOD'S. comment_1: PARALLEL OBSERVATION WITH GHRS comment_2: DURING WF/PC UV-FLOOD: GHRS TO comment_3: OBSERVE H LY ALPHA EMISSION comment_4: FROM GEOCORONA AND ISM H WHILE comment_5: POINTED AT ANTI-SOLAR POINT. comment_6: NO GS ACQUISITION OR TRACKING. comment_7: DO THIS DURING ALL UV-FLOODS. fluxnum_1: 1 fluxval_1: SURF-LINE(1216) = 1.5 +/- 1 E-12 fluxnum_2: 2 fluxval_2: W-LINE(1216) = 0.1 +/- .05 ! ! end of generic targets exposure_logsheet: linenum: 1.000 targname: WAVE config: HRS opmode: ACCUM aperture: SC1 sp_element: G160M wavelength: 1223.0 num_exp: 1 time_per_exp: 100 S priority: 2 param_1: STEP-PATT = DEF param_2: STEP-TIME = 1.0 req_1: CALIB FOR 2; req_2: SEQ 1-2 NON-INT; req_3: PCS MODE G; req_4: CYCLE 1; req_5: REPEAT 1-2 EVERY 90M +/- 10M req_6: FOR 32 MORE TIMES; comment_1: WAVELENGTH CALIBRATION FOR comment_2: SSA SPECTRUM NEEDED TO comment_3: MEASURE VELOCITY OF VLISM. comment_4: ONE CALIBRATION/OBSERVATION PER ORBIT comment_5: THROUGHOUT UV FLOOD (~20 ORBITS). ! linenum: 2.000 targname: ISM config: HRS opmode: ACCUM aperture: 0.25 sp_element: G160M wavelength: 1223.0 num_exp: 3 time_per_exp: 600 S priority: 1 param_1: STEP-PATT = DEF param_2: STEP-TIME=1.0 param_3: DOPPLER = ON param_4: FP-SPLIT = STD req_1: CYCLE 1; req_2: PCS MODE G; comment_1: GHRS SSA SPECTRA TO comment_2: MEASURE ISM H LINE comment_3: PROFILE: REPEAT 1-2 AS LONG comment_4: AS POSSIBLE DURING WF/PC comment_5: UV-FLOOD. EXPOSE ALSO DURING comment_6: EARTH OCCULTATION. ! ! end of exposure logsheet ! No scan data records found