Search Basics

ADS’s one box search form supports both fielded and unfielded queries. Queries without fields will search the metadata and the full text of the publications, which may not produce the expected results. For instance, if you are searching for papers by the author Marc Mars, you want to search for author:”Mars, M” instead of Marc Mars to make sure that you don’t return papers that simply have the words “Marc” and “Mars” somewhere in the body of the article.

Fielded Searches

Above the search box we supply shortcuts to frequently used search fields. Simply click on the field that you wish to search and enter your search term in the provided location (generally between the supplied quotation marks). Alternatively, if you start entering the name of a field an autocomplete feature will suggest a list of possible search fields. You may string several search terms or use the filters provided with your results to help narrow the search selection. For instance if you want to find articles published between 1980 and 1990 by John Huchra, you can use:

author:"Huchra, John" year:1980-1990

To get you started, here is a list of search examples for commonly used fields:

The rest of this page goes over the search syntax and fields indexed in our database.

Combining Search Terms to Make a Compound Query

You can string together any number of search terms to develop a query. By default search terms will be combined using AND as the default boolean operator, but this can be changed by explicitly specifying OR beween them. Similarly one can exclude a term by prepending a “-“ sign to it (or using the boolean “NOT”). Multiple search words or phrases may be grouped in a fielded query by enclosing them in parenthesis. Some examples:

Synonyms and Acronyms

By default most search terms in ADS are expanded by adding a list of words which are synonyms of the search term. So for example, a search of “star” in the title field will be expanded to include words such as “stars,” “stellar,” “starry,” “starlike,” and so on. (Notice that this often includes words in foreign languages such as “etoile,” “stern,” and “stella”). While this feature improves recall, it sometimes compromises the precision of the results. Our search engine allows one to turn off the synonym expansion feature by simply prepending an “=” sign in front of the search term.

Our search engine also identifies acronyms during indexing and searching (defined as words consisting entirely of uppercase characters). A search for an uppercase word will only match documents which contain that acronym, whereas a search for a lowercase word will match documents which contain any variation of the word, irregardless of its case. Acronyms can themselves have synonyms (for example “ADS” and “Astrophysics Data System” are synonyms), so one should be aware that there is an interaction between case-sensitiveness and synonym expansion. The examples below illustrate these effects:

Author Searches

Synoym expansion also applies to author names, which provide a way to account for changes in a person’s name and/or different spellings due to transliterations. In addition to this, the default author search in ADS is “greedy” in the sense that it will retun all documents in which an author signature may match the input search string. This allows, for instance, to have an author search for “Huchra, John” to return papers where the author name appears as “Huchra, John” or “Huchra, J.” By prepending the “=” character to the author search one can disable this feature (as well as any additional synonym expansion) and require an exact match on the author name. Some examples:

As a general rule we recommend to use the full name of the person for author searches since as can be seen above the matching rules in ADS are designed to find the maximal set of records consistent with the author specification given by the user. Rather than disabling the name-variation algorithm described above, we recommend performing refinement of search results via the user interface filters for author names as described in the “Filter your search” section.

Available Fields

This is a list of fields currently recognized by the ADS search engine and the preferred search format:

(*) See below for details on these filters. In most cases, filtering of results based on these fields is available in the user interface.

Properties

The “properties” search field allows one to restrict the search results to papers which belong to a particular class. The allowed properties currently include:

Bibliographic Groups

The “bibgroup” search field allows restriction of the search results to one of the ADS bibliographic groups. These groups are curated by a number of librarians and archivists who maintain either institutional or “telescope” bibliographies on behalf of their projects. Here is a partial list. For more information on the criteria behind the curation of these groups, please see the link above.

The list of current Institutional bibgroups is: ARI, CfA, CFHT, Leiden, USNO

The list of current Telescope bibgroups is: ALMA, CXC, ESO, Gemini, Herschel, HST, ISO, IUE, JCMT, Keck, Magellan, NOAO, NRAO, ROSAT, SDO, SMA, Spitzer, Subaru, Swift, UKIRT, XMM

Data Links

The “data” search field can be used to select papers which have data links associated to them. The list of archives which ADS links to can be seen under the “Data” filter selection. To generate a list of all records which have data links one can issue a simple wildcard query: data:* . Using the data search field allows one to focus on data-rich papers, for example:

data:(CXO OR XMM) AND data:HST

Finds multi-wavelength papers which have observations both in the X-ray spectrum (from Chandra or XMM) and in the optical (HST). Of course additional search terms can be used to further refine the selection criteria.

Document Type

Records in ADS are assigned a document type which is indexed in the “doctype” search field, the contents of which are an extension of the BibTeX entry types. Currently these are the document types indexed by ADS: