The Einstein Observatory (also known as HEAO-2 or HEAO-B) was
operational from 1978 November 13 until 1981 April 25 when the Einstein
attitude control system failed. The Monitor Proportional Counter
(MPC) was a non-focal plane instrument that monitored the 1 to 20 keV
X-ray flux of the source(s) being observed simultaneously by the
operational focal plane instrument. The MPC was a collimated
proportional counter filled with argon and carbon dioxide. It had a
circular field of view, 1.5 degrees in diameter (FWHM), which was
co-aligned with the telescope. A 1.5 mil Be window sealed the gas in
the detector and shielded the detector from ultraviolet radiation. The
active area of the MPC was 667 square cm. The MPC obtained useful data
from 1978 November 19 until 1981 April 17, with the exception of a
3-month period from 1980 Aug 27 to 1980 Dec 08 when operation was
intermittent, due to Einstein Observatory attitude control problems.
The characteristics of the MPC have been described in detail by
Gaillardetz et al.(1979) and by Grindlay et al. (1980).
Gaillardetz, R., et al. 1979, IEEE Trans. Nucl. Sci., 25, 437.
Grindlay, J. E., et al. 1980, Ap. J. (Letters), 240, L121.
Halpern, J.P. 1982, Harvard University Ph.D.thesis.
McIlwain, C.E. 1961 J.Geophys. Res. 66, 3681.
The MPC_RAW data files contain the Einstein Monitor Proportional Counter (MPC)
data for the Einstein (aka HEAO-B or HEAO-2) mission at a time-resolution of
2.56 seconds in FITS format. The file-naming convention uses the start-time
of the observation as its identifier, so that the file m800131_0710_p.cmb
corresponds to an observation which started at 07:10UT on 1980 Jan 31 or
800131 in YYMMDD format. The MPC obtained useful data from 1978 November 19
until 1981 April 17, with the exception of a 3-month period from 1980 Aug 27
to 1980 Dec 08 when operation was intermittent, due to Einstein Observatory
attitude control problems.
An MPC_RAW FITS file has no primary array, but does have 1 binary
table extension that contains the MPC's 8-channel spectra and associated
instrumental characteristics for every 2.56 seconds time interval in the
selected observing segment.The latter corresponds typically to some
fraction of the Einstein spacecraft orbit; thus, an Einstein observation
of an individual source will typically have many MPC_RAW FITS files
associated with it.
Target name. This came from a cross-correlation of the Einstein
Sequence Number with the EINLOG database on HEASARC's Legacy computer.
File Name of Data Product
Sequence Number of Observation
HUT Number: Major Frame # at File Start - 1
The Right Ascension of the object.
The Declination of the object.
The galactic longitude of the object.
The galactic latitude of the object.
The start time of the observation.
The stop time of the observation.
The total time the source object was observed.
The average good counting rate, #/s. This is the is the average,
background-subtracted count rate (in counts per second) for this
observation, excluding data flagged as bad by BFLAG or QFLAG. Thus, if
there are N records of good data, SRCCNT = [The Sum of
Questions regarding the MPCRAW database table can be addressed to the
HEASARC User Hotline.
Page Author: Browse Software Development Team
Last Modified: Monday, 08-Nov-2004 11:26:17 EST