Fermi Telescope, Black Holes and Dark Matter

Slides of my presentation for students of the INFIERI 2016 school hosted at Universidade de Sao Paulo. Overview of the Fermi Gamma-ray Space Telescope and science topics, with focus on black holes and dark matter.

Transcript

1. Fermi Telescope, Black Holes and Dark Matter Fermi Telescope, Black Holes and Dark Matter Rodrigo Nemmen IAG USP Jan. 31st, Feb. 1st 2017 INFIERI School @ USP
2. Practical information Where: IAG USP, sala A304 Capacity of lab: 15 people When: First lab session: Jan 31st (Tue), 2-5pm Second lab session: Feb 1st (Wed), 2-5pm The two lab sessions have the same content. If you want to attend one of the two sessions, please let us know by e-mailing: with your name and university Questions? rodrigo.nemmen [[at]] iag usp br . . https://rodrigonemmen.com fabio.cafardo [[at]] usp br .
3. Structure of this talk Overview of IAG USP / black hole group Gamma-ray astronomy Fermi space telescope Cosmic gamma-ray sources Black holes Dark matter Lab. activity
4. Universidade de São Paulo (USP) Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG) 30 professores ~30 pós-doutores ~60 alunos de pós-graduação Estrelas Galáxias Planetas Buracos negros Cosmologia rodrigonemmen.com @nemmen
5. Black hole theory / observations AGNs / stellar mass BHs / GRBs High-energy astrophysics Gamma-ray astronomy http://rodrigonemmen.com/group/
6. The extreme universe shines in gamma-rays
7. Feynman diagrams: the QED vertex • It is the nonzero electric charge of the fermion that matters (can be lepton or quark) • For full interactions, multiple vertices can be combined and momentum must be conserved annihilation radiation radiation pair creation 5 Justin Vandenbroucke Physics of Particle Detectors Slide: Justin Vandenbroucke
8. Interactions 1.5 The Structure of Matter at the Microscopic Scale 11 Fig. 1.3 A collision between two electrons is due to the exchange of one or more virtual photons. A photon can be seen as a quantum of electromagnetic force Fig. 1.4 Example of electromagnetic interactions of charged particles. In these diagrams the direc- tion of time is from left to right. An arrow pointing against the direction of time, i.e. to the left, represents an antiparticle. (a) An electron and a positron annihilate each other and materialise again as a quark-anti-quark pair. (b) An electron and a positron annihilate each other into two gamma electron-electron scattering: electron-positron annihilation to two photons: electron-positron annihilation followed by pair production: Also: Compton scattering, inverse Compton scattering 6 Justin Vandenbroucke Physics of Particle Detectors Slide: Justin Vandenbroucke
9. Particle Interactions – Examples Charged Particle Electron Ionization: γ Pair production: x γ Electron Positron Charged Particle Atom Electron Photon Electron Positron Nucleus Nucleus Compton scattering: γ γ Electron Electron Photon Photon Electron Electromagnetic interactions of electrons and photons in matter + bremsstrahlung 7 Justin Vandenbroucke Physics of Particle Detectors Slide: Justin Vandenbroucke
10. Ground-based: indirect detection via Cherenkov radiation Space-based: direct detection using techniques of particle physics Types of gamma-ray observatories
11. Fermi Gamma Ray Telescope: LSST for high-energy sky, 20 MeV - 300 GeV, whole sky every 3 hours Unique Capabilities for GeV astrophysics – Large effective area – Good angular resolution – Huge energy range – Wide field of view Large Area Telescope (LAT) Observes 20% of the sky at any instant, entire sky every 3 hrs 20 MeV - 300 GeV Gamma-ray Burst Monitor (GBM) Observes entire unocculted sky Detects transients from 8 keV - 40 MeV International and interagency collaboration between NASA and DOE in the US and agencies in France, Germany, Italy, Japan and Sweden Mission Lifetime: 5 year requirement, 10 year goal R. Nemmen
12. How to Detect a Gamma-ray?
15. All observed data is immediately public, as well as analysis software Google for: Fermi science tools
16. Fermi LAT: 20 MeV - 300 GeV. Views entire sky every 3 hours
17. Gamma-ray sky after 7 years Diffuse galactic gamma-ray emission Bühler+15 Energies 100 MeV - 300 GeV
18. Types of sources seen by Fermi LAT Acero+15
19. ≈60% of gamma-ray sources are black holes supermassive black holes
20. Bühler+15 Energies 100 MeV - 300 GeV Diffuse galactic gamma-ray emission 0 0 −30 30 −60 60 −90 90 −120 120 −150 150 −180 180 30 −30 60 −60 90 −90
21. 0 0 −30 30 −60 60 −90 90 −120 120 −150 150 −180 180 30 −30 60 −60 90 −90 90 Ackermann+15 Gamma-ray sky observed by Fermi LAT is dominated by blazars FSRQs: flat spectrum radio quasars BL Lac objects AGNs of unknown type non-blazar AGNs
22. Apparent size of Moon Centaurus A: 20 times bigger than the Moon in radio and gamma-rays
23. How can a black hole emit gamma-rays? It doesn't
24. McKinney et al. 2013, Science also, work in progress by Soares et al. electron γ electron γ Inverse Compton scattering: - self-synchrotron - external
25. Launching of Active Galactic Nuclei Jets 19 toward the polar regions as they move away from the BH. The group of field lines highlighted in green connects to the BH and makes up the twin polar jets. The jet field lines extract BH rotational energy and carry it away to large distances. These field lines have little to no gas attached to them and are therefore highly magnetized (since disk gas cannot cross magnetic field lines and is thus blocked from getting to the polar region, the jet field lines either drain the gas to the BH or fling the gas Fig. 9 [Panel (a)]: A 3D rendering of our MAD a = 0.99 model at t = 27,015rg /c (i.e., the same time as Fig. 8d). Dynamically-important magnetic fields are twisted by the rotation of a BH (too small to be seen in the image) at the center of an accretion disk. The azimuthal magnetic field component clearly dominates the jet structure. Density is shown with color: disk body is shown ith yellow and jets with cyan-blue color; we show jet magnetic field lines with cyan bands. The s approximately 300rg ⇥ 800rg . [Panel (b)]: Vertical slice through our MAD a = 0.99 e and azimuth over the period, 25,000rg /c  t  35,000rg /c. Ordered, fields remove the angular momentum from the accreting gas pinning BH (a = 0.99). Gray filled circle shows the s, and gray dashed lines indicate density of the time-average magnetic s is also seen from nd with Aberration of light in a relativistic jet: gamma-ray sky is dominated by blazars Blazar Chapte ments o shall Co discove These a that is, any mis jets asso the emi with th degrees One do less they radio so the ben Observer Observer Observer Observer v = 0 0.75c 0.94c 0.98c Tchekhovskoy
26. Unknown Known populations of γ-ray sources ? ? ?
27. 1/3 of gamma-ray sources are unknown Unknown Known populations of γ-ray sources black holes? ? ? ? Pulsars? Exotic physics: Dark matter?
28. Matéria escura
29. Ωm0 = 0.3 ΩΛ0 = 0.7 Ωr0 = 8×10-5 26% 70% 4% Standard cosmological model (ΛCDM) H0 = 70 km/s /Mpc k = 0 (flat) Ω0 = 1 ✓ H H0 ◆2 = ⌦ + 1 ⌦0 a2 p = w⇢c2 ⌦ = ⌦m + ⌦rad + ⌦⇤ Friedmann equation density parameter eq. of state ¨ a a = 4⇡G 3c2 (✏ + 3p) acceleration eq.
30. Candidatos a matéria escura Áxions: partículas hipotéticas com mc2~10-5 eV Buracos negros primordiais: m ~105 Msol Fundo cósmico de neutrinos (levemente massivos) WIMPs: Weakly Massive Interacting Particles partículas não-bariônicas como fotinos, gravitinos, axinos, sneutrinos, gluinos, etc. mc2 >10 GeV
32. Dark Sector of Vermions Varks Veptons Dark charge Dark charge Vosons Vluon Voton ? ? ? ? ? ? ? Dark Dark charge Dark charged Vosons ? ? ? ?
33. m = 65 GeV m = 65 GeV Eγ = 130 GeV DM particles annihilate Gamma-ray photon produced
34. A tentative gamma-ray line from Dark Matter annihilation w/ Fermi Large Area Telescope 2)007 Weniger+12, JCAP Significance ~3-4σ
35. Energy (GeV) 60 80 100 120 140 160 180 200 220 -4 Energy (GeV) Events / 5.0 GeV 0 10 20 30 40 50 60 70 = 133.0 GeV γ P7_REP_CLEAN R3 2D E = 17.8 evts sig n σ = 3.3 local s = 276.2 evts bkg n = 2.76 bkg Γ (c) Energy (GeV) 60 80 100 120 140 160 180 200 220 ) σ Resid. ( -4 -2 0 2 4 Ackermann+13 sglobal ~1.6σ A tentative gamma-ray line from Dark Matter annihilation w/ Fermi Large Area Telescope
36. Lab. activity: Analysis of Fermi Telescope observations of a black hole Download photons observed by the Fermi Telescope from NASA process and select photons for scientific analysis plot gamma-ray image of supermassive black hole (blazar) using python tools
37. Github Twitter Web E-mail Bitbucket Facebook Blog figshare rodrigo.nemmen@iag.usp.br http://rodrigonemmen.com @nemmen rsnemmen http://facebook.com/rodrigonemmen nemmen http://astropython.blogspot.com http://bit.ly/2fax2cT
38. Director’s cut (cf separate file)