Concepts for Future High-Energy Astrophysics Missions

NASA (often with international partners) AEGIS: Astrophysics Experiment for Grating and Imaging Spectroscopy, a concept for a high-throughput, high-resolution, moderate cost, soft X-ray spectrometer. AXSIO: Advanced X-ray Spectroscopic Imaging Observatory, a concept for a broad-bandpass, high-sensitivity, high-resolution X-ray imaging spectroscopy mission. AXTAR: Advanced X-Ray Timing Array, a concept for a large collecting area X-ray timing mission to study black holes and neutron stars. BEST: Black Hole Evolution an Space-Time Observatory, a mission concept for deep hard X-ray imaging (5 - 70 keV) and broad-band X-ray polarimetry (2 - 70 keV). Black Hole Finder, a possible component of NASA's Physics of the Cosmos program, with 2 possible proposed implementations: CASTER: Coded Aperture Survey Telescope for Energetic Radiation. EXIST: Energetic X-Ray Imaging Survey Telescope. BHI: Black Hole Imager: an X-ray mission which will directly resolve the event horizons of black holes. EPE: Extreme Physics Explorer: a concept for a timing/spectroscopy mission that would use micro-channel plate optics (MCPO) to provide 4 m2 effective area focused to ~1 arc-min onto an X-ray calorimeter. EREXS: Epoch of Reionization Energetic X-ray Survey, a mission concept to study the birth and growth of the first black holes, as well as to perform a multiwavelength time domain astrophysics survey of a wide range of objects. EXIST: Energetic X-ray Imaging Survey Telescope, a hard X-ray (5-600 keV) imaging all-sky deep survey mission that will use a coded-mask high-energy telescope (HET) with imaging CZT detectors to image sources such as AGN, black hole transients, etc., in a 70 by 90 degree field of view with 2 arcminute resolution; an accompanying optical/IR telescope (OIT) will enable multiwavelength studies and prompt follow-up of gamma-ray bursts. Gen-X: The Generation X-Ray Mission, a large effective area (50 square meters at 1 keV, or 500 x Chandra) X-ray telescope to study the new frontier of astrophysics: the birth and evolution of the first stars, galaxies, and black holes in the early Universe. HEX-P: High-Energy X-ray Probe, a concept for a probe-class next-generation high-energy X-ray mission with broadband (0.1-200 keV) response and ~40 times the sensitivity of previous missions above 10 keV. NICER: Neutron star Interior Composition exploreR, a proposed instrument on the ISS consisting of an array of 56 X-ray telescopes to study the time variability of the emission from X-ray pulsars, thereby deriving information on their radii and masses which will tightly constrain the neutron stars' equation of state. NICER was selected in the Explorer 2011 AO as a 'mission of opportunity' for evaluation as a potential future space mission and was selected for Phase B in April 2013. Pharos: a concept for a rapid response mission to study the warm-hot intergalactic medium using GRBs as its probes, as well as to study the host galaxies of GRBs and the phyics of GRBs. SMART-X: Square Meter, Arcsecond Resolution X-ray Telescope, a mission concept for a 2.3 m2 effective area, 0.5 arcsecs angular resolution X-ray telescope, with a 5 arcmins FOV, 1 arcsec pixel size microcalorimeter, 22 arcmins FOV imager, and high-throughput gratings. SAHARA: Spectral Analysis with High Angular Resolution Astronomy, a mission concept for a soft X-ray optic with high spatial and spectral resolution over a wide field of view. WhimEx: Warm-Hot Inter-Galactic Medium Explorer, a concept for a high-resolution (relection grating) spectrometer to study the WHIM, AGN outflows and many other classes of X-ray sources. WFXIS: Wide-Field X-ray Imaging Spectrometer, a proposed mission to provide wide-field X-ray imaging spectroscopy with both high energy resolution (~ 5 eV) and high angular resolution (~ 10 arcsecs). WFXT: Wide-Field X-ray Telescope, a proposed mission with an effective area 10 times Chandra's which will perform surveys of the sky in the soft X-ray band (0.4-6 keV). Xenia: a Probe of Cosmic Chemical Evolution, a concept for a medium-size cosmology mission (with international collaborators) which will use gamma-ray bursts to probe the cosmic 'web', dark energy, dark matter, and clusters of galaxies.

Multinational and International ATHENA+, an X-ray observatory to be proposed as a large mission for the ESA science program, incorporating a single telescope with a fixed focal length (12 m) and two interchangeable instruments in the focal plane, a wide-field imager (WFI) and an X-ray integral field unit (X-IFU), i.e., an X-ray calorimeter. ATHENA+ is a new version of the previously proposed ATHENA: The Advanced Telescope for High Energy Astrophysics [ESA], which itself superceded the joint ESA/JAXA/NASA concept, IXO: International X-ray Observatory) Dark Matter Satellite will search for dark matter in the universe and study cosmic ray acceleration [China] EDGE: Explorer of Diffuse emission and Gamma ray burst Explosions, a mission with a high (< 3 eV) spectral resolution wide field spectrometer (WFS), together with a wide (1.4-degree diameter) field imager (WFI), a very wide (1/4 of the sky) field monitor (WFM) and a gamma-ray burst detector (GRBD) [Europe] GRAVITAS: General Relativistic Astrophysics Via Timing and Spectroscopy, a large (1.5 m2) effective area, moderate (125 eV) spectral resolution, high (100 µs) temporal resolution broad (0.1 - 10 keV) band X-ray mission targetted at studies of the Fe K line region at 6.4 keV in compact objects [Europe] MIRAX: Monitor e Imageador de Raios X, an X-ray transient mission [Brazil] NHXM: New Hard X-ray Mission, a mission to do soft and hard (0.2-80 keV) X-ray imaging and polarimetry [Italy] PheniX, a very-broad-band (1-200 keV) high spectral-resolution (<~ 0.5 keV) focussing X-ray telescope able to do Compton polarimetry for E > 50 keV, and a coded-mask all-sky monitor [Multi-national]