Response matrices

GIS spectral response

Only one RMF is necessary for each GIS provided that PI channels 
have been used in accumulating the spectrum. These RMFs are 
g2v2_2.rmf and g3v2_2.rmf, respectively. The ARF situation is 
slightly more complex.  The GIS have beryllium windows, the 
thickness of which varies with position. The windows are supported 
by a grid structure which absorbs X-rays. The effects of these must 
be included in the ARF in addition to the telescope effective area. A 
number of ARFs have been calculated and are available in the 
calibration database:

 g2_1a.arf        GIS2 at the nominal 1-CCD pointing position (AO)
 g2_1p.arf        GIS2 at the nominal 1-CCD pointing position (PV)
 g2_2a.arf        GIS2 at the nominal 2-CCD pointing position (AO)
 g2_2p.arf        GIS2 at the nominal 2-CCD pointing position (PV)
 g2_4c.arf        GIS2 at the nominal 4-CCD pointing position
 g3_1a.arf        GIS3 at the nominal 1-CCD pointing position (AO)
 g3_1p.arf        GIS3 at the nominal 1-CCD pointing position (PV)
 g3_2a.arf        GIS3 at the nominal 2-CCD pointing position (AO)
 g3_2p.arf        GIS3 at the nominal 2-CCD pointing position (PV)
 g3_4c.arf        GIS3 at the nominal 4-CCD pointing position

These are for the standard pointing positions for point sources (you 
probably have 1-CCD pointing position) and assume that the photons
are accumulated from a circular region of radius 6 arcminutes (or 24
GIS pixels). We have also made available RSP files for these cases:

 g2v2_4_1a.rsp    GIS2 at the nominal 1-CCD pointing position (AO)
 g2v2_4_1p.rsp    GIS2 at the nominal 1-CCD pointing position (PV)
 g2v2_4_2a.rsp    GIS2 at the nominal 2-CCD pointing position (AO)
 g2v2_4_2p.rsp    GIS2 at the nominal 2-CCD pointing position (PV)
 g2v2_4_4c.rsp    GIS2 at the nominal 4-CCD pointing position 
 g3v2_4_1a.rsp    GIS3 at the nominal 1-CCD pointing position (AO)
 g3v2_4_1p.rsp    GIS3 at the nominal 1-CCD pointing position (PV)
 g3v2_4_2a.rsp    GIS3 at the nominal 2-CCD pointing position (AO)
 g3v2_4_2p.rsp    GIS3 at the nominal 2-CCD pointing position (PV)
 g3v2_4_4c.rsp    GIS3 at the nominal 4-CCD pointing position

These files are available in the directory:

 /caldb/data/asca/gis/cpf/93dec20

An FTOOL to provide a simple way of creating ARFs for more 
complicated situations is under development. In the meantime, 
adventurous users might want to try the University of Tokyo's  
JBLDARF program. This is available by anonymous FTP from 
himiko.astro.isas.ac.jp in the directory:

 asca/calibration/gis/software/jbldarf-0.45