List of Poster Presentations

No.	Name	Presentation title
01	Huan MENG	Preliminary results of Near-miss Occultation Survey for Extinct Comet Candidates
02	Peter VERES	Very close approaching NEAs - population model and survey opportunities
03	Hsing-Wen LIN (Edward LIN)	Observations of Dwarf Planets on Lulin Observatory
04	Melanie KOEHLER	Light scattering on irregular shaped dust particles
05	Pavel KOTEN	Sputtering of high altitude meteors
06	Yung-Ching WANG	The spatial distribution of Sodium on Mercury
07	Torsten LOEHNE	Distribution of Dust in Debris Disks -- A Kinetic Description
08	I-Ling LIN	A re-examination of the thermal models of Enceladus
09	Youngmin JeongAhn	Exciting the Tumbling of NEOs by the Tidal Interaction with Earth
10	Jeonghyun PYO	Ejection of Large Dust Particles from Comet 22P/Kopff
11	Jonathan HORNER	Photophoresis and Cometary Silicates
13	Rachel Smith	Hot dust around Sun-like stars: The importance of detailed modelling
14	Yasunori HORI	The Journey from Jovian Interior to the Solar System and Extrasolar Planets
15	Takayuki MUTO	On The Effect of Poloidal Magnetic Field on Planetary Migration
16	Seiji YASUDA	Three-dimensional thermo-hydro dynamics simulation: Chondrule formation in the shockwave heating model.
17	Kouhei KITAZATO	Photometry and surface mapping of asteroid Itokawa from Hayabusa NIRS observations
18	Arika HIGUCHI	Formation of the Oort Cloud due to the Galactic
19	Hideaki FUJIWARA	The Asymmetric Thermal Emission of the Protoplanetary Disk Surrounding HD 142527
20	Tsubasa FUKUE	EXOTORI'S EMISSION LINES
21	Hitoshi MIURA	Evidence of shock waves in Solar nebula: deformed spherical grains in chondritic meteorites
22	Toru SUYAMA	Compression at collisions of fluffy dust aggregates
23	Chisato OKAMOTO	Experimental Study on Collisional Disruption of core-mantle bodies
24	Toshihiko KADONO	Spin rate of fragments in impact experiments and asteroids
25	Keisuke MURATA	Crystallization-induced peak shifts of IR spectra of olivine
26	Patryk Sofia Lykawka	Trans-Neptunian Region Architecture: Evidence for a Planet Beyond Pluto
27	Kensuke HIRAOKA	Laboratory Experiments of Impact Cratering on Sintered Glass Bead-Silicate Mixture Targets
28	Kenta FUJITA	Demonstration experiment and development of square pupil stellar coronagraph
29	Tsuyoshi TERAI	A survey for the small solar system bodies with wide-field optical images
30	Masato SETOH	Impact Experiments of Sintered Glass Beads at Low and High Velocities
31	Takayuki HONDA	Laboratory study of opposition surge of meteorite chips and powders
32	Shinsuke Abe	Hayabusa and Stardust mission
33	Yukimasa OHSUGI	DSMC method and numerical calculation for wind accretion by DSMC
34	Pedro Lacerda	The Shape and Density of Trojan 624 Hektor
35	Moping Li	Modeling the Astronomical Silicate Mineralogy: On the Effects of Grains Mantles

Preliminary results of Near-miss Occultation Survey for Extinct Comet Candidates

Huan MENG

Since late 2005, we have performed a photometric survey for near-miss occultations by extinct comet candidates and inactive comets at large heliocentric distance to examine their circumnuclear environment for dust evidence. By October 2006, 30 observations of 10 objects have been performed. The currently obtained results include inexplicable brightness induced by the approach of (3200) Phaethon, inconsistent outcomes of 2005 UD, the detection of sunward coma, a jet-like feature and a possible ion tail of Encke at 2.9AU, as well as null results of some other objects.

Very close approaching NEAs - population model and survey opportunities

Peter VERES

The population of small Near Earth Objects of diameters about several meters is still not very well understood. These objects are transition objects between asteroids, comets and meteoroids. We simulated geometric conditions of small close approaching NEAs to the Earth and proposed low cost wide field survey system to be able to discover them. Numeric integration (11 million NEA orbits) was used to reveal geometrical conditions during close approaches. Results implied several opportunities to make some discoveries with such a survey system. Synthetic population model was used to calculate collisional frequency with the Earth and comparison with observational data from DoD satellites and bolide infrasonic detection grid was made.

Observations of Dwarf Planets on Lulin Observatory

Hsing-Wen LIN (Edward LIN)

To provide complementary observations and ground-based supports to space missions to the trans-neptunian objects (TNOs), the Lulin Observatory in Taiwan has started a program to study the time variabilities of several brightnesses of the large TNOs or dwarf planets. Our initial results show that 50000 Quaoar has a significant brightness variation of m = 0.3 with a rotation period of about 18.84 hours while Eris (formerly 2003 UB313) has very little brightness variation (m = 0.05) and its rotation period is hence highly uncertain even though a periodicity of 3.55 hours is suggested by our measurements.

Light scattering on irregular shaped dust particles

Melanie KOEHLER

Radiation pressure force is one of the major force acting on small particles in the solar system. The influence of the radiation pressure force depends on the light-scattering properties of the particles which depend on material composition, shape, structure and size of the grains. In our model calculations we determine the light-scattering properties of aggregates consisting of single spherical monomers where we vary the material composition and the structure of the constituent monomers. The calculations show that the influence of the radiation pressure force on dust particles depends strongly on the material compositions but less on how the material is distributed in the monomers.

Sputtering of high altitude meteors

Pavel KOTEN

Beginning heights and light curves of meteors with beginning height above 130 km we investigated and several proofs for the sputtering model were found. From the meteor light curves is possible to distinguish two different processes that govern radiation of the meteors at different altitudes. Sputtering from the meteoroid surface is the dominating process in the initial part of the meteor luminous trajectory. Around 130 km the ablation starts to prevail. The sputtering model was also successfully applied to explain the difference in the beginning heights of high altitude Leonid and Perseid meteors. Finally, this process in connection with high altitude fragmentation could explain the anomalously high beginning heights of several relatively faint meteors.

The spatial distribution of Sodium on Mercury

Yung-Ching WANG

The surface-bounded atmosphere of Mercury consists of H, He, O, Na, K, Ca atoms, etc. The number density distribution of Na could vary a lot with time and location according to the ground-based observations of the Na D-line emission. We have attempted to simulate both steady-state spatial distribution and density distribution from episodic production of Na atoms under normal solar conditions by tacing Na atoms with ballistic random walks under the influence of radiation pressure and provide a basis for comparison with observations.

Distribution of Dust in Debris Disks -- A Kinetic Description

Torsten LOEHNE

After the early protoplanetary phase, circumstellar disks have lost much of their material or collected it into planets. The moderate amount of solids in these optically thin, gas-poor disks still covers a broad range of sizes from planets down to small dust grains. The main force acting upon this circumstellar material and holding it on Keplerian orbits is the stellar gravity. Small grains below one hundred microns in size are additionally affected by stellar radiation, weakening or overpowering the gravitational bond. The material undergoes a collisional cascade from parent bodies to ever-smaller debris until it is lost to evaporation close to the star or ejection out of the system.

Based on this process, the size and the spatial distribution in debris disks develop characteristic features even if there is nothing but statistically distributed parent bodies and grains. The kinetic/statistical approach used is able to cover a mass range of many orders of magnitude while simultaneously treating radial structure. The Vega disk is used as numerical example.

A re-examination of the thermal models of Enceladus

I-Ling LIN

Enceladus, the inner icy moon of Saturn, is now made famous by the gas plumep and dust jets emanating from its south ple as discovered by the ISS camera experiment on Cassini. A comparison of the temperature distributions from theoretical models and Cassini observations, respectively, indicted strong heat flux in the vicinity of the source region of the dusty gas plumes. At the same time, the low-latitude area of peak surface temperature caused by solar radiation was found to apparently shifted from the predicted location. This effect has prompted us to re-examine the thermal conduction calculations with a range of possible thermal conductivities pertinent to porous materials. The ideal is to check whether the continuous addition of small icy grains in some regions (but not other places) would have some detectable consequences in the global surface temperature distribution of Enceladus.

Exciting the Tumbling of NEOs by the Tidal Interaction with Earth

Youngmin JeongAhn and Seung Soo Hong

Scheeres(2001) ignored change in spin angular velocity of a non-spherical asteroid while it is encountering a planet, and constructed an analytical formulation that would calculate total change of the rotational angular momentum due to the tidal encounter. With his formulation we were able to orient such a mutual orbit that would make dynamic moment of inertia, ID, become minimum for a given trajectory. The spin angular velocity is then allowed to vary in our numerical integrations of the Euler dynamics. Adopting the analytically obtained orientation as a trial start, we will find out its true minimum ID orientation for a large volume of trajectory parameters. This will assess how important the tidal interaction could be for exciting tumbling motions of NEOs.

Ejection of Large Dust Particles from Comet 22P/Kopff

Jeonghyun PYO

We have simulated orbit of large dust particles ejected from Comet 22P/Kopff and synthesized its trail. Planetary perturbations are shown to be important especially for dusts with size larger than centimeter. Comparison of the synthesized trail with the observations determines the dust production rate for the comet to be 4 kg/s, which is within a factor two from the recent estimate (Reach et al. 2006), 2 kg/s, for two dozen comets.

Photophoresis and Cometary Silicates

Horner J., Mousis O., Petit J.M., Wurm G., Krauss O., Alibert Y.

In the study of the final stages of planetary formation, one effect that has been ignored until recently is photophoresis. During the period that the nebula becomes optically thin enough for particles to see the proto-Sun, but still has a reasonable gas content, the photophoretic force acts to push dust grains outward. This provides a mechanism to transport silicaceous material from the inner Solar system to the regions in which the comets were forming. Further, the dust driven outward in this manner will eventually reach a region where the gas pressure is so low that the combined outward forces of radiation pressure and photophoresis balances the inward effects of gas drag (as opposed to closer in, where photophoresis and radiation pressure would be more effective than gas drag). For a given nebula model, this leads to a 'pile-up' of dust at around 50 Au (with size differentiation such that larger particles are stable closer to the Sun than their smaller brethren). Finally, as the gas continues to disperse, the equilibrium point moves back inward, reaching a distance of around 30 Au before the nebula is wholly dissipated.

Such a process would lead to an influx of silicates in the region of the forming Edgeworth-Kuiper belt, which could, effectively, result in 'dust-loading' of these bodies. Comets which had already been ejected from the regime of the outer planets into the Oort cloud could, conceivably, have missed this excess dust. Any comets still forming in the Outer Solar system (between Jupiter and Neptune) during this period would, of course, be swept by this outward moving dust belt, but would presumably acquire less dust than those in the 30-50 Au range, where the belt reaches its temporary equilibrium.

This model suggests that comets which originate in the Edgeworth-Kuiper belt should be observed to contain some fraction of material which formed well within the ice-line (such as the crystalline silicates), along with suggesting that a fraction of Oort cloud comets (in particular those ejected early on) should contain a much smaller mass-fraction of such material. The existence of Olivine and CAIs in the ejecta from Comet Wild 2 (found by the Stardust mission) can easily be explained by this model. Also, photophoresis offers an alternative explanation for the measurement of a surprisingly high dust/ice ratio in Tempel 1 (from the Deep Impact collision) - if objects in the Edgeworth-Kuiper belt suffered the proposed dust loading, this could easily contribute to such a dust excess.

Hot dust around Sun-like stars: The importance of detailed modelling

Rachel Smith

Studies of the debris disk phenomenon have shown that most systems are analogous to the Edgeworth-Kuiper belt. Recent observational studies have revealed a rare subset of Sun-like stars that possess dust which lies, in contrast,in the terrestrial planet region. We carried out an observational programme to investigate the occurence of this warm dust around Sun-like stars and compared the results to a simple analytical model. We find that for most of the confirmed sources in the sample, comparison to analytical modelling suggests an asteroid belt-like region in collisional equilibrium is unlikely to be the source of the emission. However, the simplifying assumptions made in this modelling may result in a misrepresentation of the evolution of such a cascade in the model predictions. A more detailed numerical model has been developed, and the results compared with the predictions of the analytical modelling to test the validity of the conclusions drawn.

The Journey from Jovian Interior to the Solar System and Extrasolar Planets

Yasunori HORI

The formation process in the Solar System has been veiled to attract us. One approach to its scenario is to determine the core mass of Jupiter [Mcore]. The latest planetary models that are consistent with observational properties suggest Mcore should range from 0 to 10 Mearth. Too extensive constraint has prevented us from understanding our system. It mostly results from uncertainties of equation of state for hydrogen, not to mention problems due to observational accuracy.

My poster will explain backgrounds mentioned above in detail and show you how we're trying to break through these problems, including our laser experiments.

On The Effect of Poloidal Magnetic Field on Planetary Migration

Takayuki MUTO

Planetary migration is the radial motion of protoplanets due to the gravitational interaction between protoplanets and circumstellar gas. Recent work has shown that when a protoplanet of an Earth mass is formed at 1AU, it falls towards the central star before the dispersal of the protoplanetary disk.

In order for protoplanets to survive, some mechanism should act to stop the infall. Recently, it has been shown that toroidal magnetic field may stop the inward planetary migration under a certain condition, so magnetic field should be important in planetary migration. In this poster, the effect of weak poloidal magnetic field is invesitgated.

Three-dimensional thermo-hydro dynamics simulation: Chondrule formation in the shockwave heating model.

Seiji YASUDA

In the shock-wave heating model, which is considered to be one of the most plausible models for chondrule formation, dust particles are heated by the gas frictional heating. So it is easily expected that the dust particle starts to melt from surface to inside. Additionally, due to the ram pressure of the fast gas flow, the liquid part is considered to strip from the solid part (Kato et al. 2006, Kadono and Arakawa 2005) In order to examine the heat evolution of the dust particle and the dynamics of the liquid part, we report the calculation code of the three phase mixed three-dimensional thermo-hydro dynamics.

Photometry and surface mapping of asteroid Itokawa from Hayabusa NIRS observations

K. Kitazato, B.E. Clark, M. Abe, S. Abe, Y. Takagi, T. Hiroi, O.S. Barnouin-Jha,
P. Abell, and F. Vilas

The near-infrared spectrometer (NIRS) on the Hayabusa spacecraft had observed the disk-resolved bidirectional reflectance spectra of the asteroid 25143 Itokawa between September 12 and November 24, 2005. Spectra were obtained over a range of phase angles from near 0 to 38 degrees, which allowed constructing a photometric model of the asteroid surface. A strong opposition surge at low phase angles and phase reddening were detected. After a photometric correction of the spectral data using Hapke modeling, we produced an albedo map on Itokawa's surface and found a nearly 10% of albedo variation derived from space weathering, thermal metamorphism, and/or particle size.

Formation of the Oort Cloud due to the Galactic

Arika HIGUCHI

The standard scenario of the formation of the Oort cloud consists of two dynamical stages: (1) giant planets raise the aphelia of planetesimals to the outer region of the solar system and (2) external forces such as the galactic tide pull up their perihelia out of the planetary region and randomize their inclinations. We show the orbital evolution of planetesimals due to the galactic tide. Using the secular perturbation theory, we derive the motion of the planetesimals analytically. We find that the galactic tide raise perihelia and randomize inclinations of planetesimals with semimajor axes larger than ~1000AU in 5G years.

The Asymmetric Thermal Emission of the Protoplanetary Disk Surrounding HD 142527

Hideaki FUJIWARA

Mid-infrared (MIR) images of the Herbig Ae star HD 142527 were obtained at 18.8 and 24.5 micron with the Subaru/COMICS. Bright extended arclike emission (outer disk) is recognized at r=0.85''(=170AU at the distance of HD 142527) together with a strong central source (inner disk) and a gap around r=0.6''(=120AU) in both images. In this poster, we examine the properties of the MIR-emitting dust in the disk, and propose an inclined disk model, which can successfully account for the MIR observations as well as the previous near-infrared images of the scattering light.

EXOTORI'S EMISSION LINES

Tsubasa FUKUE

Emission line profiles of an optically thin emitting torus in an extrasolar system are investigated with model calculation. When the torus's rotational velocity is larger than the thermal motion and the inclination angle is high, emission lines have the double peak. The dip due to the exomoon's occultation on the emission line can be periodically shifted as the exomoon orbits, and it resembles the Rossiter-McLaughlin effect. The torus is not necessary to be spatially resolved from the central object of the torus. The emission lines are on torus-host's spectrum, with the double peak, anomalous forbidden lines or ionized species.

Evidence of shock waves in Solar nebula: deformed spherical grains in chondritic meteorites

Hitoshi MIURA

In chondritic meteorites, there are the evidences that millimeter-sized silicate dust particles in the Solar nebula were heated and melted in the supersonic rarefied gas flow (shock-wave heating model). We considered the deformation of molten dust particles in the gas flow by using the three-dimensional hydrodynamic simulation. We found that the rotating molten droplet deforms to prolate shape and its shape is very similar to the prolate chondrules found in chondritic meteorite. Our results suggest that shock waves have been generated by some mechanism in our Solar nebula when the mm-sized dust particles evolves in it.

Compression at collisions of fluffy dust aggregates

Toru SUYAMA

Planets are formed from dust aggregates in protoplanetary disks. Dust growth is important for planet formation. Dust aggregates grow through mutual collisions. At collisions, aggregates would be compressed. Such compression changes their cross section and strength. In this study, we perform N-body simulations of dust aggregate collision. In our simulation, aggregates grow through collisions between the same aggregates. Repeating such simulations of aggregate collision, we examine compression of growing aggregates. As aggregates grow, the density decreases to a certain value which depends on the collisional velocity. From our results, we discuss how aggregates are compressed.

Experimental Study on Collisional Disruption of core-mantle bodies

Chisato OKAMOTO

A lot of experimental data (e.g. fragment velocity and largest fragment mass) on impact disruption have been presented by previous studies for homogeneous materials such as basalt and ice. But we do not have any experimental data on the collisional disruption of core-mantle bodies. So, we use a two-stage light gas gun set in Nagoya University and investigate the collisional strength and fragment velocities of core-mantle targets in order to clarify the difference of reaccumulation condition between homogenous targets and core-mantle targets.

Spin rate of fragments in impact experiments and asteroids

Toshihiko KADONO

The spin rates of fragments in impact experiments have been discussed based only on the data of "observable" fragments mainly from target surfaces. Using plate targets, the spin rates of most fragments can be measured. We extrapolate the relation between the size and spin rate of fragments obtained by the experiments to asteroid sizes. The extrapolated values well agree with the observational results of the member of Karin family and fast rotators. This indicates that the relation between the spin rate and size obtained by the experiments implies the initial condition of the spin rate of monolithic asteroids.

Crystallization-induced peak shifts of IR spectra of olivine

Keisuke MURATA

Characteristic 11.2 micron band of olivine has been observed around circumstellar environments of evolved and young stars and comets. Olivine crystals can form by annealing of amorphous grains. We measured IR spectra of olivine contained in the heated amorphous silicates, and Mg/Fe ratios of the olivine crystals by X-ray diffraction. The peak position of the 11.2 micron feature, the most diagnostic feature of olivine in mid-IR observations, shifts due to not only the Mg/Fe ratio but also crystallization process. Our spectral calculations also indicate that the 11.2 micron feature is sensitive to anisotropy of each crystal axis of forsterite.

Trans-Neptunian Region Architecture: Evidence for a Planet Beyond Pluto

Patryk Sofia Lykawka

Trans-Neptunian objects (TNOs) carry precious information about the origin of the solar system. TNOs orbit in two reservoirs, the Kuiper belt (30-48AU) and the scattered disk (>48AU). Main results: 1) There are five dynamical classes: centaurs, resonant, classical, scattered and detached TNOs; Resonances cannot explain the origin of detached TNOs; Stable resonant TNOs are found at 30-107AU. 2) The origin of long-term resonant TNOs beyond 50AU suggests the primordial planetesimal disk extended to 45-50AU and suffered an orbital excitation before planet migration. 3) A massive trans-Plutonian planet (0.3~0.5MEarth) can explain the ancient Kuiper belt excitation, formation of detached TNOs and many other features.

Laboratory Experiments of Impact Cratering on Sintered Glass Bead-Silicate Mixture Targets

Kensuke HIRAOKA

A strength dominated cratering continues until when the target strength becomes higher than the stress caused by impact, which propagates from impact site with attenuation. Since the cratering on brittle materials depends on both compressive and tensile stress, we must measure the compressive and tensile strength of target. We performed impact cratering experiments on sintered glass bead-silicate mixture targets. Both compressive and tensile strength of glass bead-silicate mixtures were measured with changing silicate content at low strain rate by uniaxial compression and Brazilian test, respectively. We will compare the results of previous work.

Demonstration experiment and development of square pupil stellar coronagraph

Kenta FUJITA

I present the results of the laboratory experiments of the square pupil stellar coronagraph in visible wavelength. The primary aim of this work is to demonstrate the coronagraphic performance of the square pupil stellar coronagraph. The experiment is demonstrated without a vacuum, a wavefront control, and telescope structure. Experimental results show that the closer and wider region can use for the faint object survey by the square pupil stellar coronagraph relative to a classical lyot coronagraph, for both monochromatic and polychromatic light.

A survey for the small solar system bodies with wide-field optical images

Tsuyoshi TERAI

We search the small solar system bodies with two images as a pair to make use of the data by other observations than surveys for small bodies. We have developed an automatic detection program since it makes the analysis fast and have found about 500 asteroids and more than ten TNOs with the data by Suprime-Cam. If the cumulative size distribution obtained by them follows power-law, its slope parameter with the diameter from 0.4 to 4 km agrees with past researches well.

Impact Experiments of Sintered Glass Beads at Low and High Velocities

Masato SETOH

Porous structure is common in asteroids and satellites of outer planets. In order to study the relation between structure of the small bodies and their thermal and collisional evolution, we prepared porous sintered targets and examined mechanical responses of them.

The various sintered targets were prepared by controlling sintering temperature and duration. Density, porosity, longitudinal velocity, and compressive strength were measured. Collisional disruption of these targets by both of low and high impact velocities were carried out. We compared our results with previous studies.

Laboratory study of opposition surge of meteorite chips and powders

Takayuki HONDA

Recently, it was shown the opposition surge, which appears in small phase angles in scattered light from Surfaces of small bodies such as asteroids, appears on scattered light from surface of rocks.In this study, we performed measurements of scattered light from rock chips and particle layers at low phase angles to focus on clarifying factors of differences from each opposition surge. Measurements were performed using a multi phase angle near infrared spectrometer at Kobe University with the incident angle fixed at 2 degree and the phase angle varied within 0-25 degrees. We will show the results of several types of bulk chips and particle layers, and will discuss on three factors that can make difference in opposition surge.

Hayabusa and Stardust mission

Shinsuke Abe

Hayabusa is the first spacecraft to visit one of the small (diameter of about 300 m) near-Earth asteroid, 25143 Itokawa, that startlingly made the most important asteroid mass and compositional determinations since NEAR mission explored an asteroid 433 Eros. Our results clearly showed the rubble-pile structure. I will present about Itokawa's mass density and interior structure.

On January 15, 2006, an airborne observatory NASA DC-8 was flying at the eastern edge of the Nevada state line to observe an artificial meteor formed by the Stardust Sample Return Capsule(SRC) during entering Earth's atmosphere. I will present a first result of UV spectrum of an artificial meteor with the optical image. The details of physical and chemical processes of SRC compared with natural meteors will be discussed.

DSMC method and numerical calculation for wind accretion by DSMC

Yukimasa Ohsugi

DSMC(Direct Simulation Monte Carlo) is one of explicit methods. We verified accuracy of this method by calculation for shock tube problem and Couette flow. This time, we adopted that one about simulation of wind accretion. Wind accretion is accreting flow phenomenon around massive compact star in close binary system with OB star as companion object. Numerical result is good for that calculation, and we found the strong point of this method.

The Shape and Density of Trojan 624 Hektor

Pedro Lacerda

We present a Roche binary model of the shape of Jovian Trojan 624 Hektor. Our simulations select the binary model whose lightcurve best matches rotational data for 624 Hektor taken at four observational geometries between 1957 and 1968. Together with the spin period, the best fit shape provides an estimate of its bulk density. We find that 624 Hektor is well described by Roche contact binary model density 2480(+292,-80) kg m^(-3).

Modeling the Astronomical Silicate Mineralogy: On the Effects of Grains Mantles

Moping Li

We investigate the effects of grain mantles composed of water and carbonaceous materials along the sight line towards Galactic Center (GC) in deriving silicate mineralogical composition by calculating the absorption cross section spectrum in terms of silicate core-ice mantle dust model with various dust shapes. It is shown that at least 5% crystalline silicates are hidden by the grain mantles. Therefore, the observation along the line of sight toward the GC is inappropriate to investigate the mineralogical composition of dust and determine the crystallinity of silicates in the diffuse ISM since the ISM in this sight line has been contaminated by various identified ice mixtures.