OGIP Calibration Memo CAL/ROS/93-016

ROSAT
CALIBRATION FILES
IN THE OGIP CALDB





edited by:
Ian M George
& Lorraine Breedon
and
Steve Snowden
& T. Jane Turner
HEASARC
and
NASA/GSFC ROSAT GOF
Mail Code 660.2
NASA/GSFC,
Greenbelt, MD20771
Last Update: 1996 Jan 18
(by IMG)





SUMMARY

The ROSAT calibration datasets currently in the OGIP caldb are described.
Intended audience: ROSAT hardware & GOF teams, OGIP programmers and authors of data analysis s/w.

LOG OF SIGNIFICANT CHANGES


Release Sections Changed Brief Notes
Date
1994 Aug 01 All First Update
1995 Jan 31 All Made compatible with LaTeX2HTML software
1995 Feb 17 All Cosmetics to aide LaTeX2HTML conversion
1995 Apr 20 4.3.1 & 4.3.2 HRI Detector Maps added
1995 Oct 17 3 Several new datasets added
1995 Oct 20 All added links to goodfiles.ascii & missingfiles.ascii
1996 Jan 18 3.12.1 Datasets added
2010 May 14 All Made compatible with TTH software

Contents

1  INTRODUCTION
    1.1  Overview
    1.2  The OGIP Caldb at NASA/GSFC
        1.2.1  Location
        1.2.2  Basic Structure
        1.2.3  Calibration Data File Classes
    1.3  Conventions used within this Document
    1.4  Acknowledgments
2  ROSAT XRT CALIBRATION FILES
    2.1  Summary of Available Files
    2.2  BCF: Standard Energy Grid
        2.2.1  xrt_v1.egrid
    2.3  BCF: Effective Areas
        2.3.1  xrt_v#.eff_area
    2.4  BCF: Vignetting Function
        2.4.1  xrt_v2.vignet
3  ROSAT PSPC CALIBRATION FILES
    3.1  Summary of Available Files
    3.2  BCF: Standard Energy Grid
        3.2.1  pspc_v1.egrid
    3.3  BCF: Detector Window Transmissions
        3.3.1  pspc#_v1.wind_trans
    3.4  BCF: Filter Transmissions
        3.4.1  boron_v1.trans
    3.5  BCF: Detector Efficiency
        3.5.1  pspc_v1.gas_eff
    3.6  BCF: ADC non-linearity correction
        3.6.1  adc_bins.fits
    3.7  BCF: Al-K gain history files
        3.7.1  alkhist_v1_#.fits
    3.8  BCF: Position-dependent terms for Spatial Gain Correction
        3.8.1  gain_kor3_#.fits
    3.9  BCF: Energy-dependent terms for Spatial Gain Correction
        3.9.1  gnampl_new.fits
    3.10  BCF: Energy-dependent terms for Window Correction
        3.10.1  scal3.fits
    3.11  BCF: Position-dependent maps for Window Correction
        3.11.1  tab#_093_#.fits
    3.12  BCF: Maps of mean chan from Al-K calibration obs
        3.12.1  al_#-#.fits
    3.13  CPF: Dectector Spectral Response
        3.13.1  pspc#_v#.spec_resp
    3.14  CPF: PSPC Detector Efficiency Maps
        3.14.1  det_#_#_#.fits
    3.15  CPF: PSPC Particle Background Maps
        3.15.1  detp_#_#_#.fits
    3.16  CPF: PSPC Detector Redistribution Matrices
        3.16.1  pspc#_gain#_256.rmf
        3.16.2  pspc#_gain#_256.rsp
        3.16.3  pspc#_gain#_34.rmf
        3.16.4  pspc#_gain#_34.rsp
4  ROSAT HRI CALIBRATION FILES
    4.1  Summary of Available Files
    4.2  CPF: HRI Detector Redistribution Matrices
        4.2.1  hri_90dec01.rsp
    4.3  CPF: HRI Detector Maps
        4.3.1  be.fits
        4.3.2  de_corr.fits
5  ROSAT MISCELLANEOUS CALIBRATION FILES
    5.1  Summary of Available Files

Chapter 1
INTRODUCTION

1.1  Overview

This document is intended to provide notes on the origin, format, limitations etc of all ROSAT calibration datasets within the http://legacy.gsfc.nasa.gov/docs/heasarc/caldb/caldb_intro.html By its nature, it is therefore very much a 'live' document and is expected to expand rapidly throughout the operational phases of the mission.
In the rest of this chapter, the location and structure of the http://legacy.gsfc.nasa.gov/docs/heasarc/caldb/caldb_intro.html at http://www.gsfc.nasa.gov at is briefly described, along with references to other relevant documentation. All ROSAT XRT, PSPC & HRI datasets within the caldb at NASA/GSFC are then summarized in Chapters 2, 3 & 4 respectfully, with non-instrument specific datasets summarized in Chapter 5.

1.2  The OGIP Caldb at NASA/GSFC

The location, organization and contents of the http://legacy.gsfc.nasa.gov/docs/heasarc/caldb/caldb_intro.html on-line at http://www.gsfc.nasa.gov is summarized in OGIP Calibration Memo CAL/GEN/93-006 (available on-line as ftp://legacy.gsfc.nasa.gov/caldb/docs/memos/cal_gen_93_006/cal_gen_93_006.ps and http://legacy.gsfc.nasa.gov/docs/heasarc/caldb/docs/memos/cal_gen_93_006/cal_gen_93_006.html versions).

1.2.1  Location

The http://legacy.gsfc.nasa.gov/docs/heasarc/caldb/caldb_intro.html OGIP calibration database (caldb) is physically located at The entire caldb directory tree is available to remote users via anonymous ftp at ftp://legacy.gsfc.nasa.gov/caldb.

1.2.2  Basic Structure

The contents of the /caldb area is sub-divided between the following sub-directory trees: Here we only consider the data tree. It should be noted that access to certain caldb directory trees is also available from other areas of the legacy anonymous ftp account via symbolic links (see CAL/GEN/93-006, available on-line as ftp://legacy.gsfc.nasa.gov/caldb/docs/memos/cal_gen_93_006/cal_gen_93_006.ps and http://legacy.gsfc.nasa.gov/docs/heasarc/caldb/docs/memos/cal_gen_93_006/cal_gen_93_006.html versions).

1.2.3  Calibration Data File Classes

The OGIP caldb classifies files as `Primary Calibration Files', `Basic Calibration Files' and `Calibration Product Files' (PCFs, BCFs & CPFs respectively; see also CAL/GEN/91-001, available on-line as ftp://legacy.gsfc.nasa.gov/caldb/docs/memos/cal_gen_91_001/cal_gen_91_001.ps and http://legacy.gsfc.nasa.gov/docs/heasarc/caldb/docs/memos/cal_gen_91_001/cal_gen_91_001.html versions). PCFs are 'raw' ground and in-orbit calibration datasets not of immediate interest to most users as they are not directly required for (all but the most specialized) scientific data analysis tasks. These dataset are not considered here. BCFs contain the lowest level calibration datasets potentially required by downstrem software, and can be considered the `atomic units' of the instrument calibration. CPFs contain `convolutions' of the information stored within BCFs customized for a specific analysis task and/or scientific observation.
All BCF & CPF calibration files are organized using the scheme
/caldb/data/mission/inst
where mission & inst are the OGIP-standard names for the mission and instrument. For internal management purposes, a further division into inst/bcf and inst/cpf sub-directories is made in most cases. Non-instrument specific calibration datasets, including general spacecraft housekeeping information etc, can be found in the /caldb/data/mission/mis sub-directory.

1.3  Conventions used within this Document

Throughout this document, the hash (#) symbol is used as a wild-card in filenames to indicate several files are available with slightly different names. In all cases the detailed naming scheme, along with the characters which can be used to replace the # are described in the detailed description of the file set.
PLEASE NOTE: The filenames and locations of the calibration datasets described within this document were chosen by the http://legacy.gsfc.nasa.gov/docs/rosat/rosgof.html in collaboration with the instrument teams. Please dont complain to the CALDB if you consider them confusing, inappropriate etc.

1.4  Acknowledgments

The information within this document obviously could not have been compiled without the help of very many people within the ROSAT XRT, PSPC & HRI instrument teams, to whom we owe an enormous debt. Wherever possible we acknowledge the direct source of the information within the text, but undoubtedly this may often under-represent the collective effort involved. We apologise to anybody who has inadvertently not been credited, and will be happy to add their name in the appropriate place(s).

Chapter 2
ROSAT XRT CALIBRATION FILES

2.1  Summary of Available Files

The XRT calibration files available under the
/caldb/data/rosat/xrt/type
directory tree are listed in Table 2.1. In many cases the actually files will be stored in sub-directories under this tree, as detailed in the corresponding detailed description.
Table 2.1: Summary of ROSAT XRT calibration files available within the OGIP Caldb

Filename Description Section
Basic Calibration Files (type = bcf)
xrt_v1.egrid XRT Standard energy grid 2.2.1
xrt_v#.eff_area XRT effective areas 2.3.1
xrt_v2.vignet XRT Vignetting function 2.4.1
Calibration Product Files (type = cpf)
None
An ASCII file listing all the XRT datasets marked as good within the Caldb (produced by a script periodically run automatically) is available as
ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/xrt/goodfiles.ascii
An ASCII file listing all the XRT datasets which appear to be missing from or misplaced within the Caldb (produced by a script periodically run automatically) is available as
ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/xrt/missingfiles.ascii
Obviously this file should be empty. If you find it not to be so, please e-mail the Caldb Hot-seat at:
caldbhelp@ascasrv.gsfc.nasa.gov

2.2  BCF: Standard Energy Grid

2.2.1  xrt_v1.egrid

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/xrt/bcf
Status

Current
Summary of File

This dataset consists of the 729 lower & upper boundaries of the energy bins used in many XRT calibration files.
Delivered to CALDB by:

Steve Snowden (NASA/GSFC ROSAT GOF) 1994 spring, converted to OGIP FITS format by Ian M George (HEASARC) 1994 Jul 21.
File Format

EGRIDVER = 1992a
Input Datasets, Assumptions, etc

None
Points to Note

2.3  BCF: Effective Areas

2.3.1  xrt_v#.eff_area

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/xrt/bcf
Status

Current
Summary of Files

These two datasets, using a naming scheme xrt_vi.eff_area (where i=1 & 2), contain the effective areas of the XRT (including vignetting) as a function of energy (729 bins) and off-axis angle (14 values).
Delivered to CALDB by:

Steve Snowden (NASA/GSFC ROSAT GOF) 1994 spring, converted to OGIP FITS format by Ian M George (HEASARC) 1994 Jul 21.
File Format

EARVERSN = 1992a
Input Datasets, Assumptions, etc

These datasets were converted to OGIP FITS format from the ASCII files area_b_1.asc & area_b_2.asc (for i=1 & i=2 respectively) supplied by Steve Snowden (ROSAT GOF, NASA/GSFC). The area_b_*.asc files consist of the (total) spectral response for PSPCB. The current dataset was therefore created by DIVIDING the corresponding area_b_*.asc dataset by:
(The area_b_1.asc & area_b_2.asc datasets have also been converted to an OGIP FITS format as is stored in files pspcb_v1.spec_resp & pspcb_v2.spec_resp)
Points to Note

2.4  BCF: Vignetting Function

2.4.1  xrt_v2.vignet

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/xrt/bcf
Status

Current
Summary of File

This dataset consists of the vignetting function (in the range 0.0 1.0) of the XRT as a function of energy (729 bins) and off-axis angle (14 values). The geometric reduction in collecting area at high off-axis angles is included.
Delivered to CALDB by:

Steve Snowden (NASA/GSFC ROSAT GOF) 1994 spring, converted to OGIP FITS format by Ian M George (HEASARC) 1994 Jul 21.
File Format

VIGVERSN = 1992a
Input Datasets, Assumptions, etc

This dataset was converted to OGIP FITS format from the ASCII file area_b_2.asc supplied by Steve Snowden (ROSAT GOF, NASA/GSFC). The area_b_2.asc file consist of the (total) spectral response for PSPCB. The current dataset was therefore created by DIVIDING the area_b_2.asc dataset by:
(The area_b_2.asc dataset has also been converted to an OGIP FITS format as is stored in file pspcb_v2.spec_resp)
Points to Note

Chapter 3
ROSAT PSPC CALIBRATION FILES

3.1  Summary of Available Files

The ROSAT PSPC calibration files available under the
/caldb/data/rosat/pspc/type
directory tree are listed in Table 3.1. In many cases the actually files will be stored in sub-directories under this tree, as detailed in the corresponding detailed description.
Table 3.1: Summary of ROSAT PSPC calibration files available within the OGIP Caldb

Filename Description Section
Basic Calibration Files (type = bcf)
adc_bins.fits ADC non-linearity correction 3.6.1
al_#-#.fits Map of mean chan from Al-K cals 3.12.1
alkhist_v1_#.fits Gain history from Prescott fits to Al-K data 3.7.1
boron_v1.trans Transmission of the Boron Filter 3.4.1
gain_kor3_#.fits Pos-dep terms for spatial gain correction 3.8.1
gnampl_new.fits Energy-dep terms for spatial gain correction 3.9.1
pspc_v1.egrid Standard energy grid 3.2.1
pspc#_v1.wind_trans Detector Window Transmissions 3.3.1
pspc_v1.gas_eff Detector Efficiency 3.5.1
scal3.fits Energy-dep terms for window correction 3.10.1
tab#_093_#.fits Position-dep maps for window correction 3.11.1
Calibration Product Files (type = cpf)
pspc#_v#.spec_resp Spectral Response of Detector 3.13.1
det_#_#_#.fits Snowden et al Detector Efficiency maps 3.14.1
detp_#_#_#.fits Snowden et al Particle Background maps 3.15.1
pspc#_gain#_256.rmf 256 channel detector redistribution matrices 3.16.1
pspc#_gain#_256.rsp 256 channel (full) detector matrices 3.16.2
pspc#_gain#_34.rmf 34 channel detector redistribution matrices 3.16.3
pspc#_gain#_34.rsp 34 channel (full) detector matrices 3.16.4
An ASCII file listing all the PSPC datasets marked as good within the Caldb (produced by a script periodically run automatically) is available as
ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/goodfiles.ascii
An ASCII file listing all the PSPC datasets which appear to be missing from or misplaced within the Caldb (produced by a script periodically run automatically) is available as
ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/missingfiles.ascii
Obviously this file should be empty. If you find it not to be so, please e-mail the Caldb Hot-seat at:
caldbhelp@ascasrv.gsfc.nasa.gov

3.2  BCF: Standard Energy Grid

3.2.1  pspc_v1.egrid

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/bcf
Status

Current
Summary of File

This dataset consists of the 729 lower & upper boundaries of the energy bins used in many PSPC calibration files.
Delivered to CALDB by:

Steve Snowden (NASA/GSFC ROSAT GOF) 1994 spring, converted to OGIP FITS format by Ian M George (HEASARC) 1994 Jul 21.
File Format

EGRIDVER = 1992a
Input Datasets, Assumptions, etc

None
Points to Note

3.3  BCF: Detector Window Transmissions

3.3.1  pspc#_v1.wind_trans

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/bcf
Status

Current
Summary of Files

These two datasets, using a naming convention pspcX_v1.wind_trans (where X = b or c), contain the transmission as a function of energy (729 bins) of the PSPCX detector windows.
Delivered to CALDB by:

Steve Snowden (NASA/GSFC ROSAT GOF) 1994 spring, converted to OGIP FITS format by Ian M George (HEASARC) 1994 Jul 21.
File Format

TRANSVER = 1992a
Input Datasets, Assumptions, etc

These datasets were converted to OGIP FITS format from the ASCII files pspc_b_win.asc & pspc_c_win.asc (for X = b & X = c respectively in the above naming scheme) supplied by Steve Snowden (ROSAT GOF, NASA/GSFC).
Points to Note

3.4  BCF: Filter Transmissions

3.4.1  boron_v1.trans

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/bcf
Status

Current
Summary of File

This dataset contains the transmission as a function of energy (729 bins) of the Boron filter.
Delivered to CALDB by:

Steve Snowden (NASA/GSFC ROSAT GOF) 1994 spring, converted to OGIP FITS format by Ian M George (HEASARC) 1994 Jul 21.
File Format

TRANSVER = 1992a
Input Datasets, Assumptions, etc

This dataset was converted to OGIP FITS format from the ASCII file pspcb_fil.asc supplied by Steve Snowden (ROSAT GOF, NASA/GSFC).
Points to Note

None

3.5  BCF: Detector Efficiency

3.5.1  pspc_v1.gas_eff

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/bcf
Status

Current
Summary of File

This dataset contains the PSPC detector efficiency ('gas efficiency') as a function of energy (729 bins).
Delivered to CALDB by:

Steve Snowden (NASA/GSFC ROSAT GOF) 1994 spring, converted to OGIP FITS format by Ian M George (HEASARC) 1994 Jul 21.
File Format

EFFVERSN = 1992a
Input Datasets, Assumptions, etc

This dataset was converted to OGIP FITS format from the ASCII file gas_eff.asc supplied by Steve Snowden (ROSAT GOF, NASA/GSFC).
Points to Note

None

3.6  BCF: ADC non-linearity correction

3.6.1  adc_bins.fits

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/bcf/sass_ct
Status

Current
Summary of File

The dataset is used to correct for non-linearities in the width of the PHA channels introduced by the PSPC analogue-to-digital converter. The effective lower & upper boundaries of each channel (PH_1) are stored in columns ADC_LO & ADC_HI respectively. These values were derived by MPE by fitting a smooth spline to a cumulative spectrum of a large number of ground calibration measurements. The dataset is assumed to be valid for both PSPCC & PSPCB
Given an event with an observed PH channel, a random-number generator can be used to find the effective channel PH_1, corrected for the ADC nonlinearities, by assuming equal probability between the appropriate values of ADC_LO & ADC_HI. However, it should be noted that the effective channel so derived is NOT the Pulse-Invariant (PI) channel for that event - further spatial & temporal gain corrections have also to be applied.
Delivered to CALDB by:

Rehana Yusaf (ROSAT FTOOLS) 1995 Oct 06, after having been was converted to FITS from the ASCII file ADC_BINS.DAT used by SASS.
File Format

Instrument-specific (non multi-mission OGIP standard) See OGIP Calibration Memo http://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/summary/cal_ros_95_010_summary.html for further details.
Input Datasets, Assumptions, etc

No further information beyond that given above (see also http://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/summary/cal_ros_95_010_summary.html
Points to Note

3.7  BCF: Al-K gain history files

3.7.1  alkhist_v1_#.fits

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/bcf/sass_ct
Status

Current
Summary of Files

Two files, alkhist_v1_b.fits & alkhist_v1_c.fits (for PSPCB & PSPCC respectively), containing the the results from measurements taken using the on-board Aluminum calibration source when fitted with a Prescott function. The peak channel (given in column ALK_BIN) in which the Aluminum line falls therefore gives an estimation of the "Gain" of the detector. Variations in gas density, composition, high voltage, pressure and temperature give rise to variations in gain. Thus, this can be used to correct for the gain of the detector at a given observational epoch by linearly interpolating between the Aluminum calibration measurements before and after the observation.
The times stored in the dataset (in column ISCC) are as measured by the spacecraft clock, and apply to the END of the ROSAT-day to which they refer. In cases when more than one Al measurement were taken on a given ROSAT-day (as denoted when the value in column N_PTS are greater than one), the values stored in the ALK_BIN & ALK_FWHM cloumns are the means of the values obtained from the individual fits.
Delivered to CALDB by:

Steve Snowden (NASA/GSFC ROSAT GOF) via e-mail, converted to FITS by Ian M George (HEASARC) in 1995 Oct 10.
File Format

Instrument-specific (non multi-mission OGIP standard) See OGIP Calibration Memo http://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/summary/cal_ros_95_010_summary.html for further details.
Input Datasets, Assumptions, etc

No further information beyond that given above (see also http://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/summary/cal_ros_95_010_summary.html
Points to Note

3.8  BCF: Position-dependent terms for Spatial Gain Correction

3.8.1  gain_kor3_#.fits

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/bcf/sass_ct
Status

Current
Summary of Files

Two files, gain_kor3_b.fits & gain_kor3_c.fits (for PSPCB & PSPCC respectively), required to correct for small-scale non-linearities which are introduced into the positions assigned to PSPC events by the detector wires. This dataset contains the two position-dependent correction vectors, stored in columns SGC_LF_Y & SGC_HF_Y, both of which vary as a function of position (stored in column Y_1).
Delivered to CALDB by:

Rehana Yusaf (ROSAT FTOOLS) 1995 Oct 06, after having been was converted to FITS from the ASCII files GAIN_KOR3_B.DAT & GAIN_KOR3_C.DAT used by SASS.
File Format

Instrument-specific (non multi-mission OGIP standard) See OGIP Calibration Memo http://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/summary/cal_ros_95_010_summary.html for further details.
Input Datasets, Assumptions, etc

No further information beyond that given above (see also http://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/summary/cal_ros_95_010_summary.html
Points to Note

3.9  BCF: Energy-dependent terms for Spatial Gain Correction

3.9.1  gnampl_new.fits

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/bcf/sass_ct
Status

Current
Summary of File

The dataset is used to correct for small-scale non-linearities which are introduced into the positions assigned to PSPC events by the detector wires. This dataset contains the energy-dependent correction vector, stored as a function of intermediate pulse-height (PH_3) in column SGC_HF_E. This dataset is assumed to be valid for both PSPCs.
Delivered to CALDB by:

Rehana Yusaf (ROSAT FTOOLS) 1995 Oct 06, after having been was converted to FITS from the ASCII file GNAMPL_NEW.DAT used by SASS.
File Format

Instrument-specific (non multi-mission OGIP standard) See OGIP Calibration Memo http://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/summary/cal_ros_95_010_summary.html for further details.
Input Datasets, Assumptions, etc

No further information beyond that given above (see also http://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/summary/cal_ros_95_010_summary.html
Points to Note

3.10  BCF: Energy-dependent terms for Window Correction

3.10.1  scal3.fits

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/bcf/sass_ct
Status

Current
Summary of File

The dataset is used when correcting the positions assigned to PSPC events for slight offsets arising from the bulging of the detector window as a result of the internal gas pressure versus the external vacuum of space. The distortions introduced are a function of both position and energy, however the dependencies are assumed to be separable. This dataset is normalized to unity at 0.93 keV (since the position-dependent corrections, sometimes refered to as the Golden Disc) were determined from measurements at that energy. The function is stored as a function of Pulse-Invariant (PI) channel in column WC_GA_E. This dataset is is assumed to be valid for both PSPC detectors.
Delivered to CALDB by:

Rehana Yusaf (ROSAT FTOOLS) 1995 Oct 06, after having been was converted to FITS from the ASCII file SCAL3.DAT used by SASS.
File Format

Instrument-specific (non multi-mission OGIP standard) See OGIP Calibration Memo http://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/summary/cal_ros_95_010_summary.html for further details.
Input Datasets, Assumptions, etc

No further information beyond that given above (see also http://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/summary/cal_ros_95_010_summary.html
Points to Note

3.11  BCF: Position-dependent maps for Window Correction

3.11.1  tab#_093_#.fits

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/bcf/sass_ct
Status

Current
Summary of Files

Two maps for each PSPC giving the position-dependent correction for each event in the X- & Y-axes. The naming convention used is:
tabM_093_N.fits
where M is either x or y denoting the map contains the correction for the X- or Y-axes respectively, and N is either b or c denoting the map refers to PSPCB or PSPCC respectively.
These maps are used when correcting the positions assigned to PSPC events for slight offsets arising from the bulging of the detector window as a result of the internal gas pressure versus the external vacuum of space. The distortions introduced are a function of both position and energy, however the dependencies are assumed to be separable.
The data were determined from ground calibration measurements made at 0.93 keV. The dataset is stored as a 2-dimensional array as a function of X_1 & Y_1, which are detector coordinates of an event AFTER the electronic correction has been applied.
Delivered to CALDB by:

Rehana Yusaf (ROSAT FTOOLS) 1995 Oct 06, after having been was converted to FITS from VMS binary files (named TABX_093_B.DAT, TABY_093_B.DAT, TABX_093_C.DAT & TABY_093_C.DAT) used by SASS.
File Format

Instrument-specific (non multi-mission OGIP standard) See OGIP Calibration Memo http://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/summary/cal_ros_95_010_summary.html for further details.
Input Datasets, Assumptions, etc

No further information beyond that given above (see also http://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/summary/cal_ros_95_010_summary.html
Points to Note

3.12  BCF: Maps of mean chan from Al-K calibration obs

3.12.1  al_#-#.fits

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/bcf/alk_gainmaps
Status

Current
Summary of Files

The data contained within these files are the mean PI channels of spectral fits of the on-board Al K alpha calibrations. Typically, data were collected from calibration intervals spanning about 100 days in order to achieve reasonable statistics. The range of applicability of each image is given by the range of ROSAT day number denoted in their filenames (and obviously also by header keywords within the file).
Stepping in 2 arcmin intervals in both DETX and DETY, circular regions were analyzed where the radius of the regions were set to provide approx 2500 counts. This usually required radii between 3 and 6 arcmin so the fits are not independent.
The fits were performed using the proportional counter response model of Jahoda and McCammon fixing all parameters except the gain, normalization, and a constant background. The mean channel for the fit of all events can be found in pixel(1,1). It has a typical value of slightly more than 152. The mean PI channel over the field can vary between 145 and 158.
Delivered to CALDB by:

Steve Snowden (ROSAT GOF) 1996 Jan 16
File Format

FITS Image in the Primary array
Input Datasets, Assumptions, etc

No further information beyond that given above
Points to Note

3.13  CPF: Dectector Spectral Response

3.13.1  pspc#_v#.spec_resp

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/cpf
Status

Current
Summary of Files

These 4 datasets use contain the 'spectral response' of the XRT/PSPC combination - ie are the multiplication of: The naming scheme is pspcX_vi.spec_resp where
Delivered to CALDB by:

Steve Snowden (NASA/GSFC ROSAT GOF) 1994 spring, converted to OGIP FITS format by Ian M George (HEASARC) 1994 Jul 21.
File Format

SPRVERSN= 1992a
Input Datasets, Assumptions, etc

This dataset was converted to OGIP FITS format by Ian M George (HEASARC) from the ASCII files area_b_1.asc, area_b_2.asc, area_c_1.asc and area_c_2.asc supplied by Steve Snowden (ROSAT GOF, NASA/GSFC).
Points to Note

3.14  CPF: PSPC Detector Efficiency Maps

3.14.1  det_#_#_#.fits

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/cpf/detmaps
Status

Current
Summary of Files

A total of 26 detector maps constructed by Snowden et al. in 13 channel ranges for each of the two PSPCs. The naming scheme is such that file det_n_m_X.fits contains the map for PSPC-X over the channel range n-m (out of the full resolution 256 channels).
The channel ranges are as follows:
Band Name       PI range        Energy
R1              8-19            0.11-0.284
R1L             11-19           0.11-0.284
R2              20-41           0.14-0.284
R3              42-51           0.20-0.83
R4              52-69           0.44-1.01
R5              70-90           0.56-1.21
R6              91-131          0.73-1.56
R7              132-201         1.05-2.04

Delivered to CALDB by:

Steve Snowden (NASA/GSFC ROSAT GOF) 1993 Sept, converted to OGIP FITS format by Gail Reichert (NASA/GSFC ROSAT GOF) 1993 Sept 24.
File Format

Simple image in Primary Array
Input Datasets, Assumptions, etc

These detector efficiency maps were created by using events from the ROSAT all-sky survey in detector coordinates to approximate a flat field. Point sources, particle contamination and times of short-term noncosmic background enhancements were excluded from the data set. Furthermore, an estimate of the residual particle background contribution to the data was subtracted.
Creating the maps from such a pseudo flat field has an advantage over using the theoretical vignetting function in that it accurately reflects all detector and telescope nonuniformities. Specific examples of such nonuniformities are the shadowing by the wires and ribs of the window support structure, electronic "ghost" images in the R1L (and R1) band, and variations in the window thickness and therefore the detector quantum efficiency as a function of position. The maps depend on the X-ray spectrum and their creation for each pulse-height band reflects the average spectrum of the soft X-ray diffuse background. This will create no problems in the lowest pulse-height bands where the vignetting is little changed over the energy range covered by the band. However, for the highest pulse-height band, if the spectrum of an extended object is much different from that of the SXRB, the vignetting correction will lose accuracy.
Points to Note

3.15  CPF: PSPC Particle Background Maps

3.15.1  detp_#_#_#.fits

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/cpf/detmaps
Status

Current
Summary of Files

The particle background detector maps
detp_i_l_b.fits
detp_i_h_c.fits
detp_i_h_b.fits
detp_e_l.fits
detp_e_h.fits
detp_ap_l.fits
detp_ap_h.fits

were produced using the calibration results of Plucinsky et al. (1993). The naming scheme used is detp_n_x.fits, where x is the gain state of the detector (h or l), n is the component of particle background where The 'ap' events are related to the total particle background rate.
The maps have 14.947" x 14.947" pixels (the 0.934208" x 0.934208" PSPC detector pixels binned by 16 in both X and Y), the same scale as the detector efficiency maps used for exposure correction and the casting of other noncosmic backgrounds . We have generated three maps (one for the first PSPC, two for the second PSPC for the two gain states) based on the radial functions which were used to fit the FWC data. The high gain state is denoted 'h', and is appropriate for data taken before Oct 11 1991, the low gain state is denoted 'l', and is appropriate for data taken after that date.
Delivered to CALDB by:

Steve Snowden (NASA/GSFC ROSAT GOF) 1994 Mar 02.
File Format

Simple image in Primary Array
Input Datasets, Assumptions, etc

As above
Points to Note

3.16  CPF: PSPC Detector Redistribution Matrices

3.16.1  pspc#_gain#_256.rmf

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/cpf/matrices
Status

Current
Summary of Files

The following matrices are 2-dimensional arrays (energy vs channel) containing the probabilities that a photon of a given incident energy which enters the detector will give rise to an event in a given PI channel. As such they are VALID FOR ALL REGIONS of the detector, but also require an appropriately constructed Äncillary Response File" (ARF) to enable spectral analysis to be performed in XSPEC:
Delivered to CALDB by:

Jane Turner (NASA/GSFC ROSAT GOF) 1994 Sept 21
File Format

RMFVERSN = 1992a (see http://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/summary/cal_gen_92_002_summary.html
Input Datasets, Assumptions, etc

The pspc#_gain2# matrices include a 'fudge' derived from a 1992 observation of Mkn421 made primarily to correct a ~ 10% systematic deficit in photons versus model observed in a large number of sources. It should be noted that these matrices have had a one channel (of the 256) downward shift applied with respect to all previous matrices. This is equivalent to a change in the zero-offest of the ADC (within the uncertainties given the lack of ADC zero-offset measurement pre-launch) and represents a 5% lowering of the gain. The necessity of such a change was determined from the fits to several datasets, with the formal actual best-fit actually being slightly less than a whole channel, but close enough (and uncertain enough) for one channel to be used for simplicity.
Points to Note

3.16.2  pspc#_gain#_256.rsp

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/cpf/matrices
Status

Current
Summary of Files

The following matrices are 2-dimensional arrays (energy vs channel) containing the detector redistribution (probability) matrices described in Section 3.16.1, but MULTIPLIED by the XRT effective area, window transmission etc appropriate for ON-AXIS sources ONLY:
Delivered to CALDB by:

Original #_92mar11.rmf datasets delivered by Jane Turner (NASA/GSFC ROSAT GOF) 1992 June, converted to OGIP FITS format by Ian M George 1993 Apr 09. Original pspcb_93jan12.rmf dataset delivered by Jane Turner (NASA/GSFC ROSAT GOF) 1993 Feb 03, converted to OGIP FITS format by Ian M George 1993 Apr 09.
These three original datasets were moved and renamed by Ian M George (HEASARC) at the request of Jane Turner (NASA/GSFC ROSAT GOF) 1994 Sept 27.
File Format

RMFVERSN = 1992a (see http://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/summary/cal_gen_92_002_summary.html
Input Datasets, Assumptions, etc

The pspc#_gain2# matrices include a 'fudge' derived from a 1992 observation of Mkn421 made primarily to correct a ~ 10% systematic deficit in photons versus model observed in a large number of sources. It should be noted that these matrices have had a one channel (of the 256) downward shift applied with respect to all previous matrices. This is equivalent to a change in the zero-offest of the ADC (within the uncertainties given the lack of ADC zero-offset measurement pre-launch) and represents a 5% lowering of the gain. The necessity of such a change was determined from the fits to several datasets, with the formal actual best-fit actually being slightly less than a whole channel, but close enough (and uncertain enough) for one channel to be used for simplicity.
Points to Note

3.16.3  pspc#_gain#_34.rmf

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/cpf/matrices
Status

Current
Summary of Files

The following matrices are 2-dimensional arrays (energy vs 34 channel) containing the probabilities that a photon of a given incident energy which enters the detector will give rise to an event in a given PI channel. The 34 channels are those used by SASS. These matrices are VALID FOR ALL REGIONS of the detector, but also require an appropriately constructed Äncillary Response File" (ARF) to enable spectral analysis to be performed in XSPEC:
Delivered to CALDB by:

Jane Turner (NASA/GSFC ROSAT GOF) 1994 Sept 21
File Format

RMFVERSN = 1992a (see http://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/summary/cal_gen_92_002_summary.html
Input Datasets, Assumptions, etc

No information currently available.
Points to Note

3.16.4  pspc#_gain#_34.rsp

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/cpf/matrices
Status

Current
Summary of Files

The following matrices are 2-dimensional arrays (energy vs 34 channel) containing the above detector redistribution (probability) matrices BUT MULTIPLIED by the XRT effective area, window transmission etc appropriate for ON-AXIS sources ONLY:
Delivered to CALDB by:

Jane Turner (NASA/GSFC ROSAT GOF) 1994 Sep 30, converted to OGIP FITS format by Ian M George 1994 Sep 30.
File Format

RMFVERSN = 1992a (see http://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/summary/cal_gen_92_002_summary.html
Input Datasets, Assumptions, etc

No information currently available.
Points to Note

Chapter 4
ROSAT HRI CALIBRATION FILES

4.1  Summary of Available Files

The ROSAT HRI calibration files available under the
/caldb/data/rosat/hri/type
directory tree are listed in Table 4.1. In many cases the actually files will be stored in sub-directories under this tree, as detailed in the corresponding detailed description.
Table 4.1: Summary of ROSAT HRI calibration files available within the OGIP Caldb

Filename Description Section
Basic Calibration Files (type = bcf)
None
Calibration Product Files (type = cpf)
be.fits Bright-Earth Detector map 4.3.1
de_corr Dark-Earth Detector map 4.3.2
hri_90dec01.rsp Single channel matrix for the HRI 4.2.1
An ASCII file listing all the HRI datasets marked as good within the Caldb (produced by a script periodically run automatically) is available as
ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/hri/goodfiles.ascii
An ASCII file listing all the HRI datasets which appear to be missing from or misplaced within the Caldb (produced by a script periodically run automatically) is available as
ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/hri/missingfiles.ascii
Obviously this file should be empty. If you find it not to be so, please e-mail the Caldb Hot-seat at:
caldbhelp@ascasrv.gsfc.nasa.gov

4.2  CPF: HRI Detector Redistribution Matrices

4.2.1  hri_90dec01.rsp

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/hri/cpf
Status

Current
Summary of Files

A single channel, 100 energy 'redistribution' matrix for the HRI, ie essentially simply the total effective area of the XRT, detector shields & detector quantum efficiency.
Delivered to CALDB by:

Keith Arnaud (NASA/GSFC ASCA GOF) and converted to OGIP FITS format by Ian M George 1993 Aug 12.
File Format

RMFVERSN = 1992a (see http://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/summary/cal_gen_92_002_summary.html
Input Datasets, Assumptions, etc

Dataset is a convolution of the
Points to Note

4.3  CPF: HRI Detector Maps

4.3.1  be.fits

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/hri/cpf/detmaps
Status

Current
Summary of File

This dataset was created using bright-Earth data from the SASS files. Data were selected when the Count rate was greater than 8 counts/s and the zenith angle was greater than 115 degrees. This detector map is for the vignetted component of HRI data, i.e. it should be used to cast effective exposure.
Delivered to CALDB by:

Steve Snowden (ROSAT GOF at NASA/GSFC) on 1995 Apr 20.
File Format

No formal multi-mission format (simple 2D image in Primary array)
Input Datasets, Assumptions, etc

As above
Points to Note

4.3.2  de_corr.fits

Location

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/hri/cpf/detmaps
Status

Current
Summary of File

This dataset was created using dark-Earth data from the SASS files. Data were selected when the Count rate was greater than 8 counts/s and the zenith angle was greater than 115 degrees. This detector map is for the unvignetted component of HRI data, i.e., it should be used to cast the particle background. The raw map was corrected for residual vignetted X-rays
Delivered to CALDB by:

Steve Snowden (ROSAT GOF at NASA/GSFC) on 1995 Apr 20.
File Format

No formal multi-mission format (simple 2D image in Primary array)
Input Datasets, Assumptions, etc

As above
Points to Note

Chapter 5
ROSAT MISCELLANEOUS CALIBRATION FILES

5.1  Summary of Available Files

The miscellaneous non-instrument specific & s/c-related calibration files available under the
/caldb/data/rosat/mis/type
directory tree are listed in Table 5.1. In many cases the actually files will be stored in sub-directories under this tree, as detailed in the corresponding detailed description.
Table 5.1: Summary of PSPC MIS calibration files available within the OGIP Caldb

Filename Description Section
Basic Calibration Files (type = bcf)
None
Calibration Product Files (type = cpf)
None

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