Finder Chart: Catalogs

Note that catalogs are available in two ways: (1) from the front page, via your initial search, or (2) via a blue tab at the top of the page. You can choose from any of a wide variety of catalogs for overlaying on your visualized data.

What is potentially confusing here is that, from the main search page, you could conceivably stumble into having (1) nothing overlaid; (2) only the central source overlaid, so it looks like nothing is overlaid; (3) so many sources overlaid that you can't see the image. From the layers pop-up, you can control which of these loaded catalogs are shown on the selected image (and in which colors, and what symbol shape); see the visualization section.

Contents of page/chapter:
+Initially Searching on Catalogs - Catalogs from the Search Page
+Catalogs from IRSA -- Overlaying catalogs from IRSA
+Catalogs from disk -- Overlaying your own catalogs
+Catalogs from VO -- Overlaying catalogs obtained via the VO
+Catalog from NED -- Overlaying catalog from NED
+Columns and filters -- Interacting with catalogs
+Plotting catalogs
+Example of catalog plots #1: Catalog pulled after searching
+Example of catalog plots #2: Catalogs pulled during initial search

 

Initially Searching on Catalogs - Catalogs from the Search Page

From the main search page (for more information, see searching), you can ask it to "Search Corresponding Catalog(s)." Specifically, you can ask for all the sources in the corresponding catalogs within the image boundary, or just within a certain search radius. You can further constrain it by selecting "One to One Match" -- in this case, it will find just the closest source to your position within your selected search radius, and only that closest source.

If you search on catalogs from the search results page, then Finder Chart will overlay these catalogs on your images as additional layers. These catalogs behave in the same way as the catalogs described in the rest of this section.

However, if you search on catalogs from the main search page, Finder Chart overlays the catalogs on your images right away, and it does so in a way that is quite powerful, but may be initially confusing. In order to understand what it is doing, you need to use the visualization tools, so there is more information (including an example) in the Visualization section. Critical to understanding what it is doing (and how you can change it) is the concept of the "selected image" -- different things are overlaid on different images (and image sets), and your choices change depending on which image you have selected. If you choose to search the catalogs just over a small radius, and/or further constrain it to just find the closest source (one-to-one match) to your target, the overlays of the catalogs will (presumably) all be over the same, single source, and it will be much less clear that the catalogs are overlaid at all, much less that the catalogs are different on each set of images. But, it is behaving in the same way.

Catalogs from IRSA

By clicking on the blue "Catalog" tab, a window appears with several options, as follows.

In the upper left of the window, you specify the catalog you want to search. In order to help it give you a specific list of choices, you need to first tell it the project (default: WISE) and category (default: AllWISE Database). After you have selected these items, right below those choices, you then pick the specific catalog (default: AllWISE Source Catalog). To change catalogs, first select the "project" under which they are housed at IRSA, such as 2MASS, IRAS, WISE, MSX, etc. The options under the "category" and the specific clickable catalog change according to the project you have selected. A short description is provided for each of the catalogs, with links for more information (including definitions of the sometimes cryptic column names); an example of this link for more information is here:

In the upper right is the search target and search region. By default, it pre-fills your search target to match your most recently searched target. To change the target, simply enter the new coordinates in the search box, with all the same options as searching Finder Chart in general. Next, choose your search shape ("Search Method") from the pulldown; the options below the search method change accordingly (and sometimes the target vanishes, when it is not relevant):

You can also tell it that you want specific columns returned and/or set restrictions on values in specific columns by using the table near the bottom of the window. You can choose what to display (standard or long form; 'standard' may omit some columns used less commonly), and filter what is returned (for example, only return objects with values in column y that are greater than x). You can also impose additional constraints in SQL. If you add more than one restriction, they are combined logically using an "AND" operators. Be careful, because you can thus restrict data such that none of the catalog meets your criteria.

Power user tip: By default, it may show you fewer columns than are available in the full catalog. By selecting "long form", you can access the full range of available columns. In some cases, there are literally hundreds of columns that you can access!

Click on "Search" to initiate the search. It will load the catalog into a tab of its own on the bottom left of the screen (in the catalogs window pane) and make a plot (see below) on the bottom right. The catalog objects will also be overlaid on the images you have loaded. The image and the plot and the catalog panes are interlinked -- clicking on a row in the table shows it on the image and plot; clicking on a source in the plot shows it in the image and table; clicking a source on the image shows it in the plot and table.

To close the catalog search window without searching on a catalog, click on "cancel" in the lower left.

On the speed of the catalog results...

If the catalog search is successful quickly, it will promptly return the results in a tab of its own.

NOTE THAT the search may take a long time to return, especially if you have asked for a large catalog, and you may think that nothing has happened, but be patient.

It may give you the option to put the catalog search in the background monitor (from which you can load it into a tab), or return a tab directly. If you do ask it to put it in the background monitor, the monitor will dynamically update to reflect its status, and will let you know when the catalog is ready to download or display. You may ask it to email you when it is ready. A popup appears asking if you want to load the catalog. Either click on the popup or explicitly open the background monitor and click on the catalog name to load it into a tab of its own.

Use large search radii with caution! Be sure you have a sense of how many sources you are likely to retrieve. Searches that retrieve more rows will take longer. Searches that retrieve thousands or tens of thousands of rows will take quite a while.

Note that if you overlay a catalog consisting of tens of thousands of sources, if you then save a regions file from the catalog overlay, then you will end up with only the first 500 sources from the full catalog in the regions file.

Loading your own catalogs

By clicking on the blue "Catalogs" tab, you are by default dropped into the interface for searching for catalogs at IRSA. However, you can pick another tab from the top, "Load Catalog", to load your own catalog, either from disk or from the IRSA Workspace.

Your catalog needs to be in IPAC table format, which is a varietal of plain text. IRSA has a table reformatting and validation service which may be helpful, or you can download just about any catalog you find through IRSA, and copy that format.

Your table file MUST have RA and Dec values, and unless it is specified, it assumes J2000.

You can add a "SYMBOL" parameter to change the shape (X, SQUARE, CROSS, EMP_CROSS, DIAMOND, DOT) of catalog marks, e.g.:

\SYMBOL = X

You can add a "DEFAULT_COLOR" parameter to assign a CSS color name or a HEX value to catalog marks, e.g., either of these two:

\DEFAULT_COLOR = lightcyan
\DEFAULT_COLOR = #00FF00
You can find the CSS color code or the CSS color HEX values online.

Your catalog is then shown (and interacted with) in the same way as the other catalogs described here.

Catalogs from the VO -- Overlaying catalogs obtained via the VO

(VO= Virtual Observatory.)

By clicking on the blue "Catalogs" tab, you are by default dropped into the interface for searching for catalogs at IRSA. However, you can pick another tab from the top, "VO Catalog", to search for and load catalogs from the VO.



As for the IRSA catalog search, the tool pre-fills the target position with the coordinates of the target with which you have been working. In this case, you are limited to a cone search, so the next option is the cone search radius. As usual, pick your units from the pulldown first, and then enter a number; if you enter a number and then select from the pulldown, it will convert your number from the old units to the new units. There are both upper and lower limits to your search radius; it will tell you if you request something too big or too small.

If you know your VO URL already, you can jump down to the Cone Search URL box and type or paste your URL into the box and hit search.

More commonly, however, users do not know a priori which URL to use. Click on "Find Astronomical Data Resources" to be droped into a VO search. Find the URL corresponding to the catalog you want, copy it, and go back and paste it in the URL box. The URL should not have the RA and Dec in it; the tool will add your RA and Dec as listed to the URL in the right syntax. Click on "Search" to initiate the search.

The search results are then shown (and interacted with) in the same way as the other catalogs described here.

Example

Load the tool. Search on IC1396. Go to the catalogs tab. Choose "VO Catalog." It wants the root URL for a cone search. I click on "Find Astronomical Data Resources", which takes me here. Search on IPHAS. Get this page. Look for the complete catalog release (not just one associated with one specific study). The name of the catalog goes here. Hit the [+] to expand it. There is one URL listed there, under "available endpoints for the standard interface." Copy that URL and paste it into the search form. The IRSA tool will append your coordinates and radius and return you a table.

Troubleshooting

Note that searching the VO means that you are using resources not specifically housed at IRSA, so servers may be down, or timeouts set, or limits on numbers of returned sources, etc., that are beyond our control. In most cases the solution is to specify as precise a search as possible. The URL you enter into the box in Finder Chart must be a Cone Search base URL (not containing RA and Dec parameters, which are inserted into the URL by the tool in response to the search parameters you give it).

The master list of registries is here. You can also search the registries directly via that link (as opposed to via the IRSA tools).

Catalog from NED -- Overlaying catalog obtained from NED

(NED= NASA Extragalactic Database.)

By clicking on the blue "Catalogs" tab, you are by default dropped into the interface for searching for catalogs at IRSA. However, you can pick another tab from the right, "NED", to search for and load a catalog from NED.

As for the other catalog searches, the tool pre-fills the target position with the coordinates of the target with which you have been working. In this case, you are limited to a cone search, so the next option is the cone search radius. As usual, pick your units from the pulldown first, and then enter a number; if you enter a number and then select from the pulldown, it will convert your number from the old units to the new units. There are both upper and lower limits to your search radius; it will tell you if you request something too big or too small.

The search results are then shown (and interacted with) in the same way as the other catalogs described here.

Columns and filters -- Interacting with catalogs

After you have loaded a catalog, it appears as a tab in the bottom window pane. Additional catalogs you load appear as additional tabs in this window pane. To see more of the window, grab the divider between the two window panes and slide it up, or use the expand arrow icon () to enlarge the window pane to take up the whole window.

The table is shown exactly as it appears in the corresponding database (or as it appeared on your disk), with all columns as defined for that catalog. To understand what each column is, please see the documentation associated with that catalog. (For IRSA catalogs, this documentation is available via the catalog searching popup window, see figure below, or by navigating through the IRSA website.)

The tab (and table) name itself indicates whether it is WISE, 2MASS, etc. To remove the tab, click on the "X" on the tab.

Immediately below the tab name, there are several symbols:

which we now describe.

The first thing to notice is that only the first 50 rows of the retrieved catalog are displayed in the table. In the example here, there are 1358 sources that were retrieved as part of the search. The left/right black arrows plus the page number allow you to navigate among these 'pages' of 50 sources each. Note that the entire set of results (not just the 50 rows you are currently viewing) can be sorted by clicking on any column's name.

By default, the catalogs you retrieve via this search are NOT overplotted on the images. To overplot the catalog (the entire catalog, not just the first 50 shown on the first page of the catalog tab), select the image on which you want the sources to appear, then go to the layers icon and turn on the catalog overlay.

Going from left to right along the top of the catalog tab, the next icon represents a filter: Filters are a very powerful way of exploring the catalog data. Click on this icon in order to start the process of adding filters. A text entry box appears above each of the current catalog columns, with a small version of the filter icon corresponding to that row on the far left. You can type operators and values in these boxes -- hit return or tab after typing or click in another box to implement the filter. For fields with a limited set of choices, instead of a text entry box, a filter icon will appear; click on it to select from the available choices. As an example, to show only those sources with declination above a certain value (say, 31 degrees), type "> 31" in the box above the "dec" column. Or, if you have retrieved a WISE catalog and would like to only view the objects with a W1 (3.4 micron) profile-fitted magnitude less than 6 magnitudes, above the 'w1mpro' column, type "< 6" in the form.

After you impose a filter, then the number of rows in the catalog is restricted according to the rules you have specified, and the "filters" icon on the top right of the catalog pane has changed to remind you that there has been a filter applied, in this case just one filter: . To clear the filters, click on the cancel filters icon (which also appears after you impose filters): .

Note that the filters are logically "AND"ed together -- it will impose this AND that AND this other restriction. You can relatively easily restrict things such that no data are left; if that is the case, you will get "There are no data to display." You can then cancel all the filters at once via the cancel filters icon (), or remove them individually by hand by editing the filter boxes at the top of each column, just as you did to impose the filters.

The available logical operators are :

You can also interactively impose filters from plots from the catalog - see the next section.

The next icon is -- clicking on this changes the table display into a text display. The icon then changes to -- click this again to return to the default table view.

The next icon is which is "Save" -- this is how you may save the catalog to your own local disk. If you have filtered the catalog down, it will save the filtered catalog (though as of this writing, the total number of rows retrieved in the table header will still be the original number). It will save it as an IPAC table file, which is basically ASCII text with headers explaining the type of data in each column, separated by vertical bars. By default, the file is called "GatorQuery.tbl" because, under the hood, the software is talking to the IRSA General Catalog Query Engine, powered by Gator.

The next to last option on the top of the catalog tab is this: . From here, you can change:

From this pop-up, you can also see the description of each field in the database (note that you can scroll right to see them all), and impose filters just like at the top of the columns. The set of all the imposed filters is collected at the bottom of this window (in the "Filters" box). Remember that the filters are "AND"ed together.

Note also that if you resize columns, and then go and add new columns, the original columns are resized back to their defaults after the new columns are added.

Finally, when your mouse is in the catalog window pane, you see this as the last option on the top of the catalog tab: . Clicking on this expands the catalog window pane to take up the entire browser window. To return to the prior view, click on "Close" in the upper left.

Plotting catalogs

Your catalog is plotted by default on the lower right after it is displayed as a table in the lower left. This is true whether you searched for catalogs during your initial search, or after your initial search via the catalogs tab. To see more of the catalog or plot while still viewing images, click and drag the slider between the panes to enlarge or shrink the plot window pane.

To obtain a full-screen view of your plot, click on the expand icon in the upper right of the window pane when your mouse is in the window: . To return to the prior view, click the "Close" arrow in the upper left.

The plotting tool, by default, starts with RA and Dec plotted. Note that it does so properly -- that is, RA increases to the left (following astronomical convention). To change what is plotted, click on the gears icon in the upper right of the plot window: . Configuration options then appear on the right of the plot, as shown:

Across the top of this window, the buttons are "Apply", "Clear", and "Reset". To close this window without doing anything, click on the gears again.

Below those buttons, if you have few enough points in the plot, you have several options for the plot style:

Next comes the options for the x-axis, followed by identical options for the y-axis. First, you need to tell it which column to plot on the axis. You can choose a single column to plot against another column -- if you have loaded a WISE catalog, you could plot w1snr vs. w1mpro. You can start typing a column name into the X and Y boxes, and it will help provide you viable options from the column headings. Alternatively, you can click on the magnifying glass link to bring up a pop-up window with all the columns for that catalog listed. NOTE THAT you must type in the column name exactly matching the column headings as displayed.

Optionally, if you have few enough points in your plot, you can specify the column containing the errors in whatever column you have selected. To do this, click on the error pulldown and select either symmetric or asymmetric errors and enter the column or the scalar you want to use for the error bar in that direction.

By default, it uses the column name as the axis label, but you may want to change this. Some database columns can be cryptic. You can also specify the units for the axis label.

Finally, you can choose whether to add grid lines, or reverse the axis (as seen in the screen shot above, ra is reversed so that larger numbers are on the left). "Top" places the x-axis numbers on the top of the plot (by default, they are on the bottom). "Log" changes the axis from linear (default) to log.

The options then repeat for the y-axis.

Finally, you can set the plot boundaries and the aspect ratio of the plot.

Click on the gears again to hide the plot options pop-up.

You can also do simple mathematical manipulations. For example, if you have loaded a WISE catalog, you can plot w1mpro vs. w1mpro-w4mpro, even including the errors. Here is the configuration, including getting the axes aligned in the way you are expecting such that brighter objects are at the top of the plot.

And here is the resultant plot, complete with error bars:

Click on any point to see the values under the cursor and have that source highlighted in the table and on the images.

If you have many sources, it will bin them up, and the plot will be shades of grey corresponding to how many points are represented at that location in the plot. The lightest shade of grey represent one point in the plot at that location, and the darkest shades of grey represent many more points in the plot at that location. If you click on one of the points, it will tell you how many catalog rows correspond to that point, e.g., The reason it does this is to more fairly represent the point density -- and to make the plotting faster. In these cases, though, it will not give you the option to overplot errors.

You can change the bin size and shading. If you have a binned plot, you have a "binning options" arrow near the bottom of the plot options pop-up. You can choose whether the binning is set automatically (leave boxes blank), or by you (populate the boxes). You can also choose if the grey shading is set linearly or logarithmically. NOTE THAT you can't change the bin size in just one direction; if you enter a number for the "Number of x-bins" box, you must also enter a number for the "Number of y-bins" box.

In order to have the tool plot one point per catalog row, you need to zoom in or otherwise restrict (see below) the data such that there are 'few enough' points represented in the plot. If there is just one point in the plot that needs to be rebinned, all of the points will be small blue individual points.

You can also restrict what data are plotted in any of several different ways. You can set limits from the plot options pop-up, or you can use a rubber band zoom, as follows. Click and drag in a sub-region of the plot. The icons in the upper right of the plot change corresponding to what you can do, in this case to these: . They are, from left to right: zoom in on the region of the plot you have selected, select the objects in the catalog, and filter the catalog to leave only those objects. If you click on the zoom icon, then the plot axes change to encompass just the sources you have selected (and the icons in the upper right change, leaving this -- if you click this, you go back to the original view). If you click on the select icon, then the plot symbols corresponding to your selection change shape and color, the corresponding objects overplotted on the image in the image window pane change color, and (if you change back to the table view of the catalog), the rows (corresponding to those sources) in the catalog are highlighted. (Also, the icons in the upper right of the plot change, leaving this -- if you click this, you deselect the sources and go back to the original view) If you click on the filter icon, then the catalog view is filtered down, restricted to just those sources you have selected, and the filter notes in the upper left of the plot window (and in the table view of the catalog) change to remind you that you have a filter applied. Only those sources that pass the filter are shown overlaid on the image(s). (This is the behavior of 'filter', as opposed to 'select'; the former restricts what is shown, the latter just highlights the objects.) You can also pull up an interactive filter on the catalog itself from the plot view -- click on the filter icon near the setting icon on the left. For more on filters, see the filter section.

Want to save a plot to file? Click on the diskette icon and save the plot.

Example of catalog plots #1: Catalog pulled after initial search

Example: Plotting [W1] vs. [W1]-[W4] in a star-forming region

For this example, we are trying to find young stars in a star-forming region. We will search in the WISE AllWISE catalog. Stars without circumstellar dust should be at a variety of W1 brightnesses, but all have [W1]-[W4]~0. Background galaxies should be faint and red. Stars with circumstellar dust (e.g., young stars) should be bright and red. Here, we will make a plot, identify a bright and red object in the plot, and find where it is in the WISE images.

  1. Launch the Finder Chart tool. Search on IC1396. Simbad's interpretation of the coordinates are fine. Change the default image size to be 1/2 degree (pick the units first, then enter the number) and display size (Medium) are fine. Select DSS, 2MASS, and WISE. Now, at this point, we could click on "Yes" for "Search Corresponding Catalog(s)", then tell it to "search within the image boundary." But we want to be mindful of the numbers of sources it is likely to find over half a degree in all of these catalogs (hint: a LOT). At this point, we are only interested in the WISE catalog. So, let's leave "Search Corresponding Catalog(s)" set to "No." Click "Search." Wait for it to come back with the results.
  2. Now, let's search just for the WISE catalog in this region. Click on the blue "catalogs" tab. Select Project=WISE. Select the AllWISE Database, and the AllWISE Source Catalog. By default, it is set for the same target but not the same region as our original search, so we want to change that. Leave the target coordinates as they appear. Change the search method to "cone." Change the units of the radius pulldown to "deg" and enter 0.25 degree in the cone radius. Click "Search."
  3. You may have to wait a bit for the catalog to be returned. If it puts the catalog search in the background, load it when it is ready.
  4. It may take a few more seconds to load and display the catalog, because the catalog is ~4,000 sources. Note that all ~4,000 sources are overplotted on the images. If you left catalog searching turned on in the intial search screen, the catalog may not be overlaid on the images. To get them overplotted, select an image, click on the layers icon in the image toolbox, and turn the corresponding catalog layer on over all the images.
  5. Grab the slider between the window panes and drag it up to see more of the catalog (and less of the images). Note that selecting a source in the image makes its corresponding row in the catalog turn green; this works the other way too in that clicking on a catalog row highlights the source in the image. Note that for this example, we have loaded a catalog that is slightly larger in some dimensions than the image covers, so if you pick a source at random from the catalog, it might not be in the images. (In the image, your search target is a magenta circle; the selected source in the image is a square with an x in it.)
  6. The plot on the lower right comes up with an RA/Dec plot by default. Two things to note: (1) RA is increasing to the left, as per astronomical convention. (2) If you have less than 5000 points, each point represents one line in the catalog. If you searched on a larger area such that you have more than 5000 points, the points are binned up such that each point represents more than one row of the catalog. Mouse over or click on a point to see how many rows are represented:
  7. Click on the expand icon in the upper right of the plot window.
  8. Click on the gear icon in the upper right of the plot window.
  9. Enter in the x box: w1mpro-w4mpro. This is WISE-1 profile-fitted measurement in magnitudes minus WISE-4 profile-fitted measurement in magnitudes, or [W1]-[W4].
  10. Click on the triangle next to "X label/unit", and enter "[W1]-[W4]" for the label. Enter "mag" for the unit.
  11. Enter in the y box: w1mpro. Click on the triangle net to
  12. Click on the triangle next to "y label/unit", and enter [W1] for the label. Enter "mag" for the unit. Tick the box next to "reverse" so that brighter objects (smaller numbers) are at the top of the plot.
  13. Click "Apply." Click on the gears to make the plot configuration pop-up go away.
  14. Obtain this plot:

  15. Note that each one of these points corresponds to an individual row in the catalog. In your version of this plot, click on the source that is highlighted in the screen shot above. Collapse the plot (click on 'close' in the upper left) so that you can see the images and the catalogs again. This source is highlighted in the images and in the catalog.
  16. Click and drag from corner given approximately by (2,5) to (6,9).
  17. The icons in the upper right of the plot change after you do this, and we want to select all of the bright, red sources. Click on the check mark on the upper left.
  18. These bright, red objects we selected in the plot are highlighted in the overlays on top of the images and selected (check mark on far left) in the catalog table.

Example of catalog plots #2: Catalogs pulled during initial search (using one-to-one matching)

Example: Searching all over the sky for objects with SDSS, 2MASS, and WISE data, and plotting [W1] vs. [W1]-[W4]

This example provides an opportunity to explore images and catalogs (including 1-to-1 matching, which can be powerful but may be confusing). This example does not walk through every source in detail, but sources can be found in this list where proper motions are high (such that 1-to-1 matching doesn't work well), and/or coordinates are bad, and/or the sources are not point sources, and where the WISE measurements have to be pulled out of the reject catalog.

  1. I have a target list containing 316 targets, which I have prepared in IPAC table format, of some objects claimed to be rapidly rotating K giants. They are all over the sky. Some are claimed to have IR excesses, and I want to see if they have WISE excesses, as well as look at the WISE images for them, just as these fine folks did. Some of the coordinates are good to within an arcsecond, and some are very poor coordinates. Many of the sources are very bright (some saturated). Download that IPAC table file to your disk.
  2. Launch the Finder Chart tool. Select "multiple positions". Click on "choose file" and locate the IPAC table file with the targets that you just downloaded. The default image size, and display size are fine. We are interested in these targets in all possible images here, including IRAS. Select all the surveys. Set "Search Corresponding Catalog(s)" to yes. "Search radius" is the only catalog option now, because we are using multIple targets. Leave the default search radii for each catalog. Click on the box for "One to one Match". This will make one line in each output catalog for each line in the input catalog, and it will take the source in each catalog closest to the input position within the search radius tolerance. Click "Search."
  3. It takes a bit to load in all the images and catalogs. When it loads, it looks like this:

    Things to note: The left upper pane has the list of targets, the right upper pane has the images, the bottom left pane has the returned catalogs, and the bottom right pane has plots of the catalogs. The orange row in the list of targets is the target whose images are shown on the right. No data were found for SDSS or SEIP for this target, but at least it doesn't take up any screen area. (There are other targets in the list for which there are SDSS and/or SEIP data.) There are 6 catalogs loaded in the bottom window pane. The catalog that is on top in the screen shot above is that from IRAS. We asked it for one-to-one matching within 90 arcseconds for IRAS. Out of the targets shown, it found a match for target 1 ("cntr_01" column),and it is within 3.5 arcseconds ("dist_x" column). The catalogs are overlaid in a survey-by-survey fashion -- the 2MASS catalog is overlaid on the 2MASS images, and the WISE catalog is overlaid on the WISE images, but because we asked for just one source per catalog, and because they are nicely coincident with the target position, it does not LOOK like the catalogs are overlaid... but they are!
  4. These targets are ones for which we would like to know if there are any IR excesses. Click on the WISE catalog tab in the catalog window pane. If the plot is too small to read, either grab and drag the boundary between panes, or click on the plot's expand arrows ().
  5. Now we have a full-screen view of the plot, but it's just a plot of RA and Dec. Click on the gear icon in the upper right of the plot window.
  6. Enter in the x box: w1mpro-w4mpro. This is WISE-1 profile-fitted measurement in magnitudes minus WISE-4 profile-fitted measurement in magnitudes, or [W1]-[W4].
  7. Click on the triangle next to "X label/unit", and enter "[W1]-[W4]" for the label. Enter "mag" for the unit.
  8. Enter in the y box: w1mpro
  9. Click on the triangle next to "Y label/unit", and enter [W1] for the label. Enter "mag" for the unit. Click on 'reverse' to make the brighter objects at the top.
  10. If you want, check the "grid" box for both axes.
  11. Click "Apply." Click on the gears to make the plot options go away.
  12. Obtain this plot:

    Note that each one of the points as shown is a small blue dot, so each point represents one line in the catalog (the data are not binned). The things brighter than [W1]~3 are likely saturated, given the structure seen in this plot. There are some bright red things, and some faint red things.
  13. Locate the bright red thing near [W1]-[W4]~3, [W1]~2. Click on it. Close the expanded plot view if you're in that view. Find the highlighted object in the list, which corresponds to this bright red object. It is number 241.
  14. Go up to the target list on the left. Click on the filter icon to reveal the filter boxes. Locate the "in_row_id" column. Type in the filter box "=241" and hit return.
  15. The target list is now filtered down to just be target #241, and the images change accordingly. Go and inspect the images in all bands. This sure looks like a point source!
  16. Go back to the WISE plot. Click on the expand arrows if you need to. Locate the reddest source there. Click on it. Close the expanded plot view if you need to. This red object is object 269 in the list.
  17. Go up to the target list on the left. Locate the "in_row_id" column and change the filter box to be "=269" and hit return. Look at the images. There does not seem to be a point source there at POSS or 2MASS bands, but there is a source with a very steeply rising SED through the WISE bands; it looks like it might even be there in IRAS. We conclude that this is probably not a K giant.
  18. It is useful in general to look at each set of images in concert with the catalogs. In the interest of space, we do not work through each of these ~300 sources, but this target list provides a great example of some of the things to look for. In this list of targets, at least one source has substantial proper motion, such that the automatic catalog 1-to-1 matching is not going to work well enough to find the true match across catalogs, and you have to do a separate search via the catalogs tab to find its true measurement at the other bands. Three sources have WISE measurements that do not appear in the AllWISE catalog, but erroneously instead in the catalog of WISE rejects -- that, too, you can search via the 'catalogs' tab. Many of these sources appear in other catalogs housed at IRSA, such as the AKARI IRC catalog (the AKARI FIS catalog is what is returned automatically). Many of these sources really are saturated (as you can see in the plot above), and checking the images helps assess the degree of saturation. Several of the sources were point sources for IRAS but not for WISE. Several of the IRAS point source positions are likely physically associated with but not well-matched to the positions of the brightest source seen in the WISE images, meaning that 1-to-1 matching fails because human judgement is required to make the match. There are other irregularities as well. We encourage you to explore. (The journal article that came out of this work has long discussions of individual targets if you want to learn more about them.)
  19. Saving the catalogs: For each of the catalogs, click on the diskette icon and save it to disk. Because each catalog has 316 data rows exactly, merging these lists together is straightforward. (Note that the catalogs might have different lengths of header information, however!)
  20. Saving the images: To save the FITS images to disk, click on "Download" in the upper left of the image window pane. From the pop-up, select "all targets", FITS, "separate by object". Click "prepare download" and wait until it is done to download it. Unzip it, and you have the images sorted by target name to browse offline. You can also save png images or PDF files (both of which include stretches and overlays as you customize interactively).