Japanese Virtual Observatory JVO

1
Japanese Virtual Observatory (JVO)
National Astronomical Observatory of Japan
(NAOJ) Contact Address adac_at_jvo.nao.ac.jp
We present two demos which show the
current status on construction of Virtual
Observatory in NAOJ. The first program
demonstrates a system which federates the
distributed database system using the GRID
technology. The second one demonstrates a
scientific case of searching for gravitationally
lensed system using the Subaru-XMM Deep Survey
(SXDS) data.
Demo 1 GRID-based database federation
Main Control Window
Column attributes are shown by pushing the
column_info button, where you can also control
the column layout.
Open JVO QL Editor
Write JVO SQL here
The query result is shown up in a result
page, which is a kind of VOTable viewer and
provides an easy access to both the table and
image data. For graphical viewing of the table
data, plotting tool is available. You can specify
any column or expression for X/Y axis.
Demo 2 Scientific Scenario Gravitational Lens
Search
The current JVO prototype can communicates
with four distributed database, Subaru Deep
Field i-band (SDF-i), SDF-z, Subaru XMM Deep
Survey (SXDS), and 2MASS. A main
control window provides you to specify a query
in
This program demonstrates a scientific
use-case of an Japanese Virtual Observatory. In
this demo Gravitation Lens systems are searched
by selecting a pair of two objects which are
closely located and have similar colors. The
corresponding images are also retrieved, so you
can check the morphology of the objects. Color
map is constructed from the images taken at three
bands (B, R, z) to visualize the color type of
surrounding objects, which helps to find a
multiple lens system . A Color-Color and a SED
plot are also drawn, which help to reject a
possible stellar binary which locates at stellar
locus in the Color-Color plot.
JVO Query Language. You can save/load the QL in a
file with the Export/Import button. A QL editor
is opened by pushing the editor button and
provides an easy way to specify search conditions.
The JVO system splits the user input query
into pieces of queries for each database, then
issues search commands to appropriate servers
through a globus-job-submit command of Globus
Toolkit. This example shows a demo doing a
cross-matching search between the two databases
SDF-i and SDF-z. At first a search command is
issued to the SDF-i database server, mizu-g,
then the result is transferred to the SDF-z
database server, minazuki-g, where cross-matching
search is executed. Image requests are issued at
the last two steps.The query results are
transferred through GridFTP in a VOTable format
for table data and in FITS for image data.
On JVO Query Language Editor (shown at
left button of this poster), you can specify
criteria such as separation angle of two objects,
brightness similarity, color similarity, and
parameter range. On Query Result page,
you can check the selected images and colors
visually. You can also download the FITS image
for more precise examination. The order of the
record can be sorted with values of any column.
Pushing the Catalog All button opens a new
window Table Selection which shows a list of
database accessible from the editor.
Checking a catalog and pushing the
selected_table button, a list of tables
included in the database are shown in the same
window. SXDS database consist of 20 object-list
tables and image meta data tables.
Sort with a separation angle
The above three pictures shows images around the
selected objects at B, R and z-bands from left
to right, respectively. The left picture is a
color image which is a compound of the three
bands images. Below are the color-color and SED
plot.
You can enlarge the image appearance by changing
image size here.
A list of columns of the selected table are shown
in the column-list window as below, where you can
chose the columns you want to use for a search.
Pushing the column_save button, the editor is
updated such that you can set restriction
parameters for the selected columns.
This field sets a restriction for a color of R-B
In this example, to search for a distant and
point-like object, restrictions on the
ellipticity and star parameter calculated by
Sextractor is set to 0.00.3 and 0.71.0,
respectively .
0.0
0.3