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The ChaMPlane survey is being conducted at the
Harvard-Smithsonian Center for Astrophysics.
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data_archive_.html
ChaMPlane Virtual Observatory
Deep Wide-Field Optical Images, X-ray Images, Interactive
Catalog Search, Source-Region Overlays, Graph Plotting.
Complete Optical and X-ray data for all ChaMPlane fields
are available through the DS9 VO interface . Our initial release contains
14 ChaMPlane fields in the Galactic Plane (anticenter direction: 90<l<270).
We expect to add more data as we progress with analysing
and publishing the results of our primary science mission.
The "virtual observatory" (VO) capability of SAOimage DS9 is being used to
enable detailed online search, display and analysis of our data.
Commands and results are exchanged between the user's machine running DS9
and a powerful server running analysis scripts here at CfA.
A special "ChaMPlane toolkit" is automatically installed in user's ds9, these
send commands routed through CGI scripting. All of the advanced
functionality of DS9 is available to manipulate the results in addition
to those provided by the "Champlane tools" You can select images, compare
them against your own data and images, search our catalogs and display the
results, even incorporate data from other VO sites (e.g. 2MASS & DSS)
all within DS9.
(You can also see the prototype of this system running at the Chandra-ED site)
A Quick Demonstration of the Virtual Observatory
Toolkit
(For those already familiar with DS9)
Typical Use:
Browse our website
to choose a field that you would like to investigate, then open your DS9
VO link for Champlane.
A welcom image willl apppear in DS9 and at the same timeout toolkit is
auto loaded -providing an additional set of
buttons in the analysis menu.
Select "Champlane Tools" from the analysis tool bar. Use the "Field Finder"
tool to open an image of the field you want.
A low res image of the entire Mosaic field is automatically loaded. Then
for example click "show Chandra
ACIS field of view" to see an overlay
of the ACIS chips on the optical image.
With the cursor, the user then selects a region that they want to investigate
further. -Several options are then available!
Foran example
we have extracted X-ray and high resolution optical data
for the inner quadrant of the ACIS-I3 detector (this contains the instrument
aimpoint).
At top left is the optical field with ACIS field of view shown in green,
our region of interest has been selected by drawing a red square region
on the image.
at bottom left the high res optical image of that selected region, and
on the right is the X-ray image.
These same data were then used to show the X-ray contours overlaid
on the deep R-band optical image.
The ChaMPlane archive can be used to overlay positions of detected X-ray
or optical sources.
These can be selected by user defined criteria or preset defaults,
e.g. Halpha emitters with H-R<-0.3
In this example
a small sky region was selected because it contains an X-ray point source
coincident with a
strong Halpha source. The left panel is the high resolution optical
with X-ray and Ha source positions,
on the right is the smoothed exposure-map corrected X-ray image with Ha
source positions for comparison.
Any overlaid marker or region may be selected and a "Champlane Tool" used
to query
the database for sources in that sky area . Flexible constraints can
be applied to the search.
Catalog search results appear in pop-up windows, as shown in this example.
The Interactive Plot tool enables Color-Magnitude diagrams to be generated
for any region, instantly!
In this example two circular regions were selected (green circles) from
the Mosaic image, and separate
CMD
plotted for R vs H-R.
Structure of system means that any region or image generated at any
stage
can be saved or used as a base for further analysis.
Strengths:
Most astronomers are already familiar with DS9 so it wil be easy to
use
Plus it is freely available
software on all platforms.
Only small files are transferred across the web because all intensive
tasks such as image generation and catalog searching are done on a
powerful machine at CfA. Only the commands (literally one line script
calls)
and the results -short tables and images of small sky regions are sent across
the web.
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