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The Einstein (HEAO-2) FPCS Instrument
Most of the 389 FPCS observations were designed to search for specific
spectral features: lines, absorption edges, and recombination
edges. There were about 40 aperture-map observations of the strong
point sources Cyg X-1, Cyg X-2, and Sco X-1, whose purpose was to
determine, in flight, the position of the aperture relative to the
spacecraft pointing direction. This information is particularly
relevant to the detailed analysis of data from extended sources (i.e.,
supernova remnants and clusters of galaxies, etc.). Finally, there
were three spectral surveys of compact objects, the purpose of which
was to combine a large number of individual observations, made at
about the same time, in order to obtain the equivalent of a fairly
large spectral scan. The three sources surveyed were AM Her and Her
X-1 on the range ~200-300 eV and Sco X-1 in the range ~700-1200 eV.
The procedure used to analyze FPCS data can be summarized as
follows. Timing, pulse-height, and position discrimination are used to
remove much of the background. The residual background is then
determined and subtracted, yielding the net signal from the
source. Finally, the incident flux is determined by taking into
account the known efficency of the instrument.
High Level Data Products: These data files were produced
at MIT in FITS format. Data from this instrument are also available
on the HEASARC CD-ROM
entitled "The Einstein Observatory SSS, MPC, and FPCS Data Products"
dated 1 June 1992. There exists integrated spectra derived from one
or more of the photon event list files. The three digit number used
as the filename extension for the spectra files corresponds to the
observation number used by Lum et al., Ap. J. Suppl. Series, 78,
423, 1992. There are 389 observations but only 336 of them had
sufficent quality for the spectrum to be included.
Raw data: There are 436 photon event files listing every
photon detected in each observation. There are two calibration files
contained in the same directory as the photon events: fpcseff.fit is
a FITS file containing tables of the FPCS efficency parameter as a
function of energy for all 6 crystals, fpcsres.fit is a FITS file
containing tables of the spectral resolution of each of the 6 FPCS
crystals.
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Page authors: Lorella Angelini Jesse Allen
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Last modified: Thursday, 24-Sep-2020 19:05:13 EDT
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