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BE VERY AFRAID

BE VERY AFRAID. Supernovae and the Accelerating Universe. Nicholas B. Suntzeff Mitchell Institute for Fundamental Physics & Astronomy Department of Physics & Astronomy Texas A&M University University of Texas/Austin. Cosmologia en la Playa 2010. 14 January 2010.  George Ellery Hale.

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BE VERY AFRAID

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  1. BE VERY AFRAID

  2. Supernovae and the Accelerating Universe • Nicholas B. Suntzeff • Mitchell Institute for Fundamental Physics & Astronomy • Department of Physics & Astronomy • Texas A&M University • University of Texas/Austin Cosmologia en la Playa 2010 14 January 2010

  3.  George Ellery Hale  lots of books How cosmology used to be done: Historical Visit of Einstein to Mt. Wilson Ed Hubble Al Einstein Walt Adams Chuck St. James Milt Humason

  4. The sad reality of cosmology today:Unhistorical Visit of Suntzeff to Mt. Wilson  George Ellery Hale Same books => Gaston Folatteli Mark Phillips Suntzeff

  5. can’t get no respect…

  6. SN1994D Supernovae! P. Challis CfA & NASA

  7. SN spectra Type Ia Core Collapse Type Ib/c & Type II

  8. SN SEDs II Ib/c Ia

  9. General light curves 56Ni  56Co  56Fe Leibundgut & Suntzeff 98

  10. delta m15 Calan/Tololo survey 1990-1996 One parameter family Suntzeff (1996) Color Rate of decline Peak brightness Phillips (1993)

  11. Secondary max due to Fe++ Fe+ mystery - where is Fe+ Fe0 ??

  12. Absolute magnitudes of Type Ia SNe  brighter H, K probable standard candles, Krisciunas etal 2003. 

  13. Effects of correction to m15

  14. Distance Modulus II 0.2 mag Peak effect for L is at about z~0.8. We are looking for about a 0.25m effect. fainter brighter

  15. Equation-of-State Signal Assume P = wc2 Difference in apparent SN brightness vs. z ΩΛ=0.70, flat cosmology

  16. The ESSENCE Survey • Determine w to 10% or w!=-1 • 6-year project on CTIO/NOAO 4m telescope in Chile; 12 sq. deg. • Wide-field images in 2 bands • Same-night detection of SNe • Spectroscopy • Keck, VLT, Gemini, Magellan • Goal is 200 SNeIa, 0.2<z<0.8 • Data and SNeIa public real-time

  17. ESSENCE Survey Team

  18. ESSENCE Summary • 200 SNeIa from 2002-2007 • 200 good light curves (Wood-Vasey, et al 2009) • Data from Keck, Gemini, VLT, CTIO, HST

  19. GoldUnionConstitutionwhat the **** set SDSS SN plot Lesson in plotting  Being from Texas, I suggest the Confederate Set is next

  20. Carnegie Supernova Project • Phillips, Freedman, Hamuy, Madore, Burns, Follatelli, Cadenas, Suntzeff

  21. High-z project I-band measurements

  22. Cosmology fits

  23. Carnegie Low-z Sample • 5-year project, 270n per year on 1m Swope + nights on Magellan, du Pont, VLT • Ending 2009 (around now) • ugriBVYJH(Ks). Kswith WIRC on duPont • Spectra where we can [more hot spectrographs on 2m telescopes are needed] • Follow all types with z≤0.08 (if caught early) • 200 Sne with 100 Type Ia

  24. What we are trying to do • So many data samples with so many methods of analysis have confused us • We want to “rewrite” history, that is, start with a clean data set and redo our analyses to find the weaknesses of our techniques. • Purely phenomenological guided by simple physics • Basic parameter - m15, measured from the light curves, NOT from a black box program • Measure photometry in the natural system with measured precise transmission functions • Ultimately the goal is an accuracy of <1% in distance for cosmology with no systematics.

  25. Summary of Sample

  26. First Release Contreras, C. et al 2009 arXiv:0910.3330V1 35 Type Ia, 5559 ugriBV optical , 1043 NIR YJHKs 

  27. Natural System  Definition of photometric zero-points

  28. Second Parameter Same m15

  29. Bolometric light curves The secondary maximum is not tightly correlated with the peak luminosity.

  30. ReddeningRV = 1.7 or 3.1??Wang, Goobar suggestion

  31. Distances to 3%

  32. Hubble Diagram m=0.12 z=0.001

  33. Hicken et al 2009

  34. A difficult diagram to understand 2 separation between blue and orange points??

  35. Potential sources of systematic error • Flux calibrations • Bias in distance determination codes • Extinction • Host galaxy • Our Galaxy • Atmosphere • Extinction law • Passband errors • K corrections • Photometry normalization • Nonlinearity in flux measurements

  36. More Potential Systematics • “Hubble bubble” trouble • Gravitational lensing • Evolutionary effects in SNe • Biases in low redshift sample • Search efficiency/selection

  37. (Wood-Vasey et al., 2007, ApJ)

  38. SNe and GRB’sWright (2007)

  39. Higher-Z SN Team Riess, et al (2007)

  40. The accelerating Universe poses a significant challenge to theory, experiment and observation. Current goal: w to 10% The SNIa data are consistent with a flat Universe with a cosmological constant. Summary

  41. The scale of dark matter DETF and future measures of dark energy The Hubble constant Why are we wasting our time with w’??? Why are there only 4 techniques? We need people to create realistic error models. Closing thoughts

  42. Okay, no questions Come up to the front, leave your computers behind, and let’s talk what it means to be a successful researcher.

  43. (JAXA) (ESA) (ESA)

  44. Astrophysics Division Missions 46

  45. Budget Guidance for Decadal Survey • Assumed operating missions beyond 2016 include JWST, SOFIA • HST De-orbit mission development ramps up ~2020 • “Future Missions” wedge would be used for new mission initiatives, R&A/technology augmentations, extended missions, etc. • The amount of “Future Missions” funding available between 2013 – 2020 is ~$4B

  46. Budget Guidance for Decadal Survey – Notional scenario • Assumed operating missions beyond 2016 include JWST, SOFIA; plus HST, Chandra, Fermi, etc. (e.g., Astro-H) • HST De-orbit mission development ramps up ~2020 • “Future Missions” wedge is for strategic missions recommended by the Astro2010 decadal survey • The amount of “Future Missions” funding available between 2013 – 2020 in such a scenario would be ~$2.3B

  47. The bad news • 160 PhD’s per year, 35 permanent positions per year • NASA science sees declining budgets • NSF at best is flat • DOE may step in? • Job register has ~100 postdocs and ~16 faculty positions • US budget is now heavily encumbered with future payments • Obama loves science, but don’t assume that will go to basic science except in green and health science • you probably will not live where you want to live

  48. The good news • everyone loves astronomy • it ain’t a lot worse than in 1980 • in the past, most people who stuck it out got good jobs

  49. So what to do? • don’t keep on doing your thesis over and over again • establish prominent collaborators and mentors, but appear independent • publish, publish, publish. Include useful tables of summary and colorful figures that can be easily captured. • apply for external funding • luck verus hard work • become the leader in your field • think carefully about joining large projects with time scales of > 5 years. • Spergel’s law • don’t be afraid to go out on a limb and say something weird. • The Aaronson effect in obsevations • When you apply for jobs, make sure you know all about the department – and brown nose a bit. Write your application as if there is no other job out there. Know your audience.

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