Ginga Data

The LAC and ASM data are archived at present.

LAC: Large Area Counter

ASM: All Sky Monitor

Ginga LAC Data

LAC FRF (First Reduction Files) are archived, and put in the two directories. The two directories have different structures, but the FRFs are identical.

LAC FRF (First Reduction File)

All the LAC FRFs are archived at /pub/ginga/GINGA-LAC-1.0/fits_frf/ in a time-sequence manner. Under this directory, there are sub-directories named YYMM, where YY is the year (from 87 to 91) and MM is the month. Under each sub-directory, FRFs are put in the order of operation (date and orbits).

Target Oriented Data

When the target observation has corresponding background (blank) observation, the target data and background data are put in the same directory for convenience. They are found under /pub/ginga/GINGA-LAC-1.0/dat/. Each directory has a name as YYMMddddd, where YY is the year (from 87 to 91), MM is the month, and ddddd is the last 5-digit of the sequence number (find the correspondence between the sequence number and the pass names). Note, all the observations do not have the corresponding blank sky observations. In such a case, you may use the "Hayashida-method" for background subtraction. For details see Chapter 5 of the ABC manual.

Under each observation directory, files are put in the directories listed below;

frf/ Telemetry files (FRFs; Wrapped FITS files)
lacdump/ LACDUMP files (ASCII files)
frf_bgd/ Telemetry files for recommended background data
lacdump_bgd/ LACDUMP files for recommended background data

Each dataset includes telemetry data (First Reduction File =FRF) and summary lists of the LAC housekeeping and attitude information (LACDUMP files). Each FRF is made per one satellite-operation pass (a contact or remote pass), while LACDUMP is per one day. These files are NOT divided at the times of maneuvers and therefore may contain data of previous and/or next targets as well as those during maneuvers. The recommended background data are simply selected from all the blank sky observations performed within 3 days. Before using them, however, users are strongly advised to check if they are really applicable for background subtraction in each case. Or you can search for appropriate background data utilizing the DARTS Astro Search system.

Metadata Tables

For each pointing, a 9-digit sequence number is assigned, beginning with YYMM where YY and MM is the two-digits year and month of the observation start time,respectively. The following three digits (starting from 001) tell the observation sequence number in the month. The last two digits of a sequence number is 00 for a target observation and 09 for a background observation.

Observation Log

Ginga ASM Data

Lightcurve Data

The ASM lightcurve files from 1987 to 1991 are archived. The lightcurves are derived by:

  1. fitting the raw ASM scan data with fixed targe positions considering the collimator response,
  2. determining the fluxes of all the targets (ASCII files),
  3. converting ASCI files into FITS format.

For mor details, see General Infomation.

The lightcurves are calculated in three energy bands: 1-6 keV, 6-20 keV, and 1-20 keV. The Crab flux with ASM is 2.0 count/sec/cm2 (1-6 keV) and 0.8 count/s/cm2 (6-20 keV). Latest FITS files are put in the directory /pub/ginga/GINGA-ASM-1.2/. In addition, original raw data, programs to carry out model fitting, lightcurve ASCII files and Japanese documents are archived at /pub/ginga/GINGA-ASM-1.0/rawdata/.

Metadata Tables

ASM Telemetry Data

From the Ginga raw telemetry data, the ASM all-sky scan data parts were extracted and saved in the FITS format for each scan. Dedicated software is required to extract source light-curves from these telemetry data.

Last Modified: 24 November 2021