Searching the Spitzer Heritage Archive

There are many different options for searching the Spitzer Heritage Archive (SHA). Searching by position is the most commonly used option.

Contents of page/chapter:
+Options Common to Most Searches
+Position Search
+Abstract Search
+AORKEY Search
+Campaign Search
+IRS Enhanced Products Search
+Moving Object Search
+Moving Object Precovery
+Observation Date Search
+Observer Name Search
+Program Search
+More on Enhanced Products
+API

 

Options Common to Most Searches

The individual search options are given below, in the same order in which they appear in the search pane. Most of the search panes have the following additional options:
Display search results in tabs for... Observation Request (AOR), Level 2 (PBCD), Level 1 (BCD), and sometimes SSC Enhanced Products (IRS), SEIP Super Mosaics, SEIP Source List, and/or Contributed Enhanced Products
An individual Spitzer observation sequence is an AOR, or Astronomical Observation Request. Level 2 products are higher-level products, such as mosaics. (These are also called post-BCD, or post-Basic Calibrated Data, or PBCD, products.) Level 1 products are the individual calibrated data frames that go into making, e.g., the mosaic (or spectrum). (These are also called BCD, or Basic Calibrated Data, frames.) Enhanced Products come from combining AORs or doing post processing (such as synthetic photometry from spectra or source extraction from images). These can be contributed by the community, or generated by the SSC itself.

When you do a search, the results are displayed in tabs, and these tabs correspond to these options. By default, searches return a list of AORs under the "AOR" tab, and a list of Level 2 products under the "Level 2 (PBCD)" tab. You can also choose to access the original BCD frames by selecting the "Level 1 (BCD)" option here, and then the corresponding tab will be returned by your search. Similarly, for most searches, you can choose "SSC Enhanced Products (IRS)", which returns any results in a tab called "IRS Enhanced". These IRS enhanced products were generated on an AOR basis, and as such, most of the searches that can result in a list of AORs can also return IRS enhanced products. However, the other enhanced products ("SEIP Super Mosaics", "SEIP Source List", and "Contributed Enhanced Products") typically combine more than one AOR at a time, and as such, these are really only available from the position search page.

NOTE THAT each AOR produces many Level 2 (PBCD) files and many more Level 1 (BCD) files! The number of AORs that may be returned by any given search is going to be much smaller than the number of files that appear on these other tabs. You can "restrict data in other tabs" or apply individual filters to weed down these search results.

IMPORTANT NOTES ON ENHANCED PRODUCTS:

  1. Any given search may not have any enhanced products to return -- while there are Spitzer observations scattered all over the sky, and while we have developed and had the community return back to us products from observations all over the sky, there is much of the sky not covered by these observations.
  2. In order to learn more about the particular values that are returned, how the data were reduced, its strengths and weaknesses, etc., please see the documentation corresponding to the products. The IRS documentation is available as part of the IRS Instrument Handbook at the Spitzer IRSA website. The Spitzer Enhanced Imaging Products (SEIP) Super Mosaic and Source List documentation is also on the IRSA website. Each of the contributions in the Contributed Enhanced Products has its own documentation at the IRSA site (linked from the search results).
  3. Many of the 'more options' (see below) obtainable for a position search don't apply to enhanced products of any sort. For example, if you ask the SHA to give you just IRAC observations at a particular position, but also ask it to give you IRS Enhanced Products (which are of course completely independent of any IRAC observations), it will return just IRAC observations in the AOR/Level 1/Level 2 tabs, but the IRS Enhanced Products search is independent of the AOR search, and may still return viable results in that tab. Similarly, if you restrict your search to MIPS results but still ask it to give you IRS Enhanced Products and SEIP Super Mosaics, it will give you IRS and IRAC data, respectively, in those tabs, regardless of the MIPS filter you have imposed (that filter just applies to the AOR/Level 1/Level 2 tabs).

More options: filter by Instrument Parameters or Wavelength Range
Spitzer has on board three instruments: By default, the SHA search pane comes up with the "Instrument Parameters" radio button selected. You can ask to have all data from a particular instrument returned (e.g., "All IRAC"). You can also ask to have just data from a particular observing mode returned (e.g., just "IRS Spectral Mapping"). You can also select individual bands, e.g., just 70 and 160 microns). Combine various check boxes to customize your search; go to the Spitzer website at IRSA to learn more about instruments, observing modes, and bandpasses. Alternatively, you can select the Wavelength Range radio button and just enter the minimum and maximum wavelength in which you are interested. Any data in that regime (also meeting your other search criteria) will be returned by the search.
After you search the first time, the search pane collapses so the results of your search can be displayed. A summary of the most important parameters of your search is available at the top left. To search again, just click on the triangle near that search summary, or on the blue "Spitzer Searches" tab, to recover the search pane.

Position Search

This search is the most common search performed on astronomical archives. Enter your central position and cone (circle) radius, then all observations (those meeting all the rest of your entered criteria) intersecting that cone are returned.

You may enter a target name, and have either NED-then-Simbad or Simbad-then-NED resolve the target name into coordinates. Alternatively, you may enter coordinates directly. These coordinates can be in decimal degrees or in hh:mm:ss dd:mm:ss format. By default, it assumes you are working in J2000 coordinates; you can also specify galactic, ecliptic, or B1950 coordinates as follows:

As you are completing a valid coordinate entry, the SHA echoes back to you what it thinks you are entering. Look right below the box in which you are typing the coordinates to see it dynamically change.

You may enter a search radius; the default is 500 arcseconds. You may enter the radius in arcseconds, arcminutes, or degrees; just change the pulldown option accordingly. Caution: 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; the SHA will tell you if you request something too big or too small.

The position search can also be done in "batch mode" from a list of objects given in a file. Please note, the maximum number of targets that can be requested in a batch search is 1000.

A viable input file can either be an IPAC table file, a relatively simple text file described below, or even a simple comma- or tab-separated value file. For an IPAC table file, you may find the IPAC table file verification service helpful.

If doing a regular non-IPAC table file search, the file format is:

COORD_SYSTEM: Equatorial
# Equatorial, Galactic, or Ecliptic - default is Equatorial
EQUINOX: J2000
# B1950, J2000, or blank for Galactic - default is J2000
NAME-RESOLVER: NED
# NED or Simbad - default is Simbad
#Name     RA/LON       DEC/LAT     PM-RA PM-DEC EPOCH
"NGC 001" 12h34m23.45s 34d23m56.2s 2.3    3.4 1950.3
NGC2222   23.56d       34.456d     2.3    3.4 1950.3
NGC3333   23.56h       34.456d     2.3    3.4 1950.3
NGC4444  "12 34 12.23" "34 23 45.45"
m31
legacy  "17 18 00" "59 30 00"
m32
m33       Simbad
NGC6946 
NGC5194 
ngc2992

The SHA parses on spaces, so a space is the delimeter between fields. Therefore, if there is a space in your object name (e.g., "NGC 1001" versus "NGC1001") or position ("34 23 45.45" versus 34d23m45.45s"), you need to put quotes around the target name or its position.

Having problems making this work? All of the following should be elegantly handled by the SHA, but if you are having problems, it's worth checking these. Check your filename; IPAC table files should end in .tbl, and the plain text search should end in .txt. Double-check your file formatting -- that's the most common error. Make sure there are not lots of extra whitespace (spaces, tabs, etc.) at the ends of lines, particularly the header lines. Check for and remove odd non-ASCII characters like curly quotes or Greek letters, and other non-printing special characters (like tabs). Name resolution may fail for some targets with Greek letters or other unusual characters -- provide coordinates for the troublesome names, or remove them. If you are trying an IPAC table file upload that persistently fails, pass it through the the IPAC table file verification service first. If one format (simple text or IPAC table) fails, try the other format (IPAC table or simple text).

Apply spatial constraints to AORs or Individual data products
This is an additional option for the position searches. An individual Spitzer observation sequence is an AOR, or Astronomical Observation Request. In certain cases -- often calibration or sometimes science observations -- you may also find an IER, or Instrument Engineering Request. Either one involves many individual frames. AORs/IERs can cover large areas or, by design, multiple targets. You can choose to return all AORs/IERs touching your search area, or just the individual data products enclosed within your search area e.g., just the observations that went into the portion of the sky for which you searched. Some products may only exist at the AOR level, e.g., you might get the whole Level 2 mosaic for the whole AOR, but only the Level 1 (BCD) individual data frames for the portion you requested.

(The reason you may want the whole AOR, as opposed to just the portion enclosed within your search radius, is that, depending on the nature of the observation and the target, you may want the entire AOR in order to reprocess portions of it. For example, you may want to remove latent instrumental effects, or you may want to use the rest of the AOR to assess the relative error for the region in which you are interested -- e.g., if your dark region of interest is at the end of some scan legs that included a bright region of sky. Please consult the instrument handbook for the relevant instrument in order to assess this for your particular case.)

If you do just want to download products within a spatially confined area, be sure you start from the Level 1 (BCD) or Level 2 (PBCD) tabs. Downloads initiated from the AOR search results tab will download the entire selected AOR regardless of spatial constraints.

(More information on options found in every search.)

Abstract Search

You can search on a string through all of the Spitzer program abstracts. You can search on any text you would like, from principal investigator (PI) last names to instrument names to compound terms (such as "brown dwarf"). You can also use simple logic statements, e.g., "star formation -galaxy" means find all instances of the terms "star" and "formation" but not those that also use the word "galaxy." To enforce the appearance of a compound term, e.g., the word "star" next to the word "formation", enclose the term in quotes.

(More information on options found in every search.)

AORKEY Search

An AORKEY is a large integer that uniquely identifies the observation (AOR) within the Spitzer mission. All Level 1 (BCD) and Level 2 (PBCD) files carry with them the fingerprints of this AORKEY (in the filenames, in the directory structure, in the FITS headers...). Specific AORKEYs are often listed in journal articles reporting on Spitzer results.

You can retrieve a specific observation by searching on this AORKEY. Note that a single AORKEY corresponds to a single AOR, so if you search on a single AORKEY, you will always get a single AOR in the AOR tab.

You can search for many AORKEYs at once by entering a list of them separated by commas.

Some observations were obtained with some scheduling constraints, e.g., 'observe this series of 8 AORs in this order within this time window.' In the AORKEY search panel, there is an option to retrieve all the other AORs within the same scheduling constraint. However, note that some time series observations were obtained in the following manner. For a series of observations (a, b, c, d, e), a was tied to b with a particular constraint, b tied to c, c tied to d, and d tied to e. If you search on the AORKEY corresponding to observation b, and ask the SHA to give you all of the AORs constrained to that observation, it does exactly (and only) what you asked it to do -- b is tied to a and c, but not explicitly tied to d or e. So it returns to you observations a, b, and c, and not d or e.

(More information on options found in every search.)

Campaign Search

In some cases, you may wish to browse all of the data taken during a specific campaign, e.g., to investigate bright object artifacts in your data from observations preceeding yours. This feature allows you to do exactly that. A complete list of Spitzer campaigns can be found at the Spitzer website.

Note that there are a few different ways to refer to a given Spitzer campaign, and the search only recognizes two of them. For example, IRS campaign 47 was run between 9 Jan 2008 and 23 Jan 2008. The formal campaign ID (which works in the search) is IRSX008300, and the search also works with the numerical id 1094 listed as synonymous with this campaign on the Spitzer website.

(More information on options found in every search.)

IRS Enhanced Products Search

The IRS Instrument Team at the SSC has generated IRS enhanced products from low-resolution staring-mode spectra, which include a merged spectrum (all orders), and synthetic photometry at a wide variety of bands. There are no IRS enhanced products for high-resolution spectra or spectral maps. Although IRS data were obtained in a large number of positions all over the sky, any given randomly-selected position is not likely to have any valid IRS products, so these data are not always available.

A specialized IRS Enhanced Products search, by default, searches the whole sky. (This is not the case if you select the tick box asking these products to be returned as part of another search, but it is the case if you pick "IRS Enhanced Products" explicitly from the search options.) You can look at all of the meta-data associated with the catalog in a short or long form view (pulldown menu option at the top of the pane), and the rest of the filters you can impose work just like filtering search results. You can impose multiple filters on the available parameters, and then hit the 'search' button on the lower right to return all values meeting your criteria.

Note that a plain position search of these data is best accomplished using an explicit "position" search, not from this "IRS Enhanced Products" search pane.

In order to learn more about the available parameters on which you can search, the particular values that are returned, how the data were reduced, its strengths and weaknesses, etc., please see the IRS Instrument Handbook, available at the Spitzer IRSA website

You can control which columns are displayed, but if you download/save the data, all of the columns are saved.

Moving Object Search

You can search on the name of a moving target, or the NAIF ID; moving targets are assigned NAIF IDs, which are a unique integer identifier for known Solar System bodies.

This search will retrieve data explicitly declared to be observations of these moving targets in the Spitzer database. This means, for example, that observations of a moving target performed as a fixed-target observation of an RA/Dec will not appear, nor will serendipitous observations of a moving target that happens to appear in a fixed-target observation.

(More information on options found in every search.)

Moving Object Precovery

While many moving objects were deliberately observed over the course of the Spitzer mission, many more were serendipitously observed while conducting observations of other things. The Moving Object Precovery search option enables you to detemine if there are deliberate or serendipitous observations of a given object.

You need to enter one of the following to enable the archive to calculate an orbit for a given object as a function of time and then look for observations of that object: (1) the object name or NAIF ID (moving targets are assigned NAIF IDs, which are a unique integer identifier for known Solar System bodies); (2) the MPC one-line orbital elements (specification of an object's orbital parameters); or (3) manually input the orbital parameters.

You must also specify the time range over which to search for observations. PLEASE NOTE that just asking it to look for objects over the entire Spitzer mission will take a LONG TIME. Use long time baselines with caution! There is an option, after you submit your search, to place the search in the background - this is useful if the search takes a very long time.

In any case, it will return results for your search object, both those observed deliberately and those caught serendipitously.

Observation Date Search

You can search for observations conducted between two dates. The dates must be specified in Universal Time (UT) and be in the format YYYY-MM-DD hh:mm:ss. The maximum date range allowable is small; use big date ranges with caution because thousands of observations can be obtained via this search.

(More information on options found in every search.)

Observer Name Search

You can search by name through all of the principal investigators and technical contacts for all Spitzer programs. Note that there is an auto-complete on this feature, which shows you available suggestions as you type in a string.

Note also that searching on any of the instrument PIs (Fazio, Houck, Rieke) or the Instrument Support Team leads (Reach/Carey, Latter/Noriega-Crespo, Armus) will return many programs tied to their guaranteed time (GTO) programs, or calibration programs from early in the mission.

To retrieve calibration programs during regular operations, search on "IRS Calibration" or "IRAC Calibration" or "MIPS Calibration."

(More information on options found in every search.)

Program Search

All of the observations that correspond to individual observing programs are grouped under a program identifier (PID). This program identifier can be both a string and a number. Either the string (assigned by the observer) or a number (assigned roughly by the order in which the original proposal was submitted) can be used to retrieve all of the observations that were part of that program. A complete list of all of the Spitzer programs can be found at the Spitzer website.

Note that some programs can include literally thousands of AORs, whereas others may be just one or two AORs. Note also that some large science programs may be split over multiple program IDs.

(More information on options found in every search.)

More on Enhanced Products

Enhanced Products come from combining AORs and/or doing post processing (such as synthetic photometry from spectra or source extraction from images). These can be contributed by the community, or generated by the SSC itself.

The IRS Instrument Team at the SSC has generated IRS enhanced products from low-resolution staring-mode spectra, which include a merged spectrum (all orders), and synthetic photometry at a wide variety of bands. There are no IRS enhanced products for high-resolution spectra or spectral maps.

The SSC has generated enhanced imaging products (SEIP) Super Mosaics and Source Lists from the IRAC and MIPS-24 imaging conducted during the cryogenic mission. These products usually involve more than one AOR.

Most (but not all!) of the contributed products come from Legacy Programs. The Legacy Programs were large, coherent science investigations, and the teams explicitly agreed to deliver enhanced products back to the Spitzer Science Center and IRSA. Subsequent to the Legacy program, some large Spitzer programs were called Exploration Science programs, and some of those also delivered products to IRSA. Each team delivered something different -- some just delivered images, some delivered images, catalogs, and spectra, some delivered multi-wavelength resources, extending well beyond the Spitzer bands, some delivered models. All of the products that have been ingested into IRSA are available through this SHA interface. Note that as of this writing, some teams still have pending deliveries, and that IRSA ingestion is not immediate. When a team delivers enhanced data products to IRSA, the data must go through a quality assurance (QA) and ingestion process before being available through IRSA search engines, and this process does not happen instantaneously. As these products become available, they will also be available in this fashion.

NOTE THAT, in order to learn more about the particular values that are returned, how the data were reduced, its strengths and weaknesses, etc., please see the documentation corresponding to the products. The IRS documentation is available as part of the IRS Instrument Handbook at the Spitzer IRSA website, the Super Mosaic and Source List documentation is also at the IRSA website, and each of the contributions in the Contributed Enhanced Products has its own documentation at the IRSA site (linked from the search results).

The SHA, ultimately, can lead you back to the original AORs for the SSC-generated enhanced products. Look in the headers of the enhanced product files you find to identify the original observations that went into the product, and then search on those observations in the SHA to retrieve the observations. The Super Mosaic and Source List products explicitly include a list of the input AORs. The community-generated ones cannot necessarily do this, since some were generated before the 'final' processing of the BCDs.

Since the contributed data products that are being served are so different than the rest of the SHA, the way that the files are listed is also different. Please see the section on search results for more information.

IRSA and the Spitzer Heritage Archive utilize technology developed for the Virtual Astronomical Observatory (VAO), funded by the National Science Foundation and the National Aeronautics and Space Administration under Cooperative Agreement AST-0834235.

API

Searching by application program interface (API) is covered in another section.