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AO4 Deadline, SIS PI Conversion, Screening Criteria, New PIMMS
Dear ASCA PIs and Archive Researchers:
This message contains:
1. A REMINDER THAT THE DEADLINE FOR AO4 PROPOSALS IS ONE MONTH AWAY.
2. NOTICE OF AN UPDATE TO THE SIS CALIBRATION FILE USED FOR CONVERTING
PHA TO PI. This bulletin can be found on the ASCA GOF WWW page under
"SIS News". A plain text version is appended to this message.
3. NEW DOCUMENTATION ON SCREENING CRITERIA. This bulletin can be found
on the ASCA GOF WWW page under "Screening Criteria." It will form
part of the new ABC Guide which will be released in September. A
plain text version of the bulletin is appended to this message.
4. NOTICE OF A NEW VERSION OF PIMMS. The new version is available
through a link on the ASCA GOF WWW page under "New PIMMS". It can
also be obtained via anonymous FTP at legacy.gsfc.nasa.gov in the
directory software/tools. A plain text version of the release note
is appended to this message.
The URL of the ASCA GOF WWW page is:
http://heasarc.gsfc.nasa.gov/docs/asca/ascagof.html
If you have any questions about ASCA, please send email to
ascahelp@athena.gsfc.nasa.gov.
Charles Day, ASCA GOF
------------------------------------------------------------------------
1. THE DEADLINE FOR AO4 PROPOSALS IS ONE MONTH AWAY.
The deadline for the receipt of ASCA AO4 proposals is 15 September. If
you have not received a set of AO4 appendices, please send an email to
ascanra@athena.gsfc.nasa.gov containing your postal address.
In addition, please note that:
1.1 ASCA proposals are now in two stages
To save time and resources, ASCA proposals are now in two stages, like
XTE. Stage-1 is for the science part of the proposal only. Stage-2,
which takes place after the merging of the US and Japanese programs, is
for the budget only. Details in Appendix C of the NRA.
1.2 RPS has two new, easier-to-use interfaces
The Remote Proposal Submission software (RPS) has two interfaces which
make electronic submission easier: one using email, the other using
Mosaic and Netscape (but only for workstations). Details in Appendix D
of the NRA.
1.3 SIS 4-CCD mode is now unusable
Due to various manifestations of radiation damage, SIS 4-CCD mode is
effectively unusable. Observations which would have been done in 4-CCD
mode earlier in the mission can still be performed using 2-CCD mode with
longer exposures. Proposals specifying 4-CCD mode will not be accepted
on the US side unless the proposers can demonstrate an in-depth
knowledge of the instrument and the special need for 4-CCD mode.
Details in Appendix E of the NRA.
1.4 Priority C targets no longer automatically upgraded
If a priority C target is unscheduled, then it will be dropped,
regardless of national origin. Anybody (including, obviously, the
original PI) can propose for unscheduled priority C targets.
Charles Day, ASCA GOF
------------------------------------------------------------------------
2. THE RELEASE OF A NEW SIS CALIBRATION FILE FOR CONVERTING PHA TO PI
This bulletin can also be found at
http://heasarc.gsfc.nasa.gov/docs/asca/sisph2pifits.html
As you know, the FTOOL SISPI and its associated calibration file
sisph2pi.fits enable the PI column in SIS event files to be filled. The
calibration file is also used by SISRMG to generate the PI response
matrices available in the Calibration Database. By working with PI
rather than PHA, users can correct for the gain changes induced by
radiation damage, as well as combine data from different chips.
The previous version of sisph2pi.fits was released last summer. We have
discovered two problems associated with extrapolating to more recent
data:
1. There was a bug in SISPI: it was not extrapolating the CTI trend.
2. The calibration of the CTI trend was not accurate enough to support
much extrapolation anyway.
To correct these two problems, a new version of sisph2pi.fits has just
been released. It takes care of both problems because, with the new
file, extrapolation is no longer needed to fill the PI columns in recent
datasets. [Note, however, that the extrapolation bug in SISPI remains
and will be corrected for the September 1995 release of FTOOLS.]
This new file is based on the efforts of various SIS team members. It
embodies their best understanding of the instrumental Ni line data
through November 1994 and the calibration observation of Cas A taken in
July 1994. In terms of gain, it is estimated to be currently accurate to
about 1 per cent for SIS0-chip1. The file comes with a nominal
expiration date of February 1996.
Please note, however, that:
o As before, PI does not account for DFE or RDD effects.
o Although PI can correct for time-dependent gain, it cannot, by
itself, deal with time-dependent spectral resolution. For this,
time-dependent matrices are necessary and will be supported by the
next release of SISRMG (the response matrix generator).
o There remain some inter-chip gain calibration problems.
The new file is located at:
/caldb/data/asca/sis/bcf/sisph2pi_140795.fits
in our legacy anonymous FTP area. It includes FITS keywords that make it
compatible with the HEASARC caldb access software. [This is useful
although not necessary for using the new file. The next few releases of
FTOOLS will include the same file under the name sisph2pi.fits in the
refdata area.] SISPI can be used with the new file on pre-screened,
merged data. If you find any problems with the new file, please contact
us at ascahelp@athena.gsfc.nasa.gov.
Koji Mukai and Charles Day, ASCA GOF
------------------------------------------------------------------------
3. NEW DOCUMENTATION ON SCREENING CRITERIA.
This bulletin can also be found at
http://heasarc.gsfc.nasa.gov/docs/asca/screening_criteria.html
The following documentation will from a chapter in the next version of
the ABC Guide which will be released in September.
The perl script ascascreen and its GUI counterpart tkascascreen allow
users to screen their data by applying standard criteria. These criteria
have been found by the GOF to provide the best balance between
effectiveness (getting rid of bad events, but not too many good ones)
and convenience (providing a manageable set of criteria).
The same set of standard criteria is applied during processing at
Goddard. Generally, running ascascreen with default settings will result
in a set of cleaned event lists identical to those in the "screened"
directory on an ASCA datatape or in the ASCA Archive. Note, however,
that refinements are introduced into ascascreen more quickly than the
processing scripts, so their criteria may not exactly match.
Here we describe the individual criteria and how they are used to remove
bad events. The example of the ASCA observation of GX301-2 is used to
show how effective the various criteria are. We also suggest how to
tailor the criteria to match individual analysis priorities. Since the
screening process is different for the two ASCA instruments, the GIS and
SIS are discussed separately.
GIS SCREENING CRITERIA
Summary
Ascascreen applies these screening criteria which are described in more
detail below.
1. Remove the high background ring and Calibration Source.
2. Reject background based on RTI.
3. Select events with a minimum elevation angle of 5-10 degrees.
4. Select events with a minimum cut-off rigidity of 6 GeV/c.
5. Exclude times when there are no events above the lower
discriminator.
6. Select events outside the South Atlantic Anomaly.
By interrogating the user, ascascreen creates an xselect command file to
implement these screening criteria with the desired settings. Here are
the lines in a typical command file which do the screening (the example
is for GIS2):
select mkf @g2_mkf.sel
filter region g2_randc.reg
gisclean
where the file g2_mkf.sel contains the mkf-based screening criteria and
looks like:
SAA==0&&ELV_MIN>5
&&COR_MIN>6
&&G2_L1>0.0
while the file g2_randc.reg contains the SAOimage region file which
describes the high background ring and calibration source and looks
like:
# Cal source and ring removal region
# Written by ascascreen V.0.35.
CIRCLE(124,132,81.00)
-CIRCLE(166.00,221.0,24.00)
Please note:
Individual "bad" events may be rejected by more than one
screening criterion.
Screening criteria may be written in Fortran style (e.g.,
elv.gt.5) or in C style (elv>5).
The files g2_mkf.sel and g2_randc.reg acquired their prefixes as
a result of answering "g2" to the ascascreen question "Enter
product filename root". Users are free to choose a different
name.
1. Removing the High Background Ring and Calibration Source
Most non-X-ray background events in the GIS occur close the walls of the
detector, i.e., at the edge of the Field of View (FOV). Experience has
shown that these background events concentrate in the outer 4-7 arcmin,
making it relatively straightforward to remove them. Accordingly,
ascascreen offers the user the choice of excluding events outside a
central diameter of 40.5 arcmin in the case of GIS2, and 36.5 arcmin for
GIS3. At the same time, ascascreen removes events around the internal
Fe55 calibration source which is at the edge of the FOV in both
detectors.
These two screenings are done in ascascreen using the xselect command
"filter region xsel_randc.reg", where xsel_randc.reg is the file
containing the SAOimage region file used. Note that ascascreen creates
this file for the user.
Not only is background high at the edge of the FOV, but the gain is also
less accurately known. Indeed, because of the uncertain gain, only
events within the central 44 arcmin diameter of the GIS FOV are aspected
(assigned RA and dec). This is slightly larger than the region left over
when the standard high background ring is excluded. Users interested in
obtaining the largest possible aspected FOV should therefore refrain
from removing the high background ring and rely on other screening
criteria.
Excluding the high background ring and the calibration source is very
effective at removing bad events. In the case of the ASCA observation of
GX301-2, 35805 (30 per cent) out of 117795 GIS2 events are rejected in
this way.
2. RTI-based Background Rejection
Bona fide X-ray events occupy a tightly defined region in the plane
formed by the gain-corrected - i.e., invariant - rise time (RTI) and the
pulse height (PHA). The xselect command gisclean will reject events
outside this region and is included in the standard criteria used by
ascascreen. In fact, it must be included because the response matrices
assume that this selection has been performed.
Applying gisclean to the same GIS2 data from GX301-2 gets rid of an
additional 3128 (4 per cent) of the remaining 81990 events not rejected
by excluding the high background ring and calibration source. If RTI
based rejection is applied before rather than after, 10669 events are
removed.
3. Elevation Angle
>From the satellite, the angle between the Earth's limb and the pointing
direction is known as the elevation angle. At low elevation angles the
target is viewed through the Earth's outer atmosphere which absorbs X
rays and hence distorts the spectrum. Negative elevation angles in the
mkf file identify Earth occultations. We have found that data quality
degrades with elevation angles less than 5 degrees. At angles greater
than 10 degrees, the data quality no longer depends on elevation angle.
This means that users can experiment with setting the minimum acceptable
elevation angle at 5 degrees (lax) or 10 degrees (strict), depending on
whether they want to boost signal-to-noise at the expense of possibly
compromising data quality.
Note that sensitivity to elevation angle for a given observation depends
on target position. Targets close to the ecliptic poles are the most
susceptible, as the elevation angle can remain modest throughout the
observation.
The elevation angle is recorded in the mkf file. In REV0 mkf files, the
corresponding column name is ELV_MIN. In REV1 it is ELV.
In our example, setting the minimum elevation angle at 5 degrees removes
only one additional event after the two previous criteria have been
applied.
4. Cut-off Rigidity
Cut-off rigidity (COR) is a local measure of the ability of the
geomagnetic field to repel cosmic rays. Specifically, it is the minimum
momentum (in units of GeV/c) with which a cosmic particle can penetrate
as far as the satellite orbit. Since cosmic rays induce background, low
values of COR identify those parts of the orbit which have high
background. For the GIS, a value of 6 GeV/c yields plenty of events
without seriously compromising quality.
Note that since background depends on COR, the actual spectrum used for
background subtraction should have the same distribution of COR. This
will automatically be the case if the background spectrum is extracted
from the same screened event list as the source spectrum. If, on the
other hand, blank-sky background is used, the COR distribution should
match.
The cut-off rigidity is recorded in the mkf file. In REV0 mkf files, the
corresponding column name is COR_MIN. In REV1 it is COR.
For the GIS2 data from GX301-2, setting COR to be greater than 6 GeV/c
removes an additional 3484 events.
5. Excluding Times when there are no Events above the Lower
Discriminator
The lower discriminator corresponds to the lowest PHA which can be
confidently identified above the noise level. If the GIS high voltage is
turned off (either by command or by automatic trigger), no events pass
the lower discriminator. Such periods should be rejected because they
nevertheless appear to software as good time intervals, i.e., they
erroneously contribute to the exposure. This is done by selecting on the
mkf columns G2_L1 and G3_L1 (for GIS2 and GIS3, respectively) which
contain the number of events above the lower discriminator.
6. South Atlantic Anomaly
The South Atlantic Anomaly (SAA) is a "hole" in the geomagnetic field
which allows cosmic rays to penetrate further than usual. The particle
background in the SAA is extremely high. In fact, the high voltage of
the GIS is usually turned off during passage through the SAA. At such
times, no events pass the lower discriminator (see above). SAA passages
can be explicitly excluded by selecting on the mkf column SAA: requiring
the value be zero excludes SAA passages.
In the case of the GIS2 data from GX301-2, applying the SAA criterion
does not exclude any additional events.
SIS SCREENING CRITERIA
Summary
Ascascreen applies these screening criteria which are described in more
detail under the links.
1. Remove hot and flickering pixels.
2. Select only grades 0,2,3 & 4.
3. Select events with a minimum elevation angle of 5-10 degrees and
with a minimum Bright Earth elevation angle of 15-40 degrees
(SIS0) or 15-20 degrees (SIS1).
4. Select events with a minimum cut-off rigidity of 6 GeV/c.
5. Exclude events in frames which have too many events above the
event threshold.
6. Select events outside the South Atlantic Anomaly.
7. Select events which occur more than 4 readout cycles after the
satellite passes through the South Atlantic Anomaly.
8. Select events which occur more than 4 readout cycles after the
satellite passes through the Day-Night Terminator.
By interrogating the user, ascascreen creates an xselect command file to
implement these screening criteria with the desired settings. Here are
the lines in a typical command file which do the screening (the example
is for SIS0):
select mkf @s0_mkf.sel
sisclean clean=2 cellsize=5 log_prob=-5.24 bkg_thr=3 clean_phalow=0
clean_phahi=4095 sis_plot2=no saoimage2=no
select events "grade==0||(grade>=2&&grade<=4)" save_file=no
where the file s0_mkf.sel contains the mkf-based screening criteria and
looks like:
SAA==0&&BR_EARTH>20
&&ELV_MIN>10
&&COR_MIN>6
&& s0_pixl1 > 0 &&s0_pixl1 < 400
&&(T_DY_NT<0||T_DY_NT>4)&&(T_SAA<0||T_SAA>4)
Please note:
Individual "bad" events may be rejected by more than one
screening criterion.
Screening criteria may be written in Fortran style (e.g.,
elv.gt.5) or in C style (elv>5).
The file s0_mkf.sel acquired its prefix as a result of answering
"s0" to the ascascreen question "Enter product filename root".
Users are free to choose a different name.
1. Removing Hot and Flickering Pixels
Hot and flickering pixels, which appear as false events, are a
manifestation of radiation damage. Although they are unavoidably
included in telemetry, they can be straightforwardly removed on the
ground. The "sisclean" algorithm rejects those pixels which register an
event more often than expected from Poisson statistics. Since they
contain no astrophysical information and are not accounted for in the
available response matrices, hot and flickering pixels should always be
removed.
The number of hot and flickering pixels depends on epoch (the problem
has worsened since launch) and on clocking mode (more of a problem in 4-
CCD mode than in 1-CCD mode).
In the case of the SIS0 data from GX301-2, sisclean removes 61464 hot
and flickering pixel events (45 per cent) from the total of 137415.
2. Grade Selection
Grade is a one-dimensional description of the shape of the charge cloud
created by an event. Certain grades have better spectral resolution than
others (grade 0 has the best resolution) or are more likely to be bona
fide X-ray events (grades 1, 5 & 7 contain mostly non X-ray events).
Experience with lab and in-flight data has shown that the best
combination of resolution and signal-to-noise is provided by using
grades 0, 2, 3 & 4, while discarding the others. In fact, most of the
available response matrices have been created for this combination which
is selected in ascascreen by default. However, there are two important
cases where users might want a different selection. First, Fast mode
data have different grade assignments: only grade 0 events should be
selected; they should be analyzed spectrally with "g02" matrices.
Second, since analyzing a light curve does not require a response, users
can increase the signal-to-noise of an SIS light curve by including
grade 6 events.
In addition, please note that:
On-board Bright mode data contain only grades 0-4 (up to late
November 1993) or grades 0-6 (after November 1993).
Goddard-converted Bright mode data contain only grades 0-4.
Selecting grades 0, 2, 3 & 4 for the SIS0 data from GX301-2 removes an
additional 17239 events (23 per cent) from the 75951 left after the
removal of the hot and flickering pixels.
3. Elevation and Bright Earth Angles
>From the satellite, the angle between the Earth's limb and the pointing
direction is known as the elevation angle. At low elevation angles the
target is viewed through the Earth's outer atmosphere which can absorb
X-rays and hence distort the spectrum. Moreover, in the case of the SIS,
which is also sensitive to optical and UV radiation, data quality is
further impaired when the portion of the outer atmosphere in the FOV is
illuminated by the Sun. This necessitates two elevation angle criteria:
one for when the Earth's limb is dark, and a second, stricter one for
when the limb is bright. Negative elevation angles in the mkf file
identify Earth occultations.
For the dark limb we have found that data quality is significantly
reduced with elevation angles less than 5 degrees. At angles greater
than 10 degrees, the effect no longer depends on elevation angle. This
means that users can experiment with setting the minimum acceptable
elevation angle at 5 degrees (lax) or 10 degrees (strict), depending on
whether they want to boost signal-to-noise at the expense of possibly
compromising data quality.
For the bright limb the elevation angle can be set in the range 15-40
degrees for SIS0, with 20 degrees being a sensible default. For SIS1,
the recommended range is 15-20 degrees.
Note that sensitivity to elevation angle for a given observation depends
on target position. Targets close to the ecliptic poles are the most
susceptible, as the elevation angle can remain modest throughout the
observation.
The elevation angle, regardless of whether dark or bright, is recorded
in the mkf file. In REV0 mkf files, the corresponding column name is
ELV_MIN. In REV1 it is ELV. The Bright Earth elevation angle is BR_EARTH
in the mkf file.
In our example, setting the minimum (dark) elevation angle at 5 degrees
and the bright earth angle at 20 degrees removes an additional 8170
events (14 per cent) after the two previous criteria have been applied.
4. Cut-off Rigidity
Cut-off rigidity (COR) is a local measure of the ability of the
geomagnetic field to repel cosmic rays. Specifically, it is the minimum
momentum (in units of GeV/c) with which a cosmic particle can penetrate
as far as the satellite orbit. Since cosmic rays induce background, low
values of COR identify those parts of the orbit which have high
background. For the SIS, a value of 6 GeV/c yields plenty of events
without seriously compromising quality. Note that since background
depends on COR, the actual spectrum used for background subtraction
should have the same distribution of COR. This will automatically be the
case if the background spectrum is extracted from the same screened
event list as the source spectrum. If, on the other hand, blank-sky
background is used, the COR distribution should match.
The cut-off rigidity is recorded in the mkf file. In REV0 mkf files, the
corresponding column name is COR_MIN. In REV1 it is COR.
For the SIS0 data from GX301-2, setting COR to be greater than 6 GeV/c
removes an additional 2946 events.
5. Events above Threshold
To avoid telemetry saturation and pile-up the SIS is not used to observe
very bright objects. This means that when high count rates do occur in
the SIS, it is often the result of such non astrophysical occurrences as
passing through the SAA or observing the bright limb of the Earth's
atmosphere. The mkf column Sn_PIXLm records the number of pixels per
readout (REV0) or per second (REV1) which exceed the event threshold in
SISn/chipm. By imposing an upper limit on SISn/chipm, these non X-ray
peaks can be rejected. In practice, however, the same default settings
are used for all eight chips and depend only on the readout time (i.e.,
on clocking mode).
Setting S0_PIXL1 to be less than 400 events per readout (i.e., 400
events per 4 seconds in 1-CCD mode or 100 events per second) results in
an additional 1983 events being removed.
6. South Atlantic Anomaly
The South Atlantic Anomaly (SAA) is a "hole" in the geomagnetic field
which allows cosmic rays to penetrate further than usual. The particle
background in the SAA is extremely high, though not so high that the SIS
is turned off (unlike the GIS). SAA passages can be explicitly excluded
by selecting on the mkf column SAA: requiring that the value be zero
excludes SAA passages.
In the case of the SIS0 data from GX301-2, applying the SAA criterion
after the lower discriminator criterion excludes an additional 627
events.
7. Time after Passing through the South Atlantic Anomaly
To derive the true PHA in each pixel, the "dark frame" is subtracted
from the total PHA. Dark frame varies across each chip and depends on
the radiation environment of the instrument. Because of these
dependencies, the on-board computer calculates a 16 x 16 map of the dark
frame for each chip and updates the map periodically. However, when the
satellite clears the SAA, radioactive decays persist for a few seconds,
raising the dark frame. This elevation of the dark frame occurs so
rapidly that the dark frame map is not accurately calculated until about
4 readout times have elapsed, i.e., 16, 32 and 64 seconds for 1-CCD, 2-
CCD and 4-CCD mode, respectively. The mkf column T_SAA gives the time in
seconds after a passage through the SAA. Note that before the first SAA
passage of an observation, T_SAA is negative. This means that for a 1-
CCD mode observation, for example, the appropriate setting is that T_SAA
be less than zero and greater than 16. Users should also be aware that
mkf files have 32-s bins.
Since an inaccurate dark frame affects light curves less than spectra,
users extracting light curves might want to omit the T_SAA criterion.
Applying this criterion to the SIS0 data from GX301-2 does not exclude
any additional events.
8. Time after Passing through the Day-Night Terminator
To derive the true PHA in each pixel, the "dark frame" is subtracted
from the total PHA. Dark frame varies across each chip and depends on
the radiation environment of the instrument. Because of these
dependencies, the on-board computer calculates a 16 x 16 map of the dark
frame for each chip and updates the map periodically. However, when the
satellite crosses the Day-Night (or Night-Day) Terminator, the optical
illumination, and hence the dark frame, changes rapidly - so rapidly, in
fact, that the dark frame map is not accurately calculated until about 4
readout times have elapsed, i.e., 16, 32 and 64 seconds for 1-CCD, 2-CCD
and 4-CCD mode, respectively. The mkf column T_DY_NT gives the time in
seconds after a passage through the Terminator (whether it's Day-Night
or Night-Day). Note that before the first Terminator passage of an
observation, T_DY_NT is negative. This means that for a 1-CCD mode
observation, for example, the appropriate setting is that T_DY_NT be
less than zero and greater than 16. Users should also be aware that mkf
files have 32-s bins.
Since an inaccurate dark frame affects light curves less than spectra,
users extracting light curves might want to omit the T_DY_NT criterion.
Applying this criterion to the SIS0 data from GX301-2 does not exclude
any additional events.
Charles Day & the ASCA GOF
------------------------------------------------------------------------
4. THE RELEASE OF A NEW VERSION OF PIMMS.
4.1 PIMMS 2.2 Release Note
We have discontinued the support for ASCA SIS image simulation
capability. Version 2.2 is a slight upgrade on s2.1a (see the release
note for that version below), but 'make' will call the executable
'pimms' rather than 'pimms2' (sorry for the confusion this might
cause!).
This version contains several new features:
- Updated mission specific information for ASCA instruments, suitable
for the AO-4 period (1996).
- Effective area curves and mission specific information for SAX, the
Italian/Dutch X-ray astronomy satellite.
- XTE ASM effective area curve.
- Default mission will be determined at run-time: whatever
mission/detector combination that is at the top of the
pms_mssn.lst file will be the default.
- Several bug fixes
4.2 PIMMS s2.1a Release Note
This version contains these new features and updates:
- A new version of the XTE PCA effective area curve (see below for
details).
- The HEAO-1 A4 LED effective area is now available, giving the ability
to predict count rates in the 4 bands used by Levine et al
(1984, ApJS 54, 581).
- The Spectrum-X-Gamma SODART (with LEPC, HEPC, and SIXA) effective
area is now included.
- The SAX (with LECS, MECS, HPGSPC, PDS and WFC) effective area is now
included.
- A number of miscellaneous bug fixes have been implemented.
The new XTE PCA effective area curve brings count rate estimates using
PIMMS2 and the 256 channel and 6 channel PCA matrices (used in XSPEC)
into agreement. Earlier versions of PIMMS2 used a slightly larger, but
not unreasonable, PCA effective area and used a response matrix having
an energy scale and offset different from the 6 channel matrix. The
effect is that the total count rate was larger than that obtained using
the 6 channel PCA matrix (5det_6ch.rmf) by a factor of 1.143, and that
counts in the lowest canonical channel were underestimated.
4.3 How to compile PIMMS:
* UNIX users:
Use anonymous ftp to legacy.gsfc.nasa.gov. Find pimms2_2.tar.Z file
under /FTP/software/tools
Copy the file to a suitable directory then
% zcat pimms2_2.tar | tar xvf -
It should create three subdirectories: data, models and source.
Goto the source subdirectory and edit the file called 'sitespec.inc' so
that ddir_name correctly points to the data, and mdir_name to the models
subdirectory. (Note: this is done slightly differently from old pimms)
% make arch=sun
if your machine is a Sun (other arch are 'dec' for DECstation running
Ultrix, 'alpha' for DEC Alphas running OSF). It will leave the
executable, pimms, in the directory above source; there you can also
find the LaTeX documentation file pimms.tex.
* System dependence?
This version of pimms will probably compile on all different flavors of
Suns (old SunOS or Solaris, various compiler versions etc). In fact,
make arch=sun will probably work for many non-DEC UNIX platforms, not
just Suns. Try it and let us know if you encounter problems.
Known Make problem --- we encountered one problem here at Goddard. If
you see the message 'don't know how to make sys.o' then wait a few
seconds and try again. This may be caused by the slow response of NSF-
mount (make makes a link then tries to use the link, before the file
becomes visible to the process).
* VAX/VMS users:
If you can ftp and unpack the compressed tar file, then do so. Follow
the UNIX directions above, then type @make instead of 'make arch=***'.
Otherwise, contact mukai@lheavx.gsfc.nasa.gov to arrange an alternative
method of file transfer.
Koji Mukai, ASCA GOF