Bicep2-list August 2013

bicep2-list@lists.fas.harvard.edu

13 participants
29 discussions

by Clem Pryke

Hi all, I am pleased to report that yesterday morning Chris successfully defended his thesis. Chris gave a good talk and there were good questions both from the general audience and the committee. Chris will be moving in September to KICP fellowship (for three years I think). Congrats to Chris! 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, 9 months

Tuesday telecon rules

by Clem Pryke

Based on discussion we will set rules for the Tuesday telecons as follows: 1) Telecon starts promptly at noon/11/9am and is capped at 2:30 total. This will usually be 30 minutes of general discussion followed by up to 2 hours of detail discussion of posting etc - the exact boundary may vary week to week. 2.5 hours total is a hard cutoff--any remaining postings or discussion will be deferred to subsequent weeks. 2) Please send an email when you put up any posting giving a brief summary and noting if it needs to be discussed on the next telecon. Please show up at the telecon having examined all the plots posted and prepared to give a concise summary (even if it is just "I have stared at this plot for hours and I still don't understand what is going on"). 3) Any posting made after 7am Tuesday (eastern) will be automatically deferred to the following week. Clem and John -- ********************************************************************** 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, 9 months

Two comments: (I) Sky convolution

by Sergi R. Hildebrandt

Hi All, I have written a non-linked posting about sky convolution in Planck and some suggestions: http://bicep.caltech.edu/~spuder/analysis_logbook/analysis/20130807_convolu… My alternative suggestions are anything really new. I'd rather have preferred to post a result that would prove (or improve) them, since I tacitly took this task a couple of weeks ago, but I understand from Tuesday's thread taht we need to take a decision in the next few days. I hope it helps! Cheers PS: John's email weeks ago about posting the two lists was cut, so I do not know if I am doing correctly now. Sorry for the spam in case I am not. -- Dr Sergi Hildebrandt Rafels Jet Propulsion Laboratory ---------------- California Institute of Technology 169-217 Cahill-383 4800 Oak Grove Drive 1200, E. California Bvd Pasadena, CA, 91109 Pasadena, CA, 91125 MC/169-237 MC/367-17 1-818-354-0220 1-626-395-2147

10 years, 9 months

Re: [Bicep2-list] BICEP2 Team meeting and B2/Keck CMB analysis telecon today (6 Aug 2013) noon Eastern

by Clem Pryke

Hi John, We did look into this. If I remember correctly: 1) I think the Wandelt algorithms rely on precalculating maps folded with each "beam mode" - with frightening storage and memory implications. Presumably they need to be full sky rather than the cutdowns we normally use. 2) As you know the way the pipeline works is to perform an interpolation off the input map per trajectory timestep and per detector. The computational expense of including in this operation on-the-fly convolution of an arbitrary beam shape with arbitrary rotation angle on the sky presumably scales with the number of modes necessary to describe the beam to the desired precision - even if we are just adding up precalculated numbers it will be a high cost. Many approximations are possible to speed up but they will all involve fundamental changes to the basic mode of operation (like precalculations for a limited set of angles on the sky etc). For the specific purpose of approximating the response to far sidelobes such approximations may of course be acceptable. 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, 9 months

Re: [Bicep2-list] BICEP2 Team meeting and B2/Keck CMB analysis telecon today (6 Aug 2013) noon Eastern

by Clem Pryke

This uses the "Total Convolver" algorithm from Wandelt and Gorski: http://arxiv.org/abs/astro-ph/0008227 I talked to Ben and his postdoc extensively once about this. I don't remember the details although I think there is another algorithm they ended up deciding was even better. It seems intuitively obvious that a high-resolution convolution of 4pi with 4pi at arbitrary 3 angle relative rotation is going to be expensive - I am happy to be proven wrong. My point on the telecon was simply that if such a convolution is practical in the main pipeline we should use it always - although Stefan would presumably be upset - as he has spent much time on the various multi-Gauss style approximations ;-) 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, 9 months

Re: BICEP2 Team meeting and B2/Keck CMB analysis telecon today (6 Aug 2013) noon Eastern

by Chao-Lin Kuo

Kevin gave a talk on this in W. Bridge Obcos seminar, I think before the paper was published. Any way it is a solved problem. If Sergi is unavailable or unfamiliar with this please let me know. I might be able to get someone to implement this. From: John Kovac <jmkovac(a)cfa.harvard.edu> Sent: ‎Tuesday‎, ‎August‎ ‎6‎, ‎2013 ‎2‎:‎27‎ ‎PM To: Chao-Lin Kuo <clkuo(a)stanford.edu> Cc: bicep2-list <bicep2-list(a)lists.fas.harvard.edu>, Keckarray <keckarray(a)mailman.stanford.edu> Yes, exactly--thanks for the link, Chao-Lin. I think I forwarded this same paper to Chris 5 years ago... I'd like to hear from Sergi how Planck's approach in practice compares to this, and what he thinks about implementation. John On 8/6/13 12:40 PM, Chao-Lin Kuo wrote: > sphere on sphere fast convolution. > http://arxiv.org/pdf/0709.2385v1.pdf > *From:* John Kovac <jmkovac(a)cfa.harvard.edu> > *Sent:* ‎Tuesday‎, ‎August‎ ‎6‎, ‎2013 ‎8‎:‎03‎ ‎AM > *To:* bicep2-list <bicep2-list(a)lists.fas.harvard.edu>, Keckarray > <keckarray(a)mailman.stanford.edu> > > Hi all, > > BICEP2 team meeting and B2/Keck joint analysis telecon today: > > Tuesday, 6 Aug 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 here http://goo.gl/LNvpx > Please refer to that webpage for the agenda, and continue to add items. > > > John > _______________________________________________ > 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, 9 months

Re: BICEP2 Team meeting and B2/Keck CMB analysis telecon today (6 Aug 2013) noon Eastern

by Chao-Lin Kuo

sphereon sphere fast convolution. http://arxiv.org/pdf/0709.2385v1.pdf From: John Kovac <jmkovac(a)cfa.harvard.edu> Sent: ‎Tuesday‎, ‎August‎ ‎6‎, ‎2013 ‎8‎:‎03‎ ‎AM To: bicep2-list <bicep2-list(a)lists.fas.harvard.edu>, Keckarray <keckarray(a)mailman.stanford.edu> Hi all, BICEP2 team meeting and B2/Keck joint analysis telecon today: Tuesday, 6 Aug 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 here http://goo.gl/LNvpx Please refer to that webpage for the agenda, and continue to add items. John _______________________________________________ Bicep2-list mailing list Bicep2-list(a)lists.fas.harvard.edu https://lists.fas.harvard.edu/mailman/listinfo/bicep2-list

10 years, 9 months

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

Re: [Bicep2-list] 95 / 150 GHz sky temperatures from BICEP1 -- Keck and B2 follow up by Grant and Jon?

by John Kovac

Hi Colin, I don't see an obvious error, and these numbers are at least consistent with my memory of historically measured zenith temperatures at 90-100 and 150. Note that the median zenith temperature at both 95 and 150 comes out to be around 12.3 K_cmb, very close to numbers we've quoted before. In terms of K_RJ (which you quote) this is 9.76 K_RJ @ 100 GHz, and 7.15 K_RJ @ 150 GHz. The histograms you show are nice. I have only one question on your post: what phases and scansets in our 3yr taglist are included? All of them that have passed our coarse weather cut? Grant: Can you please make a similar posting showing distribution of Keck 2012 mean elnod * abscal? And can you also use your AM model and a typical FTS-measured bandpass to predict a range of T_RJ zenith temperature for a typical winter PWV's, and compare the two? Jon Kaufman: Can you do the same for BICEP2? I think both of you have all the tools you need to do this already, so I hope this is a matter of putting together parts of existing analyses. thanks, John On 8/3/13 2:44 PM, Bischoff, Colin wrote: > hi all, > > I put up a quick posting on the Keck (and B1) logbooks, showing the > observed sky temperatures derived from BICEP1 elnods. The sky > temperature comes out significantly lower at 150 GHz, but with larger > variance (i.e. more susceptibility to weather). I'm actually a bit > shocked at how low the 150 GHz sky temperature is, compared to the > numbers that we usually assume in analysis of responsivity schedules. > So take a let look and let me know if I screwed up a factor somewhere. > > http://bicep0.caltech.edu/~bicep/analysis_logbook_north/20130803_skytemp/ > > -colin > _______________________________________________ > KeckArray mailing list > KeckArray(a)lists.stanford.edu > https://mailman.stanford.edu/mailman/listinfo/keckarray > -- ___________________________________________________________________ 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

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Bicep2-list August 2013