Procedures for Early Collaborative Use of SDSS Data with Non-Participants

September 1999


Section 4.1 of the SDSS Principles of Operation (PoO) states that data rights are in the hands of scientists at an SDSS institution ("Participants") who have PI status or whose primary responsibility is the construction of the SDSS, and of individuals at other institutions granted such Participant status. Section 4.2 of the PoO describes the principles under which SDSS data may be used collaboratively by non-Participants prior to public release. The purpose of this document is to define efficient procedures for implementing this section of the PoO. The procedures are slightly different for "inside" collaborators, who are at SDSS institutions, and for "outside" collaborators, who are not. See also "SDSS Data Access by Graduate Students and Postdocs".

Examples of the kinds of collaborations covered by this policy include:

  • follow-up observations of interesting SDSS objects with larger telescopes or at other wavelengths;
  • use of SDSS data in generating observing proposals for space observatories (e.g., AXAF), in collaboration with some non-SDSS astronomers;
  • searching the SDSS catalogues for objects with the color signature of some particular type of object (e.g., T Tauri stars), in collaboration with a non-SDSS scientist who has devised an efficient search algorithm;
  • comparison of the SDSS luminosity functions for galaxies with data on faint galaxies observed at Keck;
  • comparison of SDSS data to data from other surveys (e.g., 2MASS) in a particular area of the sky;
  • comparison of SDSS star counts with a new model for the Galaxy;
and so on.

"Inside" Collaborations

In practice, much of the scientific analysis of the SDSS data will be done by students and postdocs at SDSS institutions. These "inside" collaborators access the data through individuals at their institution with data rights. These individuals (i.e., the graduate and postdoctoral advisors) are responsible for ensuring that their collaborators read and agree to the PoO and publication policy, and they are responsible for ensuring that these policies are followed and that the data are not released outside the collaboration. They and their institutions are also responsible for providing the necessary research support: computing, page charges, trips to scientific meetings, and so forth.

Because collaborative work with students and postdocs will be the norm rather than the exception, no special permission is required to initiate such collaborations. However, as with all SDSS investigations, a team contact should provide notice to the collaboration upon the initiation of any project that is expected to lead ultimately to a publication, as described in Section 4.3.1 of the PoO and Section 8.1 of the Publication Policy. Such notification is especially important in the case of Ph.D. theses, so that those concerned are aware of any potential conflicts with other projects. The notification of initiation of an investigation should be submitted by an individual with data rights and should list all of the student, postdoctoral, and other collaborators. By submitting the notification, the individual with data rights implicitly accepts responsibility for ensuring that SDSS policies are followed by the non-Participants who are collaborating on the project.

External Collaborations with those leaving SDSS institutions

An individual at an SDSS institution who is working on projects involving SDSS data and leaves that SDSS institution may request External Collaborator status for those particular projects, so that he/she may continue working on them after he/she leaves. The request shall be made to the Chair of the Collaboration Council, and the decision will be made by the Management Committee in consultation with the leaders of the projects involved, the relevant working group chairs, and the CoCo. Normally, External Collaborator status will be granted provided that the individual has had significant involvement in the project before he/she leaves. This policy applies to faculty, postdocs, and graduate students. Individuals with portable data rights (participant status), of course, need not make such a request.

"Outside" Collaborations

Collaborations involving colleagues not at an SDSS institution and visitors at SDSS institutions (hereafter non-SDSS scientists) are treated differently. These collaborators will again access the data through Participants with data rights. At the initiation of such collaborations, the SDSS scientist(s) involved should:

  1. Inform the non-SDSS scientist(s) of the SDSS rules and guidelines (the PoO, the Publication Policy, and this Collaboration Policy) and obtain his/her consent to abide by them. In particular, non-SDSS scientists should understand and agree that they may not disseminate the SDSS data to which they have access in any way, and that publications resulting from the collaboration will be subject to the Publication Policy.

  2. Request comment and input from the relevant working groups (by e-mail to the relevant sdss- working group archives); this step is strongly encouraged.

  3. Obtain permission to proceed from the Collaboration Council (CoCo) by submitting a proposal. In an e-mail message sent to sdss-general and to the chair of the CoCo (, the SDSS Participant(s) involved should briefly describe the proposed project, list the names and institutions of the proposed collaborators, and state their willingness to ensure that the outside collaboration will proceed according to the SDSS rules, policies and guidelines. Most important, they should indicate what special resources or expertise the outside collaborators bring to the project (e.g., telescope access, experience with specific analysis techniques). This justification for inclusion of external collaborators should be a labeled, separate paragraph of the proposal so that it can be clearly evaluated.

    Permission can be expected in all cases where the outside collaborators bring resources or expertise that are not readily available within the SDSS collaboration itself. The guiding principle in these matters is to allow SDSS Participants the first opportunity to carry out science involving SDSS data, and to bring in outside collaborators only when necessary to get the science done in the pre-release period. Multiple collaborations pursuing similar ends are allowed, so the establishment of one outside collaboration does not preclude another along similar lines.

    Since collaborations involving non-participants require permission from the Collaboration Council, postings should be phrased as "proposals" rather than as "announcements", to avoid confusion.

    Objections to or comments on External Collaboration proposals from members of the collaboration or from the working group chairs should be forwarded to the CoCo chair within two weeks of the proposal's posting on sdss-general. Normally, the CoCo chair has four weeks to notify proposers of approval or of any objections to the proposed collaboration, consulting with other CoCo members, working group chairs, etc., as he/she deems necessary. If the CoCo decides that it needs more time to consider a given proposal, it may extend the time frame (within reason) and give notice to the project team of the new decision date.

    Rarely, proposals involving external collaborators will be time-critical "targets of opportunity" which require faster decision times. In these cases, the CoCo shall make every effort to respond to proposals within 10 days. Such time-critical proposals should be identified as such, and justification for the rapid time frame should be spelled out. Faster approval will only be given if a compelling case is made.

Once a project involving external collaborators is approved, the participants involved should:

  1. Post notice of the proposed project(s) to the Publication Archive, as per usual.

  2. Post papers resulting from such collaborations to the SDSS collaboration and invite authorship, as for an "internal" SDSS paper, and be sure the outside collaborators understand in advance that this will take place.

  3. Send a brief annual progress report to the Collaboration Council ( outlining progress made, future plans, and specifying the contributions made by the external collaborators.

If a project involving external collaborators is not approved by CoCo, the project team may appeal the decision to the Management Committee.

If a project is not approved and moves ahead in any case (e.g., follow-up observations are taken), the participants involved will be deemed to be in violation of this policy only if a publication results or if a public announcement of the results is made. At that time, the CoCo chair will inform the Management Committee that those involved are deemed to be in violation of the SDSS PoO.

For the case of students and postdocs supervised by SDSS Participants, see the policy on Data Access by Students and Postdocs.