<=== observer ===> "MBARLOW",\ "Barlow, M.J.",\ "Department of Physics & Astronomy",\ "University College London",\ "Gower Street",\ "",\ "WC1E 6BT",\ "London",\ "United Kingdom",\ " 44 713807160",\ " 44 713807145",\ "mjb@star.ucl.ac.uk" <=== proposal ===> "DUST2",1,3,\ {"dust properties","AGB stars","planetary nebulae"},\ {"LWS consortium","Baluteau, J.","Caux, E.","Cox, P.","Emery, R.","Nisini, B.",\ "Omont, A.","Pequignot, D","Rieu, N-Q.","Cohen, M.","Greenhouse, M.",\ "Skinner, C.","Walker, H."} <=== title ===> The far-IR spectra of cool evolved stars, post-AGB objects and planetary nebulae <=== abstract ===> SCIENTIFIC ABSTRACT This proposal is to study the (currently unknown) far-infrared emission properties of dust grains in the regions where they are formed. The study is designed to reveal the spectral dependence of the dust continuum emission and to find new dust emission features that will aid the full identification of the grains. The targets will be M-giants, Miras, OH/IR stars, S-stars, carbon stars, post-AGB transition objects (pre-planetary nebulae), and ionised planetary nebulae (PN) and their neutral shells (where present). These objects are believed to be the main sources of the refractory dust grains that are present in the general insterstellar medium. We will study the characteristics of the dust emission spectra as a function of stellar mass, evolutionary stage and chemical composition. None of the numerous mid-infared dust features now known were predicted prior to their observational discovery and one can expect a systematic study of the region longwards of 30um to reveal new dust features that will provide important insights into the nature of circumstellar and interstellar dust. A LaTex file containing fuller details of this proposal is available from mjb@star.ucl.ac.uk. OBSERVATION SUMMARY This proposal is split into four parts - this is part 2. Full (43-196.7um) LWS grating spectra will be obtained for all targets (LWS01 AOT in fast mode). The SWS Consortium is obtaining 2.43-45um low-resolution SWS grating spectra of the majority of these targets (SWS01 AOT, speed code 1), and we will obtain similar SWS spectra of the remainder of the targets. If objects in the Orion-hole should be observable (i.e. a Spring launch), the total amount of LWS Guaranteed (spacecraft) time allocated will be 28.39 hours, of which 11.04 hours will be for Priority 1 targets. For an Autumn launch (Sagittarius-hole observable), 27.86 hours of LWS Guaranteed (spacecraft) time will be allocated, of which 10.82 hours will be for Priority 1 targets. <=== scientific_justification ===> The mid-infrared has already proven to be an extremely important region for studying the properties of dust grains, via the measurement of their characteristic solid state emission and absorption features. These studies have yet to be extended systematically to wavelengths longer than 40um, although KAO observations have already revealed features at 35um (perhaps MgS; Goebel and Moseley, 1985, Ap.J., 290, L35) and at 44um and 62um (ice translation bands, e.g. Omont et al., 1990, Ap.J., 355, L27). The exact spectroscopic identification of the dust grains found in many circumstellar and nebular environments has still to be achieved. ISO's ability to obtain systematically the mid- and far-infrared spectra of many different classes of objects will greatly increase our understanding of the detailed grain emission properties and so aid their identification. It is clear from a variety of observations that hydrocarbon emission bands can be seen in 5-8um spectra in stars as cool as G-type, so that even such cool stars can excite the mid-IR bands, both in reflection nebulae and in circumstellar dust shells. Consequently, the study of stars in transition between the AGB and the planetary nebula regime provides a direct probe of the photoexcitation of the hydrocarbon bands. ISO permits observations of the long wavelength very broad bending modes of, for example, PAH molecules, which may be recognizable when the more commonly observed, sharper features in the mid-IR are lacking. The mass of gas in the neutral regions surrounding many post-AGB objects and planetary nebulae is very poorly known. Observations of the important coolant lines of [C II], [O I] and CO will allow a systematic determination of the densities, temperatures and masses of these regions for the first time. The LWS grating resolving power of 150-300 is ideally suited to resolving and measuring the detailed profiles of solid-state dust features, as well as for finding low-contrast structure. We propose to observe a number of important classes of objects, described in more detail below. The changes found in the far-IR dust spectra of AGB stars as a function of spectral type are expected to be due to the changing chemical composition of the gas out of which the grains condense, while changes in the dust spectra found in post-AGB objects, relative to the behaviour exhibited in the spectra of AGB stars of the same chemical composition, are expected to be due to the changing physical conditions, e.g. cooler gas and dust temperatures; the increasing fraction of atomic and (eventually) ionised hydrogen; and the hardening of the stellar radiation field. The full grating spectra will reveal strong atomic or molecular emission lines, where present. A companion proposal describes LWS FP observations that are to be made of lines which are expected to be be present in the spectra of a number of these objects, but the full grating spectra will enable the detection of strong lines, including those which were not expected in advance. Full LWS grating scans (43-188um) will be obtained for all the targets. In addition, 2.43-45um low resolution SWS01 grating scans will be obtained for the targets not being observed by the SWS Consortium. Such complete scans are essential for this programme, aimed at studying the overall properties of the dust emission, and for measuring a range of strong emission lines. LWS AOT's: For all targets, LWS full grating spectra (43-196.7um) will be obtained with the LWS01 AOT, with four sample points per resolution element, using the fast scan option. For the bright targets, an integration time of one second per sample point will yield a high S/N ratio, and we will not obtain a complementary offset sky spectrum, since the targets will be much brighter than the sky. The required spacecraft time will therefore be 532 seconds per target. For the fainter targets, for which integration times of two seconds per sample point will be used, offset sky spectra will be obtained and the required spacecraft time for the whole LWS observation will be 1208 seconds per target. SWS AOT's: Complete SWS spectra of many of our targets are scheduled to be obtained by the SWS Consortium (proposals by de Jong et al., Waters et al. and Beintema et al.). We will obtain SWS spectra of the remaining targets. The low-resolution SWS grating scan AOT, SWS01, will be used to obtain complete 2.43-45um SWS spectra at one eighth of the standard grating resolution. The additional spacecraft time required to obtain a complete SWS spectrum of this type is 956 seconds (one second detector reset time; speed code 1). We will observe all but three of the sources in this mode, whose resolving power matches that of the LWS grating mode. The exceptions are two sources suspected of having strong 44um ice emission bands (IRAS14541-4204 and IRAS18059-3211) and one known to do so (IRAS09371+1212). They each have low 25um IRAS fluxes and were not detected at 12um, so they will be observed for 32 minutes each, from 29.5-45.2um only, using the SWS full-resolution grating mode with the AOT SWS06. SPACECRAFT TIME SUMMARY: Orion-hole observable (Spring launch) Sgr-hole observable (Autumn launch) Priority 1 time = 11.04 hrs (38.9%) Priority 1 time = 10.82 hrs (38.9%) Priority 2 time = 8.40 hrs (29.6%) Priority 2 time = 8.07 hrs (29.0%) Priority 3 time = 8.96 hrs (31.5%) Priority 3 time = 8.96 mins (32.1%) Total S/C time = 28.39 hrs Total S/C time = 27.86 hrs Time distribution for spring launch targets: Team top 40% second 30% last 30% LWS : 39740 30224 32244 total : 39740 30224 32244 Time distribution for autumn launch targets: Team top 40% second 30% last 30% LWS : 38968 29068 32244 total : 38968 29068 32244 <=== autumn_launch_targets ===> 1, "LWS01", 1.0, "N", "W Aql", 19.21156, -7.13556, 1950, 0.,0.,532,0 2, "LWS01", 1.0, "N", "Chi Cyg", 19.81069, +32.78667, 1950, 0.,0.,684,3 3, "LWS01", 1.0, "N", "Chi Cyg off", 19.81069, +32.88667, 1950, 0.,0.,524,0 4, "LWS01", 1.0, "N", "Pi1 Gru", 22.32811, -46.20056, 1950, 0.,0.,532,0 5, "LWS01", 1.0, "N", "R Scl", 1.41108, -32.80139, 1950, 0.,0.,532,0 6, "LWS01", 3.0, "N", "U Cam", 3.62467, +62.48833, 1950, 0.,0.,684,7 7, "LWS01", 3.0, "N", "U Cam off", 3.62467, +62.58833, 1950, 0.,0.,524,0 8, "LWS01", 1.0, "N", "U Ant", 10.54983, -39.30361, 1950, 0.,0.,532,0 9, "LWS01", 2.0, "N", "AX Sgr", 18.09222, -18.56333, 1950, 0.,0.,532,10 10, "SWS01", 2.0, "N", "AX Sgr", 18.09222, -18.56333, 1950, 0.,0.,956,0 11, "LWS01", 3.0, "N", "S Sct", 18.79364, -7.96639, 1950, 0.,0.,684,12 12, "LWS01", 3.0, "N", "S Sct off", 18.79364, -7.86639, 1950, 0.,0.,524,0 13, "LWS01", 1.0, "N", "R Aqr", 23.68731, -15.56167, 1950, 0.,0.,684,14 14, "LWS01", 1.0, "N", "R Aqr off", 23.68731, -15.66167, 1950, 0.,0.,524,0 15, "LWS01", 3.0, "N", "UW Cen", 12.67386, -54.15417, 1950, 0.,0.,684,16 16, "LWS01", 3.0, "N", "UW Cen off", 12.67386, -54.25417, 1950, 0.,0.,524,17 17, "SWS01", 3.0, "N", "UW Cen", 12.67386, -54.15417, 1950, 0.,0.,956,0 18, "LWS01", 1.0, "N", "AC Her", 18.46911, +21.83056, 1950, 0.,0.,684,19 19, "LWS01", 1.0, "N", "AC Her off", 18.46911, +21.93056, 1950, 0.,0.,524,0 20, "LWS01", 1.0, "N", "HD 101584", 11.64275, -55.29694, 1950, 0.,0.,532,0 21, "LWS01", 3.0, "N", "Boomerang", 12.69856, -54.24722, 1950, 0.,0.,684,22 22, "LWS01", 3.0, "N", "Boomerang off", 12.69856, -54.34722, 1950, 0.,0.,524,23 23, "SWS01", 3.0, "N", "Boomerang", 12.69856, -54.24722, 1950, 0.,0.,956,0 24, "LWS01", 3.0, "N", "IRAS14541", 14.90425, -42.07472, 1950, 0.,0.,684,25 25, "LWS01", 3.0, "N", "IRAS14541 off", 14.90425, -42.17472, 1950, 0.,0.,524,26 26, "SWS06", 3.0, "N", "IRAS14541", 14.90425, -42.07472, 1950, 0.,0.,1730,0 27, "LWS01", 3.0, "N", "IRAS16342", 16.57139, -38.23750, 1950, 0.,0.,532,28 28, "SWS01", 3.0, "N", "IRAS16342", 16.57139, -38.23750, 1950, 0.,0.,956,0 29, "LWS01", 2.0, "N", "OH349.36", 17.25111, -37.91500, 1950, 0.,0.,532,30 30, "SWS01", 2.0, "N", "OH349.36", 17.25111, -37.91500, 1950, 0.,0.,956,0 31, "LWS01", 3.0, "N", "IRAS17347", 17.57942, -31.65306, 1950, 0.,0.,532,0 32, "LWS01", 1.0, "N", "HD 161796", 17.72814, +50.06306, 1950, 0.,0.,532,0 33, "LWS01", 1.0, "N", "89 Her", 17.89003, +26.05639, 1950, 0.,0.,532,0 34, "LWS01", 2.0, "N", "IRAS18059", 18.09944, -32.18944, 1950, 0.,0.,684,35 35, "LWS01", 2.0, "N", "IRAS18059 off", 18.09944, -32.28944, 1950, 0.,0.,524,36 36, "SWS06", 2.0, "N", "IRAS18059", 18.09944, -32.18944, 1950, 0.,0.,1730,0 37, "LWS01", 3.0, "N", "MWC 922", 18.30742, -13.04833, 1950, 0.,0.,532,38 38, "SWS01", 3.0, "N", "MWC 922", 18.30742, -13.04833, 1950, 0.,0.,956,0 39, "LWS01", 1.0, "N", "OH17.7", 18.46106, -14.51778, 1950, 0.,0.,532,0 <=== spring_launch_targets ===> 1, "LWS01", 3.0, "N", "RS Cnc", 9.12717, +31.16806, 1950, 0.,0.,684,2 2, "LWS01", 3.0, "N", "RS Cnc off", 9.12717, +31.16806, 1950, 0.,0.,524,3 3, "SWS01", 3.0, "N", "RS Cnc", 9.12717, +31.16806, 1950, 0.,0.,956,0 4, "LWS01", 1.0, "N", "W Aql", 19.21156, -7.13556, 1950, 0.,0.,532,0 5, "LWS01", 1.0, "N", "Chi Cyg", 19.81069, +32.78667, 1950, 0.,0.,684,6 6, "LWS01", 1.0, "N", "Chi Cyg off", 19.81069, +32.88667, 1950, 0.,0.,524,0 7, "LWS01", 1.0, "N", "Pi1 Gru", 22.32811, -46.20056, 1950, 0.,0.,532,0 8, "LWS01", 1.0, "N", "R Scl", 1.41108, -32.80139, 1950, 0.,0.,532,0 9, "LWS01", 3.0, "N", "U Cam", 3.62467, +62.48833, 1950, 0.,0.,684,10 10, "LWS01", 3.0, "N", "U Cam off", 3.62467, +62.58833, 1950, 0.,0.,524,0 11, "LWS01", 1.0, "N", "U Ant", 10.54983, -39.30361, 1950, 0.,0.,532,0 12, "LWS01", 1.0, "N", "UV Aur", 5.30925, +32.45917, 1950, 0.,0.,1115,13 13, "LWS01", 1.0, "N", "UV Aur off", 5.30925, +32.55917, 1950, 0.,0.,955,0 14, "LWS01", 3.0, "N", "RX Pup", 8.20783, -41.55500, 1950, 0.,0.,684,15 15, "LWS01", 3.0, "N", "RX Pup off", 8.20783, -41.65500, 1950, 0.,0.,524,0 16, "LWS01", 1.0, "N", "R Aqr", 23.68731, -15.56167, 1950, 0.,0.,684,17 17, "LWS01", 1.0, "N", "R Aqr off", 23.68731, -15.66167, 1950, 0.,0.,524,0 18, "LWS01", 2.0, "N", "UW Cen", 12.67386, -54.15417, 1950, 0.,0.,684,19 19, "LWS01", 2.0, "N", "UW Cen off", 12.67386, -54.25417, 1950, 0.,0.,524,20 20, "SWS01", 2.0, "N", "UW Cen", 12.67386, -54.15417, 1950, 0.,0.,956,0 21, "LWS01", 2.0, "N", "U Mon", 7.47339, -9.67056, 1950, 0.,0.,684,22 22, "LWS01", 2.0, "N", "U Mon off", 7.47339, -9.77056, 1950, 0.,0.,524,0 23, "LWS01", 1.0, "N", "IRAS04296", 4.49453, +34.49806, 1950, 0.,0.,684,24 24, "LWS01", 1.0, "N", "IRAS04296 off", 4.49453, +34.59806, 1950, 0.,0.,524,0 25, "LWS01", 1.0, "N", "AFGL 618", 4.65939, +36.02083, 1950, 0.,0.,532,0 26, "LWS01", 3.0, "N", "IRAS05506", 5.84442, +24.23639, 1950, 0.,0.,532,27 27, "SWS01", 3.0, "N", "IRAS05506", 5.84442, +24.23639, 1950, 0.,0.,956,0 28, "LWS01", 1.0, "N", "HD 44179", 6.29358, -10.61417, 1950, 0.,0.,532,0 29, "LWS01", 1.0, "N", "SAO 96709", 7.22372, +10.08556, 1950, 0.,0.,684,30 30, "LWS01", 1.0, "N", "SAO 96709 off", 7.22372, +10.18556, 1950, 0.,0.,524,0 31, "LWS01", 2.0, "N", "IRAS07173", 7.28950, -17.56139, 1950, 0.,0.,532,32 32, "SWS01", 2.0, "N", "IRAS07173", 7.28950, -17.56139, 1950, 0.,0.,956,0 33, "LWS01", 1.0, "N", "231.8+4.2", 7.66636, -14.59556, 1950, 0.,0.,532,0 34, "LWS01", 3.0, "N", "HD 65750", 7.93181, -58.99028, 1950, 0.,0.,532,0 35, "LWS01", 3.0, "N", "IRAS08351", 8.58531, -46.57083, 1950, 0.,0.,684,36 36, "LWS01", 3.0, "N", "IRAS08351 off", 8.58531, -46.67083, 1950, 0.,0.,524,37 37, "SWS01", 3.0, "N", "IRAS08351", 8.58531, -46.57083, 1950, 0.,0.,956,0 38, "LWS01", 1.0, "N", "IRAS09371", 9.62000, +12.20861, 1950, 0.,0.,684,39 39, "LWS01", 1.0, "N", "IRAS09371 off", 9.62000, +12.30861, 1950, 0.,0.,524,40 40, "SWS06", 1.0, "N", "IRAS09371", 9.62000, +12.20861, 1950, 0.,0.,1730,0 41, "LWS01", 1.0, "N", "HD 101584", 11.64275, -55.29694, 1950, 0.,0.,532,0 42, "LWS01", 3.0, "N", "Boomerang", 12.69856, -54.24722, 1950, 0.,0.,684,43 43, "LWS01", 3.0, "N", "Boomerang off", 12.69856, -54.34722, 1950, 0.,0.,524,44 44, "SWS01", 3.0, "N", "Boomerang", 12.69856, -54.24722, 1950, 0.,0.,956,0