Last modified: 3 April 2024

Alphabetical List of Ahelp Files

    Topic Context Summary
A acisreadcorr tools::acis Flag and relocate out-of-time CCD events
acis_bkgrnd_lookup tools::background Find the matching ACIS "blank-sky" dataset for an observation
acis_build_badpix tools::acis Create an observation-specific bad-pixel file
acis_check_pha_range tools::acis Compute approximate energy range for on-orbit PHA filter.
acis_clear_status_bits tools::acis Clear (set to 0) ACIS status bits before reprocessing with acis_process_events
acis_detect_afterglow tools::acis Identify and flag cosmic ray afterglows
acis_fef_lookup tools::response Find the FITS Embedded Function file for use by mkrmf
acis_find_afterglow tools::acis Identify cosmic-ray afterglows and hot pixels for TIMED mode observations
acis_process_events tools::acis Produce or update the time, coordinate, pulse-height, grade, and status information in ACIS event files
acis_set_ardlib tools::response Sets the bad pixel parameters of the ardlib file to the given file
acis_streak_map tools::acis Generate high frequency background maps (streakmaps) which identify ACIS streaks caused when bright source photons are applied to the wrong pixel during readout.
aconvolve tools::image Convolve an N-dimensional image with a kernel
acrosscorr tools::image Cross-correlate two N-dimensional images or autocorrelate an image
addresp tools::response Add multiple RMFs, weighted by ARFs and exposures; add mutiple ARFs, weighted by exposures.
add_colvals contrib Add a column to a crate given a name and array of values
add_col crates Add a column to a crate.
add_crate crates Add a crate to a dataset.
add_key crates Add a keyword to a crate given a CrateKey object.
add_piximg crates Add an image to a crate.
ahelp ahelp Access the CIAO help documentation.
aplimits tools::statistics Compute upper limits for the detection of a source, using data obtained from background apertures in event lists, images, and exposure maps.
apowerspectrum tools::image Compute the power spectrum of an N-dimensional input array, or from two columns (independent/dependent variable) in an input file
apply_fov_limits tools::utilities Create an image that matches the FOV file for the observation
apply_transform transform Apply a transform to the given data.
aprates tools::statistics Compute net counts, rate, and/or flux, plus credible intervals, for a point source, using data obtained from source and background apertures in event lists, images, and exposure maps.
ardlib calibration Analysis Reference Data Library
arestore tools::image Restore image resolution using deconvolution techniques
arfcorr tools::response Calculate a point source aperture correction, either as a single-energy image or as an energy-dependent correction to the ARF file.
asphist tools::aspect Bin the aspect solution into a 3D histogram of duration vs pointing offset and roll offset.
asp_offaxis_corr tools::aspect Applies off-axis boresight correction to an L1 Aspect solution file (ASPSOL).
autoname concept Autonaming is a feature available in various tools for automatically naming an output file based upon the name of an input file.
axbary tools::timing Apply barycentric corrections to event times, GTIs, and header values.

B bkg_fixed_counts tools::region Create a background region with a fixed number of counts
blanksky_image tools::background Create scaled background and background-subtracted images given an observation-specific blanksky background file and a reference image.
blanksky_sample tools::background Create a scaled background events file by using the scale factor calculated by and sampling the blanksky background file generated by the "blanksky" script for an observation.
blanksky tools::background Tailor an unscaled blanksky background file to be compatible with a given events file; combining and reprojecting the necessary background files from the CalDB.

C caldb calibration CALibration DataBase (CALDB)
calindex tools::caldb Create an index file or append data on an existing one of calibration database (CALDB) products.
calmerge tools::caldb Merge index files of calibration database (CALDB) products.
calquiz tools::caldb Find calibration files in the CALDB
calvalid tools::caldb Validate index file of calibration database (CALDB) products.
cda_data contrib Download public data by ObsId from the Chandra archive (Python interface).
cda_search contrib Find publicly-available Chandra ObsIds from the Chandra archive (Python interface).
celldetect tools::detect Use a "sliding cell" to search for sources
centroid_map tools::image Adaptively bin an image using centroid map algorithm
chandra_repro tools::composite Reprocess a Chandra dataset
check_caldb_version contrib Check whether the locally-installed version of the Chandra Calibration DataBase (CALDB) is up to date
check_ciao_caldb tools::utilities A tool to test the installation of the CIAO Calibration Database (CALDB)
check_ciao_version tools::utilities Check that the CIAO and CALDB installations are up to date.
ciao-install concept Download and install CIAO, CALDB, and the contributed script files
ciaorc concept (OBSOLETE) The .ciaorc file provides user-configuration options for CIAO
ciao_caldb contrib Utility routines for the CIAO CALDB (CIAO contributed package).
ciao_contrib contrib Useful Python routines for CIAO.
ciao_proptools contrib Experimental interface to the Chandra proposal tools (CIAO contributed package).
ciao_runtool contrib Run CIAO tools from Python as if they were functions (CIAO contributed package).
ciao_smooth contrib Simple smoothing routines for 2D data
ciao_stacklib contrib Support routines for using stacks in CIAO (CIAO contributed package).
ciao_utils contrib Utility routines for CIAO (CIAO contributed package).
ciao concept Chandra Interactive Analysis of Observations
colden proposaltools COLDEN is an interactive program to evaluate the neutral hydrogen column density at a given direction on the sky
color_color tools::response Creates a Color-Color diagram
col_exists crates Determine if a column exists in a crate.
combine_grating_spectra tools::composite Combine Chandra gratings PHA files and their associated response files.
combine_spectra tools::composite Combine PHA files and their associated response files.
convert_ds9_region_to_ciao_stack tools::region Convert ds9 region file containing special shapes to CIAO stack.
convert_xspec_script tools::utilities Convert a XSPEC save file to Sherpa commands *experimental*
convert_xspec_user_model tools::utilities Compile a XSPEC user model for use in Sherpa *experimental*
coords_chandra contrib Utility routines for working with Chandra Coordinates
coords_format contrib Convert between string and numeric formats for Astronomical positions.
coords_gratings contrib Object to convert to/from Chandra grating coordinates.
coords_utils contrib Utility routines for working with Astronomical positions.
coords chandra Coordinate systems used in Chandra analysis
copy_colvals crates Copy the column values from a crate.
copy_piximgvals crates Copy the image values from a crate.
copy_transform transform Copy the transform.
correct_periscope_drift tools::aspect Correct a Chandra aspect solution for temporal drift calculated from a fit of the drift in the sky positions of the events in a supplied circle region.
cratedataset crates The CrateDataset object is used to read and write files with multiple blocks.
cratedata crates The CrateData object is used to store column or image data.
cratekey crates The CrateKey object is used to represent a header item (keyword and value) for a file.
crates_contrib contrib Contributed CIAO routines for Crates.
crates_images contrib Image-related routines for Crates (CIAO contributed package).
crates_utils contrib Utility routines for Crates (CIAO contributed package).
crates crates Reading, writing, and changing ASCII and FITS files in Python
crate crates The TABLECrate and IMAGECrate objects represent a block in a file.
create_bkg_map tools::background Create a background map for ACIS and HRC from the event files.
create_vector_column crates Create a vector column.
create_virtual_column crates Create a virtual column.
csmooth tools::image Adaptively smooth a 2-D image

D dates proposaltools DATES is an interactive calendar and time conversion tool.
dax tools::composite Run CIAO tasks from the ds9 Analysis menu
deflare tools::timing deflare - remove flares from light curves using lc_clean or lc_sigma_clip
delete_col crates Delete a column from a crate.
delete_key crates Delete a keyword from a crate.
delete_piximg crates Delete an image from a crate.
destreak tools::acis Remove streak events from ACIS data
detilt tools::gratings Correct the time-dependent tilt of LETG/HRC-S spectra by adjusting TG_D.
dewiggle tools::gratings Straighten LETG/HRC-S spectra by applying tg_d adjustments.
dither_region tools::aspect Compute fraction of region area that covers chips
dmappend tools::core Append multiple blocks/extensions to an existing output file.
dmarfadd tools::response Add multiple grating ARF files together, weighting by exposure.
dmascii dm Using the Data Model with text files
dmbinning dm The CIAO binning syntax
dmcontour tools::region Make contour regions from a 2-D image
dmcoords tools::coordinates Convert between Chandra coordinate systems
dmcopy tools::core Filter and bin tables and images.
dmdiff tools::core Compare values in two files.
dmellipse tools::region Finds ellipse for specified fraction
dmextract tools::core Make a histogram table file (e.g. PHA file, lightcurve file) from a table column. Generate count histogram on supplied regions for a spatial table or image file.
dmfiltering dm Filtering tables and images with the Data Model
dmfilth tools::image Replace pixel values in source regions of an image with values interpolated from surrounding background regions
dmgroupreg tools::region Translates DS9 regions and groups to CIAO format.
dmgroup tools::table Group a specified column in a table with various options
dmgti tools::timing Create a Good Time Interval from limits placed on time-based files (event and Mission Time Line files).
dmhedit tools::header Edit datamodel file headers
dmhistory tools::header Extracts the tool history from the file header
dmimg2jpg tools::image Make a color JPEG image (or EPS) from three image files
dmimgadapt tools::image Adaptively smoothes an image based on number of counts
dmimgblob tools::image Identifies groups of pixels above/below threshold
dmimgcalc tools::image Perform arithmetic on images
dmimgdist tools::image Computes the distance transform of image
dmimgfilt tools::image Performs various non-linear image filtering techniques.
dmimghist tools::image Create a histogram of the pixel values in a 2-D image
dmimghull tools::region Create convex polygon around pixels in an image
dmimglasso tools::region Draw region around point with similar values
dmimgpick tools::image Maps image values to rows in a table
dmimgpm tools::image Compute a low frequency spatial (modified poisson mean) background map
dmimgproject tools::image Project image along axis
dmimgreproject tools::image Replicates table value along axis of image
dmimgthresh tools::image Set low (or high) intensity or exposure regions of an image to a constant value.
dmjoin tools::table Join two files whose sampling is different.
dmkeypar tools::header Retrieve information about a keyword from an input file
dmlist tools::core List contents or structure of a file.
dmmakepar tools::header Write header keywords to a parameter file
dmmakereg tools::region Convert the format of a region file (swap between ASCII and CXC FITS)
dmmaskbin tools::image Bins an image based on input mask
dmmaskfill tools::image Replaces mask values with those found in lookup table
dmmasks dm CIAO mask filtering syntax
dmmath concept Syntax used for writing mathematical operations in dmtcalc, dmimgcalc, and dmgti
dmmerge tools::table Merge two or more compatible tables (e.g. event files) into one.
dmnautilus tools::image Perform a quad-tree adaptive binning on 2D images
dmopt dm Controlling Data Model internal options
dmpaste tools::table Add new columns to a table.
dmradar tools::image Perform polar quad-tree adaptive binning on 2D images
dmreadpar tools::header Create header keywords from a parameter file
dmregions dm CIAO region filtering syntax
dmregrid2 tools::image shift, rotate, scale images
dmregrid tools::image Rebin a stack of 2-dimensional images.
dmsort tools::table Sort a table.
dmstat tools::statistics Compute statistics for images and columns in tables.
dmtabfilt tools::table Apply non-linear filters to columns in table
dmtcalc tools::table Modify and create columns in a table
dmtype2split tools::table Split up an array column into multiple files (e.g. PHA type 2 to PHA type 1).
dm dm CIAO Data Model: syntax for filtering and binning files
download_chandra_obsid tools::download Download public data by ObsId from the Chandra archive.
download_obsid_caldb tools::download Download the CALDB files required to analyze an OBS_ID

E ecf_calc tools::response Obtain the encircled counts fraction of an object as a function of radius.
eff2evt tools::response Compute the flux and look up the QE & effective area for event positions
energy_hue_map tools::image Creates a true color image using median-energy map and counts image.
evalpos tools::image Get image values at a specified (RA,DEC)
eventdef chandra Column definition in Chandra event files

F find_chandra_obsid tools::download Find, and optionally download, publicly-available Chandra ObsIds from the Chandra archive.
find_mono_energy tools::response Compute monochromatic for energy band given input spectrum and responses.
fluximage tools::composite Create exposure-corrected images and exposure maps for an observation.
flux_obs tools::composite Combine reprojected observations to create an exposure-corrected image.
FOVFiles contrib Check which FOV files contains the specified RA,Dec location.
fullgarf tools::response Create a grating ARF for a particular order and grating for a given observation.

G get_axis_transform crates Return the axis transform from an IMAGECrate.
get_caldb contrib Access various information about the Chandra Calibration DataBase (CALDB)
get_colvals crates Get the column values from a crate.
get_col_names crates Return an array of the column names in a crate.
get_col crates Return a CrateData object of a column from a crate.
get_crate_item_type crates Return the type of the crate item as a string.
get_crate_type crates Return the type of the crate as a string.
get_crate crates Get a crate from a dataset.
get_dither_parameters tools::aspect Determine the approximate dither period and amplitude used during an observation.
get_fov_limits tools::utilities Find the region (bounding box) covered by a FOV file in sky coordinates
get_keyval crates Return the value of a keyword in a crate.
get_key_names crates Return an array of the keywords in a crate.
get_key crates Return a CrateKey object of a keyword from a crate.
get_number_cols crates Return the number of columns in a crate.
get_number_rows crates Return the number of rows in a crate.
get_piximgvals crates Get the pixel values from an image crate.
get_piximg_shape crates Get the dimensions of the image stored in the IMAGECrate.
get_piximg crates Return a CrateData object of an image from a crate.
get_sky_limits tools::utilities Find the region covered by an image in sky coordinates
get_src_region tools::detect Outputs regions that have counts higher than background
get_transform_matrix crates Extract the transform matrix from a crate.
get_transform_type transform Return the flavor of the input Transform object.
get_transform crates Extract the coordinate transform from a crate.
glvary tools::timing Search for variability using Gregory-Loredo algorithm.
group group Provides the Python interface to the CXC grouping library
grpAdaptiveSnr group Adaptively group an array by signal to noise.
grpAdaptive group Group an array by the number of counts per group using an adaptive scheme.
grpBinFile group Group an array using the grouping applied to another dataset.
grpBinWidth group Group an array into a set of equal-width groups (by group width).
grpBin group Group an array using low and high boundaries.
grpGetChansPerGroup group Calculate the number of channels (elements) in each group.
grpGetGroupSum group Apply the supplied grouping to an array.
grpGetGrpNum group Calculate the group number for each element in the array.
grpMaxSlope group Group an array so that its absolute gradient is above a user-defined limit.
grpMinSlope group Group an array so that its absolute gradient is below a user-defined limit.
grpNumBins group Group an array into a set of equal-width groups (by number of groups).
grpNumCounts group Group an array by the number of counts per group.
grpSnr group Group an array by signal to noise.
gti_align tools::timing Align GTI to ACIS exposure times

H hexgrid tools::image Create a regular hexagonal grid and apply to input image
history concept A record of the tools that were run, along with the parameter settings, on a file.
hrc_bkgrnd_lookup tools::background Find the matching HRC "blank-sky" dataset (event file or spectrum) for an observation
hrc_build_badpix tools::hrc Create observation-specific bad pixel file for HRC
hrc_dtfstats tools::hrc Calculate statistics from hrc_calc_dead_time and a GTI
hrc_process_events tools::hrc Correct HRC event positions, times, PHA, etc.

I identify_name contrib Find the position of an astronomical object using NED or CDS.
imextent contrib Create a linear 2D transformation for the axes of an image
imgmoment tools::statistics Computes image moments (sum, mean, size, angle, etc).
install_marx tools::download Automatically download and install MARX
is_pha crates Determine if the crate dataset contains a PHA file and its type.
is_rmf crates Determine if the crate dataset contains an RMF.
is_virtual crates Determine if the input column from the crate is a virtual column.

K key_exists crates Determine if the keyword exists in the crate.

L lc_clean contrib lc_clean - remove periods of high (or low) count rates using the same technique as the ACIS background files
lc_sigma_clip contrib lc_sigma_clip - remove flares from a light curve using an iterative sigma-clipping algorithm
level chandra Describes the amount of processing performed to create a given product.
lightcurves contrib lightcurves - routines to remove periods of anomalously high (or low) count rates in a lightcurve
lim_sens tools::statistics Create an output limiting sensitivity map with the same blocking factor, dimensions and WCS

M make_image_crate contrib Create an IMAGECrate from an array.
make_instmap_weights tools::response make_instmap_weights - produces a weighted spectrum file usable with mkinstmap in order to create a weighted exposure map.
make_psf_asymmetry_region tools::response Create a region that shows the location of the HRMA PSF asymmetry for a source
make_table_crate contrib Create a TABLECrate from a set of arrays, a dictionary, or a structured array.
map2reg tools::image Convert a map file into a region file.
mean_energy_map tools::response Creates an image whose pixels are the mean energy of the events
merge_obs tools::composite Reproject and combine multiple observations to create a merged event file and exposure-corrected images.
merge_too_small tools::image Adjust input map file to meet some minimum criteria
merging_rules concept A description of the merging rules used when combining header information.
mkacisrmf tools::response Generate an RMF for Chandra imaging data
mkarf tools::response Generate an ARF for Chandra imaging data (and grating 0th order)
mkexpmap tools::response Generate a Chandra imaging exposure map (effective area vs. sky position)
mkgarf tools::response Generate a Chandra Grating ARF for one detector element.
mkgrmf tools::response Generate an RMF for Chandra grating data
mkinstmap tools::response Generate a Chandra instrument map (effective area vs. detector position)
mkpsfmap tools::response Look up the radius of the PSF for each pixel in an image
mkregmap tools::image Create map from stack of input regions.
mkrmf tools::response Generate an RMF for Chandra imaging data
mktgresp tools::response Create ARF and RMF files for each spectral order and grating arm in a TypeII PHA file
mkwarf tools::response Generate a weighted ARF.
modelflux tools::response Calculate model flux or count rate
monitor_photom tools::aspect Generate a photometric lightcurve from ACA monitor data.
mtl_build_gti tools::timing Create Good Time Interval from Mission Time Line and limits
mtl chandra A description of the Mission Time Line (MTL)
multi_chip_gti tools::acis Create a combined GTI file for multiple ACIS chips

O obsid_search_csc tools::download Search the Chandra Source Catalog by OBS_ID
obsvis proposaltools ObsVis is the Observation Visualizer created at the Chandra Science Center in Cambridge Massachusetts, USA.

P paccess paramio Returns the path to the specified parameter file.
paccess tools::parameter Gives the location of a tool's parameter file
paramclose paramio Close a parameter file opened by paramopen.
parameter concept Describes the parameter interface used by CIAO.
paramio paramio The Python interface to the CXC parameter system
paramopen paramio Open a parameter file.
pathfinder tools::image Group pixels by steepest gradient ascent to local maximum
pdump tools::parameter Dumps the values of the parameters, with one parameter per line.
pfold tools::timing Folds events into multiple periods
pgets paramio Read/write individual parameter values.
pget paramio Get a parameter value as a string.
pget tools::parameter Get parameter values
pileup_map tools::response Compute image that gives indication of pileup.
pileup chandra An overview of pileup in the Chandra ACIS detector.
pimms proposaltools PIMMS (Portable, Interactive Multi-Mission Simulator) converts source fluxes and count rates between missions.
pline tools::parameter Display the parameter values, with all parameters on a single line
plist paramio Get list of parameter names.
plist tools::parameter List the contents of a parameter file.
pquery paramio Query a parameter value.
pquery tools::parameter Query whether a parameter exists and, if so, get and return its value.
precess proposaltools PRECESS is an interactive astronomical coordinate conversion program. It provides precession of equatorial coordinates and conversion between equatorial, ecliptic, galactic, and supergalactic coordinates.
print_crate_names crates Display information on data from a crate.
prop-coords proposaltools Defines available coordinate systems for Chandra Proposal Tools
prop-time proposaltools Defines available calendars and timescales for command line versions of Chandra Proposal Tools
prop-tools proposaltools Tools that aid in the preparation and submission of Chandra proposals
pset paramio Set a parameter value.
pset tools::parameter Set parameter values on the command line
psfsize_srcs tools::region Compute the size of a circle enclosing a specified fraction of PSF.
psf_contour tools::region Create a source region file from a simulated PSF
psf_project_ray tools::response Project rays generated by ChaRT onto a semi-infinite detector plane.
psf psf A Python module to calculate the size or enclosed-counts fraction of the Chandra PSF
punlearn paramio Restore the system defaults for a parameter file.
punlearn tools::parameter Restore system default parameter values
python scripting Python is a dynamic object-oriented programming language used by CIAO

R r4_header_update tools::utilities Update file header with various keywords to match latest archive processing
rank_roi tools::region Assign overlapping region area to highest ranking source.
readout_bkg tools::background Approximate the Out Of Time source contribution to the background.
read_dataset crates Read all contents of a file.
read_ds9_contours contrib Read in the contours from a ds9 *.con file with optional coordinate conversion.
read_file crates Read FITS or ASCII data into a crate.
read_pha crates Load a PHA file into a PHACrateDataset.
read_rmf crates Load an RMF file into a RMFCrateDataset.
regArea region *DEPRECATED* Calculate the area enclosed by a region.
regExtent region *DEPRECTATED* Calculate the bounding box of a region.
regInsideRegion region *DEPRECATED* Is a point (or set of points) inside a region?
region-old region *DEPRECATED* Provides the Python interface to the CXC region library
region region Provides a Python interface to the CXC region library
regParse region *DEPRECATED* Parse a region for use by the routines in the region library
regphystocel tools::region Convert regions in physical coordinates to ds9 format regions in celestial (fk5) coordinates.
regPrintRegion region *DEPRECATED* Print out diagnostic details about a region.
regRegionString region *DEPRECATED* Converts a region object into a string.
reproject_aspect tools::coordinates Modify aspect solution file RA, Dec, and roll or updfile WCS to minimize position differences between two source lists.
reproject_events tools::coordinates Regrid an event file to a different tangent point
reproject_image_grid tools::coordinates Projects image(s) from one WCS to another
reproject_image tools::coordinates Projects image from one WCS to another
reproject_obs tools::composite Reproject a set of observations to a common tangent point and create a merged event file.
rmfimg tools::response Create a simple image of an RMF or ARF file
roi tools::region Generates source and background regions from source list

S scale_image_crate contrib Scale the pixel values in an IMAGE crate.
search_csc tools::download Perform a position search on the Chandra Source Catalog
set_colvals crates Set the values of a column in a crate.
set_keyval crates Set the keyword value in a crate.
set_key crates Add a keyword to a crate given a name and a value.
set_piximgvals crates Set the pixel values in an image crate.
simplecoordtransform contrib Convert between the different coordinate systems of an image.
simple_hist contrib Create a one-dimensional histogram of a data array
simple_stats contrib Calculate several basic statistic values for a data array
simulate_psf tools::response Simulate the Chandra PSF
sky2tdet tools::coordinates Project an image in SKY coordinates to TDET coordinates
skyfov tools::region Make a field-of-view region in sky coordinates
smooth_image_crate contrib Smooth the pixel values in an IMAGE crate.
specextract tools::composite Create source and optional background spectra for Chandra imaging-mode and zeroth-order grating data.
splitobs tools::utilities `splitobs' separates the data products for Multi-Obi and ACIS interleaved observations
splitroi tools::region Convert the output of roi into a format usable by dmfilth
srcextent tools::composite Determine if a source is extended within a confidence interval.
srcflux tools::composite Calculate the net count rates and fluxes, including uncertainties, of sources in a Chandra observation.
src_psffrac tools::response Compute approximate PSF fraction in circular source region
sso_freeze tools::coordinates Reproject sky x and y coordinates into a Solar System Object centered reference frame.
stack concept How to set a parameter to more than one value using a stack.
statmap tools::statistics Compute simple statistics for events in each map region.
stk_build tools::stacks stk_build is used to build a stack from a user-defined string. The output is to stdout, stderr, or a file.
stk_count tools::stacks stk_count is used to count the number of items in a stack. The output is to the stk_count parameter file.
stk_read_num tools::stacks stk_read_num is used to read one element of a user-defined stack. The output is to the outelement field of the stk_read_num parameter file.
stk_where tools::stacks stk_where finds the location of an item in a stack
subspace concept Describes the filtering applied to a file
summarize_status_bits tools::utilities Summarize the status bits in a Chandra event file.
symmetrize tools::gratings Adjust the tg_d values of LETG/HRC-S evt2 data to make cross-dispersion profiles more symmetric

T tgdetect2 tools::gratings Bundles three programs: tg_findzo, tg_choose_method, and tgdetect into one in order to provide a more convenient interface for determination of the zeroth order centroid.
tgdetect tools::gratings Detect and centroid the zero order image in a spatial sub-region of a grating event list.
tgextract2 tools::gratings Bin event list grating wavelengths column into a one-dimensional counts histogram, by source, grating part, and diffraction order. Optionally bin background spectrum.
tgextract tools::gratings Bin event list grating wavelengths column into a one-dimensional counts histogram, by source, grating part, and diffraction order.
tgidselectsrc tools::gratings Filter an input source list based upon a SNR threshold.
tgmask2reg tools::gratings Customize grating extaction region file for use with tgextract2
tgmatchsrc tools::gratings Match sources between two source lists by their 2-D separation files.
tgsplit tools::gratings Split a TYPE:II grating PHA file into several TYPE:I files
tg_bkg tools::gratings Creates a PHA background file for use in XSPEC
tg_choose_method tools::gratings Automatically choose between tgdetect and tg_findzo for determining the zeroth order centroid
tg_create_mask tools::gratings Create a region file to define spectrum sky boundaries
tg_findzo tools::gratings Find the zeroth order sky X,Y centroid for bright sources observed using HETG or LETG gratings with the ACIS-S detector.
tg_resolve_events tools::gratings Assign grating events to spectral orders; use detector energy resolution for order separation, if available.
times chandra "Times" used in Chandra datasets and Chandra data analysis
transform transform TRANSFORMS - Coordinate transforms in Python

V vtbin tools::image Create adaptive bin image using Voronoi Tessellation
vtpdetect tools::detect Voronoi Tessellation and Percolation (VTP) source detection

W wavdetect tools::detect Mexican-Hat Wavelet source detection (wtransform+wrecon)
wcs_match tools::coordinates Create a frame transformation to minimize the aspect difference between data from the same sky region.
wcs_update tools::coordinates Modify aspect solution file RA and Dec or infile WCS based on a transformation matrix.
wrecon tools::detect Combine wavelet transform coefficients into sources
write_arrays contrib Write arrays to an ASCII file
write_columns contrib Write out arrays (columns) to a file as a table (ASCII or FITS format).
write_dataset crates Write a dataset to an output file.
write_file crates Write a crate to an output file.
write_pha crates Write a PHACrateDataset to a file.
write_rmf crates Write an RMFCrateDataset to a file.
wtransform tools::detect Obtain wavelet transform coefficients for poisson image data