Each Suzaku proposal must include at a minimum the source coordinates, exposure time, instrument configuration and expected count rates, and any observing constraints within the four page limit. The review panels will base their decision primarily upon the justification of the proposed science to be done with the data. This chapter describes how to prepare a strong proposal, including the various software tools available to assist the proposer.
While it is conceivable that one would wish to study a previously unknown X-ray source with Suzaku, a more likely scenario would involve a spectroscopy study of an object with known X-ray flux. A viable proposal should state the scientific objective of the observation and show that Suzaku can achieve this objective. Observations that require one or more of Suzaku's unique capabilities would be especially strong canditates.
Every Suzaku proposal must have an estimate of the expected source count rates from the proposed target for all detectors. This rate is used both by the reviewers to evaluate the viability of the proposal and the operations team to evaluate any safety concerns. The simplest tool to use in estimating the expected XIS or HXD count rate is PIMMS. This tool is freely available as a stand-alone tool or on the Web as WebPIMMS (see Appendix C). The next level of detail is provided via simulations using XSPEC, and such simulations should provide significant insight into the expected spectrum obtained from a proposed observation. A brief guide to XSPEC simulations is given in § 4.3. In many case, this should be sufficient for a point source. There are also tools available to simulate imaging data, which may be useful for an extended source or a particularly bright source. In particular, the most powerful tool is xissim, which can use a FITS format image with an assumed spectral shape of the source to estimate the distribution of events in all elements of the XIS detectors.
This tool is an interactive, menu-driven program, which has an
extensive HELP facility. It is also available as the web-based tool
WebPIMMS. In either case, users specify the flux and spectral model
with its parameters, and PIMMS/WebPIMMS returns the predicted counting
rate. PIMMS/WebPIMMS can be used for a variety of other instruments,
so if for instance the counting rate and spectrum of a given source
observed with the ROSAT PSPC is known, it can calculate the flux,
which in turn can be used as input to estimate the expected counting rates.
The limitations of the input source must be considered carefully.
For example, ROSAT had no significant response to X-rays above 
keV,
and so is not useful when estimating the HXD GSO count rate.
Perhaps the easiest tool for simulating X-ray spectra is the XSPEC program (a part of the XANADU software package), which is designed to run on a variety of computer platforms and operating systems and is freely distributed on the NASA GSFC HEASARC Website (see Appendix C). The simulation of an XIS or HXD observation requires the current instrument redistribution matrix (the so-called .rmf file) and the energy-dependent effective area of the instrument (the so-called .arf file), both available on the Web or via anonymous FTP (see Appendix C).
The procedure for simulations is relatively simple: if the XSPEC program is installed, one should start XSPEC making sure that the proper .rmf and .arf files are accessible. Within XSPEC, one should specify the spectral model, such as hot thermal plasma or the like (via the model command). Specifying the model will drive XSPEC to query for the model parameters (such as temperature and abundances for an APEC collisional plasma model), as well as normalization. The key command to create a simulated spectrum is the fakeit command, which will query for the redistribution response (the .rmf file), and the ancillary response (the .arf file). The fakeit command also will request the simulated data filename, and the length of simulated observation. One can now use this file within XSPEC to determine the sensitivity of the simulated data file to changes in the model parameters.
Most of the features of XSPEC are also available as a web-based tool on the HEASARC website (see Appendix C). WebSPEC calls XSPEC behind the scenes, so all the issues described above apply here as well.
After selecting the instrument, WebSPEC allows the user to choose the spectral model, such as an absorbed collisional plasma or a power-law spectrum with an absorption component. The next page will then query for the model parameters (such as temperature and abundances for an APEC collisional plasma model), as well as normalization, exposure, upper and lower energies, and the number of bins to use in the spectral plot. WebSPEC will then create a simulated spectrum after clicking the ``Show me the Spectrum'' button, using the fakeit command. This folds the specified model through the instrument response and effective area, calculating the observed count rate and fluxes as well. WebSPEC will then allow one to download the postscript file of the spectrum, change the model parameters, or replot the data.
To show how to estimate the proper exposure, we include some simple examples of XIS and HXD observations that illustrate the process.
The Local Hot Bubble is the proposed origin for at least some of the 1/4 keV emission seen in the ROSAT All-Sky Survey at all latitudes. Although Suzaku has some sensitivity at 1/4 keV, a more profitable approach to finding this emission is to detect the OVII emission that should accompany it. In this case we need to calculate the expected count rate from the OVII and compare it to the expected background.
We first need the expected flux, based on published papers or the PI's
model. In this case, we expect the surface brightness to be 0.34
ph/cm
/s/sr, based on a number of papers. Since the XIS
field of view is 
, this value corresponds to a total
surface brightness in one XIS of
ph/cm/s.
The next question is the effective area of the XIS instruments at the
line energy. OVII is in fact a complex of lines, centered
around 0.57 keV. Examining the effective area plots for the XIS in
Chapter 6, we see that the effective area at 0.57 keV in the
BI CCD is 
cm; for the FI CCDs it is 
cm. The effective area curves for the FI and BI CCDs can
also be found by loading their responses into XSPEC and using the plot efficiency command. Warning: The XIS
.rmf response matrices are not normalized, and so must be combined
with the .arf files to determine the total effective area.
With the expected flux and the effective area, we can now determine
the expected count rate in the BI and FI CCDs to be 1.3 and 0.87
cts/ks. This is obviously a extremely low count rate and so the
expected background is very important. The resolution of the XIS is
quite good, as shown in Chapter 6, at 0.57 keV a bin of
width 60 eV will contain most of the emission. The XIS background
rate (see §6.7) at this energy is only 0.05 cts/s/keV
in both the FI and BI detectors, so we can expect a background of 3
cts/ks. In both the FI and BI detectors the line will be below the
background, but this does not intrinsically hinder detection. As will
be seen below, in the HXD this is the norm rather than the exception.
One aid for this observation is that the OVII line is
relatively isolated in this energy range, with the exception of the
nearby OVIII line. Assume we wish to detect the OVII feature with 
significance. Then the total count rate in
the XIS-S1 (the BI CCD) in our energy band will be 4.3 cts/ks, with 3
cts/ks of background. In an N ks observation, we will measure the
signal to be
. To achieve a
result, then, we need
, or 
ks.
Another common observation will be to search for faint hard X-ray tails from sources such as X-ray binaries. We describe here how to simulate such an observation, including the all-important HXD background systematics, which will dominate all such observations.
The first step is to download the latest versions of the background template files and the response files from the website listed in Appendix C. The HXD website will also describe the current best value for the systematic error in background estimation. For this AO, the HXD recommends 3% for the PIN and 5% for the GSO. Before beginning this process, the proposer should also check if contaminating sources exist in the FOV of the HXD, using existing hard X-ray source catalogs from satellite such as RXTE-ASM, INTEGRAL, and Swift.
We set up XSPEC to use these by reading the background template files as both data and background along with the response files.
XSPEC12>data ae_hxd_pinbkg_20051105.pha ae_hxd_gsobkg_20051105.pha
2 spectra in use
Source File: ae_hxd_pinbkg_20051105.pha
Net count rate (cts/s) for Spectrum:1 6.689e-01 +/- 2.082e-03
Assigned to Data Group 1 and Plot Group 1
Noticed Channels: 1-256
Telescope: SUZAKU Instrument: HXD Channel Type: PI
Exposure Time: 1.544e+05 sec
No response loaded.
Source File: ae_hxd_gsobkg_20051105.pha
Net count rate (cts/s) for Spectrum:2 3.539e+01 +/- 2.571e-02
Assigned to Data Group 1 and Plot Group 2
Noticed Channels: 1-512
Telescope: SUZAKU Instrument: HXD Channel Type: PI
Exposure Time: 5.354e+04 sec
No response loaded.
***Warning! One or more spectra are missing responses,
and are not suitable for fit.
XSPEC12>back ae_hxd_pinbkg_20051105.pha ae_hxd_gsobkg_20051105.pha
***Warning! One or more spectra are missing responses,
and are not suitable for fit.
Net count rate (cts/s) for Spectrum:1 -0.000e+00 +/- 2.944e-03 (-0.0 % total )
Net count rate (cts/s) for Spectrum:2 -0.000e+00 +/- 3.636e-02 (-0.0 % total )
XSPEC12>resp ae_hxd_pinhxnom_20051104.rsp ae_hxd_gso_20051019.rsp
Response successfully loaded.
Response successfully loaded.
Now we assume a spectrum for our source; here, we use a Crab-like spectrum (photon index 2.1) with a 10 mCrab flux. This can be set up in XSPEC via the following commands:
XSPEC12>model powerlaw
Input parameter value, delta, min, bot, top, and max values for ...
1 0.01 -3 -2 9 10
powerlaw:PhoIndex>2.1
1 0.01 0 0 1e+24 1e+24
powerlaw:norm>0.08
========================================================================
Model powerlaw<1> Source No.: 1 Active/Off
Model Model Component Parameter Unit Value
par comp
1 1 powerlaw PhoIndex 2.10000 +/- 0.0
2 1 powerlaw norm 8.00000E-02 +/- 0.0
________________________________________________________________________
Chi-Squared = 39667.42 using 768 PHA bins.
Reduced chi-squared = 51.78514 for 766 degrees of freedom
Null hypothesis probability = 0.000000e+00
Valid fit does not exist.
Now we can create fake PIN and GSO data with the ``fakeit'' command. The result will be simulated spectral files which include the instrumental background, effective area, and resolution.
XSPEC12>fakeit Use counting statistics in creating fake data? (y): Input optional fake file prefix: Fake data file name (ae_hxd_pinbkg_20051105.fak): pin_10mCrab_100ks.fak Exposure time, correction norm (154410., 1.00000): 1e+5 Fake data file name (ae_hxd_gsobkg_20051105.fak): gso_10mCrab_100ks.fak Exposure time, correction norm (53537.7, 1.00000): 1e+5 No ARF will be applied to fake spectrum #1 No ARF will be applied to fake spectrum #2
We have now created our 'faked' spectral files, named pin_10mCrab_100ks.fak and
gso_10mCrab_100ks.fak. Now we
fit these datasets with the same Crab-like model. We will use three
different background spectral models-low, medium, and high-which
vary by as much as 3% for the PIN and 5% for the GSO. This takes
into account the fact that the ``true'' background will likely vary
within these limits. One item of note is that we do not use
the ``faked'' background files afterwards which were also created by
the fakeit command. That process assumes that the background is
obtained together with the actual observation, e.g. using the
outer region of the CCD image. In an HXD observation, this is not the
case. The background is generated by modeling from the database, and
users should use the template background throughout the simulation and
also the future analysis.
We load the background files twice, once as background and once as a correction file (``corfile'') which will allow us to easily vary the total background within XSPEC.
XSPEC>back ae_hxd_pinbkg_20051105.pha ae_hxd_gsobkg_20051105.pha XSPEC>corfile ae_hxd_pinbkg_20051105.pha ae_hxd_gsobkg_20051105.pha
All the necessary data files are now loaded, and we now experiment with different background levels, set by the value of ``cornorm''. A value of 0 gives the ``normal'' background, for example, and 0.05 increases it by 5%.
XSPEC>cornorm 0.0 0.0 XSPEC>ignore 1:**-8.0 2:**-30.0 600.0-** XSPEC>setplot energy XSPEC>setplot rebin 3 30 XSPEC>plot ldata XSPEC>fit XSPEC>plot ldata res
Now we check that the same source signal would be detectable with a high background-3% for the PIN and 5% for the GSO.
XSPEC>cornorm 0.03 0.05 XSPEC>plot ldata XSPEC>ignore 2:30.0-600.0 XSPEC>fit XSPEC>plot ldata data
From the initial plot ldata command it is seen that in this case the signal is undetectable at all in the GSO band, and so the entire GSO band is ignored.
Finally, we check the source signal using low backgrounds.
XSPEC>cornorm 1 -0.03 -0.05 XSPEC>plot ldata XSPEC>fit XSPEC>plot ldata data
By comparing the different fit results from these different runs, the total expected error in the slope and normalization can be estimated.
Our goal is to measure the contribution reflected X-rays make to the X-ray spectrum of an AGN. The reflection occurs primarily with harder X-rays, so the HXD is the primary instrument and could be used without the XIS. However, measuring the continuum over a broad range will significantly reduce the errors (both systematic and statistical) in the result. In this example a moderately-absorbed Seyfert 2 simulation will be performed.
We begin be reading into XSPEC the XIS response and HXD background and response files we will need. These can be found on the Suzaku proposal website; see Appendix C. XIS-S1 is the BI chip and XIS-S2 is used to represent all three FI chips.
XSPEC12>data ae_xi1_back.pha ae_xi2_back.pha XSPEC12>data 3 ae_hxd_pinbkg_20051105.pha ae_hxd_gsobkg_20051105.pha XSPEC12>back 3 ae_hxd_pinbkg_20051105.pha ae_hxd_gsobkg_20051105.pha XSPEC12>resp ae_xi1_20051103.rmf ae_xi2_20051102.rmf XSPEC12>arf ae_xi1_onaxis_20050916.arf ae_xi2_onaxis_20050916.arf XSPEC12>resp 3 ae_hxd_pinxinom_20051104.rsp ae_hxd_gso_20051019.rsp
Next we set up the model we want.
XSPEC12>model constant*phabs( pexrav + gaussian )
Input parameter value, delta, min, bot, top, and max values for ...
1 0.01 0 0 1e+10 1e+10
constant:factor>1 -1
1 0.001 0 0 100000 1e+06
phabs:nH>50
2 0.01 -10 -9 9 10
pexrav:PhoIndex>1.8
100 10 1 1 1e+06 1e+06
pexrav:foldE>100.
0 0.01 0 0 1e+06 1e+06
pexrav:rel_refl>1
0 -0.01 0 0 10 10
pexrav:redshift>
1 -0.01 0 0 1e+06 1e+06
pexrav:abund>
1 -0.01 0 0 1e+06 1e+06
pexrav:Fe_abund>
0.45 -0.01 0.05 0.05 0.95 0.95
pexrav:cosIncl>
1 0.01 0 0 1e+24 1e+24
pexrav:norm>
6.5 0.05 0 0 1e+06 1e+06
gaussian:LineE>6.4
0.1 0.05 0 0 10 20
gaussian:Sigma>0.01
1 0.01 0 0 1e+24 1e+24
gaussian:norm>
========================================================================
Model constant<1>*phabs<2>(pexrav<3> + gaussian<4>) Source No.: 1 Active/On
Model Model Component Parameter Unit Value
par comp
1 1 constant factor 1.00000 frozen
2 2 phabs nH 10^22 50.0000 +/- 0.0
3 3 pexrav PhoIndex 1.80000 +/- 0.0
4 3 pexrav foldE keV 100.000 +/- 0.0
5 3 pexrav rel_refl 1.00000 +/- 0.0
6 3 pexrav redshift 0.0 frozen
7 3 pexrav abund 1.00000 frozen
8 3 pexrav Fe_abund 1.00000 frozen
9 3 pexrav cosIncl 0.450000 frozen
10 3 pexrav norm 1.00000 +/- 0.0
11 4 gaussian LineE keV 6.40000 +/- 0.0
12 4 gaussian Sigma keV 1.00000E-02 +/- 0.0
13 4 gaussian norm 1.00000 +/- 0.0
________________________________________________________________________
Compton reflection from neutral medium.
See help for details.
If you use results of this model in a paper,
please refer to Magdziarz & Zdziarski 1995 MNRAS, 273, 837
Questions: Andrzej Zdziarski, aaz@camk.edu.pl
Chi-Squared = 4.182172e+11 using 2816 PHA bins.
Reduced chi-squared = 1.489377e+08 for 2808 degrees of freedom
Null hypothesis probability = 0.000000e+00
Valid fit does not exist.
Next we need to adjust the normalization of the continuum and Fe-K line. Here we assume our source has a F(15-100 keV) = 5e-11. The XSPEC command:
XSPEC>flux 15 100 No overlap between matrix range ( 0.2, 12 ) and the requested range ( 15, 100 ) Upper range bound 100 reset by matrix bound to 96.375 Spectrum Number: 3 Model Flux 0.11484 photons (5.9099e-09 ergs/cm^2/s) range (15.000 - 96.375 keV) Spectrum Number: 4 Model Flux 0.11562 photons (5.9989e-09 ergs/cm^2/s) range (15.000 - 100.00 keV)shows that the current flux is 6e-9. To make the model match our desired total flux, we need to change the normalization to 8.3e-3 via the command: XSPEC> new 10 8.3e-3
To find the correct normalization for a Fe K Gaussian with equivalent width 500 eV, we use the XSPEC eqwidth command:
XSPEC>eqwidth 4 Data group number: 1 Additive group equiv width for Component 4: 3274.28 keVThe correct normalization, therefore, is 1.53e-4. We set this value and then save the model for future use:
XSPEC>new 13 1.53e-4 XSPEC>save model pexrav_100kev_fek_500ev_5e-11_model.xcm
Now run the XSPEC ``fakeit'' command, with the FI CCD simulation having three times the exposure of the other instruments:
XSPEC12>fakeit Use counting statistics in creating fake data? (y): Input optional fake file prefix: Fake data file name (ae_xi1_back.fak): pexrav_100kev_fek_500ev_BI_100ks.fak Exposure time, correction norm (32245.7, 1.00000): 1e5 Fake data file name (ae_xi2_back.fak): pexrav_100kev_fek_500ev_FI_300ks.fak Exposure time, correction norm (32245.7, 1.00000): 3e5 Fake data file name (ae_hxd_pinbkg_20051105.fak): pexrav_100kev_fek_500ev_pin_100ks.fak Exposure time, correction norm (154410., 1.00000): 1e5 Fake data file name (ae_hxd_gsobkg_20051105.fak): pexrav_100kev_fek_500ev_gso_100ks.fak Exposure time, correction norm (53537.7, 1.00000): 1e5 No ARF will be applied to fake spectrum #3 No ARF will be applied to fake spectrum #4
As with the last example we do not use the HXD backgrounds generated by fakeit but use the standard backgrounds also read in as correction files
XSPEC12>back 3 ae_hxd_pinbkg_20051105.pha ae_hxd_gsobkg_20051105.pha XSPEC12>corf 3 ae_hxd_pinbkg_20051105.pha ae_hxd_gsobkg_20051105.pha XSPEC12>corn 3-4 0.
Ignore some channels, plot the data to see where data quality drops off, then ignore some more channels
XSPEC12>ignore 1:0.0-0.3 2:0.0-0.4 3:0.0-10.0 4:0.0-30.0 XSPEC12>setplot energy XSPEC12>setplot rebin 5 100 XSPEC12>plot ldata XSPEC12>ignore 1:0.-2. 10.-** 2:0.-2. 11.-** XSPEC12>ignore 3:50.-** 4:100.-**
Try increasing the HXD background by its uncertainty to see whether the GSO data is worth using
XSPEC12>corn 3 0.03 XSPEC12>corn 4 0.05 XSPEC12>plot ldata
Clearly we won't get a detection with the GSO within the background systematics so remove this dataset from consideration.
XSPEC12>data 4 none
We can now fit and determine the uncertainties on the reflection parameters. This should be done by using the error command on the relevant parameters to get the statistical uncertainties then repeat with all three possible normalizations of the PIN background to get the systematic uncertainties.
One other source of systematic uncertainty is the relative normalization of the instrument effective areas. This is still being calibrated but a conservative assumption would be to assume a 5% uncertainty. This can be included in the modelling by reading the three datasets of interest in as separate data groups.
XSPEC12>data 1:1 pexrav_100kev_fek_500ev_BI_100ks.fak XSPEC12>data 2:2 pexrav_100kev_fek_500ev_FI_300ks.fak XSPEC12>data 3:3 pexrav_100kev_fek_500ev_pin_100ks.fak XSPEC12>back 3 ae_hxd_pinbkg_20051105.pha XSPEC12>corf 3 ae_hxd_pinbkg_20051105.pha XSPEC12>corn 3 0. XSPEC12>ignore 1:0.-2. 10.-** 2:0.-2. 11.-** 3:0.-10. 50.-**
XSPEC> setplot energy XSPEC> setplot rebin 5 100 XSPEC> ignore 1:11.-** XSPEC> ignore 2:10.-** XSPEC> ignore 3:50.-** XSPEC> ignore 4:100.-**
Now set the "const" values for data sets 2 and 3 to be constrained to vary from 0.95 to 1.05.
XSPEC12>newpar 14 1.0 0.1 0.95 0.95 1.05 1.05 XSPEC12>newpar 27 1.0 0.1 0.95 0.95 1.05 1.05
and determine errors as before.
xissim is a Suzaku XIS event simulator, based on the tool xrssim. It reads a FITS format photon list file, traces photon paths in the telescope (via ray-tracing), and outputs a simulated XIS event file. XRT thermal shield transmission and XIS detection efficiency are taken into account if requested. Each record of the photon list file describes the celestial positions, arrival time, and energy of the input photon. The mkphlist ftool can create such photon list files from FITS images (e.g., ROSAT HRI or Chandra images) and spectral models (which may be created in XSPEC). The xissim output event file may be analyzed just like a real data, using standard analysis tools such as xselect.
At the time of this writing, xissim is not yet ready for release. Please check the Suzaku Tools web page listed in Appendix C for more information about the status of xissim.
One of the first tasks in preparing a proposal is determining when and for how long a target can be observed. This can be easily done with Viewing, a simple Web-based interactive tool (see Appendix C) that can determine visibility for many different satellites. To use Viewing, simply enter the target name or coordinates, and select the satellite. Viewing will return all the available dates when that target is observable.
MAKI is another Web-based interactive tool (see Appendix C) that can determine the orientation of the XIS CCDs on the sky as a function of the observation epoch within the visibility window of the target. For Suzaku, the orientation of the solar panels with respect to the spacecraft is fixed, and at the same time, the range of the angles between the vector normal to the solar panels and the vector pointing to the Sun is restricted, which in turn restricts the roll angle of the spacecraft.
When using the tool, general instructions are available via the ``Help'' button. section. To check the visibility and available roll angles for a target, first load an image. This can be done with either an existing FITS image, or by entering the RA and Declination of the source and clicking the ``New Graph'' button. This creates an image upon which the Suzaku XIS field of view (FOV) will be shown.
The ``Mission and Roll Selector'' (in the upper right of the display) allows different instruments from different missions to be selected. Then the FOV will appear on your image. This can be rotated using the ``Roll angle'' slider bar.
RPS, or the Remote Proposal Submission tool, must be used to enter the basic proposal data into the ISAS/JAXA, HEASARC, or ESA database. Proposers should make sure they use the appropriate RPS, since they are multiple reviews. See Appendix C for the list of RPS websites and addresses. Two versions of RPS are available: a character-oriented version, where the user submits all the required information via e-mail, or a Web-oriented version.
One aspect of RPS that is not immediately obvious is how to specify the time-constrained observations. For instance, a need for such an observation may arise for a study of a spectrum of a binary system in a particular orbital phase. If some particular aspect of the observation cannot be clearly specified in the RPS form, the user should detail it in the ``comments'' field of the RPS form and/or contact either the Suzaku team at ISAS/JAXA or the NASA Suzaku GOF before submitting.
A successful Suzaku proposal, from a technical point of view, must include the following elements:
. To get the full effective area for a given instrument, the
instrument-specific aimpoint must be chosen (the HXD aimpoint is at
(DETX,DETY)=(-3.5, 0) on the XIS image). The reduction in
effective area for the non-selected instrument is 
%.
Note that the GOs are welcome to propose for targets already approved for the SWG time (see the Announcement of Opportunity). However, in the interest of maximizing the scientific return from Suzaku, the proposal must explain why the already-approved observation does not meet their scientific objectives. Valid reasons include a much longer exposure time; incompatible time constraints; different positions within an extended source.
We note also that the XISs are also subject to count rate limitations,
because of possible multiple events in an XIS pixel within one frame
(see § 6.6). This is much less of a problem than
with the ACIS aboard Chandra, as Chandra's mirror focuses the X-ray
flux into a region of a CCD that is orders of magnitude smaller. The
rule of thumb is that the XIS can tolerate a point source with a count
rate up to 
cts s
per CCD with essentially no loss
of counts or resolution. For brighter sources, these limitations can
be reduced via a variety of XIS modes, such as the use of a sub-array
of the XIS, as discussed in § 6.5.
Finally, it is important to remember that because HXD is a non-imaging
detector, contaminating sources in the field of view can significantly
affect your results. The HXD field of view is defined by a collimator
with a square opening. The FWHM of the field of view is
below 
keV and
above
keV. Considering that twice the FWHM value is required to
completely eliminate the contamination in a collimator-type detector,
and the source may happen to be located at the diagonal of the square,
nearby bright sources within a radius of 
and 
from
the aim point can contaminate the data in the energy band below and
above keV, respectively. If you specify the roll-angle to
avoid the source, the limit will be reduced to 
and
, respectively. It is the proposer's responsibility to
show that any source with a flux level comparable to or brighter than
that of your interest does not exist within these ranges. The
proposer can check this in the minimum level by using the hard X-ray
source catalogs from such satellites as RXTE-ASM, INTEGRAL, and Swift
amongst others.
There are three additional NASA-specific proposal rules that must be followed by US-based proposers: