SIMBAD references

We present the Gravitational Wave (GW) Treasure Map, a tool to coordinate, visualize, and assess the electromagnetic (EM) followup of GW events. With typical GW localization regions of hundreds to thousands of square degrees and dozens of active follow-up groups, the pursuit of EM counterparts is a challenging endeavor, but the scientific payoff for early discovery of any counterpart is clear. With this tool, we provide a website and an application programming interface (API) that allows users to easily see where other groups have searched and better inform their own follow-up search efforts. A strong community of Treasure Map users will increase the overall efficiency of EM counterpart searches and will play a fundamental role in the future of multimessenger astronomy.