Invitation to October 13-15 workshop on LISA Data Analysis Development planning

The US LISA Project has commissioned the US LISA Mission Science Office to prepare a development plan for LISA data analysis, working in consultation with the LIST (LISA International Science Team) and the LISA science community. A preliminary outline and a draft of key sections was prepared this summer by the LISA Mission Science Office and distributed to the LIST in July. The plan, nicknamed "AMIGOS" (Analysis Methods for Interferometric Gravitational-wave Observations from Space), will describe work areas, priorities, levels of effort, and timelines for the development of methods, tools, and other resources for the scientific analysis of LISA data. The structure and level of planning detail in this document parallel those of the LISA Project's Technology Development Plan (which is concerned with the development of the LISA instrument). During the Project Formulation Phase, AMIGOS will be an evolving document, held by the LISA Project, and coordinated with analogous ESA plans. It will help guide NASA-supported efforts in LISA data analysis between now and LISA's launch.

The LISA Mission Science Office at JPL is organizing a 2.5-day workshop to discuss, clarify, expand, and review the current AMIGOS draft, and more generally to gather the input of the LISA and GW science community on the planning of LISA data analysis. Tentative dates for the workshop are October 13-15 (Thu noon through Sat), in Pasadena, CA, in a venue TBD. The workshop will be organized around short topical presentations, with ample time for discussion. We are setting up a private "wiki" website and forum to collect all contributions to the workshop, and to annotate the document collaboratively in real time. The current draft of AMIGOS will be posted to the website a few weeks before the workshop. Logistical information will appear soon at the URL http://www.tapir.caltech.edu/amigos

This invitation is being extended to the LISA and GW science community in the U.S. and beyond. We are especially interested in the input of experts in GW data analysis, in GW source modeling, and in the management and analysis of large sets of scientific data. There will be no conference fee, but we will be unable to reimburse travel expenses.  Attendance will be limited by the capacity of the conference center. Interested parties should communicate their availability as soon as possible to Michele Vallisneri (vallis@caltech.edu), together with any suggestions, comments, or questions.

I look forward to hearing from you,

Michele Vallisneri
(for the LISA Mission Science Office at JPL)

First Gulf Coast Gravity Conference

The first Gulf Coast Gravity Conference will be hosted by the Center for Gravitational Wave Astronomy, at The University of Texas at Brownsville, on February 11th and 12th, 2005. The pattern will follow that of other regional meetings: equal time for every speaker; no registration fee, but there will also be no financial aid available for any of the participants; great informality. All interested researchers and students in all areas of gravitational physics are invited to attend and contribute talks. We expect to have a TGG-sponsored award for the best student presentation. The duration of the talks will be approximately 15 minutes, although the exact time will depend on the number of participants. Please submit your title/speaker/affiliation to Carlos Lousto by February 1st. (Conference webpage).

Gr-qc watch: Mission design for LISA Pathfinder

Landgraf, Hechler, and Kemble have posted their Lisa Symposium proceeding on Mission design for LISA Pathfinder [gr-qc/0411071].

Gr-qc watch: The LISA Phase Measurement System Project

Summers and Hoyland have posted a paper on their Results for the LISA Phase Measurement System Project [gr-qc/0411010].

Gr-qc watch: Probing anisotropies of GW backgrounds with a space-based interferometer

Kudoh and Taruya have posted a paper on Probing anisotropies of gravitational-wave backgrounds with a space-based interferometer: geometric properties of antenna patterns and their angular power [gr-qc/0411017].

Gr-qc watch: Trento group on Improved Torsion Pendulum

The Trento group has posted their MGX proceeding discussing their Improved Torsion Pendulum for Ground Testing of LISA Displacement Sensors [gr-qc/0411049].

Second black hole found at the centre of our Galaxy

Links: Astronomy and Astrophysics 423, 155 (2004), Nature news item

A second black hole lurks at the centre of our Galaxy, according to astronomers who have watched a cluster of stars spinning around it. [...] Jean-Pierre Maillard, an astronomer from the Institute of Astrophysics in Paris, France, led a team that looked at a very bright area of the galactic core called IRS 13, previously thought by astronomers to be a single object. Using infrared observations from the Gemini Observatory at the summit of Mauna Kea on the Big Island of Hawaii, they discovered that IRS 13 is in fact a rotating cluster of seven stars, just 0.065 light years across. Adding data from the Hubble Space Telescope and the Chandra X-ray Observatory, they calculated from the movement of the seven stars that they must be orbiting an intermediate-mass black hole, called IRS 13E, which spirals around Sagittarius A* at about 280 kilometres per second.

8th Eastern Gravity Meeting

The 8th Eastern Gravity Meeting will be held at Wake Forest University in Winston-Salem, NC on Friday and Saturday, March 18 and 19, 2005. In the tradition of the Regional Relativity Meetings in the US, this will be an open and informal meeting. All interested researchers and students in all areas of gravitational physics are invited to attend and contribute talks. The duration of the talks will be approximately 15 minutes, although the exact time will depend on the number of participants. As a regional meeting, many participants will be from the Eastern Time Zone, but all are welcome. As at past meetings, there will be no registration fee, but there will also be no financial aid available for any of the participants.

In addition to the usual regional conference, we are also celebrating the 2005 World Year of Physics by hosting two talks by Clifford Will on Thursday, March 17. Professor Will will present a Physics Department Colloquium at 4pm on Thursday followed that evening by a public lecture at 8pm titled "Was Einstein Right?" These events were timed specifically to coincide with EGM8, and we hope that those attending the meeting on Friday will be able to arrive early enough on Thursday to attend. Everyone planning to attend EGM8 is invited to attend either or both events on Thursday.

Online registration is available on the official conference web page, http://www.wfu.edu/~cookgb/EGM8/. This site will also provide updated information on travel and accommodations.

New measurements of the Lense-Thirring effect

Ignazio Ciufolini (with Erricos Pavlis) has a paper out in Nature (see also the news and views item by Neil Ashby) on "A confirmation of the general relativistic prediction of the Lense-Thirring effect". According to Ciufolini,

...this paper describes a measurement of the Lense-Thirring effect, accurate at the 5% to 10% level, using observations of the nodes only of the two LAGEOS satellites. This experimental determination of the Lense-Thirring effect agrees 99% with the theoretical prediction of general relativity.

The basic idea is the same as in the original 1984-86 proposal, using two laser-ranged satellites with supplemenatary inclinations satellites (PRL 56, 278, 1986) in order to eliminate the gravitational perturbations. This idea was analyzed in a large number of papers and official review studies by NASA, ASI, etc., (establishing an error of about 10 % in the measurement of the Lense-Thirring effect). The only difference here is that the two inclinations of the LAGEOS satellites have
now an offset from the ideal supplementary configuration of about 18 degrees and not some 0.1 degree (to allow for injection error) as in the original proposal.

However, thanks to the NASA space mission GRACE (two satellites ranging to each other to accurately measure Earth's gravity field) we now have models of the field that are several orders of magnitude better than those at the time of the 1984-86 proposal. Thereby making possible the result we obtained.

An important technical note on the error analysis of this measurement: In regards to the effect of the Earth gravitational
perturbations, even if one considers an error three times larger than the published GRACE model errors (which already include systematic errors), you are still left with a measurement of the Lense-Thirring effect at an accuracy level of about 10%! As far as the nongravitational perturbations, the total uncertainty of these perturbations has been studied in a large number of papers and in the already mentioned 1989 official review study of NASA and ASI, as reported in the supplementary information section.

Let me be a bit naughty, and suggest that Ciufolini's results may have so far been underreported in the U.S. (perhaps because of GPB's competing interests?) until GSFC joined into the fray (with Pavlis). However, Lorenzo Iorio has a different opinion on the precision of this determination.

LISA Data 2005 Summer Workshop at Aspen

Just in from the APS TGG.

LISA Data: Analysis, Sources, and Science
Aspen Center for Physics 2005 Summer Workshop, May 29 - Jun 18 2005

''The goal of this workshop is to bring together members of the astrophysics community, the gravitational wave detector community, and the data analysis community to stimulate discussions and understanding of the astrophysics that can be done using gravitational radiation.'' The organizers are Benacquista, Finn, Kalogera, and Vecchio.

www.astro.northwestern.edu/AspenS05/index.html