The ChaMPlane survey is being conducted at the Harvard-Smithsonian Center for Astrophysics.
apj_appendix

# Grindlay et al., 2005, ApJ, submitted, (astro-ph/?)

## ChaMPlane Data Archives and VO Analysis and Display Tools

We have developed a suite of analysis tools and an on-line database for both the primary
ChaMPlane X-ray data (source catalogs) as well as the optical counterpart data. On-line browse
access to ChaMPlane observations and data is organized by obsID (which can also be found on the
ChaMPlane website, where all observations can be listed and sorted) and provides a very general
and intuitive platform for access to the results. In Appendix Fig. 1 (see
http://hea-www.harvard.edu/ChaMPlane/walkthrough_xray.html) we show a screenshot example of
access to obsID 676, the field originally observed for the BH transient GROJ0422+32. The left
window allows a browse selection of obsID; the middle window enables choice of data return
(e.g. formatted text or rdb tables), while the right most windows are: top, the source catalog
for the field selected (showing X-ray source ID number, RA, Dec, etc. of the sources in that
field); and bottom, the optically identified counterparts for the given source clicked on in
the upper window. Following the link at the end of this paragraph of text in the Appendix
website leads to a walk-through'' tutorial and demonstration of how to create the composite
screen shown in Fig. 1.


Figure 1.
Screenshot from ChaMPlane online X-ray/Optical ID database showing example screens for how source mini-catalogs
and optical ID photometry can be accessed for a given field (e.g., obsID 676 = GROJ0422+32).
The source (srcid'' XS00676B3_008 = source 8 on ACIS-I CCD3) selected in the upper-right-most panel has
its key properties displayed in the lower right panel: ID=Mosaic optical ID, RA and Dec of the ID; fluxBc is observed
flux in Bc band (0.5-8 keV); FBcFr is the observed ratio of X-ray (Bc band) to optical (R band) flux; nHs is full-plane
column density for this source position computed from Schlegel et al (1998); uFBcFr is the UNabsorbed flux ratio
(corrected for nHs for an assumed PL spectrum with PL index 1.7); R, Ha-R, V-R and R-I are the R magnitude
and Halpha excess and broad-band colors of the optical counterpart; error95 is the 95 % confidence radius in
arcseconds of the X-ray source position; match is the offset between the Chandra source and this ID (after boresights
were applied to the Chandra vs. optical image); and sigma is this offset in units of the net error on the X-ray position.
This source is then displayed in the actual X-ray and optical images in Appendix Fig. 2, together with adjacent sources
that are listed in this mini-catalog.

A walk-through to generate this example is provided by following this link.


In Chandra cycle 5, we developed and released a Virtual Observatory (VO) node to facilitate
access and on-line analysis of ChaMPlane data. Database access is via the VO interface in the
image display and analysis package ds9\footnote{http://hea-www.harvard.edu/RD/ds9/}, which is a
major upgrade from the original SAOimage package and allows many new features, including VO. In
general, the user connects through the ds9 toolbar or via any web browser
(http://hea-www.harvard.edu/ChaMPlane/data/archive). Upon connection the ChaMPlane toolbar is
automatically installed on the user's own ds9 running locally on the user's machine. Commands
and results are exchanged between the user's machine and the ChaMPlane data server at CfA
running search and analysis scripts. This setup has the considerable advantage of adding custom
tools and data to an already familiar platform, while maintaining the data archive and analysis
and display tools at a central facility for maintenance and upgrades. A demonstration and link
to a walk-through'' of this ChaMPlane VO facility is given in the following paragraph.


The ChaMPlane VO provides access to our deep Mosaic optical (V,R,I,Halpha) images, catalogs of
their optical photometry, Chandra images with exposure-map correction, X-ray source data and
details of X-ray sources with identified optical counterparts. Images, datatables and plots
(e.g. color-magnitude diagrams)  can be generated for sources detected in any desired region on
the Chandra or Mosaic images. Data can be selected by defining regions with a cursor to overlay
X-ray or optical source positions selected for a given characteristic on either the ACIS or
Mosaic field of view. An example is shown in Appendix Fig. 2 from the source selection shown in
Appendix Fig. 1. Once again, following the link which is on the website Appendix just after
Fig. 2 leads to a walk-through'' tutorial and demonstration of how to create the composite
screen shown in web appendix Fig. 2. We note that as a matter of scientific interest, the two
Chandra sources identified as Halpha objects in web appendix Fig. 2 -- namely, the two sources
with red (Halpha object) source circles and optical source ID numbers overplotted in Fig. 2 on
both the optical Mosaic image (image on left) and the smoothed Chandra image (image on right),
are identified from WIYN spectroscopy (Rogel et al 2005) as a dMe star (optical ID 111135) and
a QSO at z = 1.31 (optical ID 111329), with the (red) wing of MgII at $\lambda$2802 redshifted
into the Halpha filter! Additional ChaMPlane VO tools for interactive inspection of both the
X-ray and optical data are described on a separate link
(http://hea-www.harvard.edu/ChaMPlane/walkthrough_ds9.html) and via the Data Archive/Virtual
Observatory link on the ChaMPlane homepage.

X-ray and optical data are now available on line for the initial 14 fields
in the Anticenter. X-ray and optical images and source catalogs for a given
field or region of the survey will be added to the database when the first
corresponding analysis papers are submitted for publication. Calibrated
V,R,I, Halpha Mosaic images and photometry are submitted in parallel to
the NOAO Long Term Survey archives and CDS; these have already been
archived at NOAO for the initial 14 Anticenter fields.

Figure 2:
Screenshot from the ds9 Virtual Observatory tool (see text)
showing (left) overlay of Chandra sources with optical
counterparts (cyan; optical source ID label above position) on R
band Mosaic image, with ACIS chip boundaries and
chip numbers marked. Optical candidates have been selected for display to
have (Halpha-R) <= -0.2 and labelled (red)
with their optID number (see Appendix Fig. 1).  Chandra sources are
displayed (right) in a smoothed Chandra X-ray
image extracted for the circular region (inside the ACIS aimpoint CCD) on
the Mosaic image, with Chandra sources
labelled by their Chandra source ID in blue and Halpha optical IDs overlaid
in red with their optID labels.
A walk-through to generate this example is
provided by following this link.