China-VO 2006, Guilin

VO Status @ NCU, TW Information From 2MASS Star Count

章展誥 a，高仲明 a,b，彭定弘 a

a. Inst. of Astronomy, Nat’ l Central Univ., Taiwan b. Dept. of Physics and Center for Complex System, Nat’ l Central Univ., Taiwan

Outline VO@NCU,TW Status & Strategy 2MASS Star Count (SC)

Model Data

SIMPLE 2MASS SC Tool Future Work

SC Model TAOS Light Curve DB Publish

Status & Strategy

Be a user rather than a developer Infrastructure

ex: JVO skynode toolkit……etc. Available and suitable VO resources

ex: VOPlot, 2MASS DB…etc. IT Supports

NCHC@TW , ASCC , and CSIE Dept

Science Oriented

So…There we go

2MASS Star Count

What is Star Count

Why the starry sky looks like that

Galactic structure parametersn0, Hr, Hz, Zsun, LF and extinction

0 0

2

0)()()()(

LFdLdrLrnrdFFFN

Motivation IR Sky

What kind of Galaxy Model can describe star count of the IR sky?

Famous Model Bahcall, 1984

Pop. I double exp disk, Pop. II de Vaucoleur halo Gilmore,1984

Bahcall + Pop. intermediate double exp THICK disk

Our Works(1) — Simple Model A Double exponential decay disk, spheroid not included

A Power Law Luminosity Function, L-γ, B0 to M9 No extinction

0.4(γ-1) Cutoff0.60.4(γ-1) Cutoff0.6

HrrHzz eenrn //0)(

pc 350Hz kpc, 3.5 Hr

Our Works (2) — Data 2MASS Point Source Catalog

(SNR > 5, detected in all JHKs band) HTM

~1 square degree, 32768 nodes(JHU HTM package)

Data FittingFind out the structure parameters

Simple VO Star Count Tool Software

JVO skynode 0.4.3 Tomcat 5.x JDK 1.4 above VOPlot

2MASS SC toolhttp://140.115.34.187:8080/2MASSSC

Star Count Cataloghttp://140.115.34.187:8080/skynode

Future Work

VO SC tool with model TAOS time serious data base…

……………if data is suitable for publish

Brief Introduction of TAOS

Taiwan-American Occultation Survey

KBO searching Telescopes How it works ? What we see ? Byproduct – light curve database.

TAOS Telescopes

How does TAOS work ?

What Would We See ?

t=0 t=+1s t=+2s t=+3s

TAOS Byproduct - Light Curve

Hundreds to thousands stars are monitored per night.We have huge and unique light curve database