Astro-H XRT system H.Awaki (Ehime University) + Astro-H XRT team (Nagoya Univ., NASA/GSFC, ISAS/JAXA, Ehime Univ., Chubu Univ., Osaka City Univ., Nara women’s Univ., Kobe Univ., Chuo Univ., JASRI/SPring-8, JST ) Contents 1. Astro-H satellite 2. XRT components & design 3. HXT (foil production, calibration facility) 4. SXT (improvements from Suzaku to Astro-H)

Astro-H Scientific objectives (1) Evolution of clusters of galaxies (2) Growth of super-massive black holes (3) Behavior of material in extreme gravitational field (4) Particle acceleration in the universe (5) Dark matter and dark energy Scientific objectives (1) Evolution of clusters of galaxies (2) Growth of super-massive black holes (3) Behavior of material in extreme gravitational field (4) Particle acceleration in the universe (5) Dark matter and dark energy The new Japanese X-ray mission following Suzaku Astro-H is currently planned to launch in fiscal Length: 14 m Weight: 2.5 t Launch vehicle: JAXA HII-A Orbit : 550 km circular i = 31 °

Instruments FL=5.6 m Double-sided Si Strip (4 layer) detector + CdTe double strip(1 layer) detector (Micro calorimeter) (X-ray CCD camera) Extended Optical bench Fixed Optical bench radiator SUN Si/CdTe Compton camera Soft X-ray telescopeHard X-ray telescope (HXT) FL=12 m Soft X-ray imager Soft X-ray spectrometer Soft Gamma-ray detector Hard X-ray Imager (HXI) With these instruments, Astro-H will cover the bandpass between 0.3 keV to 600 keV.

Main features of Astro-H Large collecting area above 10 keV 200cm 40 keV High-resolution spectroscopy with E/ΔE> cm 6 keV Wide band observation from 0.3 to 600 keV. Angular resolution Collecting area in the hard X-ray band Suzaku XMM-Newton Chandra Astro-H Energy resolution Collecting area in the soft X-ray band Energy band Effective area Energy [keV] Effective area [cm 2 ] HXT+HXI SGD (Compton mode) SXT+SXS SXT+SXI

Hard X-ray region: Continuum Sensitivity for point source Energy ( keV) Power law spectrum of a 1 mCrab source with Γ=1.7 Flux (photons s -1 keV -1 cm -2 ) ΔE/E=0.5 T=100 ks Thank to the hard X-ray imaging system of Astro-H, the sensitivity for point sources is much improved above 10 keV. ⇒ The detection limit of Astro-H is about two orders of magnitude fainter than that of Suzaku PIN. We will be able to obtain a spectrum of 0.01 mCrab source with N H =10 24 cm -2, HXI simulation for absorbed AGNs (Terashima) 3% of NXB T=100ks Energy ( keV) ASTRO-H HXI ASTRO-H SGD Suzaku-HXD (GSO) Suzaku-HXD (PIN)

Main features of Astro-H Large collecting area above 10 keV High-resolution spectroscopy with E/ΔE>1000 Wide band observation from 0.3 to 600 keV. Angular resolution Collecting area in the hard X-ray band Suzaku XMM-Newton Chandra Astro-H Energy resolution Collecting area in the soft X-ray band Energy band Effective area Energy [keV] Effective area [cm 2 ] HXT+HXI SGD (Compton mode) SXT+SXS SXT+SXI

High resolution Spectroscopy in the soft X-ray region FWHM ~4 eV Energy (eV) Mn Kα Takahashi et al. 2008, SPIE 1 10 Energy (keV) Astro-H/SXS A large effective area with a high energy resolution is realized by the NASA/GSFC thin foil optics (SXT-S). The thin foil optics has benefits of light weight and high throughput.

Main features of Astro-H Large collecting area above 10 keV 200cm keV High-resolution spectroscopy with E/ΔE> cm Wide band observation from 0.3 to 600 keV. Effective area Energy [keV] Effective area [cm 2 ] HXT+HXI SGD (Compton mode) SXT+SXS SXT+SXI We can obtain these features with X-ray telescope. Telescope is crucial for Astro-H  XRT system.

2. XRT component TS is placed over the entire aperture of each mirror in order to isolate the XRT from space thermally. PC is set on the top on the mirror in order to reduce the stray light. Mirrors employ tightly-nested, conically approximated thin-foil Wolter-I optics. Focal plane images formed by stray light These panels show simulated images of a point source locating at (-20’, 0) in cases of without and with pre-collimator. (Serlemitsos et al. 2007) Without PCWith PC

PET 0.2 um Polyimide XRT design parameters ~210 t0.15, 0.23, 0.31 mm h100mmx2 ~ S Light weight and high throuput Weight ~56 kg ~ 80 kg Angular resolution 1 arcmin 1.7 arcmin

Hard X-ray Telescope (HXT) Al Substrate 0.2 mm Epoxy 0.02mm Pt/C Multilayer d n < d 1 Supper mirror Depth-graded multilayer (ML) technology (supper mirror) Reflector of HXT with depth-graded ML is produced through a replication method The ML uses the Bragg reflection and enhance reflectivity beyond the critical energy by the X-ray interference. 30 keV measurement model Critical angle of Pt at 30 keV (0.161 deg) Reflectivity of Super mirror coating on float glass. The periodic structure is Å level and micro-roughness~3Å.

Sputtering Chambers Sputtering Chamber

Foil Nagoya Univ. (1) Forming foil (4) Curing(5) Separation (3) Spray epoxy(2) ML coating (6) Finished reflector Quality check

Surface profile of the reflector Axial figure profile of a recently fabricated test reflector 2m2m Replication mandrel (glass tube) Replicated reflector Figure error of this test reflector is ±1 micron (P-V). Based on a reflectivity measurement, surface roughness is about 3-4A, which is comparable to that of glass tube.  smooth surface is trasferred to the foil. E=30 keV σ~3A Reflectivity measurement

Synchrotron radiation facility SPring-8 We use this facility for Reflectivity measurement of an X-ray reflector Image quality measurement of an XRT SPring-8 BL20B2 Super Photon ring 8GeV Synchrotron radiation ranging from the soft X-ray (E=300eV) to hard X-ray (E=300keV) region is available with high intensity. These data are valuable for making the response function of HXT.

Reflectivity SPring-8 BL20B2 Experimental Hutch 2 & 3 E/  E~10 4 beam size = 0.5x0.5mm 30 keV measurement model measurement model 60 keV

Image SPring-8 BL20B2 E/  E~ m HXT Stages Beam divergence < 1”, when beam size = 0.3x0.3mm Direct beam after 4-axis slit An X-ray image will be obtained by a pencil beam scan. XRT for a balloon bone experiment Telescope holder Stages Telescope holder SUMIT XRT: 1.54 arcmin (HPD) (87pairs)

Soft X-ray telescope for SXS ~improvements from Suzaku to Astro-H ~ (1) Substrate Shaping – To use thicker Al substrate for the larger radii. – To use significantly larger number of forming mandrels for better substrate shaping (2) Precise positioning – To make precise alignment bars – Reflector will be fixed onto the bar by glue (3) Stronger housing – More mass is allocated to the mirror housing SuzakuAstro-H Diameter40 cm45 cm Focal length4.5 / 4.75 m5.6 m Foil thickness 152  m 152, 229, 305  m # of shells168/175~210 Forming Mandrels Precise Alignment bars ~40  m walk ~3  m accuracy Reflector positioning Free within a groove Fix by glue Strong housing (Housing mass) 25% of total mass 40% of total mass

Reflector fixing (testing with the Suzaku spare) Since groove width of alignment bar is wider than the reflector thickness by 25 µm and the reflectors are free to move. Test gluing using “the Suzaku spare hardware” ⇒ 1.26 arcmin (HPD) with 60 pairs. The reflector will be fixed onto the bar by glue for ASTRO-H in order to improve angular resolution Diameter (arcmin) Encircled Energy Function pairs Test 1.26 arcmin Suzaku (1.7arcmin HPD) ASCA (3.7arcmin HPD) Okajima et al. 2009

Production schedule We will start mass-production of foils for HXT in April launch Mass production of HXT foils

Summary Astro-H mission The new Japanese X-ray mission is currently planed to launch in the unique features are (1) Large collecting area above 10 keV (2) High-resolution spectroscopy with E/ΔE>1000 (3) Wide band observation from 0.3 to 600 keV.. XRT system X-ray telescope system consists of two HXT (5-80 keV) and two SXT ( keV). Mirrors employ tightly-nested, conically approximated thin-foil Wolter-I optics. HXTs employ Pt/C depth-graded multilayers, while SXTs employ a single layer of gold. Current status We are performing test productions, and are tuning production facility. Based on basic studies, detailed studies of the flight design are in progress, and production facilities for the Astro-H XRT system are close to finish.