High Energy Astrophysics Lesson 1 Goal: • To provide an overview of observational High Energy Astrophysics Literature: • S. Rosswog, M. Brüggen: "Introduction to High-Energy Astrophysics" (Cambr. 2007) • P. Schneider: "Extragalactic Astronomy and Cosmology" (2015) • Seward & Charles: Exploring the X-ray Universe • M.Longair: "High-Energy Astrophysics" I,II, III (Cambridge Univ. Press: 2011) • F. Melia: "High Energy Astrophysics" (Princeton U.P 2009) • Werner & Mernier: Hot atmospheres of galaxies, groups, and clusters of galaxies Requirements: • Home assignment with a brief presentation (topic to be determined in October) 40% • Oral exam 60% Lecture Overview Introduction: What is high-energy astrophysics? Telescopes and detectors for high-energy astrophysics • Supernovae and supernova remnants • Gamma ray bursts • Neutron stars, pulsars, X-ray binaries (TBD) • Active galactic nuclei • Clusters of galaxies and the large scale structure of the Universe • Your lectures! • (Additional lecture/exercises on X-ray data analysis) About YOU • Science Interests? • Expectations? • Wishes? • Concerns? • Previous Courses and Lectures? • Plans? Today: What is high-energy astrophysics? Telescopes and detectors for high-energy astrophysics High-Energy Astrophysics Astrophysics of high energy processes and their application in astrophysical and cosmological contexts Application of the laws of physics in the extreme physical conditions in astrophysical systems, and the discovery of new laws of physics from observations. log (wavelength, m) 9 -3 2 0- 2 -4 -6 -8 -10 -12 -14_ 1 000 000 000 K % _ , O 0) > CO Radio 1 Infrared •] Ult 1 X-ray y-ray 10 000 K 3 K i 1 _i _i '/ ' 6 8 10 12 14 16 18 20 22 24 log (frequency, Hz) log (photon energy, eV) -6-4 -2 0 2 4 6 8 10 ■91-1-1-1-1-1-1-1-1-1- log (frequency, Hz) Messengers of high-energy phenomena Observations in different wavebands can be thought of as providing different temperature maps of the Universe according to Wiens displacement law: vmax =10n(77K)Hz; ^maxr=3xl06 nm K photon energy E=hv expressed in electron volts (visible light 2-3 eV) T=E/kb thermal 0.5-10 keV X-rays trace temperatures 5 x 106-108 K; 10 MeV ~ 1010K; 10eV~ 105K In non-thermal sources - where emitting particles that don't have a Maxwellian energy distribution - the effective temperature of the emitting particles can far exceed these temperatures. Such are e.g. radio sources, quasars, X-ray and Gamma-ray sources with emitting ultra-relativistic electrons. Other messengers include cosmic rays and gravitational waves Optical waveband m • The Universe in the optical waveband is almost entirely the integrated light of stars • Significant fraction of baryons locked up in stars with photosphere 7~~ 3000—10,000 K emitting in optical waveband • Disadvantage is extinction by dust grains • Many high energy astrophysical objects are faint in optical Near-infrared waveband • Dust extinction a strong function of wavelength l=h e-Qr where a proportional to A-1 • Because of reduced extinction the Galaxy is clearly seen Adaptive optics in the near-infrared allows almost diffraction limited imaging These observations provide evidence of a 4x106 solar mass black hole in the Galactic center Far-infrared waveband • Emission of dust grains • Indicates active regions of star-formation and accretion • Mid- and far-infrared require airborne or space observatories and are thermal background limited Millimeter & sub-millimeter • dominated by the cosmic microwave background radiation • extraordinarily uniform with a perfect black body spectrum at 7-2.728 K • at the sensitivity level of 1/1000 large scale anisotropy of dipolar form is observed (due to the Solar systems motion through isotropic radiation field at 350 km/s) • at the 1/100,000 sensitivity the dust emission of the Galactic plane is intense (also bright star-forming sub-millimeter galaxies) • away from the Galactic plane fluctuations of cosmological origin Cosmic microwave background radiation from Planck • fluctuations of cosmological origin • the CMB provides a radiation background for observations of clusters of galaxies (the so called Sunyaev-Zeldovic effect) and for interaction of high energy particles CO emission of molecular gas • the most common molecular line emission (strong electric dipole moment) • regions of starformation synchrotron radiation at 408MHz tracing relativistic electrons interacting with magnetic fields especially important for studies of the physics of active galactic nuclei 21 cm line of neutral hydrogen • neutral hydrogen emits 21 cm radiation due to the small change in energy when the relative spins of electrons and protons change (probability once in 12 million years) • also molecular emission - small molecules (like CO) emit in the millimeter, larger linear molecules in the radio • X-ray binaries powered by accretion onto white dwarfs, neutron stars and black holes; stellar coronae; supernova remnants; galaxy clusters; AGN; diffuse Galactic emission • The soft X-ray emission anticorrelates with the distribution of HI because of photoelectric absorption by interstellar gas Gamma-ray sky E>1 GeV Interaction of high energy photons with matter 1 I \ T 1 1 1 1 1 1 1111 1 1 1 III \ \ - - V 1 \ i \ I - - \ \ \ i \ t - Co \ \ \ y mpton \ \ 4 N To tal ^y' ^ s - \ v 4 s y 'Pair - - Photoelec \ :tric\ k s f - - i i ■> i i i i <:. -i_U.il If a photon has a larger energy than 2mec2, then in a field of a nucleus it can decay into an electron positron pair 0.1 0.2 0.5 1 2 5 10 Photon energy, ftco/MeV 20 50 100 Geiger-Muller counters Proportional counters Scintillator detectors Charge-Coupled Devices (CCDs) Calorimeters The X-ray Universe was discovered using sounding rockets Friedmann et al. 1949 at Naval Research Lab (NRL) discovers X-ray emission from the Sun Realisation that the Sun would not be detectable at stellar distances... n 1962, Riccardo Giacconi et al. Search for X-rays from the Moon and discover the X-ray source Sco X-1. Turns out that while for the Sun Lx=10-6oPt, for Sco X-1 Lx=109LxSun Rockets typically spend only -5 min over 100 km! Collimators FIELD OF VIEW angular resolution: tan a/2 = w / (21) tan a ~w/l (for small a) w H.V.POM« SUPPLY MAIN COUNTER VOLUME ANTICOINCIDENCE VOLUME COLLIMATOR /- FILLING VALVE O-RING \ / t~ PREAMPLIFIERS B£ WINDOW U 0.051 mm Proportional counter used on early sounding rocket observations 0 «0 Ol It M M »0 330 SooXR-1 CanXR-2 C«n XR-3 Val XR-1 c--->o0oo, I I . 240* Uhuru - The first X-ray satellite 12 December 1970: UHURU ("Freedom in Swahili) launched from Kenia Angular resolution of 0.52 degrees Uhuru - The first X-ray satellite stxr sl,N SENKKS SENSORS COLLIMATOR s°x 5°FWHM COLLI m ATOR 1/2°x s°fwhm ELECTRONICS PACKAGE TELEMETRY AND SPIN CONTROL Identification of Cygnus X-1, the first strong candidate for an astrophysical black hole Discovery of the pulsing accretion-powered binary X-Ray sources such as Cen X-3, Vela X-1 and Her X-1 Uhuru all sky catalog catalog of 339 objects in the 2—6 keV band m m at in ■ ■ ■ 1 m m m a m m HfHtk Ol-1 I_l_ M M M ■ BO MO -J_' ■ ' -1-1 i_l. I V 1 Ill r M IN » SO SK J4C JSC 0 « n K ,£ IN DEGREES u_ M M R ■ M Reflection and Absorption IR, Visible, UV X-rays Index of Refraction and Total Internal Reflection Snell's law: n1 sin 01 = n2 sin 02 —> cos at = n1 / n2 Index of Refraction and Grazing Angle Complex refractive index n\ Critical grazing angle at\ phase change absorption n = 1 - 8-ip slightly less than 1 for X-rays in matter S = exactly 1 in vacuum _Te_ Nop 2tt A COS at = 1 - 8 (Snell's law) for S« 1: at = Y2j Visible light: air :::::::::::::x^äy^: :::: solid: matter: from theoretical atomic physics: 8 - E-2 8 ~ Z —> a, ~ E1 a, ~ Vz ^--' for practical use: at~ 69 Vp / E arf //? arc minutes E in ke V p in g/cm3 ---------------------------I-- The Wolter Type I telescope • achieve the best 2D resolution • collect or "gather" weak fluxes of photons • concentrate the photons on a small region of the detector to minimize the detector background • these mirrors are compact • Used first time on the Einstein observatory The first X-ray imaging telescope 1978 Nov - 1981 April NASA's Einstein X-ray Observatory 0.2 - 20 keV 9=2 arcsec First X-ray spectra Coronae of stars Supernova remnants Resolved extragalactic sources Riccardo Giacconi received the Nobel Prize in Physics in 2002 for pioneering contributions to astrophysics, which have led to the discovery of cosmic X-ray sources Chandra (NASA) Sensitivity: 555 cm2 @1 keV Spatial resolutions.2 arcsec Launched in: 1999 XMM-Newton (ESA) Sensitivity: 4650 cm2 @1 keV Spatial resolution: 6 arcsec Launched in: 1999 Chandra mirror XMM-Newton mirror X-i.iy Telescope Minois Einstein EXOSAT ROSAT BBXRT ASCA Chandra XMM Mirror Characteristic _ aperture diameter 58 cm 28 cm 83 cm 40 cm 1 2 m 70 cm _mirrors 4 nested 2 nested 4 nested 118 nested 4 nested 58 nested geometric area (cm2) 350 80 1140 1400 1100 6000 _ grazing angle (arcmin) 40-70 90-110 83-135 21-45 27-51 18-40 focal length (m) 345 1.09 2.4 3.8 10 75 mirror coating Ni Au Au Au Ir Au highest energy focused (keV) 5 2 2 12 10 10 on axis resolution (arcsec) 4 18 4 75 0.5 20 I II I I I I I ! I J M I I I I I I I J I -n—p- Thin foil mirrors better RSODART180" (@ tow energy) 100 -ffl ASTRO -E 100' EXOSAT 19m Epoxy repl. SIC (QAB) 15" IT o i "Ö I £ s \ QJ JO 1 ^ 03 I 10 Con - X10" EASY TO MAKE better 1 . Replicated Optics Directly polished mirrors XEÜS 2" CHANDRA 0.5' DIFFICULT TO MAKE (if not impossible...) i i i i i i i i I I I I 11 I ' ■ ' ' ■' 0.0 0.2 0.4 0 6 0.8 1.0 Mass/Geometrical Area (Kg/cm") ..stiffness' 1.2 1 4 The Chandra X-ray Observatory • Chandra launched in 1999 • at an elliptical orbit with apogee at r ~ 135,000 km and perigee at r ~ 14,000 km • Massive mirrors with extremely high angular resolution of 1 arcsec • Four shells with a thickness of 2-3 cm • made of Zerodur (glass with zero expansion coefficient) • effective area of 800 and 400 cm2 @ 0.25 and 5 keV respectively • focal length 10 meters • max. diameter 1.2 m • coated with Ir • challenging manufacturing X-Ray Mirrors made of polished Zerodur: Chandra Chandra's Advanced CCD Imaging Spectrometer made of ten 1024 x 1024 pixel (8.3 x 8.3 arcmin) CCDs 0.5 arcsec on axis spatial resolution -150 eV spectral resolution -22 pixels -11' not constant w ith Z 22 pixels all" \ • 10 w203c4r 0 11 wl93c2 1 . \ • 12 wl58c4r 2 X 13 w215c2r 3 • SO wl68c4r wl40c4r S2 w!82c4r = 8" .8 —**! BI chip indicator Image Region Pixel (0.0) Bottom s 1 g • } ACIS-I (aimpoint on 13 = (949.978)) 330 pixels = 163" ACIS-S (aimpoint on S3 = (235.497)) - A V +Z Pointing Coordinates Target Otiscl Coordinates +Y + AZ Sim Motion I SIM Chandra transmission grating spectrometers gratings made of free standing gold wires Diameter of each grating facet 1.6cm 540 single grating facets mounted on a ring shaped frame spectral resolution of 40—2000 7557^403405268^608366126 The XMM-Newton X-ray Observatory • XMM launched in 1999 • at an elliptical orbit with apogee at r ~ 113,000 km and perigee at r ~ 5,600 km • Three telescopes on board • each made of 58 mirror shells • shell thickness 0.5 and 1mm • effective ara @ 1 keV 1475 cm2 • spatial resolution -6-15 arcsec • focal length 7.5 m • max diameter 70 cm The XMM-Newton X-ray Observatory • three imaging CCD detectors (MOS1, MOS2, pn ) • two grating spectrometers (RGS1, RGS2) with corresponding CCDs Comparison of focal plane organisation of EPIC MPS and pn cameras A] an.- min diameter circles EPIC MOS 7 CCDs each 10.9110.9 anzmiuites A EPICpn 12CCDs each 13.614.4 aicmin European Photon Imaging Camera (EPIC) Two arrays of 7 Metal-Oxide-Silicon CCDs (0.1—10 keV band) One array of 12 back illuminated pn CCDs (0.1—15 keV band) E/DE =20—50 Diameter of the field of view 30 arcmin eRosita on Spectrum-Roentgen-Gamma • detect the hot intergalactic medium of 50-100 thousand galaxy clusters • detect up to 3 Million new, distant active galactic nuclei • study the physics of galactic X-ray emitting pre-main sequence stars, supernova remnants and X-ray binaries. Nustar - the first hard X-ray telescope eg E p. 03 CD < 102 CD > o CD It LU 10 30 Energy [keV] Optics with I 30 Nested multilayer shells: W/SiC and Pt/SiC Up to 80 keV 10 meter focal length 40 arcsec spatial resolution The Astro-H X-ray Observatory ASTRO-H is an international X-ray observatory, which is the 6th in the series of the X-ray observatories from Japan. More than 160 scientists from Japan/US/Europe/ Canada. _l-1-1-L_ _J-1-L J-1-1-1_ 5.5 6.5 7 E (observed), keV 7.5 8.5 3 - > id t 3 O 1-1-1-r- i-1-1-r -i-1-1-r ~i-1-1-r x (J C x > x 1-1-1-r~ I ^5 > 0).- d, 1-1-1-1~ x. x a; -1 I > > > XXX XXX 0) 0) I I > > X X X X I I 5.5 6.5 7 7.5 E (observed), keV 8.5 SXS is an X-ray microcalorimeter array of 6x6 pixels at the focus of the Soft X-ray Telescope, which is capable of high-resolution spectroscopy and limited imaging of 3'x3' field of view in the soft X-ray (0.3-12 keV) band The microcalorimeter detector measures the temperature rise upon each incident X-ray photon, achieving an ~5eV energy resolution. X-ray energy, HgTe 1 thermometer T capacity C It absorber Si thermal conductance G low temperature heat sink The Athena X-ray observatory Silicon pore optics Energy range 0.2-12 keV Energy resolution: ~2 eV Field of View 5' (diameter) (3840 TES) Effective area @ 0.3 keV 1500 cm2 Effective area @ 1.0 keV 15000 cm2 Effective area @ 7.0 keV 1600 cm2 Time resolution 10 us The Integral (soft) Gamma-Ray observatory IBIS SPI 15 ke V—10 MeV "SPI Camer cmin resolution) Coded Mask \ j SPI Coded Mask Coded Mask Telescopes Principle of a pinhole camera The aperture of a coded mask telescope has patterns of "pin holes". The image has to be reconstructed with mathematical algorithms (auto correlation or back projection) - large field-of-view - energy independent imaging - low spatial resolution - large detector area with spatial resolution - high background cdded mask detector area SPI on gamma-ray observatory Integral Swift Gamma-Ray Burst Mission €> NASA Coded Aperture Mask / Radiator Graded-Z Shield Optical Bench Module Control Box Burst Alert Telescope (Energy range: 15-150 keV) coded-aperture mask of 52,000 randomly placed 5 mm lead tiles. Covers over one steradian fully coded, three steradians partially coded. Locates the position of each event with an accuracy of I to 4 arc-minutes within 15 seconds. X-ray Telescope MOS CCD behind 12 nested Woltertype I X-ray mirrors take images and spectra of the X-ray afterglow Ultraviolet/Optical Telescope Measures the light-curve of the optical/UV afterglow BAT Detector Array Power Supply Box Fermi gamma-ray observatory Tracker Pair-Conversion Telescope Calorimeter Anticoincidence Detector (background rejection) Conversion > Foil Particle Tracking Detectors ^ Calorimeter (energy measurement) After distance nR, the number of (photons + electrons + positrons) is 2n and their average energy is E()/2n. Mean energy per particle or photon Distance through medium '7 H.E.S.S. MAGIC VERITAS The TeV sky from HESS ■\ 3 2 c 1 o 2 3 _4i 4 3 2 o~ I 0 ■2 3 _4i 4 3 2 c 1 0 *-l 2 3 » 3 2 o~ I ^ 0 -2 3| -41 / V / I 60 50 40 30 . \ 1 20 j{(V jrt» jf#> s\* ^^^^ 10 350 340 ifir .s\* .<ö* . .»>- . vV .\\* »nV^ .iß' .iß» 330 320 310 300 L O I 16 14 ß« 10 £ IM 4 i 50 Ö 35 2 -4 16 14 12 „ Ii) -J. 6 C 4 E 2 -2f lo M -2 I 16 14 12 u 10 Ü 16 4 2 10 16 14 10 £ IS = 6 & 4 E 2 041 0 290 280 270 260 250 CubeSats for High-Energy Astrophysics GRBAIpha Launched in March 2021 ~155 transients VZLUSAT-2 Launched in January 2022 ~100 transients GRBBeta Launched in July 2024 1st two weeks after launch! GRBAIpha detector Pal+ 2020 Csl(TI) scintillator Wrapped in Enhanced Specular Reflector (ESR) 2 readout channels of 4 MPPCs (S13360-3050 PE) by Hamamatsu GRBAIpha detector