Bicep2-list June 2013

bicep2-list@lists.fas.harvard.edu

13 participants
11 discussions

BICEP2 Team meeting today (30 Apr 2013) noon Eastern, followed by pipeline telecon

by John Kovac

Hi all, BICEP2 telecon today at the usual time, followed by CMB pipeline discussion: Tuesday, 30 Apr 2013 12:00 Eastern, 11:00 Central, 9:00 am Pacific Phone: 1-866-890-3820 (toll: 1-334-323-7229) Passcode: 59702175 # Our group-edited agenda is in the telecon notes http://goo.gl/LNvpx Thank you Walt for filling in much of it ahead of time. Clem and anyone else please continue to add appropriate items. Current snapshot is below. John Agenda: 1) General business panlfs downtime 4/29-5/3 (announced last week): impacts? collaboration meeting followups publication policy, talk postings, MOUs writing up instrument / systematics / observations topics 2) Review final report on mapmaking inputs [ Walt ] http://bicep0.caltech.edu/~bicep2/papers/final_reports/mapmaking/ 3) Other final report items and action item review - See Harvard meeting AI’s below 4) Preview of new postings 2013 Apr 23: Temperature Planck maps reobserved with BICEP2 (SRH) 2013 Apr 23: Field Outline (JET) 2013 Apr 23: Statistical precision of the polarization angle determination with the galactic field maps of BICEP2 (SRH) 2013 Apr 23: Fix Map Pager (CLP) 2013 Apr 24: Checking our pointing calculations (RWO) 2013 Apr 24: Feasibility of "traditional" noise sims for BICEP2+Keck (RWO) 2013 Apr 24: Fixing the parallactic angle calculation (RWO) 2013 Apr 25: Active Thermal Control (PID) test (UPDATED) (JPK) 2013 Apr 26: Sign Flip Noise in Comparison to Regular Noise Sims (updated) (STF) 2013 Apr 29: Cross vs. Auto Spectra, version 2 (STF) 2013 Apr 29: FTS: Attempting to Increase Repeatability With Illumination Cuts (UPDATED) (JPK) [ BICEP2 team meeting ends after one hour. ] [ Pipeline agenda to be filled in by Clem and previewed during the last stage of the main telecon ] -- ___________________________________________________________________ John Kovac jmkovac(a)cfa.harvard.edu Assistant Professor, Astronomy and Physics, Harvard University 160 Concord Ave rm 310, Cambridge MA 02138, 617-496-0611

10 years, 9 months

Summer School Poster -- Feedback Welcome

by Kate Alexander

Hello everyone, I will be attending a summer school on "New Horizons for Observational Cosmology" in Varenna, Italy next week and the school includes an opportunity to present a poster (see attached; also available online at https://www.cfa.harvard.edu/~kalexand/poster/). While this is fairly last-minute, as I need to print the poster by the end of the workday today, I welcome any feedback. Furthermore, as the poster I have put together includes results obtained from everyone's hard work, I would like to list the entire collaboration as co-authors. Please let me know if I have left anyone off the list (or if you would rather not be included). Thank you, Kate Alexander

10 years, 10 months

Down time SPUD

by Stefan Fliescher

Hi, there will be a power outage in SPUD's server room tomorrow morning (Saturday 06/22). We will shut down SPUD this evening and restart when possible. Stefan -- Stefan Fliescher - Research Associate University of Minnesota, Tate Lab Room 237, 116 Church Street S.E. Minneapolis, MN, 55455 Phone: 612-626-6581

10 years, 10 months

First steps forward for beam map convolution with flat sky

by Chin Lin Wong

Hi I was tasked to propose the immediate next steps for using the beam maps that I've constructed and convolving it with the flat sky to quantify T->P leakage. Immediate plan of work: 1. Tag subset, TnoPol, timestream deproj off for (a) set of noiseless input beam maps with AB offsets in the beam map (b) Stefan's multigauss implementation Make T,Q,U maps and power spectrum, compare T->P leakage. Is (a) the same as (b) and the same as what Chris has in his posting? This would check that I've gotten the simulation to run correctly. Start with 1 realization, and if that goes easily, do 10 realizations. 2. Tag subset, TnoPol, timestream deproj on for: (a) set of noiseless input beam maps with Ab offsets in the beam map (b) Stefan's multigauss implementation Did I use the deproj correctly? Translate the recovered deproj coefficients into beam parameters and compare vs input. 3. Tag subset TnoPol, timestream deproj on for a set of input beam maps w uber-chopper noise levels. Make T,Q,U maps and power spectrum. It would be informative to see at what level we can quantify the T->P leakage with uber chopper noise in the beam maps. Next, I think we want to use real beam maps. I plan to first make composite uber-chopper maps, using uber chopper maps at 4 different dk angles. I will mask out the ground to make these maps, and hopefully, this will result in nice, clean maps with no ground/MAPO contamination in them. The uber chopper maps are our least noisy maps, and it would be interesting to see in test (3) how well we can quantify the T->P leakage in the presence of noise. Feedback will be really welcome. Thanks! Chin Lin

10 years, 10 months

Re: [Bicep2-list] [Bispud-pipeline-list] First steps forward for beam map convolution with flat sky

by Clem Pryke

Hi Chin Lin, I think your plan looks good. I also agree that with John that template noise should be off to start with and that shifting A/B to a common center would be a funny thing to do - it also shifts the sidelobes in a non-physical way. Looking forward very much to seeing some results. Please actively seek help if you run into technical problems - the pipeline and running it on Odyssey is a pretty complex undertaking at this point. Best, Clem -- ********************************************************************** Clem Pryke - Associate Professor - Physics University of Minnesota, Room 313 Tate, 116 Church Street S.E. Minneapolis, MN, 55455 Tel: 612-624-7578 Fax: 612-624-4578 email: pryke(a)physics.umn.edu **********************************************************************

10 years, 10 months

Re: [Bicep2-list] First steps forward for beam map convolution with flat sky

by Clem Pryke

Hi Immanuel, We have been doing TnoPol sims for a long time to assess false B-modes. Are you saying that is not valid? Clem -- ********************************************************************** Clem Pryke - Associate Professor - Physics University of Minnesota, Room 313 Tate, 116 Church Street S.E. Minneapolis, MN, 55455 Tel: 612-624-7578 Fax: 612-624-4578 email: pryke(a)physics.umn.edu **********************************************************************

10 years, 10 months

Re: [Bicep2-list] [Bispud-pipeline-list] First steps forward for beam map convolution with flat sky

by John Kovac

Hi Chris, On 6/12/13 6:13 PM, Chris Sheehy wrote: > - Your 1) and 2) are the same thing ... as long as you set mapopt.deproj=true, you pretty much get > dprojected and undeprojected maps for free. Yep, thanks for this clarification--procedurally these are not really separate steps, but they are separate tests. > - We talked about this on the telecon, but unless we have a way to turn > off A/B offsets, what we're going to see is leakage from A/B offsets and > nothing more. After deprojection we will see residual leakage from A/B > offsets and nothing more. By "residual leakage from A/B offsets" you mean due to template noise, right? I think we should turn off template noise. See my comment below. > It will still be interesting to add noise to > the beam maps and see what happens, and once you proceed to real beam > maps, it is possible we will see more than just residual A/B offsets, > which would imply an undeprojected residual that is strong enough to > affect us. If we don't see anything, we can be glad that undeprojected > residuals are below what we care about. This is the main point of the test, yes. The key at this stage is to establish the limiting level of the beam map noise in assessing residual T->P. > And it might be interesting to be able to see beamwidth / ellipticity > deprojection do something when you simulate real beam maps. > > I'm in favor doing one more sim, which is with beam maps that have no > A/B centroid mismatch, and running with simopt.diffpoint='ideal'. I > don't see the downside to doing this and I think it gives is more > information about our beams. Without doing it, even if there are weak > undeprojected residuals in our beams that we have a shot at seeing via > these sims, we'd make ourselves blind to them by always including A/B > offsets. Yes, the fact that we'd be blind to them would mean that > they're so weak we don't care about them, but if they're there it'd be > nice to know. > > What do people think? It seemed to me like you guys were opposed. I'm not adamantly opposed, but the issue I have with this is that it confuses the intent of this exercise. We are trying to simulate our actual beam mismatch in a way that is independent of any modeling or fitting, and then ask what winds up in our CMB maps before and after the kinds of actual deprojection operations we apply. "Turning off" differential pointing means assigning a specific value to the A-B offsets, which we fit from the main beam. But performing the shift you are talking about, which doesn't happen to our real data, affects the main beam and sidelobes, symmetric and asymmetric parts. If we want to ask the question "what is our best estimate of the undeprojected residual from beam leakage after ideal removal of the difpoint mode we deproject" then isn't it better to deproject this specific mode, whether on the beam maps or on the timestreams? We had planned to do both, but primarily rely on the results of the latter. And for those I think we should turn off template noise entirely, for all of these sims. We can re-include (Planck-level) template noise at the end, but it should just be adding back in a known effect, and one which is already accurately debiased. If you want to ask the question "what would the undeprojected residual look like if our map making code were able to assign A and B beam pointings separately, based on some fit to individual centers, rather than to their common centroid" then I think you want the sim you are talking about. I don't object to it, but unless we are considering that kind of change to our map making code I don't think it is the primary question. I just talked to Chin Lin and she agrees. John > > -Chris > > > > On Wed, Jun 12, 2013 at 2:13 PM, Chin Lin Wong > <clwong(a)physics.harvard.edu <mailto:clwong@physics.harvard.edu>> wrote: > > Hi > > I was tasked to propose the immediate next steps for using the beam > maps that I've constructed and convolving it with the flat sky to > quantify T->P leakage. > > Immediate plan of work: > > 1. Tag subset, TnoPol, timestream deproj off for > (a) set of noiseless input beam maps with AB offsets in the > beam map > (b) Stefan's multigauss implementation > Make T,Q,U maps and power spectrum, compare T->P leakage. Is (a) the > same as (b) and the same as what Chris has in his posting? This > would check that I've gotten the simulation to run correctly. Start > with 1 realization, and if that goes easily, do 10 realizations. > > 2. Tag subset, TnoPol, timestream deproj on for: > (a) set of noiseless input beam maps with Ab offsets in the > beam map > (b) Stefan's multigauss implementation > Did I use the deproj correctly? Translate the recovered deproj > coefficients into beam parameters and compare vs input. > > 3. Tag subset TnoPol, timestream deproj on for a set of input beam > maps w uber-chopper noise levels. > Make T,Q,U maps and power spectrum. It would be informative to see > at what level we can quantify the T->P leakage with uber chopper > noise in the beam maps. > > Next, I think we want to use real beam maps. I plan to first make > composite uber-chopper maps, using uber chopper maps at 4 different > dk angles. I will mask out the ground to make these maps, and > hopefully, this will result in nice, clean maps with no ground/MAPO > contamination in them. The uber chopper maps are our least noisy > maps, and it would be interesting to see in test (3) how well we can > quantify the T->P leakage in the presence of noise. > > Feedback will be really welcome. > > Thanks! > > Chin Lin > > > > > > _______________________________________________ > Bispud-pipeline-list mailing list > Bispud-pipeline-list(a)lists.fas.harvard.edu > <mailto:Bispud-pipeline-list@lists.fas.harvard.edu> > https://lists.fas.harvard.edu/mailman/listinfo/bispud-pipeline-list > > > > > -- > ********************************************************************** > Christopher Sheehy - Ph.D. candidate - University of Chicago > Research Specialist, University of Minnesota, Department of Physics > Room 220 Tate, 116 Church Street S.E. Minneapolis, MN, 55455 > Tel: 612-625-1802 Fax: 612-624-4578 email: csheehy(a)uchicago.edu > <mailto:csheehy@uchicago.edu> > ********************************************************************** > > > _______________________________________________ > Bicep2-list mailing list > Bicep2-list(a)lists.fas.harvard.edu > https://lists.fas.harvard.edu/mailman/listinfo/bicep2-list > -- ___________________________________________________________________ John Kovac jmkovac(a)cfa.harvard.edu Assistant Professor, Astronomy and Physics, Harvard University 160 Concord Ave rm 310, Cambridge MA 02138, 617-496-0611

10 years, 10 months

Final report page: abscal

by Walt Ogburn

Hi all, I have posted a "final report" for absolute calibration. Comments are welcome. http://bicep0.caltech.edu/~bicep2/papers/final_reports/abscal/ - Walt

10 years, 10 months

Thesis submitted!

by Randol Aikin

Hi Folks, Just wanted to let you know that my thesis has been submitted. The copy submitted to Caltech will be embargoed until the BICEP three-year paper becomes available. In the mean time, you can find a copy here: http://bicep.caltech.edu/~bicep2/papers/theses/ By the way, after next week, I'll be losing my current email address (rwa(a)caltech.edu), though I'll still have message forwarding for a while. Future correspondences will be from raikin(a)gmail.com. Thanks, Randol -- Randol Aikin California Institute of Technology 1200 E. California Blvd. Pasadena, CA 91125 371 Cahill, MC 367-17 (626) 395-2016 raikin(a)gmail.com

10 years, 11 months

Planck vs WMAP abscal, including slope parameter

by John Kovac

Hi Walt and Sergi, I'm expecting on tomorrow's telecon we will discuss Sergi's posting (deferred now twice): 2013 May 6: Planck 143 nominal maps versus BICEP2 revisited (SRH) http://bmode.caltech.edu/~spuder/analysis_logbook/analysis/20130506_planck_… Sergi added "NOTE Added 20130514: Do not check out this posting..." Ignoring this warning, I see the posting claims a detection of the 2.2% calibration power scaling between Planck and WMAP, similar to the level Planck has reported at degree scales. In talking with Kris Gorski on Friday we reviewed the spectral shape of this discrepancy that Planck and WMAP have been fretting over--it appears roughly consistent with linear slope which ranges from 0 at low ell to 2-2.5% at ell=200, and roughly constant above that. I'm eager to see a side-by-side abscal analysis of B2 derived from WMAP vs from Planck, including the slope parameter introduced by Walt in this posting: http://bmode.caltech.edu/~spuder/analysis_logbook/analysis/20121101_abscal_… Perhaps it would be worth running this slope specifically for our ell=30-200 bins (rather than our usual 100-300). I'd like to see the average difference in slope parameter for individual detectors on Planck vs WMAP, and the same for the coadded abscal as well. It is not clear to me whether our beam measurements can reach high enough precision to be able to say whether it is Planck or WMAP that has the "right" slope--that would be quite newsworthy--but as a first step it would be interesting to see whether we can detect this ell-dependent discrepancy between the two experiments. Walt, is this abscal analysis already in the works? thanks, John -- ___________________________________________________________________ John Kovac jmkovac(a)cfa.harvard.edu Assistant Professor, Astronomy and Physics, Harvard University 160 Concord Ave rm 310, Cambridge MA 02138, 617-496-0611

10 years, 11 months

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Bicep2-list June 2013