The LIGO-TAMA Kyoto Accord

Pictured are (l-r): Nobuyuki Kanda, TAMA; Masa-Katsu Fujimoto, TAMA; Yoshihide Kozai, TAMA; and Barry Barish, LIGO.

An important milestone was just achieved during the recent GWDAW 2002 meeting in Kyoto, Japan. After almost a year of discussion between the LIGO Laboratory, the LIGO Scientific Collaboration (LSC) and the Japanese gravitational wave detection project, the TAMA300, an attachment to the LIGO-TAMA Memorandum of Understanding (MOU) was signed that officially commences a collaboration on joint analysis of data taken simultaneously by the two organizations.

The initial effort will focus on joint analysis of a 9-plus hour segment of coincident data taken during LIGO's S1 and TAMA's DT7 runs in August-September 2002. This data set constitutes a testbed for prototyping joint analysis approaches. Plans are also being made to run simultaneously during the upcoming two-month-long LIGO S2 and TAMA DT8 runs in February-April 2003.

To promote close cooperation and exchange of information and ideas for this activity, a small working group of five individuals each from the LSC and TAMA has been established. The working group includes the following people:

- Masaki Ando (University of Tokyo)
- Patrick Brady (University of Wisconsin-Milwaukee)
- Sam Finn (Pennsylvania State University)
- Nobuyuki Kanda (Osaka City University)
- Erik Katsavounidis (MIT)
- Albert Lazzarini (Caltech)
- Hideyuki Tagoshi (Osaka University)
- Ryutaro Takahashi (National Astronomical Observatory of Japan)
- Daisuke Tatsumi (National Astronomical Observatory of Japan)
- Peter Saulson (Syracuse University)

The initial searches to be conducted in collaboration will target unmodeled signals from bursts or transient sources (explosive gravitational wave signals from sources unexpected or unpredicted, a particularly challenging signal to hunt), and chirps from binary inspiral coalescences (the much sought collisions of neutron stars or black holes that spiral into one another as their orbits decay with the emission of gravitational waves). At the present time, TAMA and GEO are also defining an MOU to enable data from the two groups to be analyzed together. LIGO concluded an earlier agreement with GEO and data taken together is now being jointly analyzed. The upcoming S2/DT8 runs will incorporate data from a total of five interferometers arrayed around the globe: three from LIGO, plus the GEO600, and the TAMA300. The commitment among these interferometer groups to work in collaboration assures that the laser interferometers now in operation will utilize their sensitivities in the most optimal manner.