GLAST Large Area Telescope Overview Elliott Bloom SLAC - KIPAC Stanford University

Transcription

1 GLAST Large Area Telescope Overview Elliott Bloom SLAC - KIPAC Stanford University GLAST LAT Dark Matter and New Physics Working Group Workshop July 11-13, 2005

2 GLAST Large Area Telescope: Gamma-ray Large Area Space Telescope Dark Matter and New Physics Science Group Workshop Meeting Agenda

3 Monday Agenda Please Register 9:00 9:10 AM Welcome Steve Kahn, Deputy Director KIPAC (10 min) 9:10 9:50 AM GLAST Overview Elliott Bloom (40 min) 9:50 10:30 AM Current GLAST related DM work in Italy Aldo Morselli (40 min) 10:30 10:50 AMBreak (20 min) 10:50 11:30 AMReport on the DC-2 meeting in Italy, and DC2 plans Richard Dubois (40 min) 11:30 12:10 PMDark Matter Overview I Theory Ted Baltz (40 min) 12:10 1:30 PM Lunch (80 min) 1:30 2:10 PM Dark Matter experimental Challenges Larry Wai (40 min) 2:10 2:50 PM Extra Dimension overview Theory Andrea Lionetto (40 min) 2:50 3:30 PM Lorentz Invariance Tests Theory Michael Peskin (40 min) 3:30 3:50 PM Break (20 min) 3:50 4:30 PM Experimental challenges for Extra Dimensions Eduardo do Couto e Silva (40 min) 4:30 5:10 PM Experimental Challenges for Lorentz Invariance Jeff Scargle (40min) 5:10 6:00 PM Discussion (50 min) 7:00 PM No host dinner out at Celia s Mexican Restaurant (one of the best in the area). Please Sign up With Chris before the end of lunch today.

4 Tuesday Agenda Mini Symposium on Diffuse: (Organized by Seth Digel) 9 AM 9:45 AM Modeling the diffuse emission of the Galactic center and at high latitudes - what we will do to try to improve over what was possible for EGRET- Seth Digel (40 min) 9:45 10:30 AM Studies of diffuse emission with GALPROP - Igor Moskalenko (45min) 10:30 10:50 AM Break (20 min) 10:50 11:35 AM Gamma-ray observations of the Galactic center and inner Galaxy - Olaf Reimer (45 min) 11:35 noon Discussion (35 min) Noon 1:30 PM Lunch (90 min) 1:30 6:00 PM Contributed talks of 30 minutes each. 1:30 2:00 PM The search for DM in M31 using CELESTE Eric Nuss (30 min) 2:00 2:30 PM Energy Cross Calibration of GLAST with ACTs Lester Miller (30 min) 2:30 3:00 PM Limits on the baryon asymmetry in the universe from the low energy (<100 MeV) extra galactic background and prospects for GLAST. Gary Godfrey (30 min) 3:00 3:30 PM Break (30) 3:30 6 PM More talks or discussion. (2 _ hours) (5 more talks requested! Volunteers please Contact Elliott Bloom)

5 Wednesday Agenda (1/2 day) 9AM 12:00 PM 10:30 11 AM break. (30 min) Planning for pre launch publications, Collaboration meeting in Late August, and DC2 in January 06. Discussion led by Elliott and Aldo. Meeting ends when Discussion ends.

6 GLAST Large Area Telescope: Gamma-ray Large Area Space Telescope Introduction

7 Why study γ s? γ rays offer a direct view into Nature s largest accelerators. the Universe is mainly transparent to γ rays with < 20 GeV that can probe cosmological volumes. (Can see to z ~ 700.) Any opacity is energy-dependent for higher energy. Most particle relics of the early universe produce γ rays when they annihilate or decay. Two GLAST instruments: LAT: 20 MeV 300 GeV GBM: 10 kev 25 MeV Launch: August year mission (10-year goal) Large Area Telescope (LAT) spacecraft partner: GLAST Burst Monitor (GBM)

8 Precision Si-strip Tracker (TKR) ~80 m 2 Si, 18 XY tracking planes. Single-sided silicon strip detectors (228 µm pitch) Measure the photon direction; gamma ID. Hodoscopic CsI Calorimeter(CAL) Array of 1536 CsI(Tl) crystals in 8 layers. Measure the photon energy; image the shower. Segmented Anticoincidence Detector (ACD) 89 plastic scintillator tiles. Reject background of charged cosmic rays; segmentation removes selfveto effects at high energy. Electronics System Includes flexible, robust hardware trigger and software filters. Overview of LAT ACD e + e Systems work together to identify and measure the flux of cosmic gamma rays with energy 20 MeV - >300 GeV. γ Grid Tracker Calorimeter

9 Precision Si-strip Tracker (TKR) - Italy (ASI/INFN): provide Si-strip detectors & test all detectors, assemble & test detector trays, assemble & test TKR modules - Japan: provide Si-strip detectors & oversee detector production - SU-SLAC & UCSC (USA): provide Si-strip detectors, front-end electronics, cable plant Hodoscopic CsI Calorimeter (CAL) - IN2P3 (France): mechanical structure; CEA (France): engineering model prototypes of CDEs & test equipment; - Sweden: CsI xtals & acceptance testing; - NRL (USA): front-end electronics, provide photodiodes, assemble & test CDEs and CAL modules Segmented Anticoincidence Detector including micro-meteoroid shield / thermal blanket - GSFC (USA) Electronics System - SU-SLAC & NRL (USA): global electronics and DAQ equipment; flight software Mechanical Thermal System - SU-SLAC (USA): provide LAT Grid, thermal radiators, heat pipes & ancillaries Large Area Telescope (LAT) ACD LAT I&T γ e + e Grid Tracker Calorimeter - SU-SLAC (USA): assembly & test of LAT; provide particle/photon test beams - NRL (USA): instrument-level environmental tests

10 GLAST Large Area Telescope: Gamma-ray Large Area Space Telescope GLAST Organization

11 GLAST is an International Mission LAT Collaboration (PI: P. Michelson - SU) NASA - DoE Cooperation on LAT GBM Collaboration (PI: C. Meegan - UofA, Huntsville ) Small Context instrument Spacecraft and integration - Spectrum Astro Mission Management: NASA/GSFC Sweden Italy France Germany USA Japan

12 LAT Collaboration United States California State University at Sonoma (SSU) University of California at Santa Cruz - Santa Cruz Institute of Particle Physics (UCSC/SCIPP) Goddard Space Flight Center Laboratory for High Energy Astrophysics (NASA/GSFC/LHEA) Naval Research Laboratory (NRL) Ohio State University Stanford University Hanson Experimental Physics Laboratory (SU-HEPL) Stanford University - Stanford Linear Accelerator Center (SU-SLAC) Texas A&M University Kingsville (TAMUK) University of Washington (UW) Washington University, St. Louis (WUStL) France Centre National de la Recherche Scientifique / Institut National de Physique Nucléaire et de Physique des Particules (CNRS/IN2P3) Commissariat à l'energie Atomique / Direction des Sciences de la Matière/ Département d'astrophysique, de physique des Particules, de physique Nucléaire et de l'instrumentation Associée (CEA/DSM/DAPNIA) Italy Agenzia Spaziale Italiana (ASI) Istituto di Astrofisica Spaziale (IASF, CNR) Istituto Nazionale di Fisica Nucleare (INFN) Japan GLAST Collaboration (JGC) Hiroshima University Institute for Space and Astronautical Science (ISAS) RIKEN Swedish GLAST Consortium (SGC) Royal Institute of Technology (KTH) Stockholm University total US Collaboration members: Members: Affiliated Sci Postdocs: 17 4

13 LAT Organization Chart: Science Operations Phase Current Collaboration Science Groups 1a. Catalog - Seth Digel (SU-SLAC); Isabelle Grenier (CEA/ Saclay) 1b. Diffuse (Galactic and Extragalactic) and Molecular Clouds - Seth Digel (SU-SLAC); Isabelle Grenier (CEA/ Saclay) 2. Blazars and Other AGNs Paolo Giommi (ASI), Benoit Lott (Bordeaux) 3. Pulsars, SNRs, and Plerions - Roger Romani (Stanford); David Thompson (GSFC) 4. Unidentified Sources, Population Studies, and Other Galaxies - Patrizia Caraveo (ASI ); Olaf Reimer (Stanford) 5. Dark Matter and New Physics - Elliott Bloom (SU-SLAC); Aldo Morselli (INFN Rome) 6. Gamma-Ray Bursts - Jay Norris (GSFC); Nicola Omodei (INFN-Pisa) 7. Solar System Sources - Gerry Share (NRL) 8. Calibration and Analysis Methods - William Atwood (UCSC); Steve Ritz (GSFC) 9. Multiwavelength Coordination Group Roger Blandford (SU KIPAC); David Thompson (GSFC)

14 GLAST Large Area Telescope: Gamma-ray Large Area Space Telescope LAT Science

15 Connections: Quarks to the Cosmos The Universe as a Laboratory What powered the big bang? What is the mysterious dark matter that binds the universe? What is the dark energy that drives the universe apart? What is the nature of black holes and gravity beyond Einstein? Are there hidden space-time dimensions? Beyond Einstein and the Big Bang

16 GLAST LAT Dark Matter and New Physics Working Group Activities Center on the Discovery Reach of GLAST in Addressing a Number of these Issues. Particle Dark Matter (and Other Relics From the Big Bang) Search for Extra Dimensions Violations of Lorentz Invariance The Search for Large Scale Matter - Antimatter Annihilations in the Universe (Why is There Only Matter in the Universe Now). GLAST was Recommended by the National Academy of Sciences in their 2000 decadal study as the highest priority mid-sized mission

17 GLAST is on the trail of Dark Matter GLAST Team

18 - There Are Signs of Dark Matter Everywhere - Big Bang CMB Spiral Galaxies Rotation Curves Total matter Baryonic matter Dark matter Evolution of Universe ΛCDM Cosmology Galaxy Clusters X-ray measurements

19 Cosmology: Origin of Extragalactic Diffuse Radiation _ origin is a mystery; either sources there for GLAST to resolve (and study!) OR there is a truly diffuse flux from the early Universe EGRET constrains blazars to be > 25% of diffuse; annihilation of cosmological neutralinos has, in principle, a distinctive spectral signature Elasser & Mannheim, astro-ph/ E 2 dj/de (kev/(cm2-s-kev-sr) Seyfert II galaxies steepspectrum quasars Seyfert I galaxies Type 1a Supernovae discovery space blazars normal galaxies cluster mergers primordial diffuse new physics EGRET Also see: de Boer, Astro-ph/ (2004) EGRET data show an intriguing hint of DM annihilation. Appears as an excess of diffuse galactic γ rays. M wimp ~ GeV. Energy (kev) LAT baseline background limit Unique science for GLAST

20 Halo Dark Matter Search with GLAST Wimp Annihilations in halo Clumps (b > 10 deg): gamma continuum from pions very hard ~100 MeV (~ E 0 ) lines (2 γ, γζ) Inverse Compton scattering (IC) from pions -> electrons (Baltz & Wai 04) >GeV IC from e + starlight near galactic plane < 30 deg (trapping by B field) Halo substructure models (figure) (J. Taylor & Babul 03 and Baltz preliminary) subhalos away from plane backgrounds much reduced KK DM Scenario electron line (20% Br) smeared into a sharp edge via mainly IC >500 GeV: ~ 100e ± /year edge height (Baltz & Hooper 05) all-sky signature!

21 Discovery Potential: large extra dimensions GLAST is a new dimension search engine -- Savas Dimopoulos Theories with large (sub-millimeter) extra dimensions: - alternative way to solve the hierarchy problem of particle physics. - move the Planck scale to near the weak scale - observed weakness of gravity due to presence of n new spatial dimensions large compared to electroweak scale (Arkani-Hamed, Dimopoulos & Dvali 1998) Hannestad & Raffelt (2002, 2003) pointed out that Super Novae would produce Kaluza - Klein gravitons that are generic for these theories. - produced non - relativistically, so many are gravitationally bound to SN core (i.e., neutron star) KK particle halo that shines in ~ 100 MeV γ rays. - KK gravitons have gravitational strength decay (τ ~ 10 9 years) to nn, e + e -, and γγ f KK is the fraction of SN energy emitted as KK gravitons. Authors calculate potential GLAST limit of F KK < 10-7 for this source for n = 2, and < 0.5x10-7 for n =3.

22 Discovery Potential: Large Extra Dimensions Constraints from EGRET observations (Hannestad & Raffelt 2003;Cassé, et al, Phys.Rev.Lett. 92 (2004) ): Hannestad & Raffelt consider limits from viewing single neutron stars. Cassé, et. al. focus on the sum over galactic bulge neutrons stars. Limits set by Cassé, et. al. using EGRET GB diffuse observations and estimates of the excess over that expected from the pure diffuse for 100 < E γ < 300 MeV. The apparent excess is ascribed to KK γ rays coming from the total of neutron stars in the galactic bulge, ~ 7x10 8. For n < 5 these are the best limits on the size of extra dimensions, and for n=1, 2, and 3 the effective Planck Scale is well beyond current collider technology. GLAST will do much better!

23 High Energy Behavior of γ-ray Bursts GRB pulse structure at GeV energies + Gigaparsec distances may constrain E Quantum Gravity ~ GeV See: G. Amelino-Camelia, John Ellis et al., Nature 393 (1998) Using GLAST, Search for possible in vacuo velocity dispersion, dv ~ E/E QG of gamma rays from gamma ray bursts at cosmological distances. For many GRB (EGRET) current best estimate is, dn γ /de γ ~ 1/E γ 2 For certain string formulations of an expanding Robertson-Walker-Friedman cosmology, photon propagation velocity in vacuum appears increased or decreased as energy increases, v γ = c(1 ± E γ /E QG + O[(E γ /E QG ) 2 ]) For 0.3 Gpc, and E γ = 10 GeV should observe Δ t relative, to 100 MeV of about ± 30 ms. Using only the 10 brightest bursts yr -1, GLAST would easily see the predicted energy- and distance-dependent effect.

24 GLAST Large Area Telescope: Gamma-ray Large Area Space Telescope LAT Performance Current Collaboration Standards for our Studies.

25

26 Absolute Calibration of Energy and Cross Calibration with ACTs is important to DM&NPWK Science. See Lester s talk on Tuesday afternoon. There are some important differences between the above plots from the proposal and the expected flight LAT performance. First, we expect the PSF to be significantly improved, particularly for selected major subsets of events. Second, the effective area will be ~25% smaller (though still significantly exceeding the requirement). This is due to a number of important design choices, including a reduction in the thickness of the converter in the "BACK" layers of the TKR (18% r.l. instead of 25% r.l.), which improves the PSF, and a small reduction in the instrument footprint to provide additional mass margin at the early stages of the project. Third, the energy resolution at low energy will likely be somewhat worse, due to two effects: a small increase in the size of the gaps between calorimeter modules and more efficient background rejection analyses that keep more photon events -- these events are otherwise good, but they tend to have worse energy resolution.

27 Point Source Sensitivity Plots Using an updated instrument performance characterization, there are two additional plots related to point source sensitivity: The first is a single-energy sensitivity plot, showing the 5-sigma sensitivity to a high-latitude source whose spectrum is a delta function at the energy shown on the horizontal axis. The assumptions are one-year (livetime) all-sky survey diffuse background flux 1.5x10-5 /cm 2 /s/sr (E>100 MeV), spectral index -2.1

28 Experiments are often compared using an integral sensitivity plot (5-sigma sensitivity for E>E 0 ), e.g., by Morselli et al, Nucl. Phys. B85(2000), assuming a 1/E 2 spectrum source at high latitude.

29 Dramatic Improvement in Point P Spread Source Localization over EGRET and pread Function and EGRET source position error circles are ~0.5, resulting in counterpart confusion. GLAST will provide much more accurate positions, with ~30 arcsec - ~5 arcmin localizations, depending on brightness. Cygnus region (15x15 deg)

30 Cen A is at 3.5 Mpc, and its Jet axis is at 68 o to our line of sight. EGRET has reported a tentative signal What is it?

31 γ-ray Bursts & Transients ~50 events/day

32 ,000 GRB Spectra in EGRET and GLAST

33 GLAST Large Area Telescope: Gamma-ray Large Area Space Telescope Integration and Test Overview

34 LAT Schedule ( ) TKR A 2/4/05A TKR 14 9/9/05 ACD 7/29/05 CAL A 12/08/04A CAL 6/10/05A DAQ 11/8/05 FSW Complete TEM/PS A 2/17/05A TEM/PS 6/29/05 X-LAT 6/1/05 FSW Formal Test 08/30/05 GRID Assembly 2/25/05A Install Twrs A&B 8 wks 2 Tower CPT 3 wks Install Twrs wks Install Tower 14 1 wk 11/08/05 Install Global Items 12/02/05 02/12/05 05/14/05 System Test 9 wks Ship LAT 1 wk Enviro Test LAT RFI Observ. Integration Launch 2007 Jun '05 Pre- Review Color Code Subsystem I & T Test Mission

35 GLAST LAT Technical Status 18 CAL modules at SLAC. 7 SLAC. ~80m 2 of silicon detectors in hand. Two Towers in the GRID 04/11/05 Six Towers in the GRID on Tuesday 6/14/05 ACD being tested at GSFC. Delivery to SLAC in early August.

36 Almost Instant 4 & 6 Tower Gratification (SVAC)

37 A Two-Tower Gamma Ray Candidate

38 Extra Slides Follow

39 GLAST LAT High Energy Capabilities EGRET on CGRO firmly established the field of high-energy gamma-ray astrophysics and demonstrated the importance and potential of this energy band. GLAST is the next great step beyond EGRET, providing a leap in capabilities: Very large Field of View (FOV) (~20% of sky), factor 4 greater than EGRET Broadband (4 decades in energy, including unexplored region E > 10 GeV) Unprecedented Point Spread function (PSF) for gamma rays (factor > 3 better than EGRET for E>1 GeV). On axis >10 GeV, 68% containment < 0.12 degrees (7.2 arc-minutes) Large effective area (factor > 5 better than EGRET) Results in factor > 30 improvement in sensitivity below < 10 GeV, and >100 at higher energies. Much smaller deadtime per event (27 µsec, factor ~4,000 better than EGRET s) No expendables long mission without degradation (5 year requirement, 10 year goal).

40 GLAST Survey: 3 rd EGRET ~10,000 ~300 Catalog sources (2 days) years) AGN - blazars unidentified pulsars LMC

41 GLAST Large Area Telescope: Gamma-ray Large Area Space Telescope Science Analysis Software (SAS)

42 LAT Data Challenges Brings the collaboration together to work on science related activities, and encourages LAT collaborators to really focus on the science that the LAT will do. This provides a taste for what things might be like after launch. Drives a detailed study of the high level performance of the LAT. A detailed description of the instrument response over all energies and inclination angles is necessary for the high level analysis tools. End-to-end test of the simulation and analysis software all the way from low level detector simulations through to high level science analysis and source catalog generation. Design a progression of studies: DC1. Modest goals. Contains most essential features of a data challenge. DC2 in early More ambitious goals, incorporate lessons learned from DC1. ~One simulated month. DC3 in Support for flight science production.

43 DC Components Focal point for many threads Orbit, rocking, celestial coordinates, pointing history Plausible model of the sky Background rejection and event selection Instrument Response Functions Data formats for input to high level tools First look at major science tools Likelihood, Observation Simulator Generation of datasets Populate and exercise data servers at SSC & LAT Code distribution on windows and Linux Involve new users from across the collaboration Teamwork! see R.Dubois

44 Extragalactic diffuse The Simulated DC1 Sky Galactic diffuse Fiddling 3C273/279 EGRET 3EG Our Sky R.Dubois

45 GLAST Large Area Telescope: Gamma-ray Large Area Space Telescope Schedule and Conclusions

46 THE LOOK AHEAD The GLAST mission is completing the fabrication phase and is well into integration. LAT, GBM, and spacecraft assembly complete by January Delivery of the LAT and GBM instruments for observatory integration spring Observatory integration and test spring 2006 through summer CY07. Major scientific conference, the First GLAST Symposium, being planned for Launch in August 2007 Science Operations begin within 60 days Join the fun! Fabrication Instrument & S/C I&T Observatory I&T Launch