Theory in the VO

In this document we discuss the introduction of theoretical results and data, for example that generated by large scale numerical simulations, into ongoing virtual observatory (VO) activities. The whitepaper has two main target audiences. The first is the community of theorists who either wish to take the initial steps necessary to publish their results online, or who want to make their existing online presence "VO compatible", in both cases ensuring consistency with well defined standards. For this audience, we attempt to describe existing VO efforts, with particular emphasis on the standardization efforts embodied by the International Virtual Observatory Alliance (IVOA). The second audience comprises developers working in the various VOs, especially those involved in the IVOA. For this group, we describe how theoretical archives and related services imply interesting new requirements on these efforts. Our approach in this whitepaper is to adopt the style of a FAQ, in the hope of provoking discussion based on the particular questions asked. In certain instances, only tentative answers are suggested, since it is expected that the reader will provide the relevant answers. In other cases we provide answers which are not necessarily IVOA approved, but are drawn from the authors ongoing participation in the IVOA process together with extensive experience in the analysis of large scale cosmological simulations as well as a background in a business IT environment heavily aimed at data modelling and (web) service design. In some cases, we give answers to questions that have yet to bee addressd in the IVOA, in particular in the area of what it means to publish archives and the role that data modeling efforts can or should play in relation to this. We further support the creation of a specialized working group dealing with theory data in the IVOA. This group should ensure that other working groups are made aware of theory specific issues and that these are addressed. Ideally the group should propose a road map for the development of theory specific standards and reference implementations based on these. The current document, or later versions thereof, can form the basis of a charter for this working group. 1 German Astrophysical Virtual Observatory (GAVO), Max-Planck-Institut für extraterestrische Physik, Garching, Germany. E-mail: [email protected] 2 National Virtual Observatory (NVO), University of Pittsburgh, USA. E-mail: [email protected]