The Journey of the Sun A Virtual Reality Simulation A.J…

   The Journey of the Sun
   A Virtual Reality Simulation

        A.J. Hanson and P.C. Frisch
  Computer Science Department, Indiana University
                       and
     Department of Astronomy and Astrophysics
               University of Chicago

AISRP 2001, John Hopkins University
       Applied Physics Lab
                                                    1
                   Abstract
Give context to the "empty" space around us by re-
constructing and visualizing the Galactic surround-
ings of the Sun and nearby stars, using state-of-
the-art visualization techniques applied to the task
of comparing and interpreting multispectral data
sets.



                                                2
        Goals of Our Work
Virtual Reality Simulation: Support interactive
visualization, modeling, and pedagogical anima-
tion of multispectral data sets.
Science Applications: Apply modeling tools to
Solar neighborhood, Local Bubble, Astrospheres
and Space Motions of Stars and Clouds, and
especially Galactic Weather.

                                           3
              Resources

Software developed under this and other pro-
grams.

NASA and ESA Data Sources. MAST, ADS,
GSFC, NED, ROSAT, etc.

Models and Data from colleagues and individ-
ual databases on the Web.


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         Our Recent Results

Software: VRML DistEdTool, GLUI DistEdTool,
StarViewer, Large Spacetime Scale Navigation,
Movie Animation Tools, Image Alignment Tool.
Hardware Targets: System-independent desk-
top applications, CAVE applications, Elumens
Kiosk, and Video.
Outreach and Education: Produce pedagogi-
cal movies, provide resources for Adler Plane-
tarium
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    Outline of Following Slides

Modeling Methods: Strategy, Kinematics, Stars,
Data Sources
Tool Development: Distance Editing Tool, Star
and interstellar material simulation, Alignment
Tool.
Demonstrations: Editing Tool, Interactive Movie
Scenes.

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        Synthesize 3D Models from
            Multispectral Data
Model distribution of interstellar matter in the Local
Bubble (out to ~500 pc)

   Strategy: Use emission maps to establish 2D
   positions and cloud types, use absorption lines
   in stars of known distance to establish distance
   and physical properties of emission feature.
   Kinematics: Compare 3D space motions of stars
   and clouds for nearby stars.
                                                  7
. . . 3D Models from Multispectral Data . . .

Interstellar (IS) Dust: Reddening of starlight
AV ,
(       E(B-V), E(b-y)), polarization of starlight,
infrared emission, heated dust.
                            2
Molecular Clouds (CO/H ): 1­0 CO rotational
line (115 GHz); survey in galactic plane, se-
lected regions out of plane.
Hot (106 K) plasma: Soft X-ray emission (0.1­
1.5 keV), UV absorp. lines (OIV, CIV, NV, SiIV).
                                                8
. . . 3D Models from Multispectral Data . . .

IS Neutral Gas: UV, optical, EUV absorption in
both lines and EUV continuum. All-sky maps of
 o
H 21-cm emission & absorp. X-ray shadows.
IS Ionized Gas: H   +H     emission (partial ve-
locity data), all-sky radio continuum (408 MHz),
pulsar dispersion, UV absorption.
Stars: Distances, proper motions (Hipparcos),
Nearby stars (Gliese: 3800 stars within 25 pc).

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                  Tool Summary

3D Interstellar Material Modeling
-- Distance Editing Tool --
Project Description       Capabilities
Version 1.0 (VRML)        Utilize stellar spectral lines to deduce
                          intervening gas structure
Version 2.0 (VRML)        Enhanced to support additional data
                          types and formats
Version 3.0 (GLUI)        Essential new features,       improved
                          performance, platform independence,
                          and OpenGL button/box user inter-
                          face
                                                         10
                   Tool Summary . . .

Star Image Rendering and Simulation
Star Viewer        Instrumental and         artistic   imaging
                      characteristics of stars, interactivity
Interactive Visualization at Large Spacetime Scales
Large     Spacetime Support interactive exploration of data
Scale Navigation      exceeding the capabilities of built-in
                     computer graphics hardware
Tools for Registering Data Sources
Image     alignment Place cropped or distorted images at
tool (alpha)          true position, etc.

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                  Tool Summary . . .

Outreach and Educational Materials
Movie animation tools Customize movie path planning and
                        interpolation to overcome limitations
                        of traditional systems. Unique prob-
                       lems for earth-fixed-camera views.
Museum Inter. Graphics Provide interactive versions and
Kiosk Animation         custom enhancements of pre-stored
                        movie   sequences     for   individual
                        planetarium attendees.

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           Tools for Interpreting
           and Visualizing Data
Working inward with large-scale navigation:

   Galaxy -- Data Alignment Tool, Large Scale
  Navigation, etc.
   Local Bubble -- DistEdTool
   Local Fluff -- DistEdTool
   Heliosphere -- Visualize theoretical models
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          Synergistic Activities

Computer Science. Hierarchical Methods in Visualiza-
tion (published). Reports on star rendering and editing
tools (in preparation).
"Solar Journey" & "Cosmic Clock": short pedagogical
computer animations; rendering, modeling, and interac-
tivity enhancements in progress.
Adler Planetarium. Resource provider for "Sun-Earth
Connection" show. Delivered interactive movie software
for adaptation to Elumens kiosks.

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              SUMMARY

Data sets. Assembled, aligned, analyzed local
galactic environment data sets for use in simu-
lations and movies.
Interactive systems. General tools for 3D anal-
ysis, alignment, and interactive movie scenes
at all scales. CAVE applications for very large
scales.

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               Future Work


Distance Editing Tool and Data Alignment Tool
for release to astronomical community
Develop advanced gas and star rendering meth-
ods, incorporate into interactive movie tools
Improve modeling and rendering methods for
"Solar Journey" interactive and film simulations
Modeling and rendering ISM data as a resource
for the NVO.
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Supplementary Appendix Material:




                                   17
Using Multispectral Data to create 3D Model of
    Interstellar Matter in the Local Bubble:
                     Process:

Synthesize the distribution of interstellar matter in
the local Solar environment out to ~500 pc.

   Stars: Place distances on interstellar clouds
   seen in absorption towards stars of known dis-
   tances (Hipparcos data, 10% accuracy at 100
   pc). Sampling interval: 118,000 stars and   ,        one
   star per 0.5 square degree; 20,500 O, A, B, F
                                                   18
stars within 500 pc. (Gliese catalog: 3800 stars
within 25 pc.)
                              +       o
Optical Absorption Data. Ca , Na lines. Put
                                  o
distances on maps of cold ISM (H 21-cm emis-
sion, CO emission, dust infrared emission at
100 m)
UV Absorption Data. Give physical conditions
of clouds identified in optical absorption lines
and multispectral emission data. "Walls" of Lo-
cal Bubble.
UV and EUV Absorption Data. Map distribu-
tion of ISM in the Local Fluff (where column
densities are too low for optical lines or 21-cm
emission).
Ho 21-cm Emission. 2D distribution of clouds
with Log N(Ho) 19.5 cm,2.
CO 1=0 rotational transition, 115 GHz. Distri-
                     2
bution of CO and H molecular clouds, for Log
N(H ) 19.5 cm, .
    2            2
Soft X-ray Diffuse Emission, 0.1­1 keV. Dis-
tribution of supernova remnants and hot (10 K6
plasma, fills 80% space).
UV Absorption Data.      OIV, CIV, SiIV, NV
absorption lines in stars ( 100 pc) give distance
of hot plasma.
H   emission: Gives 2D distribution of warm
( 10,000 K) ionized gas, distances fixed by UV
absorption lines. (WHAM data, Gausted data).
APPENDIX: Data Summary Tables: I




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Interstellar Dust
 V
A , E(B-V), Reddening of starlight     Lucke:1978
E(b-y)
Polarization   Polarization of starlight Leroy:1999
of stars      by interstellar dust
Dust infrared Cleaned all-sky maps Schlegel,
emission       compiled from infrared Finkbeiner,
               and microwave data    Davis:1998
Heated dust    Hot   stars   heating Gaustadvan,
               nearby dust             Bu-
                                       ren:1993
           Data Summary Table II

Interstellar Neutral Gas
N(Ho)          UV, optical,   and FrischYork:1983,
              EUV      absorption Paresce:1984,
              (both lines and EUV Warwicketal:1993,
              continuum)           Diamondetal:1995,
                                   Welshetal:1999,
                                Sfeiretal:1999
Ho 21-cm data All-sky maps with ColombPoppelHeiles:1980,
              cloud velocity, reso- Hartmann:1997
              lution 0.5o
                                                     20
            Data Summary Table II . . .

Interstellar Neutral Gas
X-ray shad- Shadows         in   soft Snowetal:2000
ows -rays      X-ray   background,
               caused by ISM with
               log    N(Ho) 19.5
              cm,2
X-ray   emis- ROSAT        1/4   keV Snowdenetal:1995
sion           PSPC all-sky survey


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Data Summary Table III




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Interstellar Ionized Gas
H+      H All-sky H      emission Haffner,
emission    (northern hemisphere Reynolds,
            with velocities)          Tufte:1999,
                                      Gaus-
                                 tad:1997
Radio con- All-sky 408 MHz emis- Berkhuijsen:1971
tinuum      sion, ionized gas, cos-
            mic ray synchrotron
            emission
Data Summary Table IV




                        23
Molecular Clouds
CO/H2 distri- Galactic plane, high and Dame:1987,
bution       low latitudes                        Magnani-
                                                  etal:2000,
                                                  Hartman-
                                                  netal:1998
Stars
Hipparcos    Distances (10% accuracy at 100       Perryman:1997
catalog      pc) and photometry for 118,000

             stars, or up to one star per   0.5
             square degrees on the sky
Nearby stars Complete catalog of stars Gliese:1991
(Gliese)     within 25 pc (3800 objects
             with small astrometric dis-
             tances)