THE NUCLEAR SPECTROSCOPIC TELESCOPE ARRAY ( NuSTAR ) HIGH-ENERGY X-RAY MISSION

The Nuclear Spectroscopic Telescope Array (NuSTAR) mission, launched on 13 June 2012, is the first focusing high-energy X-ray telescope in orbit. NuSTAR operates in the band from 3 – 79 keV, extending the sensitivity of focusing far beyond the ∼10 keV high-energy cutoff achieved by all previous X-ray satellites. The inherently low-background associated with concentrating the X-ray light enables NuSTAR to probe the hard X-ray sky with a more than one-hundred-fold improvement in sensitivity over the collimated or coded-mask instruments that have operated in this bandpass. Using its unprecedented combination of sensitivity, spatial and spectral resolution, NuSTAR will pursue five primary scientific objectives: 1) probe obscured AGN activity out to the peak epoch of galaxy assembly in the universe (at z <∼ 2) by surveying selected regions of the sky; 2) study the population of hard X-ray emitting compact objects in the Galaxy by mapping the central regions of the Milky Way; 3) study the non-thermal radiation in young supernova remnants, both the hard X-ray continuum and the emission from the radioactive element Ti; 4) observe blazars contemporaneously with groundbased radio, optical and TeV telescopes, as well as with Fermi and Swift, to constrain the structure of AGN jets; and, 5) observe line and continuum emission from core-collapse supernovae in the Local Group, and from nearby Type Ia events, to constrain explosion models. During its baseline two-year mission, NuSTAR will also undertake a broad program of targeted observations. The observatory consists of two co-aligned grazing-incidence X-ray telescopes pointed at celestial targets by a three-axis stabilized spacecraft. Deployed into a 600 km, near-circular, 6◦ inclination orbit, the Observatory has now completed commissioning, and is performing consistent with pre-launch expectations. NuSTAR is now executing its primary science mission, and with an expected orbit lifetime of ten years, we anticipate proposing a guest investigator program, to begin in Fall 2014. Subject headings: space vehicles: instruments – telescopes 1 Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125; fiona@srl.caltech. edu. 2 Lawrence Livermore National Laboratory, Livermore, CA 94550 3 Space Sciences Laboratory, University of California, Berkeley, CA 94720 4 DTU Space National Space Institute, Technical University of Denmark, Elektrovej 327, 2800 Lyngby, Denmark 5 Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 6 NASA Goddard Space Flight Center, Greenbelt, MD 20771 7 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 8 ASI Science Data Center, c/o ESRIN, via G. Galilei, I-00044 Frascati, Italy 9 INAF Osservatorio Astronomico di Roma, via di Frascati 33, I-00040 Monteporzio, Italy 10 RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan 11 Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 12 Department of Physics, McGill University, Rutherford Physics Building, 3600 University Street, Montreal, Quebec, H3A 2T8, Canada 13 Universit de Toulouse; UPS-OMP; IRAP; Toulouse, France & CNRS; Institut de Recherche en Astrophysique et Planétologie; 9 Av. colonel Roche, BP 44346, F-31028 Toulouse cedex 4, France 14 Inter-University Center for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune 411007, India 15 Department of Physics, Durham University, Durham DH1 3LE, UK 16 Department of Physics and Astronomy, Sonoma State University, Rohnert Park, CA 94928 17 Dipartimento di Matematica e Fisica, Università Roma Tre, via della Vasca Navale 84, 00146 Roma, Italy 18 IASF-Milano, INAF, Via Bassini 15, I-20133 Milano, Italy 19 Physics Department and Santa Cruz Institute for Particle Physics, University of California Santa Cruz, Santa Cruz, CA 95064 20 Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, Atlanta, GA 30332 21 Pontificia Universidad Católica de Chile, Departamento de ar X iv :1 30 1. 73 07 v1 [ as tr oph . I M ] 3 0 Ja n 20 13