Andrei Frolov Ted Baltz Phil Marshall Wynn Ho Anatoly Spitkovsky Weiqun Zhang Tom Abel

Size: px

Start display at page:

Download "Andrei Frolov Ted Baltz Phil Marshall Wynn Ho Anatoly Spitkovsky Weiqun Zhang Tom Abel"

Brittany Kelley
5 years ago
Views:

1 Andrei Frolov Ted Baltz Phil Marshall Wynn Ho Anatoly Spitkovsky Weiqun Zhang Tom Abel

2 ANDREI FROLOV: KIPAC/SITP RESEARCH INTERESTS: I am interested in gravitational physics and cosmology. I work on models of early Universe, problems in the black hole physics (classical solutions and quantum effects), and numerical relativity. My primary interest is in theory, but I find interactions with astrophysicists and observers very beneficial, particularly for cosmology. KIPAC provides a good environment for that. CURRENT RESEARCH PROJECT: With Kristján Kristjánsson and Lárus Thorlacius (University of Iceland), we are currently investigating quantum effects in charged black holes using 2D gravity models, where quantization is tractable. KIPAC DOE Review June 15,

3 INSIDE A CHARGED BLACK HOLE Z(v,u) Internal structure is destroyed by quantum pair production! KIPAC DOE Review June 15,

4 !"#$%&"''(#%)*(+#,%"'%-./012%. 3435%/*(6+7(6+8+9, ><(%#(8?=%C(6<?',%8?$(8?*++C%D>6='?+6%'+%9>?C(%<("#=*%?6%*?9*%C?7(6<?+6< D>88%E!%F"#"7('(#%<F"=(%<'>C?(C%AG"8'H%I%:+6C+8+%JEB 0==(8(#"'+#%F*,<?=<%!%C"#$%7"''(#%=+66(='? %<F(='#>7%K%=#+<<%<(='?+6<%'+%L(%7("<>#(C%"'%MN1O%.M1 D?6C%=+6<?<'(6'%P("$Q<="8(%F"#"7('(#%<('<%ARE%F"#"7('(#<B%L,%&1&1 ="8=>8"'(%#(8?=%C(6<?'?(<%?7F8?(C%L,%'*(<(%F"#"7('(#%<('< A/(<$?6%I%G"8'HO%?6%F#(F"#"'?+6B

5 !"#$%&"''(#%)*(+#,%"'%-./012%..!3#(4'%5('(4'3+6%71!&89%('4:; @"="4'34%F="6(Q%<?(%?F(4'#<AR%7G"='H9%G=++A9%)",=+#9%P"39%36%F#(F"#"'3+6; -"=<H"U-=(36%5"#$%A"''(#%?4(6"#3+ 53#(4'%"663*3="'3+6%'+%(=(4'#+6VF+?3'#+6%5+A36"'(?%7WJX%GD;

6 Gravitational KIPAC: Theory Cosmic shear of correlated sources (Morganson, Blandford) Multiple image formation, lens anatomy (Suyu, Blandford) Fast source and lens reconstruction algorithms: regularised substructure mapping and potential reconstruction (Suyu, Blandford, Marshall) Higher order catastrophes: quantification, and rate prediction for LSST/ SNAP (Baltz) Slide 1

7 Cosmic shear of Correlated Sources New probe of matter power spectrum (Morganson, Blandford): Faintest galaxies are correlated Shear measurement needs more data: Slide 2

8 Quad Lens Anatomy Strong lensing of extended sources: additional information on potential between limit curves Direct potential reconstruction in this way demonstrated (Suyu et al 2005) but not practical Qualitative and quantitative guides to data modeling Slide 3

Potential correction (Koopmans 2005) implementation underway:

9 Semi-linear Lens Inversion Regularised maximum likelihood technique Appropriate regularisation type and strength inferred from data Potential correction (Koopmans 2005) implementation underway: uncertainties from MCMC (Suyu, Blandford, Marshall, Baltz in prep.) Slide 4

10 GLAMROC: Gravitational Lensing Adaptive- Mesh Ray-tracing Of Catastrophes General purpose raytracing of gravitational lens systems (Baltz 2005, in preparation) Arbitrary number of lens atoms - point lenses, elliptical halos (isothermal, NFW), boxy / disky halos Arbitrary number of lens planes Adaptive mesh refinement: use more rays when magnification is larger accurately map the critical curves Higher derivatives of lens map: identify catastrophes where several images are merging crit. curve (2), cusp (3), swallowtail (4), umbilics (4), butterfly (5) Huge surveys (SNAP, LSST) will see some of these: what can be learned about dark matter halos / dark matter physics? halo cores (self interacting dark matter?) substructure (how much small scale density fluctuation power)

11 GLAMROC in action: 3 lenses on separate planes critical curve cusps swallowtail source-plane magnification 15 million rays 7 image configuration

12 Gravitational KIPAC: Theory Cosmic shear of correlated sources (Morganson, Blandford) Multiple image formation, lens anatomy (Suyu, Blandford) Fast source and lens reconstruction algorithms: lens identification, regularised substructure mapping (Suyu, Blandford, Marshall) Higher order catastrophes: quantification, and rate prediction for LSST/ SNAP (Baltz) Work in progress, keeping pace with hardware development application to current data continues... Slide 7

of state Thermal evolution ν and hi-energy particle processes

13 Neutron Star Science: Probe of Extreme Densities NS matter above nuclear densities ρ ~ g cm -3 M-R relation equation of state Thermal evolution ν and hi-energy particle processes (Lattimer & Prakash 2004) RX J (Yakovlev & Pethick 2004)

Neutron Star Science: Probe of Extreme Magnetic Fields Giant flare from SGR 1806-20 NS magnetic field above quantum limit B > B Q = m e 2 c 3 /e = 4.

14 Neutron Star Science: Probe of Extreme Magnetic Fields Giant flare from SGR NS magnetic field above quantum limit B > B Q = m e 2 c 3 /e = G QED-field NS, ie magnetar Exotic photon and particle processes Vacuum polarization (RXTE-Ibrahim et al. 2002) kev (Swift-Palmer et al. 2005) (RHESSI-Hurley et al. 2005)

Simulations of relativistic collisionless shocks A.

Extragalactic radio sources γ ~ 10 Gamma ray bursts γ > 100 Galactic superluminal sources γ ~ few Sources

Particle acceleration -- Fermi mechanism? Something else?

15 Simulations of relativistic collisionless shocks A. Spitkovsky (KIPAC) Relativistic collisionless shocks in astrophysics Pulsars + winds (plerions) γ ~ 10 6 Extragalactic radio sources γ ~ 10 Gamma ray bursts γ > 100 Galactic superluminal sources γ ~ few Sources for UHE CR? Open issues: What is the structure of collisionless shock waves? Particle acceleration -- Fermi mechanism? Something else? Generation of magnetic fields (GRB shocks, primordial fields?) By using direct ab-initio numerical simulations of collisionless shocks we can place constraints on astrophysical models of composition and structure of relativistic outflows in nature.

Numerical simulations of collisionless shocks E xey q Particle-in-cell method: Collect currents at the cell edges Solve fields on the mesh (Maxwell s eqs) Interpolate fields to particles positions

16 Numerical simulations of collisionless shocks E xey q Particle-in-cell method: Collect currents at the cell edges Solve fields on the mesh (Maxwell s eqs) Interpolate fields to particles positions Move particles under Lorentz force Modified code TRISTAN : 3D cartesian electromagnetic particle-in-cell code Radiation BCs Charge-conservative current deposition (no Poisson eq) Filtering of current data Fully parallelized (128proc+) domain decomposition Very demanding calculations: >3x10 9 particles Simulation setup: Relativistic e ± or e - - ion wind (γ =15) with B field (σ = ω c 2 /ω p 2 =B 2 /(4πnγmc 2 ) = 0-10) Reflecting wall (particles and fields) Upstream c/ω p =15 cells, c/ ω c >5 cells; 800x150x150 grid, 60x10x10 c/ω p

Unmagnetized shocks are mediated by Weibel instability, which generates magnetic field: Plasma

17 Simulations of relativistic collisionless shocks Why does a collisionless shock exist? Particles are slowed down either by instability (two-stream-like) or by magnetic reflection. Unmagnetized shocks are mediated by Weibel instability, which generates magnetic field: Plasma density Field generation Relativistic flow is reflected from a wall and sends a reverse shock through the simulation domain

show nonthermal acceleration Magnetized shock is mediated by Larmor

18 Magnetized perpendicular pair shock Shock structure with magnetic field p x 3D density p y pz Spectrum - Maxwellian Pair shocks do not show nonthermal acceleration Magnetized shock is mediated by Larmor reflections from compressed B field Is Fermi acceleration really viable?

19 Conclusions Relativistic collisionless shocks exist, mediated by two-stream instability (Weibel) in low magnetization flows, and coherent reflections in higher magnetization flows. Transition is observed in simulations. Efficient thermalization of the flow. Little diffusive nonthermal acceleration. Compositionally this suggests weak acceleration efficiency in pair plasma flows. Additional component of the ions maybe necessary.

20 Numerical Simulations Of Relativistic Explosions Weiqun Zhang (KIPAC) Andrew MacFadyen (IAS) Stan Woosley (UC Santa Cruz) Alex Heger (LANL)

21 RAM: A Relativistic Adaptive Mesh Refinement Hydrodynamics Code (Zhang & MacFadyen 2005) Study of Gamma-Ray Bursts (GRBs) and Supernovae special relativistic hydro (5th order WENO) rotation, viscosity nuclear physics: photodisintergration, burning neutrino emission EOS (Ideal nucleons, radiation, relativistic degenerate electrons & positrons) post-newtonian Gravity Parallel (MPI)

Adaptive Mesh Refinement Based on FLASH 2.3 Advantage: Very High Resolution Emery Step: Relativistic Wind Flowing into a Step Discontinuities (e.g., shocks) ==> Higher resolution 1.

22 Adaptive Mesh Refinement Based on FLASH 2.3 Advantage: Very High Resolution Emery Step: Relativistic Wind Flowing into a Step Discontinuities (e.g., shocks) ==> Higher resolution 1.0 rho P

23 GRB Central Engine: Collapsar Collapse of Rotating Massive Stars ==> Black Hole, Accretion Disk, Relativistic Jets ==> SNe, GRBs & Afterglows Accretion Disk Jet Zhang, MacFadyen, & Woosley 2005

24 Relativistic Jet Propagation In Massive Stars GRBs : Death of Massive Stars; Relativistic Jets Run on a DOE Computer: Seaborg at NERSC

25 Long-Term Evolution of Jets (Relativistic => Newtonian) Observation Implications MacFadyen & Zhang 2005 GRB Afterglow Light Curves Harrison et al Remnant: GRB or SN?

26 A vision for KIPAC computing Tom Abel with much input from Stuart Marshall, Roger Blandford and many at SLAC s computing services

27 Motivation Outside of meetings almost all work is done on a computer independent of theorists or observer and the large fraction of scientists that do are in both categories Efficient use enables science and saves time and money Tom Abel

28 Science First Fundamental Forces & Constituents Largest Data-sets just good enough What to do with 20 Tb/night? Understand what we see? understanding 3D + time model Tom Abel

29 Unique opportunity Build a first class environment for efficient computing New institute New buildings Strong expertise in existing groups Tom Abel

30 Current KIPAC HPC computing Tom Abel Cosmological Hydrodynamics (Abel s group: 5 students + 2FTE s + postdocs) compute here and Oakridge W. Zhang, relativistic hydro + A. Spitkovsky, relativistic shocks, pulsars + computing here, NERSC, Oakridge, UCSC clusters 3 new postdocs will use significant computing

31 Data Challenge Haggles project (P. Marshall) mine entire HST archive for lenses ~10 Tb, 10 proc SN SDSS II follow up 30 Tb, 10s of processors LSST 20 Tb/night... Tom Abel

32 Scientific Visualization Considerable Strengths in 2D data plotting library: HippoDRAW Collaboration with LLNL using and extending VisIt Expertise in Photon Science and Accelerator design deploying stereoscopic visualization lab Tom Abel

33 Scientific Visualization Plan for Pierre Schwob computing and information center for the Fred Kavli building Enhance connections with Stanford Stereoscopic immersion for science, education and outreach Tom Abel

34 Voyage to Virgo movie Our place in the Universe Tom Abel Viz: Stuart Levy, Bob Patterson, Donna Cox (NCSA) Hipparcos, Brent Tully, and other sources

35 Tom Abel Photogenic highlights

36 the first stars First Stars movie Simulation: Tom Abel (KIPAC/Stanford), Greg Bryan (Oxford), Mike Norman (UCSD) Viz: Ralf Kähler (AEI, ZIB), Bob Patterson, Stuart Levy, Donna Cox (NCSA), Tom Abel (KIPAC/Stanford) Tom Abel The Unfolding Universe Discovery Channel 2002

37 Nature of Dark Matter Smallest objects -> highest annihilation rates Small halos -> DM trapped more effectively WIMP mass & physics -> size of first structures Tom Abel

38 SMBH formation All distances are proper Color scales differ between slides Full Box (92 kpc) Tom Abel Density John wise & Tom Abel Temperature

39 Tom Abel John wise & Tom Abel

40 Tom Abel John wise & Tom Abel

41 v rms / c s Myr 63 kyr Final Energies per particle [erg] 1e-11 1e-12 Thermal Potential Thermal + Turb M gas [M sun ] Tom Abel

42 New Methods Pulsars: A. Spitkovsky Tom Abel

43 Tom Abel

44 Impact of early stars O Shea, Abel, Norman & Whalen 05 ApJL

45 A Galaxy, one star at a time Long range ambitious program that builds a galaxy one star at a time starting from cosmological initial conditions. Phenomenology only for stellar evolution, dust physics... Tom Abel

46 Close dialogue & exchange with SCS and all HEP efforts Photon sciences Campus departments Tom Abel

47 Training Computing seminar focus on tools - run by students Bring in nearby vendors and local experts code kitchens, coding and optimization environments, parallel computing quick courses Tom Abel

48 Challenges Issues of Integration of existing solutions Training Communication and Collaboration embrace multi-disciplinary computing Tom Abel

The first stars and primordial IMBHs

The first stars and primordial IMBHs Ab initio predictions of black hole merger rates by the time LISA flies? Tom Abel Penn State Initial Conditions Time Evolution z=100 z=24 z=20.4 10 comoving kpc Cosmological