TECHNOLOGY INNOVATION AND SCIENTIFIC DISCOVERIES IN HIGH ENERGY ASTROPHYSICS

Aurora Simionescu ! Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency

High energy photons allow insights into extremely compact and/or extremely hot ! regions of the cosmos

First non-solar X-ray source: Scorpius X-1 (accreting neutron star) discovered in 1962 by Riccardo Giacconi during a rocket experiment UHURU first satellite launched specifically for the purpose of X-ray astronomy, in December1970 ! +SKYLAB, EINSTEIN, RXTE, ROSAT, BEPPOSAX XMM-NEWTON, CHANDRA, ASTROSAT…

History of JAXA’s X-ray satellites since 1979

Hakucho Tenma Ginga ASCA Suzaku Reflection and Absorption

IR, Visible, UV X-rays

Challenge #1:! How do we obtain sharp, focused X-ray images?

Chandra mirror XMM-Newton mirror XMM-Newton mirrors

Wolter type I telescope gold has a high reflectivity and is usually used to coat the mirror shells X-ray mirror development and testing facilities at ISAS CHANDRA X-RAY OBSERVATORY so far the clearest X-ray pictures ever obtained (sub-arcsecond resolution, comparable to optical telescopes!) Detectors: CCDs SN1006 (X-ray/radio composite)

Centaurus A jet

“Bullet Cluster” Challenge #2:! How do we obtain sharp X-ray spectra? Project Status since SM13 (Mar.2-4) JAXA’s Hitomi X-ray satellite

Project Status since SM13 (Mar.2-4)

THE SOFT X-RAY SPECTROMETER (SXS)

Micro-calorimeter pixels cryogenically cooled to 50mK provide a spectral resolution ~30 times better than CCDs

NuStar (Nuclear Spectroscopic Telescope Array)

First focusing hard X-ray telescope 40” spatial resolution CdZnTe detectors Launched 2012 on Pegasus rocket, still operational NuSTAR measurement of black hole spin in NGC1365 INTEGRAL (INTErnational Gamma-Ray Astrophysics Laboratory) Launched by ESA in 2002, still operational 15 keV - 10 MeV

“coded mask” imaging technique example of important science output: gamma-rays from radioactive elements formed during supernova explosions Fermi

Launched in 2008, still operational Maps entire sky every 3h 8 keV - 300 GeV Pair conversion telescope

Using Cherenkov radiation to detect the highest energy particles

Idea: particle moving faster than speed of light in a given medium (air) generates a Cherenkov shock wave and loses energy in the form of (usually bluish) light

This method is used to detect cosmic rays with energies 30 GeV to 100 TeV Typical angular resolution 0.05-0.1 degree HESS, MAGIC, VERITAS Future high energy astrophysics telescopes

ATHENA (Advanced Telescope for High Energy Astrophysics) ESA mission planned for launch in 2028

Cherenkov Telescope Array (10x sensitivity improvement over e.g. Veritas) Athena Technological Developments

New mirror technology: “silicon pore optics” (idea: the reflecting surface is an array of very regular, rectangular pores made by stacking Si wafers etched and coated with Ir or Au)

Transition edge sensor: use the temperature-dependent resistance of the superconducting phase transition Practical applications

High-resolution images in hard X- rays can track radioactive decay products used for cancer treatment

Indium111 and Iodine125 can be used in eradicating cancer stem cells and decay by emitting hard X-ray photons in the 27-35 keV energy range