RXTE GOF |
RXTE Standard Data Products Recipes from the RXTE Cook Book |
RXTE FAQ |
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- Overview: RXTE Archival Observations at a Glance
- A Brief Introduction to RXTE
- The Standard Products
- Filenames and Contents
- The Use of Standard Products
- The Fine Print: Details of StdProd Generation
As the RXTE mission matures, the archive of high quality data on
individual X-ray sources and classes of source is becoming
increasingly valuable to researchers. The extensive and rich RXTE
public data archive now contains over 250,000 individual observations
(ObsIds) and well more than a terabyte of data, and continues to grow.
In an effort to make mining this archive straightforward and rewarding for
seasoned and novice RXTE users alike, the RXTE Guest Observer Facility
(GOF) has begun generating standard data products (StdProds) from the
standard data modes of the PCA and HEXTE, for all archival
observations.
These standard data products allow the user to get a quick, accurate
overview of each archival observation. Light curves, spectra, and
other high-level products created from generic analysis of
standard-mode data reveal the amount of good time, PCA and HEXTE count
rates (source, background, and net), spectral shape, spectral
hardness, and any features in the light curves (flares, eclipses, and
other brightness transitions). The archive contains the product files
themselves for each ObsId -- light curves, spectra, and response
matrices in FITS format -- and also a set of GIF products to
facilitate browsing.
The StdProds are not intended to take the place of careful analysis by
the user; rather, they offer a glimpse of the quality and details of
archival observations. All observations in the RXTE archive contain
StdProds, and they are also included with the fully processed proprietary
obs-id data made available to PIs.
NASA's Rossi X-ray Timing Explorer (RXTE) was launched into low-Earth
orbit on December 30, 1995. On board are three science instruments:
the All Sky Monitor (ASM), which scans the entire viewable sky and
measures the time histories of source intensities in three energy
bands from 1.5--12.0 keV; the Proportional Counter Array (PCA),
composed of five co-aligned Xenon detectors (PCUs) with a total
collecting area of 6500 square cm, most sensitive over the 2-25 keV
energy range; and the High Energy X-ray Timing Experiment (HEXTE), two
clusters of "phoswich" scintillation detectors that rock on and off
source along mutually orthogonal directions for realtime background
measurements, sensitive to high-energy X-rays from 15-250 keV. All
instruments continue to perform well, and exciting results regularly
attract the attention of the scientific community as well as the
popular press.
All RXTE observing time is awarded through the Guest Observer
Program. Proprietary data is available to Guest Observers online with
PGP-encryption. All observations become public and enter the HEASARC
archive after one year. The StdProds described here are designed to
add value and accessibility to the PCA and HEXTE data in this archive.
Overview: RXTE Archival Observations at a Glance
A Brief Introduction to RXTE
PCA | |
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xpObsId_M2B.lc |
16 second source, background, and net light curves in 5 bands: B = {a,b,c,d,e} where a = 2-9 keV b = 2-4 keV c = 4-9 keV d = 9-20 keV e = 20-40 keV |
xpObsId_n1.lc | 0.125 second net light curve, all channels |
xpObsId_M2.pha xpObsId.rsp |
Source and background Standard2 spectra Corresponding response matrix |
HEXTE | |
xhObsId_MCB.lc |
128s source, background, and net light curves in three bands: C = cluster 0(A) or 1(B) B = {a,b,c} where a = 15-30 keV b = 30-60 keV c = 60-250 keV |
xhObsId_MC.pha xh*pwa.rmf xh*pwb013.rmf hexte*.arf |
Archive mode spectra for source and background, both clusters. .RMF file for spectral analysis; Cluster 0 (A) .RMF file for spectral analysis; Cluster 1 (B) .ARF files for spectral analysis of both clusters |
Miscellaneous Products | |
xObsId.gti xObsId.xfl |
Good Time Interval file used in the data extraction RXTE Filter File; attitude and HK parameters versus time |
The GIFS directory contains a set of gif products, many of which correspond directly to entries in the FITS file directory. As these will be the first point of entry into the archive for many users, we will describe these in more detail::
- PCA light curves
- xpObsId_net_lc.gif:
Combined plot of the Std2 net light curves in the five energy bands
2-9, 2-4, 4-9, 9-20, 20-40 keV, from xpObsId_n2[a-e].lc
- xpObsId_src_lc.gif:
Combined plot of the Std2 source light curves in the five
energy bands listed above: xpObsId_s2[a-e].lc
- xpObsId_bkg_lc.gif: Combined plot of the Std2 background light curves in the five energy bands listed above: xpObsId_b2[a-e].lc
- xpObsId_M2B_lc.gif: The individual Std2 source, background, and net light curves
- xpObsId_n1_lc.gif, xpObsId_s1_lc.gif, xpObsId_b1_lc.gif: Std1 net, source, and background light curves
- xpObsId_net_lc.gif:
Combined plot of the Std2 net light curves in the five energy bands
2-9, 2-4, 4-9, 9-20, 20-40 keV, from xpObsId_n2[a-e].lc
- PCA spectra
- xpObsId_both_pha.gif: PCA source and background spectra, overlaid, with statistics showing the adequacy of the background subtraction
- xpObsId_s2_pha.gif, xpObsId_b2_pha.gif, xpObsId_net_pha.gif: Std2 source, background, and net spectra
- HEXTE light curves
- xhObsId_0net_lc.gif: Combined plot of the HEXTE Cluster 0 net lightcurves in the three energy bands 15-30, 30-60, 60-250 keV: xhObsId_n0[a-c].lc
- xhObsId_1net_lc.gif: The same plot, for HEXTE Cluster 1: xhObsId_n1[a-c].lc
- xhObsId_MCB_lc.gif: Individual source, background, and net light curves for each energy band
- HEXTE spectra
- xhObsId_0both_pha.gif: Cluster 0 source and background spectra, overlaid
- xhObsId_1both_pha.gif: Cluster 1 source and background spectra, overlaid
- xhObsId_s0_pha.gif, xhObsId_b0_pha.gif, xhObsId_0net_pha.gif: Cluster 0 source, background, and net spectra
- xhObsId_s1_pha.gif, xhObsId_b1_pha.gif, xhObsId_1net_pha.gif: Cluster 1 source, background, and net spectra
- Miscellaneous
- xhObsId_rock.gif: The HEXTErock tool takes the date and time; RA, dec, and roll; and the Cluster rocking patterns, and produces a file showing the fields of view of the clusters on the sky, with X-ray sources from the ASM catalogue also plotted
- xObsId_xfl.gif: Plot of ELV, offset, NUM_PCU_ON, TIME_SINCE_SAA, electron0 (or electron2) with time, from the Filter File
While the StdProds provide a handy user-friendly way of examining the
contents of the RXTE archive, they should not be considered as
definitive products for generating publishable scientific
results. There may be some cases where useful science can be performed
using the StdProds alone, but generally the purpose of these files and
figures is to enable interested archival investigators to get an
accurate idea of the quality and extent of the data, and of the source
behavior, for observations of interest. Since the StdProds are
generated using a general script and employ one single set of
filtering criteria for all observations, the results will not
typically be optimized to yield only the most useful and reliable data
in each individual case. The filtering criteria may have
excluded too "much" data from the spectra or too "little," newer
background-subtraction models may exist, and so on. As always, when
doing scientific investigations, there is no substitute for performing
the step-by-step analysis carefully for yourself.
To ensure uniformity and consistency within the StdProds, they have
been generated using a standard set of FTOOLS and PCA backgrounds,
with some changes when a clearly better product became available.
After an initial testing phase that generated test products for faint
and bright sources in every epoch, tested filter file production,
tested and refined GTI criteria, and scrutinized PCA and HEXTE background
subtraction and response matrix generation, the generation of StdProds
commenced. Each set of StdProds goes through a rigorous (and rather
time-consuming) process of validation and verification. With the
exception of slews and scanning observations, each archival ObsId
flows through the StdProd script and is processed identically.
The selection criterion used to ensure 'clean' data is:
ELV > 10.0 && OFFSET < 0.02 && PCU[n]_ON == 1
PCA
Data is used from the PCUs that were reliably on throughout the
observation. The algorithm selects the PCU with the maximum amount of
viewing time (in practice, generally PCU2), and then includes data
summed from all PCUs with 95% or greater of this value. The data are
not filtered on ELECTRON0 (or ELECTRON2) as this criterion can exclude
valid data for the cases of brighter sources. HEXTE data
are extracted using the identical GTIs used for PCA data extraction.
In addition, PCU0 is not included in standard product generation
from May 13, 2000 onward, and PCU1 is not included after December 25,
2006 at 12:56:08. These PCUs suffered loss of propane from their top
(veto) layer at those times, and therefore are much noiser after those
dates.
To see which PCUs were actually extracted for a given stdprod observation,
you can look at the ROWIDn keywords in any spectrum or lightcurve file
(eg, xp*_s2.pha).
The PCA Team has provided "bright" and "faint" models for the
background. The "bright" background models are most appropriate for
sources where the source+background measurement exceeds 64 c/s/PCU;
the "faint" models for sources below this count rate. The Std1 data
are used to determine the source brightness level.
The background models used in StdProd processing are:
NOTE: dates below refer to the file creation date, NOT the observation date!
For files made before February 17, 2004:
Epoch 1, bright:
For files made from February 17, 2004 - February 5, 2007:
Epoch 1, bright:
And for files made from February 6, 2007 until present:
Epoch 1, bright:
HEXTE
As stated above, when a HEXTE cluster is not rocking, there is no sampled
background, and therefore no background or net standard products are
generated for that cluster. From December 2005 through June 2006, HEXTE
cluster 0 experienced numerous non-rocking episodes, and from July 2006
onward has been permanently fixed in an on-source, staring position. Thus,
there are no cluster 0 background or net StdProds after July 2006.
Both Instruments
The net light curves include a column containing
barycentrically-corrected time. The light curve plots are generated
using simple (non-corrected) time, for consistency with other HEASARC
archival holdings.
Use of Standard Products
The Fine Print: Details of StdProd Generation
pca_bkgd_skyvle_e1v19990916.mdl
pca_bkgd_allskyactiv_e1v19990917.mdl
Epoch 1, faint:
pca_bkgd_faintl7_e01v03.mdl
pca_bkgd_faint240_e01v03.mdl
Epoch 2, bright:
pca_bkgd_skyvle_e2v19990916.mdl
pca_bkgd_allskyactiv_e2v19990917.mdl
Epoch 2, faint:
pca_bkgd_faintl7_e2v19990824.mdl
pca_bkgd_faint240_e2v19990909.mdl
Epoch 3, bright:
pca_bkgd_skyvle_e3v19990916.mdl
pca_bkgd_allskyactiv_e3v19990917.mdl
Epoch 3, faint:
pca_bkgd_faintl7_e3v19990824.mdl
pca_bkgd_faint240_e3v19990909.mdl
Epoch 4, bright:
pca_bkgd_skyvle_e4v20000131.mdl
pca_bkgd_allskyactiv_e4v20000131.mdl
Epoch 4, faint:
pca_bkgd_faintl7_e4v19991214.mdl
pca_bkgd_faint240_e4v19991214.mdl
Epoch 5, bright:
pca_bkgd_skyvle_e4v20000131.mdl
pca_bkgd_allskyactiv_e4v20000131.mdl
Epoch 5, faint:
pca_bkgd_faintl7_e4v19991214.mdl
pca_bkgd_faint240_e4v19991214.mdl
pca_bkgd_cmbrightvle_eMv20030330.mdl
epoch 1, faint:
pca_bkgd_cmfaintl7_eMv20031123.mdl
epoch 2, bright:
pca_bkgd_cmbrightvle_eMv20030330.mdl
epoch 2, faint:
pca_bkgd_cmfaintl7_eMv20031123.mdl
epoch 3, bright:
pca_bkgd_cmbrightvle_eMv20030330.mdl
epoch 3, faint:
pca_bkgd_cmfaintl7_eMv20031123.mdl
epoch 4, bright:
pca_bkgd_cmbrightvle_eMv20030330.mdl
epoch 4, faint:
pca_bkgd_cmfaintl7_eMv20031123.mdl
epoch 5, bright:
pca_bkgd_cmbrightvle_eMv20030330.mdl
epoch 5, faint:
pca_bkgd_cmfaintl7_eMv20031123.mdl
pca_bkgd_cmbrightvle_eMv20051128.mdl
epoch 1, faint:
pca_bkgd_cmfaintl7_eMv20051128.mdl
epoch 2, bright:
pca_bkgd_cmbrightvle_eMv20051128.mdl
epoch 2, faint:
pca_bkgd_cmfaintl7_eMv20051128.mdl
epoch 3, bright:
pca_bkgd_cmbrightvle_eMv20051128.mdl
epoch 3, faint:
pca_bkgd_cmfaintl7_eMv20051128.mdl
epoch 4, bright:
pca_bkgd_cmbrightvle_eMv20051128.mdl
epoch 4, faint:
pca_bkgd_cmfaintl7_eMv20051128.mdl
epoch 5, bright:
pca_bkgd_cmbrightvle_eMv20051128.mdl
epoch 5, faint:
pca_bkgd_cmfaintl7_eMv20051128.mdl
If you have a question about RXTE, please send email to one of our
help desks.