The X-Ray Telescope onboard Suzaku

• Published in: Publications of the Astronomical Society of Japan Vol. 59; no. sp1; pp. S9 - S21
• Main Authors: Serlemitsos, Peter J., Soong, Yang, Chan, Kai-Wing, Okajima, Takashi, Lehan, John P., Maeda, Yoshitomo, Itoh, Kei, Mori, Hideyuki, Iizuka, Ryo, Itoh, Akiharu, Inoue, Hirohiko, Okada, Shunsaku, Yokoyama, Yushi, Itoh, Yumi, Ebara, Masatoshi, Nakamura, Ryoko, Suzuki, Kensuke, Ishida, Manabu, Hayakawa, Akira, Inoue, Chiaki, Okuma, Satoshi, Kubota, Ren, Suzuki, Masaki, Osawa, Takeyuki, Yamashita, Koujun, Kunieda, Hideyo, Tawara, Yuzuru, Ogasaka, Yasushi, Furuzawa, Akihiro, Tamura, Keisuke, Shibata, Ryo, Haba, Yoshito, Naitou, Masataka, Misaki, Kazutami
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford Universtiy Press 30.01.2007
• Subjects: instruments: detectors; telescopes; X-rays: general
• ISSN: 0004-6264; 2053-051X
• DOI: 10.1093/pasj/59.sp1.S9

We present the design parameters, production process, and in-flight performance of the X-ray telescope (XRT) onboard Suzaku. The imaging capability is significantly improved over the ASCA XRT, which had half-power diameters of ${3\rlap {.}{}^{\mathrm {\prime }}6}$ , to ${1\rlap {.}{}^{\mathrm {\prime }}8}$ – ${2\rlap {.}{}^{\mathrm {\prime }}3}$ for all four XRT-I modules. The optical axes are found to be distributed within a radius of ${1\rlap {.}{}^{\mathrm {\prime }}3}$ , which makes the observation efficiency of all the XRTs more than 97% at the XIS-default observing position. The vignetting over the XIS field of view predicted via ray-tracing coincides with that measured for observations of the Crab Nebula to within $\sim 10\%$ . Contemporaneous fits of a power law to all of 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 and Seward (1974, AJ, 79, 995) to within $\sim 2\%$ . 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.