Athena ESAs next generation Xray observatory Gregor Rauw

Athena+, ESA’s next generation X-ray observatory Gregor Rauw High-Energy Astrophysics Group Liège University

The X-ray Universe today

X-ray astrophysics provides a complementary view of the Universe, revealing highly energetic phenomena. Crab Nebula Orion Sirius B Moon

XMM-Newton (ESA) and Chandra (NASA) are now in orbit for more than 10 years and have deeply changed our view of the X-ray Universe. Cas A M 82 NGC 6231 Cen A Among the many discoveries: • Establishing charge-exchange as the mechanism for X-ray emission of comets • Quantitative diagnostics of hot plasma in the coronae and winds of stars • Images of the particle acceleration shocks in supernova remnants • Direct measurement of rotation of black holes and neutron stars • Resolving the cosmic X-ray background into discrete sources, mostly AGN • Contributions to the study of dark matter and dark energy via observations of galaxy clusters. • …

The science to be addressed by Athena+ Where are the hot baryons and how do they evolve? How do black holes grow and shape the Universe? The life cycle of matter and energy in the local Universe High z groups and clusters. AGN feedback. Star formation and evolution. Evolution of hot baryons. Accretion physics. Compact Objects Missing baryons at low z. Obscured accretion and galaxy formation. SNRs and the ISM Physics of clusters and groups. Solar System and exo-planets. Growth of SMBHs. Diagnose hot/energetic cosmic plasmas in a wide variety of astrophysical environments using spatially resolved medium and high-resolution X-ray spectroscopy

• Where are the hot baryons and how do they evolve? • Reveal and map the first virialized baryonic structures • Determine their dynamical, thermal and chemical evolution E. g. measure the chemical composition of the hot plasma in galaxy clusters as a function of z. • Complete the census of baryons in the local Universe Trace large-scale-structures and detect the WHIM via high resolution X-ray spectroscopy • Understand the physics of clusters and groups Determine intra-cluster gas velocities as a function of z via imaging X-ray spectroscopy. Cosmic Web Cluster Physics

• How do black holes grow and shape the Universe? • Reveal the causes and effects of AGN feedback • Understand the physics of accretion onto compact objects X-ray tomography of inner accretion disk, determination of the spin rate of black holes (Fe K line shape), hot spot tracking (short-term variability of Fe Kα line). • Track obscured accretion through the ages • Perform a census of black hole growth at high redshift Cosmic Feedback Accretion physics Obscured accretion High z SMBH

• Life cycle of matter and energy in the local Universe • Star formation and evolution Young stars, stellar winds, stellar activity • End points of stellar evolution X-ray binaries, neutron star, pulsars, white dwarfs • Supernova remnants and the interstellar medium Disentangle the 3 -D structure of SNR via high-resolution integral field spectroscopy, study the acceleration of particles by the SNR shock through the resulting non-thermal emission. • The Solar System and exo-planets Compact Objects Stellar Activity SNRs Charge Exchange

A few more specific examples Wind-wind collisions in massive binaries: dynamics of hot gas well traced by Fe K line. E. g. colliding winds in WR 140: diagnose the physics of the innermost parts of the wind-wind interaction. But also: study X-ray emission and variability of single massive stars, Doppler -map their magnetospheres, …

A few more specific examples X-ray emission from planets of the Solar System. E. g. Jupiter (emission due to charge exchange, solar X-ray scattering and electron bremsstrahlung) Integral field spectroscopy with Athena+ will resolve the disk and auroral charge exchange emissions and resolve the charge exchange ions (hence specify their origin) But also: look for Saturn’s auroral X-rays, Mars: solar X-ray scattering in the atmosphere, charge-exchange in the exosphere

Athena+ mission concept Focal plane Service Module 12 m Fixed Focal Length Payload: Wide Field Imager (WFI), X-ray Integral Field Unit (X-IFU) microcalorimeter. Sensitivity ~ 30 times better than XMM: stacked Si pore optics, 5” (3”) resolution Mirror Assembly L 2 orbit, 5 yr nominal lifetime (starting 2028)

Athena+ requirements Effective Area Requirement Driver 2 m 2@ 1 ke. V (goal 2. 5 m 2) Hot Baryons Black hole evolution Accretion Physics 0. 25 m 2 @ 6 ke. V (goal 0. 3 m 2) Angular Resolution 5” (goal of 3”) Black Hole Evolution Hot Baryons Fields of view WFI: 40’ diameter (goal 50’) X-IFU: 5’ x 5’ (goal 7’ x 7’) Hot Baryons Black Hole Evolution Spectral resolution 150 e. V @ 6 ke. V (WFI) 2. 5 e. V (X-IFU) goal 1. 5 e. V Black Hole Evolution Hot Baryons Count rate capability >1 Crab Accretion Physics Timing resolution 50 ms Accretion Physics TOO response 8 hours (2 hours goal) Hot Baryons

Athena+ white paper in response to ESA call for L 2/L 3 currently in preparation (due 24 May). Athena+ will be the most sensitive X-ray observatory ever. It will lead to substantial breakthroughs in many different fields of astrophysics. • Find out more about Athena+: http: //www. the-athena-x-ray-observatory. eu • And sign up to support the project! • Athena+ Open Meeting: 1 -2 July in Paris