Understanding Your Search Results from the Spitzer Heritage Archive

This section is an overview of what exactly is returned by a Spitzer Heritage Archive (SHA) search. After a general description of some common options, including how to download data, the individual tabs are discussed, and then we discuss how to further refine the search results by imposing filters.

Contents of page/chapter:
+Common Options
+Observation (AOR) Tab
+Level 1 (BCD) Tab
+Level 2 (PBCD) Tab
+Filtering -- Imposing additional filters to get the most out of your search results
+Restricting data in other tabs
+Tagging -- Tagging a search so that you can reference it later.
+IRS Enhanced Products Tab
+Super Mosaics Tab
+Source List Tab
+Contributed Enhanced Products Tab
+Orbit Precovery Search Results

 

For an introduction to terminology, please see this summary in the overview section.

 

Common Options

Downloading Data
In order to download data, click on the checkbox to the left of the entry you want to download, and then click on the "Prepare Download" button at the top of the column. (Select all of them at once by clicking the checkbox at the top of that column.) The Background Monitor is then launched to prepare your data for download. When your packaged data are ready, save your data to disk. (The Contributed Enhanced Products are a little different; see below.)

Note that you control where the data are saved on your disk through your browser; your browser may be configured to store all downloads in a particular location on your disk. For some overly helpful browsers and small downloads, it may appear to have not done anything; it just did it transparently quickly.

Red lines -- some searches may return lines that are shaded red. These data cannot be downloaded because they are still proprietary. If they are your data, log in and you should be able to download them. If they are not your data, you can download those data after they become public, usually about 12 months after they were taken. You can add the release date as one of the additional columns to display in the search results pane.

Restricting data in other tabs
By default, the search results come up with a list of all returned AORs in the AOR tab and a list of a lot of corresponding files in the Level 1 and Level 2 tabs -- and it can be a long list -- for ALL of those AORs. These specific files vary according to the observation; they include the pipeline products such as a mosaic or extracted spectrum that is probably the primary goal of your search. If you want to limit exactly which files are listed in the Level 1 and Level 2 tabs, be sure that the "Restrict data in other tabs" box is checked (it should be by default) and then check the box in the row you want to examine. This is most conceptually straightforward if you select an AOR entry and then examine all of the Level 1 and/or 2 files that correspond specifically to that AOR, as opposed to selecting one of the subsidiary files and then going to another tab, though it works that way too.

Note that the enhanced products tabs are different. The SHA can't take you back to the AORs from the contributed products (since some were created from intermediate processing versions); the SSC-generated enhanced products include within them pointers to the original AORs that were used to create them, but this is not currently retrievable via a single click within the SHA.

Saving the results
The search results can be saved to a text file by clicking the "Save" button or viewed as a text file by clicking the "Text View" button. Various information is included in the header of the file to give some indication of the origin of the search.

Filtering
Filters can be added interactively -- see Filtering below for more information.

Adding/removing columns or rows
Several columns come up in each of these tabs by default, and the default number of rows returned is 50 per page. These values can be changed by clicking on the table options on the far upper right of the corresponding tab's columns (). If you can't see this icon, it may be that the results pane is too small; grab the divider between panes and slide it to the right until you can see this icon.

Note that the entire set of results can be sorted alphabetically by clicking on any column's name.

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.

You can scroll through pages by the arrows on the top center of the search results and see how many rows there are total via the count indicated there. Do you have "too many rows" to easily sift through? Further restrict the search by imposing additional filtering; see below!

Note that expanding the page size to numbers much greater than 50 may result in a substantial performance degradation (e.g., your browser will appear to freeze or not appear to be doing anything while it manages and renders the large table).

Getting more information on any row
Letting your mouse hover over many items will reveal some information in a "tool tip". Selecting any of the table entries results in different items appearing in the Details Pane. Please see that section for more information.

Changing the size of the window or columns
You can click and drag the divider between the columns or window pane. There is also a pair of black arrows () that appears in the upper right corner of any window pane when your mouse hesitates; clicking on that expands the window to take up the whole browser window. To return to the prior view, click "Close" in the upper left corner of the expanded view.

Observation (AOR) Tab

(An individual Spitzer observation is an AOR, or Astronomical Observation Request; see terminology above.)

Each AOR that was found via your search is returned here in this tab. Because each AOR can result in many other files, this AOR tab is the best place to start browsing! (The other tabs -- Level 1 and Level 2 -- will have more additional files listed per AOR, and once you download the data, you'll have even more files that come with the download. The enhanced products will have a different sort of diversity of files, depending on which products are available.)

Column Headings:

Do you have "too much data" in the subsidiary search result tabs? See restricting data in other tabs -- for example, limit the Level 1 and Level 2 tabs to be just the files from one AOR. Do you have "too many rows"? Further restrict the search by imposing additional filtering -- for example, limiting it to be just IRAC channel 1 data. In summary, restricting data in other tabs means selecting the checkbox for a row of the table and seeing the files corresponding to that row in the other tabs, whereas filtering corresponds to limiting the rows to specific values in the columns.

(More information on using the details pane.)

(More information on options found in every tab.)

Level 1 (BCD) Tab

(The individual data frames that emerge [calibrated] from the Spitzer pipeline are Level 1, or Basic Calibrated Data, or BCDs; see terminology above.)

Each AOR that was returned by your search can result in many other files. This Level 1 (BCD) tab contains all of the BCDs that correspond to the AORs returned (or selected) in the AOR tab. (Additional Level 1 products will arrive with your download, such as errors and masks.)

Note: For IRAC subarray data, only Level 1 (BCD) data are returned. There is no Level 2 product.

Column Headings:

(More information on using the details pane.)

(More information on options found in every tab.)

Level 2 (PBCD) Tab

(The products that come from combining these individual data frames [such as mosaics of individual pointings] are Level 2, or post-BCD, or PBCD data; see terminology above.)

Each AOR that was returned by your search can result in many other files. This Level 2 (post-BCD) tab contains all of the Level 2 products that correspond to the AORs returned (or selected) in the AOR tab. (Additional Level 2 products will arrive with your download, such as errors and coverage maps.)

Note: For IRAC subarray data, there are no Level 2 products.

Column Headings:

(More information on using the details pane.)

(More information on options found in every tab.)

Filtering -- Imposing additional filters to get the most out of your search results

Even if your search returned only one AOR, you could have many files that appear in the Level 2 (PBCD) or Level 1 (BCD) tabs. In order to quickly weed through what files appear in the tab and find/examine the file you care about, filtering is a very powerful tool.

At the top of the tab window, there is this icon, which represents a filter: Click on it in order to add a filter. 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 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.

For example, if you have searched on an IRAC AOR and would like to only view the files relevant to the 3.6 micron channel, locate the 'Bandpass' column, click on the filter icon, and select 'IRAC 3.6 um' from the pop-up with the list of choices. Hit return or click in another box to implement the filter.

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): .

You can add additional filters to further restrict your list of files. Note that the filters are logically "AND"ed together -- that is, if you impose "Bandpass=IRAC 3.6 um" and "Bandpass=IRAC 4.5 um", no data will result, because no data are both 3.6 and 4.6 microns at the same time. If you want to see just the 3.6 and 4.5 micron data, select more than one bandpass from the pulldown by selecting "select multiple" and selecting the multiple options you want.

A more complex but still common application of filters would be downloading all the most recent data from a given program (e.g., data from one program that have just been released). To do this: Search by campaign for the most recent campaign. Many AORs will be returned. Once the results appear, click on "Filters". Locate the "Program ID" column. If you have a text box, type "=" and the program ID you want. If you have a pop-up with finite choices, select the program ID you want. Just the AORs from that campaign and that program will remain.

NOTE THAT the filters as imposed this way only apply to your current tab, even if "restrict data in other tabs" is selected! (See "Restricting data in other tabs" above for more information on this option -- in summary, restricting data in other tabs means selecting the checkbox for a row of the table and seeing the files corresponding to that row in the other tabs, whereas filtering corresponds to the values in the columns.)

The available logical operators are :

Tag It -- Tagging a search

Many of the papers published on Spitzer data include a list of all the individual AORKEYs (the integer number corresponding uniquely to each AOR) used for data discussed in that paper. This provides an easy way for readers to retrieve the data from the Spitzer archive, and links can be made from ADS directly back to the SHA.

However, many papers use many AORs. Data tagging allows you to customize the data set you use so that the link back from ADS (or embedded in your paper itself) refers to a single unique identifier that corresponds to all your data. (That is, a single identifier, as opposed to a potentially long list of AORKEYs.)

You yourself (independent of any publications) may also wish to repeat a search later on for any of a number of reasons. Tagging a search means that you can easily recreate it later. Once you have established a search that you like and wish to repeat in the future, click on the blue "History/Tags" tab near the top of the browser window, then click on the "Tags" tab. At this point, you can enter a name for your tag, then click on the "Tag It" button. It will then return the tag URL you can save and distribute. It also appears in your tagging history. If you have logged in, this tagging history is available to you any time you log into the SHA.

To recreate the search, highlight the tag row you want, and click on the "Resubmit Search" button. To remove it, click on the "Remove" button.

IRS Enhanced Products Tab

(Enhanced Products come from combining AORs or doing post processing; see terminology above. The SSC has generated enhanced products for IRS.)

The SSC has generated enhanced products for the IRS observations in the Archive. For complete documentation on these products (how they were generated, etc.), please see the IRS Instrument Handbook, available at the IRSA website.

If there is an IRS enhanced product available that meets your search criteria, it is shown in the "IRS Enhanced" tab. Many columns are shown, including extraction information, observation information, synthetic photometry for a variety of bands, and links to a merged spectrum. You can access additional columns available for this product by searching the IRS Enhanced Products directly, e.g., not via a position search per se.

Filtering and column operations (adding, removing, sorting) work in exactly the same way as they do through the rest of the SHA.

Selecting any of the table entries results in different items appearing in the Details Pane, and the related tabs. Please see that section for more information.

Super Mosaic (SEIP Super Mosaics) Tab

(Enhanced Products come from combining AORs or doing post processing; see terminology above. The SSC has generated enhanced imaging products (SEIP) for IRAC and MIPS-24.)

The SSC has generated enhanced imaging products (SEIP) for the IRAC and MIPS-24 observations in the Archive. For complete documentation on these products (how they were generated, etc.), please see the Documentation for these products, available at the IRSA website.

If there is a SEIP super mosaic available that meets your search criteria, it is shown in the "Super Mosaic" tab. The basic columns are shown, including RA, Dec, and the filename of the mosaic.

Filtering and column operations (adding, removing, sorting) work in exactly the same way as they do through the rest of the SHA.

Selecting any of the table entries results in different items appearing in the Details Pane, and the related tabs. Please see that section for more information.

Source List (SEIP Source List) Tab

(Enhanced Products come from combining AORs or doing post processing; see terminology above. The SSC has generated enhanced imaging products (SEIP) for IRAC and MIPS-24.)

The SSC has generated enhanced imaging products (SEIP) for the IRAC and MIPS-24 observations in the Archive. If there is a SEIP source list product available that meets your search criteria, it is shown in the "Source List" tab. The columns that are shown by default include RA, Dec, quality flags, and flux density measurements at a variety of bands, including 2MASS and WISE. For complete documentation on these products (how they were generated, what these quality flags mean, etc.), please see the Documentation for these products, available at the IRSA website. Additional columns listed in the documentation but not shown in the SHA interface can be accessed via Gator.

Filtering and column operations (adding, removing, sorting) work in exactly the same way as they do through the rest of the SHA.

Selecting any of the table entries results in different items appearing in the Details Pane, and the related tabs. Please see that section for more information.

Contributed Enhanced Products Tab

(Enhanced Products come from combining AORs or doing post processing; see terminology above. The community has contributed many enhanced products to the archive.)

Most of the enhanced products currently available via the SHA come from the deliveries made back to IRSA from the Legacy Teams, though other teams including the Exploration Science teams have also made deliveries. (More on enhanced product searching.)

In response to a search, the Contributed Products Results tab comes up with a "Summary View" of the search results. By default, the results are grouped by type -- images, catalogs, or spectra. You can also choose to sort the results by originating project.

The images come up quickly, and the summary page indicates how many images from each project are returned. Note that sometimes this could mean one image for each band, or it could mean image, errors, and coverage for each band, or it could mean multiple resamplings of the same bands, etc. To investigate exactly what images are available, click on the first link in each line, the one corresponding to the delivering project's name. Additional tabs are spawned for each click, containing a summary of the contents of each image or catalog. You can make those tabs go away when you are done with them by clicking on the x that appears when you put your mouse on the tab.

Please consult the original documentation that came with the delivery for definitions, explanations, and caveats that might go with each product. Note that some teams delivered, e.g., GALEX and Halpha images, so you may obtain non-Spitzer data from the Spitzer Heritage Archive! The delivery documentation can be found on the project's page in IRSA, which can be obtained by clicking the second link in each line in the summary, the one that tells you more about the delivery.

Catalogs come up more slowly (because they are harder to search!), and depending on your search, the SHA may tell you that it has completed searching on "8 of 10 catalogs" or a similar phrase. Here too, the catalog contents vary across projects, and even between deliveries within the same project. In the case of the catalogs, the "count" tells you how many individual catalog entries there are in that catalog for your search parameters. Click on the first link in each line, the one corresponding to the delivering project's name, to spawn an additional tab with the catalog values. Note that by default, only 50 lines are shown, but as these catalogs can be very long, it may take a second or two to read in and render. The catalog columns as displayed are exactly as provided by the original Legacy team (with some additional columns added by IRSA to reformat the RA/Dec into standard options), so the columns are effectively different for each catalog. Please consult the original documentation that came with the delivery for column definitions, caveats, etc. Such information can be found on the project's page in IRSA, which can be obtained by clicking the second link in each line in the summary, the one that tells you more about the delivery.

NOTE: Currently, the Contributed Products search performs a cone search of the IRSA holdings, and if you go to IRSA directly to do what seems to be the identical search on the same source material, it does a box search. This will result in some apparent inconsistencies (e.g., different numbers of images or sources) as a result of the corners of the box search area.

For a complete background on the Legacy program, information on individual programs, and information on individual deliveries, please click the link that appears next to each project's entry on the summary. This will take you to the IRSA page corresponding to the project, from which you can learn more about the project and its deliveries.

Visualization here is similar to visualization elsewhere in the SHA. You can investigate the observation coverage and overlay catalogs on an image.

Orbit Precovery Search Results

The search results for a Solar System Object Orbit precovery search are presented in a very different way than those for the other searches discussed here. Because it is looking for a series of observations of something that is moving on the sky, it presents the results of that search as a series of tiled images, as opposed to a list of observations. You can switch between these views via this pair of "view options" in the upper right of the results page: The left icon is the tiled view, and the right icon is the table or list view.

Image Previews: In the tiled view, similar to the moving object search in the WISE Image Service, each image in which the position of the input object is predicted to have been covered at the time of observation. The predicted position is indicated by a blue square on the image. An orange "x" indicates the predicted position of the input object in previous or subsequent images (or image sets). Clicking on any of the positions will highlight (in blue) all the corresponding positions in the surrounding images.

Orbital Path Coverage : The Orbital Path Coverage tab in the coverage pane displays the orbital path (blue line) of the input object during the time limits specified. The observations returned by the search of the orbital path are indicated by orange "x" symbols.

Table (or List) View: The table of results provides a list of all individual images in which the predicted position of the input moving object is predicted to appear, given the input orbital path.