KITP_Big3_Surveyors


 * Report on the mini-workshop, see list of questions (4!) at the end:**

From November 5-9, we hosted a special "Surveys of Nearby Star Forming Regions Mini-Workshop." We invited the leaders and representatives from several survey programs to all come to KITP simultaneously. In the case of the two largest surveys (c2d and COMPLETE), several survey team members were present in addition to the principals, and many of those were postdocs and graduate-student affiliates.

The week began with an opening session hosted by co-organizer Alyssa Goodman on "What do we hope to learn this week?". The session offered a long list of questions crafted by Goodman and co-organizer Chris McKee, and urged participants to think about which questions (either from the long list, or others) were perhaps answerable in the near-term, given what we would learn that week about each others' surveys.

During the week, Neal Evans, P.I. of the Spitzer Legacy "Cores-to-Disks" (c2d) program spoke about how c2d has changed our thinking on the rates for star formation in nearby regions. And, postdoc Melissa Enoch gave another c2d talk, summarizing the team's work identifying and understanding the densest condensations that lead to the forming stars Evans had discussed.

Alyssa Goodman summarized the COordinated Molecular Probe Line Extinction Thermal Emission (COMPLETE) Survey of Star-Forming Regions, which is coordinated with c2d to provide all the contextual information about large-scale cloud structure and gas dynamics that Spitzer cannot measure. She and postdoc Rahul Shetty also discussed how both the observers present, and the theorists, can ramp-up their involvement in a new collaborative program called "Taste-Testing," which is designed to systematically inter-compare observations--especially from big surveys--with simulations of star-forming regions. The Taste-Testing program is using the Computational Astrophysics Data Analysis Center (CADAC) service founded, in preparation for this KITP program, by co-organizer Paolo Padoan to host simulation data.

Taurus, one of the nearest and thus well-studied star-forming regions, was the focus of talks by Paul Goldsmith (PI of the large FCRAO Survey of Taurus); Debbie Padgett (PI of the Spitzer Survey of Taurus), and Scott Schnee (postdoc studying the best-studied dense core in Taurus, TMC-1C). The Taurus projects are not directly coordinated, so it was great that many new synergies and opportunities for collaboration presented themselves at the meeting. Much follow-up is expected as a result.

Tom Megeath rounded out the set of surveyors, by discussing the extensive Spitzer observations of star cluster-forming regions. Megeath's talk was intended to, and did, raise the issue of whether we can understand the formation of clusters and massive stars as part of the same story that leads to the production of lower-mass, less-clustered, groups of stars. Phil Myers' gave a presentation entitled "Why do Core Mass Functions Resemble the IMF?," which also bore in part on the issue of whether we can consider the same physics throughout the star-formation process, or whether effects like feedback from massive stars so alter the situation as to require modifications.

The week saw two spontaneous contributions by visiting observers, one on new velocity statistics by Edith Falgarone, and the other on magnetic field surveys by Dick Crutcher. Crutcher's talk was particularly timely, because he has just (at KITP) dervied a key result showing that clouds are likely to be primarily "super-Alvénic," as was predicted in controversial theoretical work by Paolo Padoan nearly a decade ago. Super-alfvénic clouds are less magnetically-dominated throughout most of their volume than is allowed by some current theories of star formation, and Crutcher's support for Padoan's picture is likely to send a bit of a shock wave through our community.

On the final day of the program, Phil Myers gave a wrap up of what we had learned, and we had a discussion hosted by Alyssa Goodman about a list of questions upon which it would be best to focus in the near-term. We were very fortunate that many very observationally-engaged theorists were visiting KITP the week of our Mini-Workshop, and had participated actively all week. By the time of the concluding discussion, they, and all the observers, had plenty to say! Some **key issues** upon which the group agreed to focus include: **1)** how filamentary are structures in star-forming regions, as a function of spatial scale, and why?; **2)** how can we create better semantic definitions of structure, so as to avoid confusion? (e.g. who means what by "star formation efficiency" and "star formation rate"); **3)** can we do a better job (observationally) of connecting column density measurements of cores and their "environments"?; and **4)** can we improve stellar age and velocity measurements?.

Overall, the week was a tremendous success and we highly recommend such a mid-course observationally focused session to other organizers.