CMBPol Mission Concept Study Telecon notes 16 January, 2008 Revised 18 January 2008 Participants: Bock, Cooray, Dunkley, Glenn, Hanany, Hinshaw, Hu, Kogut, Lee, Meyer, Page, Ruhl, Seiffert, Shimon - Did I miss someone? ____________________________________________________________ Workshop updates. Systematics workshop dates are set. July 28 - Aug 1 in the Maryland area. Workshop topics from later in the discussion: The workshop leaders should be responsible for meshing the input from the detailed studies and external contributors. Study leaders should feel free to volunteer contributions to the workshops. ___________________________________________________________ Detailed Study Status 1. Foregrounds (Cooray) Cooray described the software tool his group has built to estimate the foreground removal for instruments with different focalplane configurations. The current tool is designed for low resolution instruments. Checkout Amblard et. al (2007) arXiv:astro-ph/0610829. Additions planned: 1) higher resolution to enable the foreground subtraction estimation for the lensing signal. 2) add Fourier space analysis. It is now a pixel-space analysis only. 3) Need improved template maps. Input is planned for the theory workshop. Clearly this tool should be a element in the systematics workshop as well. The question of frequency coverage was worked for the EPIC proposal with constraints on total number of detectors. Some thought about generalizing the range of instrument constraints is worth it. There was a question about building a website for the calculation of foreground removal. This could become a reference foreground removal site. 2. Foregrounds (Dunkley) Goals of this study overlap with the Cooray study. This study is a pixel-based calculation of the foreground cleaning. The method is to marginalize over the foreground contributions and explore the resulting inflation of the error bars. The methods are complementary. So far no connection between this study and the systematics workshop. Input into the theory workshop includes an overview of foreground types and foreground science. __________________________________________________________ Clive Dickenson comments regarding the foreground meeting at JPL and the foreground tools used at IPAC. Our CMBPol group has two things to consider. 1. We should have a presence at the JPL meeting. Who and how much? 2. We should encourage input into our workshops. The timing is good for input into the systematics workshop at the end of July. Clive's input on the workshop and the foreground tools at IPAC: 1. The JPL/Caltech/IPAC group plans to use the commander code (Eriksen et al., 2008, in press), or "fgfit" code (Eriksen et al. 2006) if necessary (it already works in polarization), to help understand what is the optimal experimental design is for removing foregrounds. Although commander still requires some work to work in polarization, in principle, it is the perfect tool for studying the recovery of CMB on large angular scales. This is because it fits for foregrounds in pixel space but calculate the full likelihood of the Cls at the same time thus giving is realistic propagated error bars. We can use the Planck sky model as a first go at a polarized sky model although we may want to add more complicated models including spectral curvature etc. 2. The foregrounds meeting in Pasadena, California (14-18 July 2008) might be a good chance to either hold the foregrounds workshop, or at least, for some of us to discuss work/results. There will be a room available along side the meeting (to hold up to ~40 people) which I can arrange. The afternoon of Friday 18th July would be the best because the main meeting will finish early that day. We could also continue on campus (Saturday) if necessary.