The XIS and XRT team have released a set of response files that are suitable for the preparation of AO-5 proposals.
There are two units of XIS with a frontside illuminated (FI) CCD, and one unit (XIS1) with a backside illuminated (BI) CCD. We provide an RMF and an ARF for the BI CCD and those for FI CCDs separately.
The ARF files include the transmission of the thermal shield, the XRT-I effective area, and the loss of the low-energy efficiency. We prepare three cases as follows; for a point source observed at the XIS nominal position, a point source at the HXD nominal position, and for a circular flat field sky with a 20' radius. The XIS RMF includes the transmission of the optical blocking filter (OBF) and the quantum efficiency of the CCD.
This release consists of the following 8 files.
Note: In Cycle 5, the Spaced-row Charge Injection (CI) is performed by default. This technique mitigates the charge transfer loss and improves the energy resolution. However, the energy resolution has been slightly degraded with time since the first application of the Spaced-row CI at August 2006. Therefore, we have calculated the energy resolution expected in October 2010 in these RMFs.
The degradation of the low-energy efficiency is taken into account in these ARF files. Although the degradation progresses gradually with time, we have applied the loss expected in October 2010 to the ARFs.
For the FI CCDs, please note that we have summed the responses of XIS0 and XIS3 into ARFs labeled "2FI". (Because of the XIS2 anomaly, the XIS2 contribution is not included.)
We also note that the Spaced-row CI introduces dead areas on the CCDs. The fractions of these dead areas are 5.6%. This correction, as well as that of bad columns, is considered in the above response files.
The segmant A of XIS0 showed an anomaly June 23, 2009. Since then, there is the leakage of charge in a part of the segmant A (ACT X = 70 -- 150), and that area cannot be used for observations. However, the above RMF files do not take into account the dead area, because that area is close to the edge of the field of view and the loss of the effective area is small. Proposers who care about the dead area should evaluate the impact of the dead area by themselves.
For simulation of relatively faint point sources, these responses can be used with the night earth data, containing the particle (but not the cosmic X-ray) background.