This form allows you to select tables, specify search constraints and initiate queries. Many of its features are dynamic. In this tutorial we'll work through a series of increasingly complex examples. Detailed screenshots illustrate how you can use the system. If you try these examples you'll get a taste of many of Xamin's capabilities. The Xamin web interface is under development and the appearance can change a little from browser to browser, so the screen shots may be slightly different from what you'll see.
The example queries we'll try are:
Note how the Find matches in... box becomes active as soon as you start typing in the position (or start time) field. Xamin can't 'find' anything until you tell it what to look for. This discovery query takes a little while. It's looking at all HEASARC tables, for each using a default radius appropriate for that table.
In the result pane each row shows a table name, the number of rows matched, and the title of the table. If the table has an associated mission, wavelength regime or if it specializes in a particular class of objects, that's shown too.
Xamin shows the results of each query in a new result pane rather than popping up new browser windows. In only a few cases, e.g., displaying this help page does Xamin actually create a new window in the browser (or new tab if you are using tabbed browsing). You may find maximizing the Xamin window makes it easier to keep track of everything since a lot of panes can be visible at once.
You can sort your results by any column just by clicking on the column headers. The initial default order is just the alphabetical list of table names.
To see the matching rows from a particular table, you can click almost anywhere in the row. We scrolled down a bit and clicked on the chanmaster (1) and got a pane of Chandra results (2) and then clicked on dixon (3) rows which yielded a second query result (4).
The title bars on the panes identify the table that each pane is associated with. These are single table queries of the two tables we picked out at the position of 3C 273.
There's a bit more going on in the results from the Chanmaster table. Each row has a little '+' icon at the beginning. You can expand that to see data products associated with a row. The pane also has buttons on top for selecting the data products associated with selected rows. We show how to download products in the next example.
There are several different approaches to finding tables using the Xamin Tables Explorer:
chanmaster' and we can either finish or click in the list
below. The list is automatically refined as we type in more.
to
open this node of the tree and see what's there. A quick scan shows that
chanmaster lists observations for the Chandra mission.
If we click on the name
we'll see the documentation for that table pop up in the Information pane at the
bottom of the query window. We
can click on the add, 
, icon next to Chanmaster to select that table.
You can also drag the name and drop it into the selected tables box.
Alternatively we might have started with the Missions tree but since there
are currently about 90 tables associated with Chandra it might have been hard
to pick out the right one. Or we could have looked inside Regimes/X-ray, but
there are over 300 of those!
Whenever you see the
, you can
select all of the tables in that node in a single click.
Then you can do
a discovery query on just the selected tables. E.g., you can select all of
X-ray tables and look for which of these have matches to 3c273.
chandra observations in the "Search by keywords" box and hit
return or the Search button adjacent.chanmaster, looks pretty good.
To select a table from the keyword search results, we can click on the icon just
as we did when looking at the category trees.
chanmaster into the selected tables list.
Regardless of what method you use, if you happen to select a table accidentally you can use the delete
icon, 
, or double click on the table name in the
Selected tables tree to de-select it.
Once you've selected the table (1), if you just want matches to a given target or position, enter the position in the position box (2) and click on the Query to ... Table (3) button. We get a new pane with three matching observations (4).
In this example say we're interested in data products for the HETG grating observation. We click on the row we're interested in (1) to highlight it and then ask for data products from the highlighted rows (2) by clicking on the appropriately labelled button. The products cart pane pops up (3) with our selected observation (5). We can ask to download the products as a Tar file (5). Your browser should start its usual dialog for saving a file on your system.
We didn't have to download the products right away. In an Xamin session you can accumulate products from multiple queries (possibly of different tables) and then download data whenever you are ready.
Note, if you wanted to look for specific data products you could either
expand the products for a given row using the 
or use the Limit Products button to select a specific set
of products for each row.
Finally, you don't need to download the data as part of your Xamin session. You can get use the product cart to build a Curl or Wget script which allows you to download the files directly onto your machine. This is the recommended approach for any significant download since it can easily be restarted in the middle if the download gets interrupted for any reason.
First we need to select the appropriate tables for the missions: We
can use any of the methods we tried in the previous query.
Since we are doing two observation tables, using the 'Master
observation tables' tree node may be particularly attractive. The
the Tables Explorer might look like
immediately after we select the rosmaster table. We just dragged the
rosmaster and ascamaster entries into the selected tables area.
Correlations between two complete mission tables are likely to
show a lot of results.
By default Xamin only shows the first 100 rows of results. We want
to see everything, so we go to the Query control menu (1,2) and clear the
Max Rows limit -- or just set it to some very large number (3).
Just click in the box and fill it with a big number or leave it empty. You may need to click somewhere outside the menu to get it to close.
Our first iteration of this query is going to generate almost 20,000 rows of results. The Grid output format we've used so far is not very efficient in handling such large results. Also, the Grid format by default will look for the data products for all of those rows. That could take quite a while too. So if we stay with the Grid format our query is likely to time out.
You can also set the format to Aligned Text and a number of other
formats (e.g., FITS, VOTable, Excel) using the Options/Output Formats menu.
OK... We've dealt with an annoying subsidiary issue. What do we need to do to actually set up the correlation? It turns out that we don't need to do anything. As soon as we select two tables, Xamin sets things up to do the correlation. All we need to do is Query to...Correlate (1). In about 10 seconds we see a new pane pop up(2). It uses a simple text rendering of the results. If you want to set the correlation radius we talk about that a few paragraphs below.
The ASCA columns are at the left of the table prefixed with a. If we scroll right we find the ROSAT columns prefixed wit b. If there were more tables in the cross-correlation we might have c and d prefixes as well.
Simple spatial correlations are fine, but we often want to put additional constraints on the query. E.g., we may only be interested in observations where the ROSAT observation is comparably deep to the ASCA one. To add any constraints to a query, other than position or time, we use the Parameters Explorer.
To open the Parameters Explorer we click on the '+' on the bar where it say "Set Parameters Constraints ..." page. Actually we can click anywhere on that bar (1). This area is available only when we have specified one or a few tables to query. Xamin limits correlations to 4 tables since larger correlations are likely to take a long time (let us know if you'd like to get around this!).
When we click here (1) the Tables Explorer collapses into a single bar, and the Parameters Explorer pops up. Only one of these two can be active at any given time. You can click on the Tables Explorer bar to get it to reappear if you want to change the table[s] you are querying.
The fields of the input tables are listed in the Parameter constraints area. If there are multiple tables, then each parameter is prefixed with a letter, a,b,c, or d corresponding to the 1st through 4th tables. So here a refers to ASCA and b to ROSAT.
At the very top of the Parameters explorer is a yellow line with a bit of mysterious
content ||a,b|| < Dft . This line is the constraint that Xamin added
for us saying that the offset between the rows in table a and and the rows
in table b must be less that some default value -- the value depends
upon the first table and generally represents the size of the observations or the uncertainty of the
positions in that table. The value used is listed at the very end of the query results (in text format
or viewed using the ? tool for a Grid output).
You can edit this field
and replace Dft with any correlation radius that you want -- expressed
in arcminutes.
We'll add two contraints: We want to make sure the ASCA SIS observation is at least twice as long at the ROSAT exposure (2). The constraints we set on a row can include references to any rows in the participating tables, not just constants. We also put a minimum on the ROSAT exposure time (3).
When we re-execute the query (click on Query to... Correlate) the resulting table (2) has only a tenth of the rows of our original table (2). We scrolled to the end of each query to get to the query summary. By the bye, this illustrates one nice feature of Xamin: It's really easy to compare query results with one another since they show up in separate panes. Of course this means that you need to clean up those panes eventually.
Setting up this query requires that we spend a bit of time in the Parameters Explorer area. So we click on the Parameters Explorer bar to bring up that area after we've selected the RASSFSC table.
When we start we see a set of parameters then a red bar (1) and then some more parameters. Fields above the red bar will be displayed, while those below will not. We can specify constraints on any row, displayed or not. We can drag and drop fields (one at a time or in groups) to specify the order in which to display results. We can drag the red bar to add or delete fields from the results (or equivalently drag other fields over the red bar).
Xamin allows users to add new tables to a column. In fact in this example we are going to run a query where all of the output columns are ones we add to the table. To add a column we need to click on the User-defined column button at the bottom right. This brings up a small pane that allows us to define a new column in the table.
We specify a name for the column avg_count_rate and ask for the
average of the count_rate column for each group of rows in the output to be returned in this
column using the SQL avg aggregate function avg(count_rate).
We repeat this for two more columns: The count column is
defined as count(*), the number of rows in each group. Finally we define
a column bii_bin as the largest integer smaller than the Galactic
latitude using floor(bii).
New columns can use a wide variety of SQL expressions and may involve
multiple fields from the input tables.
After we've added all three new columns our Parameter Constraints area looks like:
Our new fields are distinguished by color and are placed, by default at the top of the grid of output rows.
When you use aggregate functions in a query (e.g., avg and count), Xamin takes a look at the query and examines each of the output fields. It finds each of the output fields that are not aggregate functions and creates a query where for each distinct combination of these non-aggregate fields, the fields that are aggregate functions are computed. Consult a manual on SQL for more information on aggregate functions.
We want to compute the average flux in a Galactic latitude bin, so we want to suppress all of the other fields that are shown in a RASSFSC query by default. They would break up our simple latitude bins. E.g., if we left in the name field, then each of the rows that share the same latitude bin would have different names, so instead of one bin for each latitude bin, we'd have a separate bin for every distinct name in each latitude which would defeat the whole purpose of the query. To get rid of the unwanted fields we can drag the red bar from its original location to just under the three rows we've added. Now only these three columns will be returned in the output.
Now we run the query... We get an output table that looks like:
Clearly it would be more useful if we sort the output. We can do that in the Parameter Constraints as well. We enter the sort criterion floor(bii) in the box at bottom left.
When we rerun the query we get the results in an order that makes sense
It would be much nicer to see this graphically. That's easy. Instead of clicking on Query to...Table we try Query to...Plot. A Plot Control pane pops up. This has lots of options, but we just
In a second or two we get a plot of the results.
If you look carefully, you might notice that the plot only seems to run from -90 < bii < 10. Why is that? We mentioned above that by default Xamin only plots the first 100 rows. That's true regardless of whether the output fields are found in the stored table, or generated dynamically as they are here. To get the entire sky we'd need to change this limit as we did in the previous example. There is a checkbox on the plot control pane which allows you to override this limit. You can also go into the Options menu to change the row limits. In recent versions of Xamin, you can also modify the query at the bottom of the query pane.
This almost looks like science. What's going on here? The ROSAT All-Sky Survey is not uniform. It's most sensitive at the ecliptic poles. The ecliptic south pole is at Galactic latitude -30. The north pole is off our plot at +30.
You'll need to specify a name, E-mail and password. When you
are done, click submit and if there are no problems you'll get
You might need to pick another name if someone else already has the
one you tried. The name should begin with a letter and contain only
letters, numbers and the _ character.
After you get this acknowledgement you should receive an E-mail like:
Click on the first URL, or copy it into a browser window
to activate the account. You should see a simple page
Your account is permanent unless you or
the Xamin system administrators delete it. So you only need to
set it up once and you can log in directly in all future Web sessions.
Now you are ready to login. Of course if you already
have a HEASARC services account, you skipped down to here.
Just do Session/Login and enter your name and password.
When you log into your account you'll see a number of capabilities in the session
menu that
used to be grayed out jave become active, notably the Upload (1)
option. The user name in the query
pane title bar should also change to your account name.
Now that you have an account you can save files and use them to
correlate with other tables. Uploads are supported for a few
different formats, notably VOTables, TDAT files (a HEASARC internal
format), and CSV files. The simplest format is a source file
which just has one source name or position per line. Positions
and names can be intermingled on different lines. E.g., a simple
list might be
Abell 1656
10 14 12.9 -38 16 2.4
10.737 +18.29
If you specify positions rather than target names, the coordinate
system is assumed to be whatever is set in the Input Coordinate System
option.
Session/Upload menu. This was one of the options that was grayed
out before we logged in.
When we start the upload, we got a file upload pane. We specified a table name we for how we want to save the table, and specify the file we are going to upload. Xamin will look at the file and determine the file type automatically.
After the file is uploaded we got a notification that the upload was successful.
The uploaded table is now available for queries just like all of the native tables. A tree of User tables is available up in the Table Explorer (marked 1 in the figure below) and or we can enter the name directly (but remember to include your user name as a prefix for the table name).
Now that our table is uploaded, we're ready to do the anticorrelation.
In the examples
we've switched to log into the test user account. That's available to
you to play with (the password is also test) but you can't add or delete
tables from that account, so uploads won't work there. However it already
has a copy of the messier catalog as a user table.
We click on the User tables (1) to open them up. Then select our new table (2). Next we add XMMMaster to the correlation. We just entered it in the direct entry box (3), but you can choose one of the other methods. With both tables selected (4), we selected the Correlation options and indicted that we wanted an anticorrelation(5).
We also decide that we'd prefer to set the cross-correlation offset allowed. We open the Parameters explorer (1), and replace the Dft in the automatically generated correlation constraint with an explicit numerical value in arcminutes. We chose 30 (2). We're doing an anticorrelation, so that means we're asking for all of the rows in our uploaded table for which there is no XMM observation within 30'.
Finally run the query by clicking on Query to ... Correlate (3). We find all of the rows in our list that haven't yet been observed by XMM (4). By scrolling to the bottom of the result we see that almost half, 44, of the Messier objects have never been observed by XMM. You might see a number that's a little less if you try this if XMM happens to have observed a few more since this figure was made.
We can run this query easily enough and see that there over 700 Chandra observations near Messier objects already. We want to know when there are more or when the status of one of the existing ones changes (e.g., when the data is archived).
The first step is to save the results of this query as a user table. We just
click on Query to... Save.
This causes a window to pop up asking us for the name we want to
save the table as, similar to what we had with the upload (but
we don't need to specify the source file).
After we give it the table name the query runs, but no output is
displayed. We just get a confirmation that the table has
been saved.
Our saved table is now ready to be queried itself or perhaps
correlated against another table. To see all of the tables that
you have available in your account
you can click on the Session/User tables-Info option (1)
This brings up a pane that lists all of the tables in your account (see below).
There's also a list of saved query states, but we won't discuss those here.
You can use this window to manage your tables, deleting obsolete ones with
the icon.
However, what we're interested in
is the Offline Checks? column for the tables. We find our
saved table (2) and click on the the Never value set there (3).
This brings up another form that allows us to request that
Xamin check periodically for changes.
We can specify the frequency (4) with which to do the checks, and
also what is to happen if a change is detected (5).
The default action when a change is detected is to send E-mail
and update the table. The next time the check
runs it will only find further changes, not re-notify you about the older
changes.
You can ask only
to be informed of changes leaving your saved the table alone.
That doesn't mean
that you're doomed to getting continual notifications: no check is run if there
hasn't been a change to one of the participating tables since the last check.
You can also ask that the table be updated without notifying you.
Perhaps you want a table of the
100 longest Chandra exposures and you'd like to have it updated
automatically as new observations come on-line.
Make your choices and click on the Update button.
You can reset your choices anytime.
If you want to do a manual check to see whether something has changed,
you can click on the Changed? link for the table. That immediately
reruns the query that generated the saved table and displays any differences.
Note that you can't check for changes in uploaded tables -- although you
can (we did!) use an uploaded table in a correlation query you save and then check. Uploaded
tables are something that's maintained by you not by the server. It only
changes if you change it.
The current grid will redisplayed with only the selected data products shown (4, see figure below). This setting will apply to all future rosmaster results. After the new results are displayed a Product Limits pulldown menu will appear at the top of the Window (5). Entries will be added to this menu for tables that have had their products filtered. To change or reset data product selections find and click the table name in this menu or click the Limit Data Products button in the table results grid.
Wget and curl are included in most distributions of Unix/Linux. Information on wget can be found at the GNU Wget site and on curl at this Curl site.
Many panes are persistent. They can be dismissed and recovered with the same state. Results panes, e.g., tables and plots are not saved and the database must be re-queried to regenerate them if you delete them. You can minimize or hide them if you want to get them out of the way. Table 2.1 summarizes the Xamin panes. Only the major interface panes are shown. Various prompts, errors and acknowledgements also use small popups but their meaning should be clear in context.
A set of Pane control buttons at the very top of the Xamin window is provided to help users manage the primary panes of the interface. When Xamin starts there are three buttons there which toggle the visibility of the Feedback, Query and Products Cart panes. If there is a Plot Control pane another button appears which toggles this visibility of that pane. If there are table, plot results or product selection panes, then menus appear which have entries that allow for toggling the visibility of each result individually and global hide, show and delete options.
| Pane | Initiated by... | Purpose |
|---|---|---|
| Query | Xamin startup | Main window of the interface. Compose and initiate queries. |
| Table | Query to ... Table | Show table results. May show data products. |
| Plot control | Query to ... Plot | Specify plot parameters. |
| Plot | Submit on Plot Control Pane | Show plot results. |
| Products cart | Product selection on Table pane | Filter and download products. |
| Matching tables | Keyword search in Tables Explorer | Show tables matching keyword search. |
| User account | Session menu/User tables-info | Manage user account and tables. |
| Monitor tables | User account pane Frequency column (for saved tables) | Set schedule to monitor query result for changes. |
| Feedback | Panes control | Provide feedback and bug reports |
| Product selection | Table pane/Edit products | Select which product to retrieve for a table |
These options allow you to get information about the query. This
is shown after the query text for text output. It can be viewed in
the grid query by clicking on the ? tool.
Multiple positions may be included in the position box separated by semicolons.
When making queries of tables that have only a single time
specified, Xamin normally looks within 0.5 days of the
specified time for each row in the table.
HEASARC tables may be entered directly. When typing in user names possible completions will be shown and may be selected. HEASARC tables are available through a variety of table hierarchies (alphabetical, by mission, by regime, and by object type). The keyword search will find HEASARC tables whose metadata matches the search terms.
Documentation on a HEASARC table can be displayed in the Information area by clicking on the table name.
You find Vizier tables in the table tree under External/Vizier. You can enter table names directly, or you can use the metadata query to match against Vizier tables. Vizier tables will not be returned in discovery queries.
Many Vizier tables do not have positional columns. Vizier tables support field selection, sorting and simple constraints natively. More complex queries may require the Vizier data to be downloaded into a temporary local table where the complex constraints can be addressed. No data products are associated with Vizier tables.
Documentation for Vizier tables can be displayed in the Information area by clicking on a table or resource name.
Image and spectral services generally provide a link to a single product for each row in the returned results. Since this is a link and not an archive file they cannot be added to the download cart.
VO resources can only be accessed through the table tree in the External/Queryable tables, External/Image services and External/Spectral services entries. These link to services the user the VO Table, Simple Image, and Simple Spectral Access protocols respectively.
No documentation is avaiable for VO tables other than the row documentation available in the Parameters explorer.
No documentation is avaiable for user tables other than the row documentation available in the Parameters explorer.
) or double
clicking on th etable.
The entire set of selected tables can be cleared using the Clear...Tables0
or Clear...All buttons.
If the user selected a sub-tree of tables,
then the entire subtree will be shown in the selected tables
tree, including the branch nodes. The entire subtree may be
deleted by deleting the parent node. E.g., you could select all
of the Observation master tables by clicking on the Add icon
in the available tables tree. A 'Master observation tables'
node will be added to the selected tables tree. Deleting
that node will deleting all of the contained tables.
If no tables are selected the user may make discovery
queries which search all HEASARC tables.
If exactly one table is selected, queries will be made of that table. The user may specify positional, temporal or parameter constraints in the query (using the additional constraints area).
If 2-4 tables have been selected then the user may do either
discovery queries looking for the number of matches for the
specified positions and/or times, or they may do a
correlation of the selected tables. The
Options/Correlations/Correlate Tables menu items controls
which is performed. When correlation parameter constraints
can be levied against any and all of the tables involved in
the correlation. If the Options/Correlate/Anticorrelate flag
is set, then the correlation is an anticorrelation against
the last table selected. E.g., if the selected tables are
ROSMASTER, ASCAMASTER and CHANMASTER, then the result
includes the correlation of ROSMASTER and ASCAMASTER where
no corresponding Chandra observation is found.
If more than 4 tables have been selected then only discovery
queries are supported. [Generally correlations get very slow
when many tables are involved.] Note that user and external
tables are not currently 'discoverable' so that you cannot
determine the number of matches against them using a
discovery query. When doing a discovery query they are
ignored. Only the number of matches against the specified
HEASARC tables will be returned.
The parameters explorer is only available for single table queries or for correlations. It is reset every time you change the selected table or tables. To open the Parameters Explorer simply click on the its title bar. The Parameters Explorer and Tables Explorer share the same space. Only one can be open at a time.
Options/Query control menu.
In a text comparisons a '*' may be used as a wildcard match along with the SQL standard '%'. Text comparisons are generally not case sensitive. A case sensitive comparison may be made in a table by specifying it using an generic constraint unassociated with a particular field.
Users can click on any of the headers to bring up a menu to control which fields will be displayed. In addition to the defaults, the table name, minimum and maximum for each each field are available.
upper() function on both sides of an = operator).expr1[:-],expr2[:-]
where the default direction for each field is ascending. A
:- is appended
to make it descending.
sum(exposure) as the only two
fields we are going to output. Xamin notes your use of an
aggregate function in the new column and groups the output
by any parameters which are not aggregate functions. So you
get one row output for each distinct target name. The
aggregate functions available include count, sum, stddev,
variance, min and max. Rows where the argument of the
aggregate function would be null are omitted from the query.This area is used to display information about tables or classes of tables. If the user clicks on a table entry in either of the table trees or in the keyword search pane, the documentation for that table is shown. If the user clicks on a branch node of a tree, then the information shown depends on the node. Typically if these is a penultimate node, i.e., its children are tables, then a summary listing of the contents will be shown. Tables can be selected from this listing by clicking on the Add icon.
For most grids, mousing over the column headers will show the descriptions given for the columns in the documentation of the associated table. Similarly mousing over the row number at the beginning of each row will show all of the fields associated with that row. This is displayed in a persistent pane that the user must explicitly dismiss.
The data product selection buttons in the results pane allow users to select data products for particular rows or the entire result. If users have expanded a products tree they can select products individually by clicking on the shopping cart icon before a product. Users can directly go to the URL associated with a product by clicking on the product name. After products are transferred to the shopping cart, users can download products using its capabilities.
The products cart has three tabs. The products tab provides a listing of the data products where users can delete products (or jump to them as URLs). This is the only tab in which products may be deleted. Users can delete all products, or just those that have been highlighted (by clicking on them) using the appropriate buttons.
The WGET and CURL tabs allow the user to download scripts that they can run on their machine to access data, but do not allow a user to delete selected products.
Sumbit button on the plot control
pane to generate a plot.
Session/User Tables--Info menu entry.
This pane shows the saved user tables and query configurations.
Session/Upload),
or using the Query to...Save
option to run a query. Saved tables can be used just like system tables
in any query or
correlation. Two saved tables can be correlated against one another.
This delete icon () can be used to delete a saved table. For non-uploaded tables
users can click on the entry in the 'Offline checks?' column to ask that the
system reissue the query and see if it returns the same results. If not then
the user can request that they be mailed a notice of the changes, have the
table updated or both (the default). The 'Changed' link at the end of the row
allows the user to check immediately whether the results have changed, but only
a simple summary will be given.
If the user specifies a table that already exists when upload or saving a table, then the results of the upload or query will be appended to the existing table so long as the query fields are compatible. Otherwise the query will fail.
Session/Save Session
menu. Click on the Apply link to restore the session. Saved configurations can
be deleted by clicking on the delete icon ().
If you name a session 'Default', then that session will be automatically restored when you log in.
A single session can be saved to an browser cookie even without an account.
A product
explorer pane is created when users select the Edit Products
button in grid table result.
A product explorer pane is associated with a specific table or correlation.
Users can select the products they wish to extract from tree of avialable
products. The product selections may be applied to the current query if
the product node was made visible by clicking on edit products for a specific
query and regardless they will become the selection for future queries of the
associated table.
If a plot control pane is available, then a fourth button toggles its visibility. However plot control panes may be deleted. There is never more than one plot control pane which is associated with the last plot request.
There may be many table, plot and products selection panes. If there are
any table results present, then a select box with the name
'Queries' shows. It will have the options 'Show All' , 'Hide
All' and 'Delete All' which will show, hide or delete all of
the table results. These three entries will be followed by a
single entry for each pane. Clicking on this entry will
toggle the visibility of the specified pane. When a pane is
shown, it is also moved to the top of the viewing stack.
Similar select boxes with the name 'Plots' and 'Edit products' will be shown
whenever any plots or product explorer panes are available.
Users can collapse most panes by clicking on the - widget at the top right of the pane. This collapses the pane to just its title bar. The collapse widget changes from a - to a +. To restore the pane, just click on that.
Panes can be dragged anywhere in the browser window. Clicking on a pane title bar will normally move it to the top of the pane stack.
| Token types | |||
|---|---|---|---|
| Type | Description | Example[s] | Heuristic |
| Positions | Numeric positions in sexagesimal or decimal format, multiple positions can be specified. | 10 10 10, 20 20 20.3 10.124,8.763 |
Token sequences that match sexagesimal format or pairs of numbers that have magnitudes < 1000 |
| Target names | Names of targets that can be resolved into positions. If names or positions include spaces they should be enclosed in quotes though sometimes such names can be recognized without quoting. | 'eta carina' '3c 273' 3c273 sirius |
Tokens not otherwise identified are checked using a name resolver. Tokens that are not targets are treated as keywords. |
| Radius | The radius for cone searches. | 10' 30" 1.5d |
A valid number followed immediately by ', " or d |
| Times | Times may be specified in JD, MJD or ISO formats. Time ranges may be given. | 1990-10-10T14:15 50143.276 2003-10-04..2004-10-04 |
String matching ISO time formats. Positive numbers > 10000 are treated as MJD times, (or JD if > 1000000) |
| Coordinate systems | The coordinate system used for input and output | J2000, Galactic, B1950, E2000 | Case insensitive keyword match |
| Table names | HEASARC and Vizier table names | rosmaster I/284 |
Exact match for HEASARC tables, tokens including "/" are assumed to be Vizier tables. |
| Formats | The format for the output of a table query or correlation | Text, Excel, FITS, VOTable | Case-insensitive keyword match |
| Missions | Mission names. These are largely treated as keywords but may be converted to standard form. Multiple missions may be specified as M1|M2|M3 | ROSAT XMM |
Case insensitive match |
| Metadata Keywords | Look for tables that have these keywords in their metadata or description. Only tables that match all keywords will be used. | dwarf novae clusters of galaxies |
Any token that is not otherwised matched which does not seem to be part of a target name is assumed to be a keyword. |
| Constraints | Constraints on the query. If a literal string value is used it must be enclosed in single quotes. | exposure>10 status='archived' |
Tokens containing <,> or = are assumed to be constraints. |
If no tables are specified, but there are keywords, then tables matching those keywords are found and if there are position/temporal constraints a discovery query on the tables matching the keywords is done.
Users are left in an Xamin session using thssh ase standard web interface. Depending upon their inputs they may find themselves with a set of tables matching their keywords, a discovery query result, a single table query or a correlation. They can extend or correct the actions that were taken and do further analysis.