<=== observer ===> "DWHITTET",\ "Whittet, D.C.B",\ "Department of Physics",\ "Rensselaer Polytechnic Institute",\ " Troy",\ "",\ "",\ "New York 12180--3590",\ "USA",\ "1 518 2768413",\ "1 518 2766680",\ "doug@whittet.phys.rpi.edu" <=== proposal ===> "ICE_BAND", 1, 2,\ {"dust properties",\ "molecular clouds",\ "abundances"},\ {"P. R. Wesselius",\ "SRON Laboratory for ",\ "P.O. Box 800",\ "9700 AV Groningen",\ "The Netherlands.",\ "A. Tielens",\ "NASA--Ames Research ",\ "MS 245--3",\ "Space Sciences Divis",\ "Moffett Field",\ "CA 94035",\ "USA.",\ "Th. de Graauw",\ "SRON Laboratory for ",\ "P.O. Box 800",\ "9700 AV Groningen",\ "The Netherlands.",\ "T. Prusti",\ "Astrophysics Divisio",\ "ESTEC",\ "P.O. Box 299",\ "2200 AG Noordwijk",\ "The Netherlands."} <=== title ===> INFRARED SPECTROSCOPY OF INTERSTELLAR DUST ABSORPTION <=== abstract ===> SCIENTIFIC ABSTRACT The nature and evolution of interstellar dust, and its significance as an active ingredient of the interstellar medium regulating both physical and chemical processes, are key problems in modern astrophysics. It is proposed to use the ISO Short Wavelength Spectrometer (SWS) to investigate a number of key problems relating to the composition, structure and evolution of interstellar dust grains. The proposal is designed to exploit the unique capability of the SWS for high-resolution spectroscopy in the 2.4 to 45 mu waveband. This spectral range contains virtually all of the vibrational resonances arising in solids of astrophysical interest, and includes regions of high telluric absorption which are as yet unexplored. The spectral resolving power of the SWS is ideally suited to the project, allowing investigation of fine structure in the solid state features which provide important diagnostic tests of composition and annealing. A primary objective of the proposal is to determine the abundances of carbon-bearing molecules in grain mantles, including CO2, CH_4, CH_3OH, H_2CO and the nitriles (XCN). A new determination of the ^12C/^13C ratio will be made using the strong resonance of CO2 near 4.3 mu, and we will also investigate the deuterium abundance in the organic component of the mantles. Results will be used to assess the importance of grain surface reactions for gas phase and solid state chemistry in the interstellar medium, and to study the composition and evolution of the mantles. At lower priority, the structure of the silicate component of the dust will be investigated by detailed study of the 9.7 and 18.5 mu profiles. The question of whether interstellar silicates are significantly hydrated will be addressed by means of precision observations in the 2.6 to 2.9 mu waveband. Finally, the region from 25 to 45 mu will be explored in a search for new features. OBSERVATION SUMMARY A total of 31 targets have been selected for this program (Table 1). All have known interstellar dust features (ice, silicates) studied with ground-based telescopes. The proposal uses primarily the SWS: only nominal amounts of time are requested on other ISO instruments. Two SWS AOTs will be used: SWS01 (full 2.4--45 mu grating scans at reduced resolution) and SWS06 (wavelength-selective scans at full grating resolution without F--P). For the SWS06 observations, wavelength ranges have been selected to optimize coverage of important interstellar features at high signal-to-noise, consistent with the available time. The important interstellar resonances fall mostly in the short-wavelength part of the SWS spectral range, but use will also be made of the serendipitous long-wavelength observations that are acquired simultaneously. Sources in which interest focuses mainly on the broad silicate features will be observed exclusively with SWS01, and some bright sources will be observed with both SWS01 (to give ``overview'') and SWS06 (to give profile details of selected features). A summary of the integration times required for each source and AOT is given in Table 2 (Spring launch) and Table 3 (Fall launch). These have been estimated using the SOTE program and fluxes from the NASA Catalog of Infrared Observations and the IRAS Point Source Catalog. The total integration time allocated to the proposal is 20 hours. <=== scientific_justification ===> Sping Launch Team : top 40% second 30% last 30% SWS : 53709 0 19176 Fall Launch Team : top 40% second 30% last 30% SWS : 51990 0 20257 Table 1: Source list, coordinates and launch hole Source name RA (1950) Dec (1950) Other ID IRAS Hole NGC891 02 19 24.5 +42 07 13 02193+4207 W3 IRS5 02 21 53.1 +61 52 20 02219+6152 GL490 03 23 39.0 +58 36 35 03236+5836 Elias 1 04 15 34.6 +28 12 01 V892 Tau 04155+2812 Elias 7 04 26 22.0 +24 26 29 Haro 6-10 04263+2426 HL Tau 04 28 44.4 +18 07 37 L1551 IRS1 04287+1807 Elias 16 04 36 34.4 +26 05 35 04365+2605 O Elias 18 04 36 51.8 +25 39 13 IC2087-IR 04369+2539 O NGC2024 IRS2 05 39 14.3 -01 55 59 05393-0156 O Mon R2 IRS3 06 05 21.9 -06 22 26 N2170 IRS3 06053-0622 O S255 IRS1 06 09 58.4 +18 00 12 06099+1800 O GL961 06 31 58.9 +04 15 09 06319+0415 O GL989 06 38 25.3 +09 32 29 N2264-IR 06384+0932 O OH231.8+4.2 07 39 58.9 -14 35 44 QX Pup 07399-1435 O HR3126 07 55 54.5 -58 59 25 V341 Car 07559-5859 Cha T32 11 06 39.6 -77 23 01 HD97048 11066-7722 NGC4565 12 33 52.1 +26 15 44 12338+2615 Cha II IR 12 49 38.0 -76 50 45 12496-7650 Lynga 8 IRS3 16 15 28.3 -50 17 11 16153-5016 G Elias 29 16 24 07.7 -24 30 40 WL15 16240-2430 G VS17 16 24 28.6 -24 21 00 Elias 33 G Sgr A-W 17 42 29.5 -28 59 17 17424-2859 G W33A 18 11 43.7 -17 53 02 18117-1753 G GL2136 18 19 36.6 -13 31 40 18196-1331 G CK1 18 27 25.2 +01 12 01 SVS20 18274+0112 G HH100 IR 18 58 28.3 -37 02 27 R CrA 18 58 31.6 -37 01 30 18585+3701 W51 IRS2 19 21 22.1 +14 25 12 GL2381 19213+1424 GL2591 20 27 35.8 +40 01 14 20275+4001 Cyg OB2 #12 20 30 53.4 +41 04 12 20308+4104 NGC7538 IRS9 23 11 52.8 +61 10 59 23118+6110 Table 2: Observations for Spring Launch (Orion Region visible). All integration times are in seconds per AOT, merged with overhead. Source name lambda AOT S/N AOT (mum) Time NGC891 3.02--4.05 SWS06 30 2460 16.0--19.5 SWS06 20 W3 IRS5 2.4--45 SWS01 50 1142 4.05--4.55 SWS06 100 1625 5.70--7.00 SWS06 100 19.5--22.5 SWS06 20 25.0--29.5 SWS06 20 GL490 2.4--45 SWS01 50 1142 4.05--4.55 SWS06 100 1572 14.5--16.0 SWS06 100 2.60--3.02 SWS06 20 19.5--22.5 SWS06 20 Elias 1 , , *** Will be observed by Wesselius et al. *** Elias 7 4.05--4.55 SWS06 50 1367 19.5--22.5 SWS06 20 HL Tau 4.05--4.55 SWS06 50 3640 5.70--7.00 SWS06 50 19.5--22.5 SWS06 20 25.0--29.5 SWS06 20 Elias 16 4.05--7.00 SWS06 50 4499 19.5--29.5 SWS06 20 Elias 18 4.05--10.0 SWS06 50 4295 19.5--39.0 SWS06 20 NGC2024 IRS2 2.4--45 SWS01 50 1142 4.05--10.0 SWS06 100 4295 19.5--39.0 SWS06 20 Mon R2 IRS3 2.4--45 SWS01 50 1142 4.05--4.55 SWS06 100 1625 5.70--7.00 SWS06 100 19.5--22.5 SWS06 20 25.0--29.5 SWS06 20 S255 IRS1 4.05--4.55 SWS06 100 1625 5.70--7.00 SWS06 100 19.5--22.5 SWS06 20 25.0--29.5 SWS06 20 Table 2 (continued) GL961 2.4--45 SWS01 50 1906 4.05--10.0 SWS06 100 5878 14.5--19.5 SWS06 100 2.60--4.05 SWS06 20 19.5--39.0 SWS06 20 LWS04 120 CAM01 180 GL989 2.4--45 SWS01 50 1142 4.05--10.0 SWS06 100 4987 14.5--16.0 SWS06 100 2.60--3.02 SWS06 20 19.5--39.0 SWS06 20 OH231.8+4.2 2.4--45 SWS01 50 1906 HR3126 2.4--45 SWS01 50 1906 2.5--12 PHT40 120 Cha T32 , , *** Will be observed by Wesselius et al. *** NGC4565 3.02--4.05 SWS06 30 2959 16.0--19.5 SWS06 20 Cha II IR 2.4--45 SWS01 50 3554 HH100 IR 4.05--4.55 SWS06 100 2064 5.70--7.00 SWS06 100 19.5--22.5 SWS06 20 25.0--29.5 SWS06 20 R CrA , , *** Will be observed by Wesselius et al. *** W51 IRS2 2.4--45 SWS01 50 1142 4.05--4.55 SWS06 100 1625 5.70--7.00 SWS06 100 19.5--22.5 SWS06 20 25.0--29.5 SWS06 20 GL2591 2.4--45 SWS01 50 1142 4.05--4.55 SWS06 100 880 19.5--22.5 SWS06 20 Cyg OB2 #12 2.4--45 SWS01 50 3554 2.5--12 PHT40 120 NGC7538 IRS9 2.4--45 SWS01 50 1142 4.05--10.0 SWS06 100 4987 14.5--16.0 SWS06 100 2.60--3.02 SWS06 20 19.5--39.0 SWS06 20 TOTAL TIME 72885 sec (20.25 hrs) Table 3: Observations for Fall Launch (Galactic Center visible). All integration times are in seconds per AOT, merged with overhead. Source name lambda AOT S/N AOT (mum) Time NGC891 3.02--4.05 SWS06 30 2460 16.0--19.5 SWS06 20 W3 IRS5 2.4--45 SWS01 50 1142 4.05--4.55 SWS06 100 1625 5.70--7.00 SWS06 100 19.5--22.5 SWS06 20 25.0--29.5 SWS06 20 GL490 2.4--45 SWS01 50 1142 4.05--4.55 SWS06 100 1572 14.5--16.0 SWS06 100 2.60--3.02 SWS06 20 19.5--22.5 SWS06 20 Elias 1 2.4--45 SWS01 50 1906 Elias 7 4.05--4.55 SWS06 50 1367 19.5--22.5 SWS06 20 HL Tau 4.05--4.55 SWS06 50 3640 5.70--7.00 SWS06 50 19.5--22.5 SWS06 20 25.0--29.5 SWS06 20 HR3126 2.4--45 SWS01 50 1906 2.5--12 PHT40 120 Cha T32 , , *** Will be observed by Wesselius et al. *** NGC4565 3.02--4.05 SWS06 30 2959 16.0--19.5 SWS06 20 Cha II IR 2.4--45 SWS01 50 3554 Lynga 8 IRS3 2.4--45 SWS01 50 1142 Elias 29 2.4--45 SWS01 50 1906 4.05--10.0 SWS06 100 4295 19.5--39.0 SWS06 20 VS17 4.05--4.60 SWS06 50 9619 5.70--7.00 SWS06 50 19.5--22.5 SWS06 20 25.0--29.5 SWS06 20 Sgr A-W 2.4--45 SWS01 50 1142 2.5--12 PHT40 120 CAM01 180 Table 3: (continued) W33A 2.4--45 SWS01 50 1906 4.05--7.00 SWS06 100 3418 14.5--16.0 SWS06 100 2.60--3.02 SWS06 20 19.5--29.5 SWS06 20 GL2136 2.4--45 SWS01 50 1906 4.05--7.00 SWS06 100 2726 19.5--29.5 SWS06 20 CK1 4.05--4.60 SWS06 50 3838 5.70--7.00 SWS06 50 19.5--22.5 SWS06 20 25.0--29.5 SWS06 20 HH100 IR 4.05--4.55 SWS06 100 2064 5.70--7.00 SWS06 100 19.5--22.5 SWS06 20 25.0--29.5 SWS06 20 R CrA , , *** Will be observed by Wesselius et al. *** W51 IRS2 2.4--45 SWS01 50 1142 4.05--4.55 SWS06 100 1625 5.70--7.00 SWS06 100 19.5--22.5 SWS06 20 25.0--29.5 SWS06 20 GL2591 2.4--45 SWS01 50 1142 4.05--4.55 SWS06 100 880 19.5--22.5 SWS06 20 Cyg OB2 #12 2.4--45 SWS01 50 3554 2.5--12 PHT40 120 NGC7538 IRS9 2.4--45 SWS01 50 1142 4.05--10.0 SWS06 100 4987 14.5--16.0 SWS06 100 2.60--3.02 SWS06 20 19.5--39.0 SWS06 20 TOTAL TIME 72247 sec (20.07 hrs) <=== autumn_launch_targets ===> 1, "SWS06", 3.,"N", "NGC891 ", 2.32347, 42.12030, 1950,0.,0., 2460, 0 2, "SWS01", 1.,"N", "W3 IRS5 ", 2.36475, 61.87220, 1950,0.,0., 1142, 3 3, "SWS06", 1.,"N", "W3 IRS5 ", 2.36475, 61.87220, 1950,0.,0., 1625, 0 4, "SWS01", 1.,"N", "GL490 ", 3.39417, 58.60970, 1950,0.,0., 1142, 5 5, "SWS06", 3.,"N", "GL490 ", 3.39417, 58.60970, 1950,0.,0., 1572, 0 6, "SWS01", 1.,"N", "Elias 1 ", 4.25961, 28.20030, 1950,0.,0., 1906, 0 7, "SWS06", 1.,"N", "Elias 7 ", 4.43944, 24.44140, 1950,0.,0., 1367, 0 8, "SWS06", 1.,"N", "HL Tau ", 4.47900, 18.12690, 1950,0.,0., 3640, 0 9, "SWS01", 1.,"N", "HR3126 ", 7.93181, -58.99030, 1950,0.,0., 1906, 10 10, "PHT40", 1.,"N", "HR3126 ", 7.93181, -58.99030, 1950,0.,0., 120, 0 11, "SWS06", 3.,"N", "NGC4565 ", 12.56450, 26.26220, 1950,0.,0., 2959, 0 12, "SWS01", 1.,"N", "Cha II IR ", 12.82720, -76.84580, 1950,0.,0., 3554, 0 13, "SWS01", 3.,"N", "Lynga 8 IRS3", 16.25790, -50.28640, 1950,0.,0., 1142, 0 14, "SWS01", 1.,"N", "Elias 29 ", 16.40210, -24.51110, 1950,0.,0., 1906, 15 15, "SWS06", 1.,"N", "Elias 29 ", 16.40210, -24.51110, 1950,0.,0., 4295, 0 16, "SWS06", 3.,"N", "VS17 ", 16.40790, -24.35000, 1950,0.,0., 9619, 0 17, "SWS01", 1.,"N", "Sgr A-W ", 17.70820, -28.98810, 1950,0.,0., 1142, 18 18, "PHT40", 1.,"N", "Sgr A-W ", 17.70820, -28.98810, 1950,0.,0., 120, 19 19, "CAM01", 1.,"N", "Sgr A-W ", 17.70820, -28.98810, 1950,0.,0., 180, 0 20, "SWS01", 1.,"N", "W33A ", 18.19550, -17.88390, 1950,0.,0., 1906, 21 21, "SWS06", 1.,"N", "W33A ", 18.19550, -17.88390, 1950,0.,0., 3418, 0 22, "SWS01", 1.,"N", "GL2136 ", 18.32680, -13.52780, 1950,0.,0., 1906, 23 23, "SWS06", 1.,"N", "GL2136 ", 18.32680, -13.52780, 1950,0.,0., 2726, 0 24, "SWS06", 1.,"N", "CK1 ", 18.45700, 1.20028, 1950,0.,0., 3838, 0 25, "SWS06", 1.,"N", "HH100 IR ", 18.97450, -37.04080, 1950,0.,0., 2064, 0 26, "SWS01", 1.,"N", "W51 IRS2 ", 19.35610, 14.42000, 1950,0.,0., 1142, 27 27, "SWS06", 3.,"N", "W51 IRS2 ", 19.35610, 14.42000, 1950,0.,0., 1625, 0 28, "SWS01", 1.,"N", "GL2591 ", 20.45990, 40.02060, 1950,0.,0., 1142, 29 29, "SWS06", 3.,"N", "GL2591 ", 20.45990, 40.02060, 1950,0.,0., 880, 0 30, "SWS01", 1.,"N", "Cyg OB2 #12 ", 20.51480, 41.07000, 1950,0.,0., 3554, 31 31, "PHT40", 1.,"N", "Cyg OB2 #12 ", 20.51480, 41.07000, 1950,0.,0., 120, 0 32, "SWS01", 1.,"N", "NGC7538 IRS9", 23.19800, 61.18310, 1950,0.,0., 1142, 33 33, "SWS06", 1.,"N", "NGC7538 IRS9", 23.19800, 61.18310, 1950,0.,0., 4987, 0 <=== spring_launch_targets ===> 1, "SWS06", 3.,"N", "NGC891 ", 2.32347, 42.12030, 1950,0.,0., 2460, 0 2, "SWS01", 1.,"N", "W3 IRS5 ", 2.36475, 61.87220, 1950,0.,0., 1142, 3 3, "SWS06", 1.,"N", "W3 IRS5 ", 2.36475, 61.87220, 1950,0.,0., 1625, 0 4, "SWS01", 1.,"N", "GL490 ", 3.39417, 58.60970, 1950,0.,0., 1142, 5 5, "SWS06", 3.,"N", "GL490 ", 3.39417, 58.60970, 1950,0.,0., 1572, 0 6, "SWS06", 3.,"N", "Elias 7 ", 4.43944, 24.44140, 1950,0.,0., 1367, 0 7, "SWS06", 3.,"N", "HL Tau ", 4.47900, 18.12690, 1950,0.,0., 3640, 0 8, "SWS06", 1.,"N", "Elias 1 ", 4.25961, 28.20030, 1950,0.,0., 4499, 9 9, "SWS06", 1.,"N", "Elias 1 ", 4.25961, 28.20030, 1950,0.,0., 4295, 0 10, "SWS01", 1.,"N", "NGC2024 IRS2", 5.65397, -1.93306, 1950,0.,0., 1142, 11 11, "SWS06", 1.,"N", "NGC2024 IRS2", 5.65397, -1.93306, 1950,0.,0., 4295, 0 12, "SWS01", 1.,"N", "Mon R2 IRS3 ", 6.08942, -6.37389, 1950,0.,0., 1142, 13 13, "SWS06", 1.,"N", "Mon R2 IRS3 ", 6.08942, -6.37389, 1950,0.,0., 1625, 0 14, "SWS06", 3.,"N", "S255 IRS1 ", 6.16622, 18.00330, 1950,0.,0., 1625, 0 15, "SWS01", 1.,"N", "GL961 ", 6.53303, 4.25250, 1950,0.,0., 1906, 16 16, "SWS06", 1.,"N", "GL961 ", 6.53303, 4.25250, 1950,0.,0., 5878, 17 17, "LWS04", 1.,"N", "GL961 ", 6.53303, 4.25250, 1950,0.,0., 120, 18 18, "CAM01", 1.,"N", "GL961 ", 6.53303, 4.25250, 1950,0.,0., 180, 0 19, "SWS01", 1.,"N", "GL989 ", 6.64036, 9.54139, 1950,0.,0., 1142, 20 20, "SWS06", 1.,"N", "GL989 ", 6.64036, 9.54139, 1950,0.,0., 4987, 0 21, "SWS01", 3.,"N", "OH231.8+4.2 ", 7.66636, -14.59560, 1950,0.,0., 1906, 0 22, "SWS01", 1.,"N", "HR3126 ", 7.93181, -58.99030, 1950,0.,0., 1906, 23 23, "PHT40", 1.,"N", "HR3126 ", 7.93181, -58.99030, 1950,0.,0., 120, 0 24, "SWS06", 3.,"N", "NGC4565 ", 12.56450, 26.26220, 1950,0.,0., 2959, 0 25, "SWS01", 1.,"N", "Cha II IR ", 12.82720, -76.84580, 1950,0.,0., 3554, 0 26, "SWS06", 1.,"N", "HH100 IR ", 18.97450, -37.04080, 1950,0.,0., 2064, 0 27, "SWS01", 3.,"N", "W51 IRS2 ", 19.35610, 14.42000, 1950,0.,0., 1142, 28 28, "SWS06", 3.,"N", "W51 IRS2 ", 19.35610, 14.42000, 1950,0.,0., 1625, 0 29, "SWS01", 1.,"N", "GL2591 ", 20.45990, 40.02060, 1950,0.,0., 1142, 30 30, "SWS06", 3.,"N", "GL2591 ", 20.45990, 40.02060, 1950,0.,0., 880, 0 31, "SWS01", 1.,"N", "Cyg OB2 #12 ", 20.51480, 41.07000, 1950,0.,0., 3554, 32 32, "PHT40", 1.,"N", "Cyg OB2 #12 ", 20.51480, 41.07000, 1950,0.,0., 120, 0 33, "SWS01", 1.,"N", "NGC7538 IRS9", 23.19800, 61.18310, 1950,0.,0., 1142, 34 34, "SWS06", 1.,"N", "NGC7538 IRS9", 23.19800, 61.18310, 1950,0.,0., 4987, 0