1 / 22

Weighing Neutrinos including the Largest Photometric Galaxy Survey: MegaZ DR7

Weighing Neutrinos including the Largest Photometric Galaxy Survey: MegaZ DR7. “A combined constraint on the Neutrinos”. Arxiv: 0911.5291. Shaun Thomas: UCL. Moriond 2010. Outline: Neutrinos have mass! Neutrino signatures in cosmology Probes of the Model Cosmic Microwave Background

tieve
Download Presentation

Weighing Neutrinos including the Largest Photometric Galaxy Survey: MegaZ DR7

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Weighing Neutrinos including the Largest Photometric Galaxy Survey: MegaZ DR7 “A combined constraint on the Neutrinos” Arxiv: 0911.5291 Shaun Thomas: UCL Moriond 2010

  2. Outline: • Neutrinos have mass! • Neutrino signatures in cosmology • Probes of the Model • Cosmic Microwave Background • Galaxy Surveys • Supernovae and Baryon Oscillations • Work: Thomas, Abdalla & Lahav (2009): arXiv:0911.5291 (+ In prep. 2010) • For the Future…? Shaun Thomas: UCL Moriond 2010

  3. Neutrino oscillations indicate they have mass! But not on the absolute scale of mass… For example… • Beta-decay kinematics KATRIN • Neutrinoless double beta-decay nemo • Cosmology! Thomas, Abdalla, Lahav (2009) http://www-ik.fzk.de/~katrin/index.html Not just interesting physics but, Age of precision Cosmology an integral part of the cosmological model… Shaun Thomas: UCL Moriond 2010

  4. Signatures in the Model • Act as radiation or matter and affect the Universe’s expansion history • Suppress the growth of matter structure and cosmological perturbations Neutrinos have large thermal velocities and Free-stream out of over-densities/inhomogeneities thus suppressing the clustering of matter and galaxies Neutrino fraction is directly related to sum of masses (RHS) Which we might see in a power spectrum… Shaun Thomas: UCL Moriond 2010

  5. Probes of Cosmology Cosmic Microwave Background (CMB) With the CMB the effect depends on whether neutrinos are relativistic or not: • Suppress potentials - change heights of peaks OR • Affect matter-radiation balance Model Data Constraint WMAP 5 year (CMB) : < 1.3 eV (95% CL) Suggestive of a CMB limit ~ 1.5 eV (E.g. Ichikawa 05) Komatsu et al. [arXiv:0803.0547] Thomas et al. [arXiv:0911.5291] Shaun Thomas: UCL Moriond 2010

  6. Probes of Cosmology E.g. Supernova Legacy Survey Supernovae (SN) Standard candle allows one to measure the expansion history Tighter matter/hubble constraint aids neutrino determination E.g. Percival et al Baryon Acoustic Oscillations (BAOs) Primordial CMB photon-baryon oscillations are imprinted onto late-time matter power spectrum: BAO Standard ruler allows one to measure the expansion history Tighter matter/hubble constraint aids neutrino determination CMB + SN + BAO : < 0.69 eV (95% CL) Komatsu et al. [arXiv:0803.0547] Thomas et al. [arXiv:0911.5291] Shaun Thomas: UCL Moriond 2010

  7. Probes of Cosmology + Galaxy Clustering! Sloan Digital Sky Survey (SDSS) • Suppress the growth of matter structure and cosmological perturbations Smaller Scales Shaun Thomas: UCL Moriond 2010

  8. Probes of Cosmology + Galaxy Clustering! Sloan Digital Sky Survey (SDSS) Luminous Red Galaxies (LRGs) Largest galaxy survey 723,556 LRGs 7,746 square degrees Photometric Redshift 0.45 < z < 0.65 Volume: 3.3 (Gpc /h)^3 Four redshift bins Thomas, Abdalla & Lahav - in prep Padmanabhan et al. 2007 ANNz - Collister and Lahav 2004 2SLAQ - 13’000 spectroscopic training/evaluation set Shaun Thomas: UCL Moriond 2010

  9. Probes of Cosmology + Galaxy Clustering! Sloan Digital Sky Survey (SDSS) MegaZ DR7 One of the largest galaxy surveys to date Thomas, Abdalla & Lahav - in prep Including the production of a new SDSS galaxy clustering angular power spectra We can use this with the BAO(!) - Improves combined neutrino constraint further! Shaun Thomas: UCL Moriond 2010

  10. Probes of Cosmology + Galaxy Clustering! Sloan Digital Sky Survey (SDSS) 4 bins: 0.45 < z < 0.65 Luminous Red Galaxies (LRGS) Max multipole l=300 MegaZ DR7 CMB + SN + BAO + SDSS LRGs + HST: < 0.28 eV (95% CL) 12 Parameters: Thomas et al. [arXiv:0911.5291] Shaun Thomas: UCL Moriond 2010

  11. Cosmology and Neutrinos Komatsu et al. [arXiv:0803.0547] < 1.3 eV (CMB) < 0.67 eV (CMB+SN+BAO) Tereno et al. [arXiv:0810.0555] < 0.54 eV (CMB+SN+BAO+WL) Ichiki, Takada & Takahashi [arXiv:0810.4921] < 0.54 eV (CMB+SN+BAO+WL) Seljak et al. [arXiv:0604335] < 0.17 eV (+ Lyman Alpha…) Systematics - e.g. winds? CMB + SN + BAO + SDSS LRGs +HST Thomas, Abdalla & Lahav [0911.5291] 0.28 eV Using all the aforementioned probes for complementary data constraint Recent BAO data and production of newest galaxy clustering angular power spectrum CMB+SDSS+SN+BAO+HST With luminous Red Galaxies (LRGs) sampling a large cosmic volume Cosmology is starting to predict that experiments such as KATRIN (mentioned earlier) will not detect anything Shaun Thomas: UCL Moriond 2010

  12. WOOHOO! Shaun Thomas: UCL Moriond 2010

  13. ‘Systematics and Limitations’ Work for the Future… Cosmology = Good  Although we want tighter neutrino constraints We also want trustworthy neutrino constraints. However Galaxy Bias Non-linearities Parameter Degeneracies Model underlying matter power spectrum but measure the galaxy power spectrum Scale dependence…mimic…? Bias result or lose data Most quoted results assume cosmological constant cosmology Perturbation theory/ N-body simulations Degeneracy with w increases error bar E.g. Saito et al 09 Brandbyge & Hannestad 09 L_max = 300 => 0.28 eV L_max = 200 => 0.34 eV Work In Progress… E.g. Hannestad Shaun Thomas: UCL Moriond 2010

  14. Summary • Cosmology is a sensitive neutrino experiment! (Funded billions of years ago!) • Massive neutrinos suppress the growth of structure • Probes such as galaxy clustering or weak lensing are sensitive to growth • Integral part of cosmological model and parameter space • Have a complete complementary constraint on neutrinos (sub eV region) • Systematics and limitations still exist though… • The Future is promising but with work to be done… Having produced data for a tighter constraint Tighter neutrino constraint. Trustworthy neutrino constraint. Shaun Thomas: UCL Moriond 2010

  15. Related and Further Reading • Cosmology and Neutrinos • Thomas, Abdalla & Lahav [arXiv:0911.5291] • Komatsu et al. [arXiv:0803.0547] • Tereno et al. [arXiv:0810.0555] • Elgaroy and Lahav [arXiv:0606007] • Seljak et al. [arXiv:0604335] • Brandbyge & Hannestad [arxiv:0812.3149] • Saito et al [arxiv:0907.2922] • Galaxy Clustering • Thomas, Abdalla & Lahav (In Prep. (v. soon)) • Neutrino Experiments • NEMO [arXiv:0810.5497] • KATRIN Thank You for Listening! :) Contact: sat@star.ucl.ac.uk Shaun Thomas: UCL Moriond 2010

  16. Simulation - testing the code by reconstructing input cosmology Evaluated the previous DR4 release which was consistent with Blake et al. (MegaZ DR4) Shaun Thomas: UCL

  17. 1,2 1,4 1,3 2,3 Shaun Thomas: UCL

  18. 2,4 3,4 Shaun Thomas: UCL

  19. Mixing matrix profile Little correlation between multipole bands introduced by partial sky after binning Shaun Thomas: UCL

  20. Excess Power Shaun Thomas: UCL

  21. Shaun Thomas: UCL

More Related