Tycho's supernova remnant was observed by the XIS and HXD instruments onboard the Suzaku satellite on 2006 June 26-29 for 92 ks. The spectrum up to 30 keV was well fitted with a two-component model, consisting of a power-law with photon index of 2.7 and a thermal bremsstrahlung model with temperature of 4.7 keV. The former component can alternatively be modeled as synchrotron emission from a population of relativistic electrons with an estimated roll-off energy of around 1 keV. In the XIS spectra, in addition to the prominent Fe K_alpha line (6.445 keV), we observe for the first time significant K_alpha line emission from the trace species Cr and Mn at energies of 5.48 keV and 5.95 keV, respectively. Faint K_beta lines from Ca (4.56 keV) and Fe (7.11 keV) are also seen. The ionization states of Cr and Mn, based on their line centroids, are estimated to be similar to that of Fe K_alpha (Fe XV or XVI).
We present the in-flight performance of the X-ray telescopes (XRTs) onboard Suzaku. The imaging capability is significantly improved over the ASCA XRT, which had half-power diameters of 3'.6, to 1'.8-2'.3 for all four XRT-I modules. Contemporaneous fits of a power law to all the XIS spectra of the Crab Nebula taken at the two standard observing positions (XIS/HXD-default positions) gives a flux consistent with that obtained by Toor & Seward (1974) to within〜2%. The pre-collimator on the top of each XRT module successfully reduces the intensity of the stray light from the 20' and 50'-off directions down to the level of pre-flight expectations. We also present the thermal wobbling of the satellite. The wobbling causes the alignment error between the XRT-XIS system and the attitude and orbit control system. The wobbling of the alignment is as large as〜1arcmin. In the currently processed data, the absolute coordinate also has systematic uncertainty of up to〜1arcmin.