Arcus: Exploring the Formation and Evolution of Clusters, Galaxies, and Stars
Randall K. Smith1, R. Allured1, M. Bautz2, J. Bookbinder3, J. Bregman4, L. Brenneman1, N. Brickhouse1, D. Burrows5, V. Burwitz6, P. Cheimets1, E. Costantini7, S. Dawson3, C. DeRoo1, A. Falcone5, A. R. Foster1, C. Grant2, R. K. Heilmann2, E. Hertz1, D. Huenemoerder2, J. Kaastra7, K. K. Madsen8, R. McEntaffer5, E. Miller2, J. Miller4, E. Morse15, R. Mushotzky9, K. Nandra6, M. Nowak2, F, Paerels16, R. Petre10, K. Poppenhager11, A. Ptak10, J. Sanders6, M. L. Schattenburg2, N. Schulz2, A. Smale10, P. Temi3, L. Valencic10,12, R. Willingale13, J. Wilms14, S. Wolk1 1Smithsonian Astrophysical Obs, 2MIT, 3NASA/Ames, 4U. Michigan, 5Penn State University, 6MPE, 7SRON, 8Caltech, 9U. Maryland, 10NASA/GSFC, 11Queens University Belfast, 12JHU, 13U. Leicester, 14FAU, 15Orbital-ATK, 16Columbia We present the scientific motivation and performance for Arcus, an X-ray grating spectrometer mission to be proposed to NASA as a MIDEX in 2016. This mission will observe structure formation at and beyond the edges of clusters and galaxies, feedback from supermassive black holes, the structure of the interstellar medium and the formation and evolution of stars. Key mission design parameters are R= l/Dl >3000 with >500 cm2 of effective area at the crucial O VII and O VIII lines, with the full bandpass going from ~10-50Å. Arcus will use the silicon pore optics developed for ESA’s Athena mission, paired with off-plane gratings being developed at Pennsylvania State University and combined with MIT/Lincoln Labs CCDs. With essen- tially no consumables, Arcus should achieve its mission goals in under 2 years, after which we anticipate a substantial period of operation as a general observatory.
EXPLORING MATTER AT THE EDGES OF GALAXIES GOALS METHOD SELECTED INSTRUMENT REQUIREMENTS FEEDBACK FROM SUPERMASSIVE BLACK HOLES
Bright extra- Determine how Measure the radial Spectral Resolution (21.6-25Å) 2500 1.5 NGC 5548 S XI (39.24Å) Exploring how physics be- 15 2 galactic sources baryons cycle profiles of hot gas at Aeff(21.6-25Å) (avg) 500 cm haves at the extremes of
illuminate hot 14 in and out of and beyond the virial Background @ 24Å 0.006 cts/s space and time near a black 2 1 gas beyond the galaxies radii of galaxies and Aeff(16-21.6Å) (avg) 500 cm hole and learning how su- edges of galax- 13 clusters, and all phases Spectral Resolution (16-21.6Å) 2000 permassive black holes have Log N(O VII) [cm ] N(O Log Relative A cal per resol. element ±10% ies. Combined of gas in our Galaxy eff Normalized flux
0. 5 formed and evolved requires Bandpass 8-51Å with spectra 12 CCD energy resolution 150 eV high resolution X-ray spec- of Milky Way Arcus 100 ks simulation & model tra of density-dependent Determine Measure the mass, en- Wavelength calibration 0.4mÅ Chandra LETGS 345 ks observed 0 sources, Arcus −2000 −1500 −1000 −500 0 how black ergy, and composition Absolute Aeff calibration ±20% lines. Arcus will allow us to
0.1 Velocity (km/s) will expose a 4 mÅ EqW, holes grow and of outflowing winds Time Resolution 10 s identify features in hot gas 10 mÅ EqW, 6 mÅ EqW, 100 km/s complete 200 km/s 100 km/s z = 0.08 influence their from the inner regions outflow that match cooler gas detected by HST, and use their den- z = 0.05 z = 0.06 picture of the s Å ) (counts Flux surroundings of black holes sity sensitivity to measure the total mass outflow from the SMBH.
0.05 Understand Observe material ac- Bandpass 8-51Å formation and 500 ksec Arcus Blazar Observation Fx(0.1-2.4 keV) = 1.5x10 ergs cm s how accre- creting onto young Min Spectral Res. (8-51Å) 1000 THE BIRTH AND EVOLUTION OF STARS cycling of 22.6 22.8 23 23.2 23.4 Wavelength (Å) 2 Accreting young stars tion forms and stars along with stellar Aeff(8-51Å) (avg) 300 cm Capella O VIII Region metals in and 2 evolves stars coronae from young Aeff(19Å) 300 cm are spinning too slow- out of galaxies Arcus Simulation (5 ksec) and circumstel- and main sequence ly, given that they are Chandra HETG (542 ksec) and clusters. Absorption of lar disks stars still contracting. Does S = O VIII DR Satellite
bright blazars by material at N VII the accretion drive Cr XVICr O VIII α Ly
a range of redshifts will al- N VII a wind that removes low us to map the location, Arcus will address all of the scientific angular momentum? motion, and temperature Arcus will detect tur- of hot gas around galaxies, recommendations of the 2010 Decadal S bulent broadening that S S S S S groups, and clusters, testing Survey for soft X-ray grating science would test this, as well models for the origin and Wavelength (Å) in a MIDEX mission. as the DR satellite lines evolution of the hot gas. that will test coronal heating models.
Arcus Spacecraft & Instrument Optical Design Silicon Pore Optics (SPO) Arcus uses power, • Arcus optical design uses 4 identi- • Arcus’ design leverages ESA’s substantial and ongoing in- telemetry, and point- cal ‘channels,’ each of which has vestment in advancing SPO technology by using the same ing systems with Radiator focal length 38 SPO mirror modules mounted Full PSF substantial heritage. in one ‘petal’ with 32 Off-Plane and radii of ~ 24 arcsec Launch into a high Extendable Boom Grating (OPG) grating modules 330 mm curvature 200 altitude 4:1 lunar res- (deployed) mounted in a second ‘petal,’ as mirrors as Thermal onant orbit will be by Pre-collimator shown at right. Athena. 600 mm a Falcon 9 or similar. SPO Door • Arcus • The photons are dispersed into 435 mm Optical (open) Dispersion The 12m focal length an arc at the focal plane, with the design Direction Focal Plane is achieved with an channels aligned so that one CCD aligns the 100 Transverse PSF extendable optical detector array can read out photons from two highly (pixel) Y Position FWHM 1.05 arcsec Spacecraft bench. Spacecraft channels. SPO & OPG asymmetric Plate scale: 12m focal length “Channel” will be provided by OPG • CCDs will be built by MIT/Lincoln Labs with SPO PSF 0.25 arcsec/pixel Data from Petal Dispersed Spectra cosine Research Orbital ATK based SPO 1.6m in order to Petal requirements similar to the Suzaku mission. 0 100 200 on their high heritage • Uses high-throughput silicon-mesh filters simi- disperse the X Position (pixel) LEOStar platform. lar to those used for he Hitomi SXS detector. “transverse” • Overall design achieves a figure of merit for PSF into a spectrum, primary science achieving the equivalent Off-Plane Gratings (OPGs) 2000 Figure of Merit = Sqrt(R x Ae ) requirement to de- FoM needed to observe of a 1’’ mirror in one • Arcus leverages NASA’s long-term in- tect weak absorp- Arcus O VIII, O VII C VI 4mÅ EqW in <500 ksec dimension, all that is vestment in OPGs for Con-X, IXO, and 1500 from >7.5x10 cgs blazar (40+ known) required for a non- now X-ray Surveyor. tion features from O VII, O VIII, and imaging spectroscopy • Flight-like gratings meeting Arcus size, 1000 mission like Arcus. efficiency, flatness, and resolution -re C VI that is nearly • Test data from PANTER quirements have been fabricated (pic- an order of mag- runs shown here at right ture at right) with preliminary testing at nitude larger than 500
currently available Line Detection FoM (cm) XMM-Newton RGS find a 1’’ HEW in the transverse PSF, meeting Arcus NASA/MSFC’s stray light facility (see Chandra Gratings with Chandra or requirement. talk by R. McEntaffer at this meeting) 0 XMM-Newton ob- • Further PANTER tests planned for September to test latest • Tests at NASA/MSFC stray light facility 10 20 30 40 50 60 Wavelength (Å) generation of 12m SPO mirror module from Cosine Re- show that R>3000 can be obtained for a servatories. search with a flight-like grating module. single grating plate
O -Plane Grating Off-Plane Grating Modules 300 λ/δλ ∼ 3900 2 Graze, 6th Order • Tested at MSFC SLF Al Kα An Arcus grating module will consist of 15 81.1$mm 250 Al Kα 99.0$mm 8.93 nm aligned and mounted OPG plates 11.16 nm 200 Best-t model including 15.06 nm • Translational tolerances are easily met through line natural width 150 machine tolerances and mechanical constraints • Rotational tolerances require optical and UV 53.2$mm 100 8.339Å
Flux (photons/mÅ) Flux metrology and tracking throughout module 8.342Å 161.9 nm 50 population. See poster by R. Allured at this meeting for details -10 -5 0 5 10 Relative Dispersion (mÅ)