Motivations

In order to facilitate the citation of all types of Chandra data in the scientific literature, the Chandra Data Archive (CDA) adopted Digital Objects Identifiers (DOIs) in 2019. The CDA mints DOIs for distinct archival observations (ObsIDs) and Chandra Source Catalog (CSC) stack and observation-level data products. The CDA now offers a new type of DOIs that can be associated with a collection of Chandra datasets meant to be used in the same publication or project. This new class of DOI is called "Chandra Data Collection" DOI.

Chandra Data Collection DOIs

The Chandra Data Collection (CDC) DOI is a new class of Chandra DOIs that allows the citation and linking in publications of an arbitrary combination of Chandra archival observations and CSC data entities. Users can request the creation of a CDC DOI for their Chandra data collection using this webform. The CDA will collect the information provided by the users and contact them when the details of the CDC DOIs are available.

CDC DOIs usage

A CDC DOI can be conveniently included in a LaTeX manuscript that complies with the AASTeX standard (v6.3) using the \dataset markup as follows:

Example: This paper employs a list of Chandra datasets, obtained by the Chandra X-ray Observatory, contained in the Chandra Data Collection (CDC) 'collection_id'~\dataset[doi:10.25574/cdc.'collection_id']{https://doi.org/10.25574/cdc.'collection_id'}

If the \dataset command is not available, the CDC DOI can be simply linked in the manuscript as follows:

Example: This paper employs a list of Chandra datasets, obtained by the Chandra X-ray Observatory, contained in the Chandra Data Collection (CDC) 'collection_id'~\href{https://doi.org/10.25574/cdc.'collection_id'}{doi:10.25574/cdc.'collection_id'}

The full CDC DOIs includes a fixed proxy and fixed prefix, and a variable suffix based on the the CDC DOI identifier ('collection_id'). This suffix, necessary to determine the unique CDC DOI name, will be communicated to the user by the CDA staff by email.

Q&As about CDC DOIs

• I use a single ObsID or catalog-style observation/stack in my paper. Do I need to request a CDC DOI?
  YES. CDC DOIs replace direct citation of single-object DOIs and should be requested for collections comprising any number of single Chandra data objects.
• I am using in my paper the exact same set of Chandra data for which I obtained a CDC DOI for a previous publication. Do I need to request a new CDC DOI?
  NO. As long as the sets of data used in different publications are identical, the same CDC DOI can be used.
• I am using a set of Chandra data objects that is the union of two separate sets for which I previously obtained two separate CDC DOIs. Can I cite the two CDC DOIs instead of requesting a new one?
  NO. Even if the collection of Chandra data you are currently using is the sum of two collections for which CDC DOIs have already been created, please request the creation of a new CDC DOI.