Minutes 2nd LISA PE telecon 15.11.2007 ================================================ Partial list of participants: Curt Cutler Alicia M Sintes sintes#aei.mpg.de B.S.Sathyaprakash Chris van den Broeck Arun Han Wang Emanuele Berti Marta Volonteri Miquel Trias miquel.trias#uib.es Carlos F. Sopuerta ,sopuerta#ieec.uab.es John Baker John.G.Baker#nasa.gov, Neil Cornish Stas Babak , Jonathan Gair Ed Porter ========================================================= 1-SMBH status of the various check and comparisons: Neil summarizes the information posted on our wiki: http://www.tapir.caltech.edu/dokuwiki/lisape:home There we can find a description of the exercises and the conventions that coincide with those from the MLDC. There are 4 cases as examples: for 1 year observation time and merger exactly at the end of that year and for 1 year observation but with a time to merger of 1.05 years. - Cornish and Hughes results are posted for all cases giving the parameter errors and the Fisher correlations. - Independent code by Cornish and Porter provided also the same kind of results. These results are in high agreement with those of Cornish and Hughes. -Trias and Sintes have posted also results for the 4 cases. The information they provide are the errors and so far the fisher matrices (for one detector case, the two detector case the Fisher matrices were not yet posted). The results by Trias and Sintes are within factors ~1.5 from those by Cornish and collaborators, but they are consistent in a way that when they obtain a bit larger SNR the errors are smaller and for lower SNR errors are a bit larger. -Cardiff group was working on it but did not yet post results -There was a discussion on conventions and the importance of the orientation angles that affects both SNR and errors and also how waveforms are terminated. Berti also asked information regarding the noise employed by different groups. All groups will make an effort to follow MLDC conventions > Action items were to plot the waveforms in frequency domain, real, > imaginary parts and envelope. ========================================================= 2. Report by Berti & Volonteri on binary black hole population models - a document titled: Binary black hole formation models in the parameter estimation taskforce by Emanuele Berti & Marta Volonteri is posted on the wiki. - The purpose is to produce input files listing masses and redshifts of black holes in a specified black hole formation model. -They explain how they compute the merger trees: they consider the Volonteri-Haardt-Madau (VHM) scenario, where light seed black holes of m_seed ? few times 100 Ms are produced as remnants of metal-free stars at redshift z >= 20. Results are averaged over several merger trees (~10). -the document contained a number of topics for discussion, e.g : -the importance of the cosmological parameters for setting the masses of the systems. -the need to include or not spin evolution in the population models. This became an action item. -how is the weighting done among the different trees - number of candidates to be included in the files and if those should contain o not angular information. In such case we all agree that the assumption of isotropy was reasonable, and that we should produce an over complete set to be used by the MC parameter estimation codes. - there was a discussion on different scenarios and how many files should be produced with how many binaries, so that these numbers could be meaningful and easy to handle. First numbers mentioned were of 8000 binaries per scenario. There is also a discussion on which are the most probable binaries and how to extract those from the files, i.e., how to weight the binaries, how to select them (SNR, Z, mass, mass-ratio, etc). People involved in the discussion: Baker, Berti, Cornish Cutler, Sathyaprakash, Volonteri,... Cutler suggest to produce a very long list file and several other short lists. Also that the goal is to provide figures of merit for LISA, run our codes for certain realizations of the universe and how different LISA configurations affect the science LISA could do. The discussion continues regarding the spins, how to include them and treat them dynamically. It is mentioned that it is not easy to constrain the evolution of spin, be we could impose some pre-determined distributions of spins, depending on accretion, spin aligment, magnetic coupling etc... clearly uncertainties will be very large. Action items: > Marta would produce stadistical meaningful data sets: a long list and short lists, not cutting just on SNR but on the probalility that event to happen and for different scenarios, > Marta: a 1st step to include spin in her models (without spin precession yet) and study the evolution for different 'seed' configurations of plausible distributions of spins. This should be discussed at the next telecon ========================================================= 3. Discussion on EMRIs - EMRI's Neil is going to post some links. Study and compare some of the systems from the MLDC 1.3.1 & 1.3.X (?), sample results on the wiki, and compare result of some training sets, people involved are Neil, Stas, Ed (using Johnathan's code) ========================================================= Next telecon: Nov 29th 8:15 PST, 11:15 EST, 16:15 UTC, 17:15 CET Please send comments or correction to sinte