VOYAGE Virtual Observatory, Yet Another Great Extension ?!

should simulation data be included in a Virtual Observatory ?

Alexander Knebe, Swinburne University

• what ? • why ?

• how ?

…this is all biased towards cosmological n-body simulations

VOYAGE what are (cosmological) simulations anyway ?

what ?

• rotation curves of galaxiesrotation curves of galaxies

existence of Dark Matter DM

• hierarchical structure formationhierarchical structure formation

nature of Dark Matter CDM

• high redshift observationshigh redshift observations

cosmology CDM

testing model using N-body simulations reveals…

(Bahcall et al. 2001)

VOYAGE what determines the model ?

what ?

model fixed ?

ob

serv

atio

ns

ob

serv

atio

ns

• high resolution N-body simulations:high resolution N-body simulations: • observations:observations:

• steep, cuspy density profiles

• hundreds of satellite galaxies

• small disk sizes

• mostly shallow density cores

• only a few satellites observed

• larger disk sizes

what ?

VOYAGE what’s the problem ?

breakdown of CDM paradigm on scales < 1 Mpc ?

VOYAGE time for a VOYAGE ?

i.e., observed number ofsatellite galaxies orbiting

in dark matter halo

more data needed:• from observers• from simulators

why ?correctly measured?

correct models ?

(Klypin et al. 1999)

VOYAGE why should VO be extended ?

simulations are time intensive

simulations contain 6D information: x(t), v(t)

cross-comparison of models possible

let’s pull the strings together:

• problems get solved only by exchange of ideas

• simulators need observers to gauge and improve models

• observers need simulators to calibrate observations

why ?

VOYAGE simulations lead to observations ?!

one ring encompasses it all ?

simulated tidal stream of disrupted satellite galaxy

milky way type dark matter halo

observed stellar stream in own milky way halo

why ?

(Odenkirchen et al. 2003)

(Gill et al. 2002)

VOYAGE a little survey

what code do you use ?

0 20 40 60 80 100

public

own

what analysis tools do you use ?

0 20 40 60 80 100

IDL

own

what sort of data do you store ?

0 20 40 60 80 100

grid

particles

what do you compare your data to ?

0 20 40 60 80 100

observations

others other models

own other models

would you make your data available ?

0 20 40 60 80 100

no

already available

yes

based on questionaire returned by 53 out of 106, Astrophysical Supercomputing Using Particle Simulations,IAU Symposium 208, Tokyo, July 2001 (P. Teuben, astro-ph/0204470)

how ?

VOYAGE has the VOYAGE already begun ?

all in non-compatible data formats,but the data is being used !

VIRGO SCDM, CDM, OCDM, CDM model2563 particles

239.5 Mpc/h box

“Hubble Volume” CDM, CDM model10243 particles3000 Mpc/h box

“COBE grid” 68 (COBE-normalized) models (more than you can poke a stick at…)

643 particles128 Mpc/h box

NEMO data archive collection of links to data releases

plus some more by individual groups…

how ?

VOYAGE can one feed on data alone ?

how ?

MLAPM adaptive multi-grid code (Knebe et al. 2001)

GADGET tree-SPH code (Springel et al. 2000)

HYDRA AP3M code (Couchman et al. 1995)

hierarchical TreeCode ultra-fast (!?) tree code (Dehnen 2000)

PM code simple PM code (Klypin 1995)(incl. analysis tools !)

available codes: (mostly no analysis tools distributed !)

http://astronomy.swin.edu.au/cosmology

most codes are proprietary products !

VOYAGE is there any consistency ?

how ?

The Santa Barbara Cluster Comparison Project (Frenk et al. 1999)

• the oponents

6 Lagrangian codes (particle based)vs.

5 Eulerian codes (grid based)

• the outcome

reassuring but also confusing

• the winner

?

VOYAGE what’s the bottomline ?

how ?

add data

add basic analysis (“simulated observations”)

add software:

codes

analysis tools

VOYAGE is it feasible ?

hmm ?

requires great coordination

requires input from simulators

simulations outdate quickly...

VOYAGE Swinburne’s contribution

!!!

MLAPM is already publically available http://astronomy.swin.edu.au/MLAPM

next MLAPM version will contain on-the-fly analysis

we do have sophisticated visualisation tools for MLAPM data

we do have high-resolution data (cf. Daisuke Kawata’s talk)

we are more than happy to be part of this VOYAGE !

VOYAGE Swinburne’s contribution

!!!

filament fragmentation

C

DM

W

DM

z=5 z=3 z=1 z=0

(Knebe et al. 2003)

VOYAGE Swinburne’s contribution

!!!

streams from disrupted satellite galaxies

(Gill et al. 2002)

VOYAGE Virtual Observatory, Yet Another Great Extension ?!

thank you for your attentionand

bon voyage...

Alexander Knebe, Swinburne University

VOYAGE is there any consistency ?

how ?

The Santa Barbara Cluster Comparison Project

grid based codes

particle based codes

particle based codes

grid based codes

temperature profile entropy profile

(Frenk et al. 1999)

VOYAGE a little survey

what analysis tools do you use ?

0 20 40 60 80 100

IDL

own

what sort of data do you store ?

0 20 40 60 80 100

grid

particles

what do you compare your data to ?

0 20 40 60 80 100

observations

others other models

own other models

would you make your data available ?

0 20 40 60 80 100

no

already available

yes

based on questionaire returned by 53 out of 106, Astrophysical Supercomputing Using Particle Simulations,IAU Symposium 208, Tokyo, July 2001 (P. Teuben, astro-ph/0204470)

how ?

what code do you use ?

0 20 40 60 80 100

public

own

VOYAGE a little survey

what code do you use ?

0 20 40 60 80 100

public

own

what sort of data do you store ?

0 20 40 60 80 100

grid

particles

what do you compare your data to ?

0 20 40 60 80 100

observations

others other models

own other models

would you make your data available ?

0 20 40 60 80 100

no

already available

yes

based on questionaire returned by 53 out of 106, Astrophysical Supercomputing Using Particle Simulations,IAU Symposium 208, Tokyo, July 2001 (P. Teuben, astro-ph/0204470)

how ?

what analysis tools do you use ?

0 20 40 60 80 100

IDL

own

VOYAGE a little survey

what code do you use ?

0 20 40 60 80 100

public

own

what analysis tools do you use ?

0 20 40 60 80 100

IDL

own

what do you compare your data to ?

0 20 40 60 80 100

observations

others other models

own other models

would you make your data available ?

0 20 40 60 80 100

no

already available

yes

based on questionaire returned by 53 out of 106, Astrophysical Supercomputing Using Particle Simulations,IAU Symposium 208, Tokyo, July 2001 (P. Teuben, astro-ph/0204470)

how ?

what sort of data do you store ?

0 20 40 60 80 100

grid

particles

VOYAGE a little survey

what code do you use ?

0 20 40 60 80 100

public

own

what analysis tools do you use ?

0 20 40 60 80 100

IDL

own

what sort of data do you store ?

0 20 40 60 80 100

grid

particles

would you make your data available ?

0 20 40 60 80 100

no

already available

yes

based on questionaire returned by 53 out of 106, Astrophysical Supercomputing Using Particle Simulations,IAU Symposium 208, Tokyo, July 2001 (P. Teuben, astro-ph/0204470)

how ?

what do you compare your data to ?

0 20 40 60 80 100

observations

others other models

own other models

VOYAGE a little survey

what code do you use ?

0 20 40 60 80 100

public

own

what analysis tools do you use ?

0 20 40 60 80 100

IDL

own

what sort of data do you store ?

0 20 40 60 80 100

grid

particles

what do you compare your data to ?

0 20 40 60 80 100

observations

others other models

own other models

would you make your data available ?

0 20 40 60 80 100

no

already available

yes

based on questionaire returned by 53 out of 106, Astrophysical Supercomputing Using Particle Simulations,IAU Symposium 208, Tokyo, July 2001 (P. Teuben, astro-ph/0204470)

how ?