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GINGAASMLC - Ginga ASM Source Lightcurves

HEASARC
Archive

Overview

The GINGAASMLC database table contains information derived from the FITS lightcurves obtained with the ASM on board the Ginga mission. The lightcurves are rates as function of time, and they can be used with the general FITS tools within HEAsoft or XRONOS.

Catalog Bibcode

1989PASJ...41..391T

References

All Sky Monitor on board the GINGA satellite and its performance.
    Tsunemi H., Kitamoto S., Manabe M., Miyamoti S., Yamoshita K., Nakagawa, M.
   <Publ. Astron. Soc. Japan, Vol. 41, 391 (1989)>
   =1989PASJ...41..391T

Provenance

The FITS lightcurves are a copy of the GINGA ASM lightcurves hosted at the DARTS archive, located at ISAS (https://darts.isas.jaxa.jp/astro/ginga/data_asm.html). The plots in GIF format were generated by the HEASARC.

Description

Ginga was the third Japanese X-ray astronomy satellite. It was launched into a low Earth orbit on 5th February 1987 and re-entered the atmosphere on 1st November 1991. The scientific payload consisted of the Large Area Counter (LAC; Turner et al. 1989), the All-Sky Monitor (ASM; Tsunemi et al. 1989) and the Gamma-ray Burst Detector (GBD; Murakami et al. 1989). A full description of the satellite is given by Makino et al. (1987). During its lifetime, Ginga performed over 1000 observations of approximately 350 different targets, covering all of the then-known classes of cosmic X-ray sources.

The ASM experiment consisted of two identical gas proportional counters operating in the energy range between 1-20 keV. Each detector is composed of three chambers that operate independently and provide each other with mutual anti-coincidence shielding. The instrument is subtended by six different collimators with a field of view of roughly 1 deg x 45 deg and covers about the 70% of the sky when the satellite rotates around the Z-axis. Each of the ASM chamber has a maximum effective area of about 70 cm2.

The ASM experiment worked from 1987 until 1991 and was the only ASM hard X-ray detector operating during that period. (ROSAT was launched in June 1990.)

The lightcurves are calculated for 208 sources using all the detectors in the ASM. The lightcurves are in three energy bands 1-6 keV, 6-20 keV, and 1-20 keV, and they are stored in a single FITS file in three separate extensions. The count rates are background-subtracted.


Parameters

Name
Designation of the observed object.

RA
The nominal Right Ascension of the source sky object. This parameter was originally given in B1950 equatorial coordinates with a precision of 0.0001 degrees.

Dec
The nominal Declination of the source sky object. This parameter was originally given in B1950 equatorial coordinates with a precision of 0.0001 degrees.

LII
Nominal Galactic Longitude of the source sky object.

BII
Nominal Galactic Latitude of the source sky object.

Time
The start time of the observation.

End_Time
The end time of the observation.

Duration
The duration of the observation (i.e., End_Time minus Start_Time), in days.

Num_Points
Number of points in the lightcurve.

Count_Rate
Mean count rate of the 1-20 keV lightcurve in units of count/s/cm2. This is calculated using all the points within the lightcurve. (See the parameter Num_Points.)

Min_Count_Rate
Minimum count rate of the 1-20 keV lightcurve in units of count/s/cm2.

Max_Count_Rate
Maximum count rate of the 1-20 keV lightcurve in units of count/s/cm2.

Sigma_Count_Rate
Standard deviation of the 1-20 keV lightcurve rates. This is calculated using all the points within the lightcurve. (See the parameter Num_Points.)

Fileroot
This parameter identifies the file names of the FITS lightcurve data product and the GIF plot for the specified source.


Contact Person

Questions regarding the GINGAASMLC database table can be addressed to the HEASARC User Hotline.
Page Author: Browse Software Development Team
Last Modified: Tuesday, 12-Jun-2018 14:34:30 EDT