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.
6.1.2 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).
6.1.3 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.
6.1.4 Filtering
Filters can be added interactively -- see Filtering below for more information.
6.1.5 Adding/removing columns
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 small grid 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.
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 be doing anything while it manages and renders the large table).
6.1.6 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. See below for more information.
6.1.7 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 or "Collapse" the upper left corner of the expanded view.
6.2 Observation (AOR) Tab
6.2.1 Introduction
(An individual Spitzer observation is an AOR, or Astronomical Observation Request.)
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.)
6.2.2 Column Headings
The target name was supplied by the original observer and may be enlightening or cryptic.
The RA and Dec are for the target of the AOR as observed.
If the object was observed as a moving target, the NAIF ID is listed; otherwise, this is blank.
The instrument and observing mode are listed next.
The AORKEY is a large integer that uniquely identifies this observation in the SHA.
The AOR label was supplied by the original observer and may be clear or cryptic.
The Observation start time is the time, in UT, that the observation was begun.
The Program ID is the integer identifier for the program under which these observations were obtained.
The Principal Investigator (PI) for these data is listed last in the default display.
An additional column can be added which indicates whether the observation was an AOR or an IER; other columns can be added as well. (click on at the top right of the tab window to do this.)
Do you have "too much data" in the subsidiary search result tabs? See restricting data in other tabs below -- 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.
6.3 Level 1 (BCD) Tab
6.3.1 Introduction
The individual data frames that emerge [calibrated] from the Spitzer pipeline are Level 1, or Basic Calibrated Data, or BCDs.
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.
6.3.2 Column Headings
The AORKEY is a large integer that uniquely identifies this observation in the SHA. (Note that each AOR results in many files, and that you can restrict the contents of this tab to be just those files corresponding to one AOR; see "Restricting data in other tabs" above.)
The BCD ID is a large integer that uniquely identifies this particular file in the SHA.
The instrument and observing mode are listed next.
The specific band pass of this individual file is in the next column.
The RA and Dec are listed in hh:mm:ss dd:mm:ss format. If "no data" or other unusual values appear here, this is most likely a calibration file.
The exposure time corresponding to this file is given in seconds.
Particularly in the case of MIPS, the arrays may be on and collecting data even if the telescope is being used to observe using one of the other fields of view in the instrument. For any given row, if the telescope was optimized for use of the field of view to which the specific file applies, then the "primary field" column is 1; other values indicate that this is serendipitous data. See the MIPS portion of the SSC website for more information on how to use these data.
Since there can be files at the BCD level that are not images (such as tables of data), the "File Type" column lists the nature of the file. "Image" will be the most common.
The file name of the corresponding file once it is unpacked and resident on your disk is listed. The filename contains information about the instrument, channel, and originating AOR as well as the specific contents of the file; see the Spitzer website for a comprehensive listing of the files available at the BCD level (Level 1).
Several additional columns can be added to the BCD view. Most of these should be self-explanatory from the column headers (or the tool tips) appearing in the pop-up window that appears when you add columns (in brief, click on the little grid icon at the top right of the tab window).
6.4 Level 2 (PBCD) Tab
6.4.1 Introduction
(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.)
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 – there is no Level 2 product for IRAC subarray data.
6.4.2 Column Headings
The AORKEY is a large integer that uniquely identifies this observation in the SHA. (Note that each AOR results in many files, and that you can restrict the contents of this tab to be just those files corresponding to one AOR; see "Restricting data in other tabs" above.)
The instrument and observing mode are listed next.
The specific band pass of this individual file is in the next column.
The RA and Dec are listed in hh:mm:ss dd:mm:ss format. If "no data" or other unusual values appear here, this is most likely a calibration file.
Since there can be files at the BCD level that are not images (such as tables of data), the "File Type" column lists the nature of the file. "Image" will be the most common; IRS data results in a lot of tables.
The file name of the corresponding file once it is unpacked and resident on your disk is listed. The filename contains information about the instrument, channel, and originating AOR as well as the specific contents of the file; see the Spitzer website for a comprehensive listing of the files available at the PBCD level (Level 2).
Several additional columns can be added to the PBCD view. Most of these should be self-explanatory from the column headers (or the tool tips) appearing in the pop-up window that appears when you add columns (in brief, click on the grid icon at the top right of the tab window).
6.5 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.
Click on "Add filters" in order to add a new filter. Each of your current columns can be selected in a pull down menu, as well as an operation (=, <, etc). If you select a field with a limited set of choices, an additional pull down appears with those limited 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, select 'Bandpass', '=', and 'IRAC 3.6 um' from the relevant pull downs, then "ADD" the filter and "APPLY" it to your search results. Then, the number of files is restricted, and the notice on the top right of the search results pane reminds you that there has been a filter applied.
You can add additional filters to further restrict your list of files. Note that, at this time, 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, ask it to give you all band passes less than 5.8 microns, e.g., "Bandpass", "<", and "IRAC 5.8 um".
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 "add filters". Click on "Program ID" from the first drop-down menu. Leave the operator as the default "=". Enter the program ID you want. Apply the filter and close the filters window. 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:
= means 'equal to' (exactly!), e.g., the parameter on which I am querying (such as "Bandpass") is exactly equal to this value I am specifying (such as "IRAC 3.6um" from the pull down menu).
> means 'greater than'
< means 'less than'
!= means 'not equal to' (exactly!)
>= means 'greater than or equal to'
<= means 'less than or equal to'
IN means 'included within this list', e.g., the parameter on which I am querying (such as "Bandpass") is included within the list I am specifying (such as, from the list of bandpasses provided, where more than one can be selected by holding down the command key and clicking on the bands desired)
As an example of that last logical operator, 'IN', suppose you have a program that contains IRS Peakup Image, IRS Map, MIPS PHOT, MIPS SED, and IRAC MAP, but only want to examine the imaging data. Use the filter dialog to select “Instrument/Mode” with operator “IN” and select IRS Peakup Image, MIPS Phot, and IRAC Map by holding down the Command Key while clicking on those instrument modes. Click on “Add,” and the filter will be set to only examine the imaging data AORs.
6.6 Tag It -- Tagging a search
Many of the papers published on Spitzer data include a list of all 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 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 (or in the future, any IRSA service).
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.
6.7 IRS Enhanced Products Tab
(Enhanced Products come from combining AORs or doing post processing. 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.
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 the next chapter for more information.
6.8 Contributed Enhanced Products Tab
(Enhanced Products come from combining AORs or doing post processing. 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.
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.
). 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.
at the top right of the tab window to do this.)