List of Figures

• 2.1. The 96 minute Astro-E2 orbit.
• 2.2. [Left] Schematic picture of the bottom of the Astro-E2 satellite. [Right] A side view of the instrument and telescopes on Astro-E2.
• 2.3. Effective area as a function of photon energy of the combined XRT + XRS system, for all 30 pixels. The upper (solid) curve shows the effective area with the open position of the filter wheel; the lower (dashed) curve shows it with the 300 $\mu$m Be filter.
• 2.4. XIS Effective area of one XRT + XIS system, for both the FI and BI chips.
• 2.5. The XRS calorimeter array, showing the layout of the pixels. Each pixel has a dimension of 0.64 mm $\times$ 0.64 mm, corresponding to a sky projection of $\sim 0.49' \times 0.49'$; the entire X-ray sensitive portion of the array projects a solid angle of $\sim 2.9' \times 2.9'$ on the sky. The pixel numbers are determined by the geometry of the detector assembly; the marked but unlabeled pixel is inactive as of March 2004. In this Figure, the array is shown projected onto the sky.
• 2.6. The Encircled Energy Function (EEF) showing the fractional energy within a given radius for one quadrant of the XRT-I telescopes on Astro-E2 at 4.5 and 8.0 keV. The XRT-S EEF is expected to be similar.
• 2.7. Total effective area of the HXD detectors, PIN and GSO, as a function of energy.
• 2.8. Comparison of the effective area of the XRS against XMM-Newton's RGSs and Chandra's grating instruments.
• 2.9. Comparison of the energy resolution of the XRS and XIS against XMM-Newton's RGSs and Chandra's grating instruments.
• 2.10. The fraction of X-ray photons processed into the ``low-res,'' ``mid-res,'' and ``high-res'' events by the XRS for a point source with a power-law spectrum ($\Gamma =2.0$) between 0.5-10 keV. The mid-res counts are separated into primary events, which have nearly the same resolution as the hi-res events, and secondary events (marked with an ``S'') which have somewhat lower resolution. Secondary events occur when the event time is within 142 ms of an earlier pulse (see also Fig.6.5).
• 2.11. Similar to Fig.2.10, but showing the counting rate as a function of source flux. This figure includes the effects of the point-spread function of the mirror.
• 5.1. Layout of the 5 XRTs on the Astro-E2 spacecraft.
• 5.2. An Astro-E2 X-Ray Telescope
• 5.3. A thermal shield.
• 5.4. The predicted effective area of a quadrant of the Astro-E2 XRT-Is compared to measurements taken at particular energies for three different XRTs.
• 5.5. (a) Encircled Energy Function at Ti-K (4.5 keV) and Cu-K (8.0 keV). (b) Point Spread Function for the same energies. .
• 5.6. Stray light images of the spare quadrant in the field of view of the XIS at $45'$ off aixs. The [Left] and [Right] panels correspond to the images at Al-K (1.49 keV) before and after the pre-collimator installation, respectively. In each panel the right side is dominated by a stray light component from ``secondary-only reflection'' while the left side is by dominated by ``backside reflection.'' The stray flux is reduced by two orders of magnitude after the pre-collimator installation. The small filled circles in both images are identified as background particles, i.e., cosmic rays.
• 6.1. The Astro-E2 XRS in the lab.
• 6.2. A schematic diagram of the entire XRS instrument, showing the main subsystems.
• 6.3. Principle of operation of the XRS. The deposited photon energy $E_{\rm ph}$ creates a temperature rise $\Delta T = E_{\rm ph} / C$, where $C$ is the heat capacity of the pixel. The pulse subsequently decays with the time constant $\tau$ of about $C/G$, where $G$ is the thermal conductance of the pixel supports.
• 6.4. Calibration spectrum from the XRS flight detector array showing the resolution and centroiding for emission lines between 4.5-12 keV.
• 6.5. Diagram showing the event grade determination in the XRS data processing chain.
• 6.6. [Left] XRS spectral resolution at Mg K$\alpha$ using Hi-res events only. [Right] The same plot using Mid-res (primary) events only.
• 6.7. XRS measurement of Cu K$\alpha$ emission line on a logarithmic scale compared to a simple Gaussian fit.
• 7.1. The four XIS detectors before installation onto Astro-E2.
• 7.2. One XIS instrument. Each XIS consists of a single CCD chip with $1024 \times 1024$ X-ray sensitive cells, each 24 $\mu$m square. Astro-E2 contains four CCD sensors (XIS-S0 to S3), two AE/TCUs (AE/TCE01 and AE/TCE23), two PPUs (PPU01 and PPU23), and one MPU. AE/TCU01 and PPU01 service XIS-S0 and XIS-S1, while AE/TCE23 and PPU23 service XIS-S2 and XIS-S3. Two of the XIS CCDs will be front-illuminated (FI) and two will be back-illuminated (BI).
• 7.3. Time sequence of the exposure, frame-store transfer, CCD readout, and data transfer to the pixel RAM in PPU is shown (1) in normal mode without options, (2) in normal mode with Burst option, and (3) in normal mode with Window option. In this example, the 1/4 Window option is assumed.
• 7.4. Information sent to the telemetry is shown for $5 \times 5$, $3 \times 3$, and $2 \times 2$ modes. 1-bit information means whether or not the PH of the pixel exceeds the outer split threshold. In $2 \times 2$ mode, the central 4 pixels are selected to include the second and the third (or fourth) highest pixels among the 5 pixels in a cross centered at the event center.
• 7.5. Definition of the grades in the P-Sum/timing mode. Total pulse height and the grade of the event are output to the telemetry. Note that the grades are defined referring to the direction of the serial transfer, so the central pixel of a grade 1 event has the larger RAWX value, while the opposite is true for a grade 2 event.
• 8.1. The Hard X-ray Detector before installation.
• 8.2. Schematic picture of the HXD instrument, which consists of two types of detectors: the PIN diodes located in the front of the GSO scintillator, and the scintillator itself.
• 8.3. The HXD background, including both intrinsic and cosmic components for both the PIN and GSO detectors.
• 8.4. [Left] The sensitivity of the HXD to continuum emission, taking into account the expected background. [Right] Same, for line emission.