---

Each identified distinct X-ray source on the sky is represented in the catalog by one or more "source observation" entries—one for each observation contributing to the stack in which the source has been detected—and a single "master source" entry. The entries per observations record all of the properties about a detection extracted from a single observation, as well as associated file-based data products, which are observation-specific.

Note: Source properties in the catalog which have a value for each science energy band (type "double[6]", "long[6]", and "integer[6]" in the table below) have the corresponding letters appended to their names. For example, "flux_aper_b" and "flux_aper_h" represent the background-subtracted, aperture-corrected broad-band and hard-band energy fluxes, respectively.

Switch to: Columns listed alphabetically

---

Context	Column Name	Type	Units	Description
Observation Identification	obsid	integer		observation identifier (ObsID)
	obi	integer		Observation Interval number (ObI)
Pointing Information	targname	string		target name for the observation
	ra_targ	double	deg	target position specified by observer, ICRS right ascension
	dec_targ	double	deg	target position specified by observer, ICRS declination
	ra_pnt	double	deg	mean spacecraft pointing during the observation, ICRS right ascension
	dec_pnt	double	deg	mean spacecraft pointing during the observation, ICRS declination
	roll_pnt	double	deg	mean spacecraft roll angle during the observation
	chipx_pnt	double	pixel	detector (chip coordinates) Cartesian x position corresponding to (ra_pnt, dec_pnt)
	chipy_pnt	double	pixel	detector (chip coordinates) Cartesian y position corresponding to (ra_pnt, dec_pnt)
	chip_id_pnt	integer		detector (chip coordinates) identifier used to define (chipx_pnt, chipy_pnt)
	ra_nom	double	deg	observation tangent plane reference position, ICRS right ascension
	dec_nom	double	deg	observation tangent plane reference position, ICRS declination
	roll_nom	double	deg	observation tangent plane roll angle (used to determine tangent plane North)
Timing Information	gti_start	double	s	start time for the valid observation data in mission elapsed time (MET: seconds since 1998 Jan 01 00:00:00 TT)
	gti_stop	double	s	stop time for the valid observation data in mission elapsed time (MET: seconds since 1998 Jan 01 00:00:00 TT)
	gti_elapse	double	s	total elapsed time of the observation (gti_stop - gti_start)
	gti_obs	string	(TT)	start time of valid observation data (TT), ISO 8601 format (yyyy-mm-ddThh:mm:ss)
	gti_end	string	(TT)	stop time of valid observation data (TT), ISO 8601 format (yyyy-mm-ddThh:mm:ss)
	gti_mjd_obs	double	MJD (TT)	modified Julian date for the start time of the valid observation data (TT)
	mjd_ref	double	MJD (TT)	modified Julian date reference corresponding to zero seconds mission elapsed time
Observing Cycle	ao	integer		Chandra observing cycle in which the observation was scheduled
Instrument Configuration	instrument	string		instrument used for the observation: 'ACIS' or 'HRC'
	grating	string		transmission grating used for the observation: 'NONE', 'HETG', or 'LETG'
	datamode	string		instrument data mode used for the observation
	readmode	string		ACIS readout mode used for the observation: 'TIMED' or 'CONTINUOUS'
	cycle	string		ACIS readout cycle for alternating exposure (interleaved) mode observations: P (primary) or S (secondary). Value is P for all other ACIS modes.
	exptime	double		ACIS CCD frame time
	timing_mode	boolean		HRC precision timing mode
Aspect Information	sim_x	double	mm	SIM focus stage position during observation
	sim_z	double	mm	SIM translation stage position during observation
	dy	double	mm	mean aspect dy offset during observation
	dz	double	mm	mean aspect dz offset during observation
	dtheta	double	deg	mean aspect dtheta during observation
	deltax	double	arcsec	SKY coordinate system X translation correction required to co-align observation astrometric frame within observation stack
	deltay	double	arcsec	SKY coordinate system Y translation correction required to co-align observation astrometric frame within observation stack
	deltarot	double	deg	SKY coordinate system roll angle correction required to co-align observation astrometric frame within observation stack
	dscale	double	deg	SKY coordinate system scale factor correction required to co-align observation astrometric frame within observation stack
	man_astrom_flag	boolean		SKY coordinate system scale factor correction required to co-align observation astrometric frame within observation stack
Processing Information	ascdsver	string		software version used to create the Level 3 observation event data file
	caldbver	string		calibration database version used to calibrate the Level 3 observation event data file
	crdate	string		creation date and time of the Level 3 event file, UTC
Source Identification	region_id	integer		detection region identifier (component number)
Position and Position Errors	theta	double	arcmin	PSF 90% ECF aperture off-axis angle, θ
	phi	double	deg	PSF 90% ECF aperture azimuthal angle, φ
	chipx	double	pixel	detector (chip coordinates) Cartesian x position corresponding to (theta, phi) (θ, φ)
	chipy	double	pixel	detector (chip coordinates) Cartesian y position corresponding to (θ, φ)
	chip_id	integer		detector (chip coordinates) identifier used to define (chipx, chipy)
Source Significance	flux_significance	double[6]		significance of the single-observation detection determined from the ratio of the single-observation detection photon flux to the estimated error in the photon flux, for each $srcband;
	likelihood	double[6]		significance of the single-observation detection computed by the single-observation detection algorithm for each source detection energy band
Source Flags	conf_code	integer		compact detection may be confused (bit encoded: 1: background region overlaps another background region; 2: background region overlaps another source region; 4: source region overlaps another background region; 8: source region overlaps another source region; 256: compact detection is overlaid on an extended detection)
	dither_warning_flag	boolean		highest statistically significant peak in the power spectrum of the detection source region count rate occurs at the dither frequency or at a beat frequency of the dither frequency of the observation
	edge_code	coded byte		detection position, or source or background region dithered off a detector boundary (chip pixel mask) during the observation (bit encoded: 1: background region dithers off detector boundary; 2:source region dithers off detector boundary; 4: detection position dithers off detector boundary)
	extent_code	integer[6]		detection is extended, or deconvolved compact detection extent is inconsistent with a point source at the 90% confidence level in one or more energy bands (bit encoded: 1, 2, 4, 8, 16, 32: deconvolved compact detection extent is not consistent with a point source in each science energy band
	multi_chip_code	byte		source position, or source or background region dithered multiple detector chips during the observation (bit encoded: 1: background region dithers across 2 chips; 2: background region dithers across >2 chips; 4: source region dithers across 2 chips; 8: source region dithers across >2 chips; 16: detection position dithers across 2 chips; 32: detection position dithers across >2 chips)
	pileup_warning	double	counts/frame/pixel	ACIS pile-up fraction estimated from the coiunt rate of the brightest 3x3 pixel island
	sat_src_flag	boolean		detection is saturated; detection properties are unreliable
	streak_src_flag	boolean		detection is located on an ACIS readout streak; detection properties may be affected
	var_code	byte		detection displays flux variability in one or more energy bands (bit encoded: 1,2,4,8,16,32: intra-observation variability detected in each science energy band
Source Extent and Errors	mjr_axis_raw	double[6]	arcsec	1σ radius along the major axis of the ellipse defining the observed detection extent of a source for each science energy band
	mjr_axis_raw_lolim	double[6]	arcsec	1σ radius along the major axis of the ellipse defining the observed detection extent (68% lower confidence limit) for each science energy band
	mjr_axis_raw_hilim	double[6]	arcsec	1σ radius along the major axis of the ellipse defining the observed detection extent (68% upper confidence limit) for each science energy band
	mnr_axis_raw	double[6]	arcsec	1σ radius along the minor axis of the ellipse defining the observed detection extent for each science energy band
	mnr_axis_raw_lolim	double[6]	arcsec	1σ radius along the minor axis of the ellipse defining the observed detection extent (68% lower confidence limit) for each science energy band
	mnr_axis_raw_hilim	double[6]	arcsec	1σ radius along the minor axis of the ellipse defining the observed detection extent (68% upper confidence limit) for each science energy band
	pos_angle_raw	double[6]	deg	position angle of the major axis of the ellipse defining the observed detection extent for each science energy band
	pos_angle_raw_lolim	double[6]	deg	position angle of the major axis of the ellipse defining the observed detection extent (68% lower confidence limit) for each science energy band
	pos_angle_raw_hilim	double[6]	deg	position angle of the major axis of the ellipse defining the observed detection extent (68% upper confidence limit) for each science energy band
	psf_mjr_axis_raw	double[6]	arcsec	1σ radius along the major axis of the ellipse defining the local PSF extent for each science energy band
	psf_mjr_axis_raw_lolim	double[6]	arcsec	1σ radius along the major axis of the ellipse defining the local PSF extent (68% lower confidence limit) for each science energy band
	psf_mjr_axis_raw_hilim	double[6]	arcsec	1σ radius along the major axis of the ellipse defining the local PSF extent (68% upper confidence limit) for each science energy band
	psf_mnr_axis_raw	double[6]	arcsec	1σ radius along the minor axis of the ellipse defining the local PSF extent for each science energy band
	psf_mnr_axis_raw_lolim	double[6]	arcsec	1σ radius along the minor axis of the ellipse defining the local PSF extent (68% lower confidence limit) for each science energy band
	psf_mnr_axis_raw_hilim	double[6]	arcsec	1σ radius along the minor axis of the ellipse defining the local PSF extent (68% upper confidence limit) for each science energy band
	psf_pos_angle_raw	double[6]	deg	position angle of the major axis of the ellipse defining the local PSF extent for each science energy band
	psf_pos_angle_raw_lolim	double[6]	deg	position angle of the major axis of the ellipse defining the local PSF extent (68% lower confidence limit) for each science energy band
	psf_pos_angle_raw_hilim	double[6]	deg	position angle of the major axis of the ellipse defining the local PSF extent (68% upper confidence limit) for each science energy band
	major_axis	double[6]	arcsec	1σ radius along the major axis of the ellipse defining the deconvolved detection extent for each science energy band
	major_axis_lolim	double[6]	arcsec	1σ radius along the major axis of the ellipse defining the deconvolved detection extent (68% lower confidence limit) for each science energy band
	major_axis_hilim	double[6]	arcsec	1σ radius along the major axis of the ellipse defining the deconvolved detection extent (68% upper confidence limit) for each science energy band
	minor_axis	double[6]	arcsec	1σ radius along the minor axis of the ellipse defining the deconvolved detection extent for each science energy band
	minor_axis_lolim	double[6]	arcsec	1σ radius along the minor axis of the ellipse defining the deconvolved detection extent (68% lower confidence limit) for each science energy band
	minor_axis_hilim[6]	double	arcsec	1σ radius along the minor axis of the ellipse defining the deconvolved detection extent (68% upper confidence limit) for each science energy band
	pos_angle	double[6]	deg	position angle (referenced from local true north) of the major axis of the ellipse defining the deconvolved detection extent for each science energy band
	pos_angle_lolim	double[6]	deg	position angle (referenced from local true north) of the major axis of the ellipse defining the deconvolved detection extent (68% lower confidence limit) for each science energy band
	pos_angle_hilim	double[6]	deg	position angle (referenced from local true north) of the major axis of the ellipse defining the deconvolved detection extent (68% upper confidence limit) for each science energy band
	src_area	double[6]	sq. arcseconds	area of the deconvolved detection extent ellipse, or area of the detection polygon for extended detections for each science energy band
Aperture Photometry	cnts_aper	long[6]	counts	total counts measured in the modified source region for each science energy band
	cnts_aperbkg	long[6]	counts	total counts measured in the modified background region for each science energy band
	src_cnts_aper	double[6]	counts	aperture-corrected detection net counts inferred from the source region aperture for each science energy band
	src_cnts_aper_lolim	double[6]	counts	aperture-corrected detection net counts inferred from the source region aperture (68% lower confidence limit) for each science energy band
	src_cnts_aper_hilim	double[6]	counts	aperture-corrected detection net counts inferred from the source region aperture (68% upper confidence limit) for each science energy band
	src_rate_aper	double[6]	counts s-1	aperture-corrected detection net count rate inferred from the source region aperture for each science energy band
	src_rate_aper_lolim	double[6]	counts s-1	aperture-corrected detection net count rate inferred from the source region aperture (68% lower confidence limit) for each science energy band
	src_rate_aper_hilim	double[6]	counts s-1	aperture-corrected detection net count rate inferred from the source region aperture (68% upper confidence limit) for each science energy band
	photflux_aper	double[6]	photons s-1 cm-2	aperture-corrected detection net photon flux inferred from the source region aperture, calculated by counting X-ray events for each science energy band
	photflux_aper_lolim	double[6]	photons s-1 cm-2	aperture-corrected detection net photon flux inferred from the source region aperture, calculated by counting X-ray events (68% lower confidence limit) for each science energy band
	photflux_aper_hilim	double[6]	photons s-1 cm-2	aperture-corrected detection net photon flux inferred from the source region aperture, calculated by counting X-ray events (68% upper confidence limit) for each science energy band
	flux_aper	double[6]	ergs s-1 cm-2	aperture-corrected detection net energy flux inferred from the source region aperture, calculated by counting X-ray events for each science energy band
	flux_aper_lolim	double[6]	ergs s-1 cm-2	aperture-corrected detection net energy flux inferred from the source region aperture, calculated by counting X-ray events (68% lower confidence limit) for each science energy band
	flux_aper_hilim	double[6]	ergs s-1 cm-2	aperture-corrected detection net energy flux inferred from the source region aperture, calculated by counting X-ray events (68% upper confidence limit) for each science energy band
	cnts_aper90	long[6]	counts	total counts observed in the modified PSF 90% ECF aperture for each science energy band
	cnts_aper90bkg	long[6]	counts	total counts observed in the modified PSF 90% ECF background aperture for each science energy band
	src_cnts_aper90	double[6]	counts	aperture-corrected detection net counts inferred from the PSF 90% ECF aperture for each science energy band
	src_cnts_aper90_lolim	double[6]	counts	aperture-corrected detection net counts inferred from the PSF 90% ECF aperture (68% lower confidence limit) for each science energy band
	src_cnts_aper90_hilim	double[6]	counts	aperture-corrected detection net counts inferred from the PSF 90% ECF aperture (68% upper confidence limit) for each science energy band
	src_rate_aper90	double[6]	counts s-1	aperture-corrected detection net count rate inferred from the PSF 90% ECF aperture for each science energy band
	src_rate_aper90_lolim	double[6]	counts s-1	aperture-corrected detection net count rate inferred from the PSF 90% ECF aperture (68% lower confidence limit) for each science energy band
	src_rate_aper90_hilim	double[6]	counts s-1	aperture-corrected detection net count rate inferred from the PSF 90% ECF aperture (68% upper confidence limit) for each science energy band
	photflux_aper90	double[6]	photons s-1 cm-2	aperture-corrected detection net photon flux inferred from the PSF 90% ECF aperture, calculated by counting X-ray events for each science energy band
	photflux_aper90_lolim	double[6]	photons s-1 cm-2	aperture-corrected detection net photon flux inferred from the PSF 90% ECF aperture, calculated by counting X-ray events (68% lower confidence limit) for each science energy band
	photflux_aper90_hilim	double[6]	photons s-1 cm-2	aperture-corrected detection net photon flux inferred from the PSF 90% ECF aperture, calculated by counting X-ray events (68% upper confidence limit) for each science energy band
	flux_aper90	double[6]	ergs s-1 cm-2	aperture-corrected detection net energy flux inferred from the PSF 90% ECF aperture, calculated by counting X-ray events for each science energy band
	flux_aper90_lolim	double[6]	ergs s-1 cm-2	aperture-corrected detection net energy flux inferred from the PSF 90% ECF aperture, calculated by counting X-ray events (68% lower confidence limit) for each science energy band
	flux_aper90_hilim	double[6]	ergs s-1 cm-2	aperture-corrected detection net energy flux inferred from the PSF 90% ECF aperture, calculated by counting X-ray events (68% upper confidence limit) for each science energy band
	ra_aper90	double[6]	deg	center of the PSF 90% ECF and PSF 90% ECF background apertures, ICRS right ascension for each science energy band
	dec_aper90	double[6]	deg	center of the PSF 90% ECF and PSF 90% ECF background apertures, ICRS declination for each science energy band
	mjr_axis_aper90	double[6]	arcsec	semi-major axis of the elliptical PSF 90% ECF aperture for each science energy band
	mnr_axis_aper90	double[6]	arcsec	semi-minor axis of the elliptical PSF 90% ECF aperture for each science energy band
	pos_angle_aper90	double[6]	deg	position angle (referenced from local true north) of the semi-major axis of the elliptical PSF 90% ECF aperture for each science energy band
	mjr_axis1_aper90bkg	double[6]	arcsec	semi-major axis of the inner ellipse of the annular PSF 90% ECF background aperture for each science energy band
	mnr_axis1_aper90bkg	double[6]	arcsec	semi-minor axis of the inner ellipse of the annular PSF 90% ECF background aperture for each science energy band
	mjr_axis2_aper90bkg	double[6]	arcsec	semi-major axis of the outer ellipse of the annular PSF 90% ECF background aperture for each science energy band
	mnr_axis2_aper90bkg	double[6]	arcsec	semi-minor axis of the outer ellipse of the annular PSF 90% ECF background aperture for each science energy band
	pos_angle_aper90bkg	double[6]	deg	position angle (referenced from local true north) of the semi-major axes of the annular PSF 90% ECF background aperture for each science energy band
	area_aper	double	sq. arcsec	area of the modified elliptical source region aperture (includes corrections for exclusion regions due to overlapping detections)
	area_aperbkg	double	sq. arcseconds	area of the modified annular background region aperture (includes corrections for exclusion regions due to overlapping detections)
	area_aper90	double[6]	sq. arcseconds	area of the modified elliptical PSF 90% ECF aperture (includes corrections for exclusion regions due to overlapping detections) for each science energy band
	area_aper90bkg	double[6]	sq. arcseconds	area of the modified annular PSF 90% ECF background aperture (includes corrections for exclusion regions due to overlapping detections for each science energy band
	psf_frac_aper	double[6]		fraction of the PSF included in the modified elliptical source region aperture for each science energy band
	psf_frac_aperbkg	double[6]		fraction of the PSF included in the modified annular background region aperture for each science energy band
	psf_frac_aper90	double[6]		fraction of the PSF included in the modified elliptical PSF 90% ECF aperture for each science energy band
	psf_frac_aper90bkg	double[6]		fraction of the PSF included in the modified annular PSF 90% ECF background aperture for each science energy band
	phot_nsrcs	integer[6]		number of detections fit simultaneously to compute aperture photometry quantities
Model Energy Fluxes	flux_powlaw_aper	double[6]	ergs s-1 cm-2	source region aperture model energy flux inferred from the canonical absorbed power-law model [NH = NH(Gal); γ = 2.0] for each science energy band
	flux_powlaw_aper_lolim	double[6]	ergs s-1 cm-2	source region aperture model energy flux inferred from the canonical absorbed power-law model [NH = NH(Gal); γ = 2.0] (68% lower confidence limit) for each science energy band
	flux_powlaw_aper_hilim	double[6]	ergs s-1 cm-2	source region aperture model energy flux inferred from the canonical absorbed power-law model [NH = NH(Gal); γ = 2.0] (68% upper confidence limit) for each science energy band
	flux_bb_aper	double[6]	ergs s-1 cm-2	source region aperture model energy flux inferred from the canonical absorbed black body model [NH = NH(Gal); kT = 0.75 keV] for each science energy band
	flux_bb_aper_lolim	double[6]	ergs s-1 cm-2	source region aperture model energy flux inferred from the canonical absorbed black body model [NH = NH(Gal); kT = 0.75 keV] (68% lower confidence limit) for each science energy band
	flux_bb_aper_hilim	double[6]	ergs s-1 cm-2	source region aperture model energy flux inferred from the canonical absorbed black body model [NH = NH(Gal); kT = 0.75 keV] (68% upper confidence limit) for each science energy band
	flux_brems_aper	double[6]	ergs s-1 cm-2	source region aperture model energy flux inferred from the canonical absorbed bremsstrahlung model [NH = NH(Gal); kT = 3.5 keV] for each science energy band
	flux_brems_aper_lolim	double[6]	ergs s-1 cm-2	source region aperture model energy flux inferred from the canonical absorbed bremsstrahlung model [NH = NH(Gal); kT = 3.5 keV] (68% lower confidence limit) for each science energy band
	flux_brems_aper_hilim	double[6]	ergs s-1 cm-2	source region aperture model energy flux inferred from the canonical absorbed bremsstrahlung model [NH = NH(Gal); kT = 3.5 keV] (68% upper confidence limit) for each science energy band
	flux_apec_aper	double[6]	ergs s-1 cm-2	source region aperture model energy flux inferred from the canonical absorbed APEC model [NH = NH(Gal); kT = 6.5 keV] for each science energy band
	flux_apec_aper_lolim	double[6]	ergs s-1 cm-2	source region aperture model energy flux inferred from the canonical absorbed APEC model [NH = NH(Gal); kT = 6.5 keV] (68% lower confidence limit) for each science energy band
	flux_apec_aper_hilim	double[6]	ergs s-1 cm-2	source region aperture model energy flux inferred from the canonical absorbed APEC model [NH = NH(Gal); kT = 6.5 keV] (68% upper confidence limit) for each science energy band
	flux_powlaw_aper90	double[6]	ergs s-1 cm-2	PSF 90% ECF aperture model energy flux inferred from the canonical absorbed power-law model [NH = NH(Gal); γ = 2.0] for each science energy band
	flux_powlaw_aper90_lolim	double[6]	ergs s-1 cm-2	PSF 90% ECF aperture model energy flux inferred from the canonical absorbed power-law model [NH = NH(Gal); γ = 2.0] (68% lower confidence limit) for each science energy band
	flux_powlaw_aper90_hilim	double[6]	ergs s-1 cm-2	PSF 90% ECF aperture model energy flux inferred from the canonical absorbed power-law model [NH = NH(Gal); γ = 2.0] (68% upper confidence limit) for each science energy band
	flux_bb_aper90	double[6]	ergs s-1 cm-2	PSF 90% ECF aperture model energy flux inferred from the canonical absorbed black body model [NH = NH(Gal); kT = 0.75 keV] for each science energy band
	flux_bb_aper90_lolim	double[6]	ergs s-1 cm-2	PSF 90% ECF aperture model energy flux inferred from the canonical absorbed black body model [NH = NH(Gal); kT = 0.75 keV] (68% lower confidence limit) for each science energy band
	flux_bb_aper90_hilim	double[6]	ergs s-1 cm-2	PSF 90% ECF aperture model energy flux inferred from the canonical absorbed black body model [NH = NH(Gal); kT = 0.75 keV] (68% upper confidence limit) for each science energy band
	flux_brems_aper90	double[6]	ergs s-1 cm-2	PSF 90% ECF aperture model energy flux inferred from the canonical absorbed bremsstrahlung model [NH = NH(Gal); kT = 3.5 keV] for each science energy band
	flux_brems_aper90_lolim	double[6]	ergs s-1 cm-2	PSF 90% ECF aperture model energy flux inferred from the canonical absorbed bremsstrahlung model [NH = NH(Gal); kT = 3.5 keV] (68% lower confidence limit) for each science energy band
	flux_brems_aper90_hilim	double[6]	ergs s-1 cm-2	PSF 90% ECF aperture model energy flux inferred from the canonical absorbed bremsstrahlung model [NH = NH(Gal); kT = 3.5 keV] (68% upper confidence limit) for each science energy band
	flux_apec_aper90	double[6]	ergs s-1 cm-2	PSF 90% ECF aperture model energy flux inferred from the canonical absorbed APEC model [NH = NH(Gal); kT = 6.5 keV] for each science energy band
	flux_apec_aper90_lolim	double[6]	ergs s-1 cm-2	PSF 90% ECF aperture model energy flux inferred from the canonical absorbed APEC model [NH = NH(Gal); kT = 6.5 keV] (68% lower confidence limit) for each science energy band
	flux_apec_aper90_hilim	double[6]	ergs s-1 cm-2	PSF 90% ECF aperture model energy flux inferred from the canonical absorbed APEC model [NH = NH(Gal); kT = 6.5 keV] (68% upper confidence limit) for each science energy band
Hardness Ratios	hard_hm	double		ACIS hard (2.0-7.0 keV) - medium (1.2-2.0 keV) energy band hardness ratio
	hard_hm_lolim	double		ACIS hard (2.0-7.0 keV) - medium (1.2-2.0 keV) energy band hardness ratio (68% lower confidence limit)
	hard_hm_hilim	double		ACIS hard (2.0-7.0 keV) - medium (1.2-2.0 keV) energy band hardness ratio (68% upper confidence limit)
	hard_hs	double		ACIS hard (2.0-7.0 keV) - soft (0.5-1.2 keV) energy band hardness ratio
	hard_hs_lolim	double		ACIS hard (2.0-7.0 keV) - soft (0.5-1.2 keV) energy band hardness ratio (68% lower confidence limit)
	hard_hs_hilim	double		ACIS hard (2.0-7.0 keV) - soft (0.5-1.2 keV) energy band hardness ratio (68% upper confidence limit)
	hard_ms	double		ACIS medium (1.2-2.0 keV) - soft (0.5-1.2 keV) energy band hardness ratio
	hard_ms_lolim	double		ACIS medium (1.2-2.0 keV) - soft (0.5-1.2 keV) energy band hardness ratio (68% lower confidence limit)
	hard_ms_hilim	double		ACIS medium (1.2-2.0 keV) - soft (0.5-1.2 keV) energy band hardness ratio (68% upper confidence limit)
Spectral Properties	flux_powlaw	double	ergs s-1 cm-2	net integrated 0.5-7.0 keV energy flux of the best fitting absorbed power-law model spectrum to the source region aperture PI spectrum
	flux_powlaw_lolim	double	ergs s-1 cm-2	net integrated 0.5-7.0 keV energy flux of the best fitting absorbed power-law model spectrum to the source region aperture PI spectrum (68% lower confidence limit)
	flux_powlaw_hilim	double	ergs s-1 cm-2	net integrated 0.5-7.0 keV energy flux of the best fitting absorbed power-law model spectrum to the source region aperture PI spectrum (68% upper confidence limit)
	powlaw_gamma	double		photon index, defined as FE ∝ E-γ, of the best fitting absorbed power-law model spectrum to the source region aperture PI spectrum
	powlaw_gamma_lolim	double		photon index, defined as FE ∝ E-γ, of the best fitting absorbed power-law model spectrum to the source region aperture PI spectrum (68% lower confidence limit)
	powlaw_gamma_hilim	double		photon index, defined as FE ∝ E-γ, of the best fitting absorbed power-law model spectrum to the source region aperture PI spectrum (68% upper confidence limit)
	powlaw_gamma_rhat	double		photon index convergence criterion of the best fitting absorbed power-law model spectrum to the source region aperture PI spectrum
	powlaw_nh	double	N HI atoms 1020 cm-2	NH column density of the best fitting absorbed power-law model spectrum to the source region aperture PI spectrum
	powlaw_nh_lolim	double	N HI atoms 1020 cm-2	NH column density of the best fitting absorbed power-law model spectrum to the source region aperture PI spectrum (68% lower confidence limit)
	powlaw_nh_hilim	double	N HI atoms 1020 cm-2	NH column density of the best fitting absorbed power-law model spectrum to the source region aperture PI spectrum (68% upper confidence limit)
	powlaw_nh_rhat	double		NH column density convergence criterion of the best fitting absorbed power-law model spectrum to the source region aperture PI spectrum
	powlaw_ampl	double		amplitude of the best fitting absorbed power-law model spectrum to the source region aperture PI spectrum
	powlaw_ampl_lolim	double		amplitude of the best fitting absorbed power-law model spectrum to the source region aperture PI spectrum (68% lower confidence limit)
	powlaw_ampl_hilim	double		amplitude of the best fitting absorbed power-law model spectrum to the source region aperture PI spectrum (68% upper confidence limit)
	powlaw_ampl_rhat	double		amplitude convergence criterion of the best fitting absorbed power-law model spectrum to the source region aperture PI spectrum
	powlaw_stat	double		χ2 statistic per degree of freedom of the best fitting absorbed power-law model spectrum to the source region aperture PI spectrum
	flux_bb	double	ergs s-1 cm-2	net integrated 0.5-7.0 keV energy flux of the best fitting absorbed black body model spectrum to the source region aperture PI spectrum
	flux_bb_lolim	double	ergs s-1 cm-2	net integrated 0.5-7.0 keV energy flux of the best fitting absorbed black body model spectrum to the source region aperture PI spectrum (68% lower confidence limit)
	flux_bb_hilim	double	ergs s-1 cm-2	net integrated 0.5-7.0 keV energy flux of the best fitting absorbed black body model spectrum to the source region aperture PI spectrum (68% upper confidence limit)
	bb_kt	double	keV	temperature (kT) of the best fitting absorbed black body model spectrum to the source region aperture PI spectrum
	bb_kt_lolim	double	keV	temperature (kT) of the best fitting absorbed black body model spectrum to the source region aperture PI spectrum (68% lower confidence limit)
	bb_kt_hilim	double	keV	temperature (kT) of the best fitting absorbed black body model spectrum to the source region aperture PI spectrum (68% upper confidence limit)
	bb_kt_rhat	double		temperature (kT) convergence criterion of the best fitting absorbed black body model spectrum to the source region aperture PI spectrum
	bb_nh	double	N HI atoms 1020 cm-2	NH column density of the best fitting absorbed black body model spectrum to the source region aperture PI spectrum
	bb_nh_lolim	double	N HI atoms 1020 cm-2	NH column density of the best fitting absorbed black body model spectrum to the source region aperture PI spectrum (68% lower confidence limit)
	bb_nh_hilim	double	N HI atoms 1020 cm-2	NH column density of the best fitting absorbed black body model spectrum to the source region aperture PI spectrum (68% upper confidence limit)
	bb_nh_rhat	double		NH column density convergence criterion of the best fitting absorbed black body model spectrum to the source region aperture PI spectrum
	bb_ampl	double		amplitude of the best fitting absorbed black body model spectrum to the source region aperture PI spectrum
	bb_ampl_lolim	double		amplitude of the best fitting absorbed black body model spectrum to the source region aperture PI spectrum (68% lower confidence limit)
	bb_ampl_hilim	double		amplitude of the best fitting absorbed black body model spectrum to the source region aperture PI spectrum (68% upperer confidence limit)
	bb_ampl_rhat	double		amplitude convergence criterion of the best fitting absorbed black body model spectrum to the source region aperture PI spectrum
	bb_stat	double		χ2 statistic per degree of freedom of the best fitting absorbed black body model spectrum to the source region aperture PI spectrum
	flux_brems	double	ergs s-1 cm-2	net integrated 0.5-7.0 keV energy flux of the best fitting absorbed bremsstrahlung model spectrum to the source region aperture PI spectrum
	flux_brems_lolim	double	ergs s-1 cm-2	net integrated 0.5-7.0 keV energy flux of the best fitting absorbed bremsstrahlung model spectrum to the source region aperture PI spectrum (68% lower confidence limit)
	flux_brems_hilim	double	ergs s-1 cm-2	net integrated 0.5-7.0 keV energy flux of the best fitting absorbed bremsstrahlung model spectrum to the source region aperture PI spectrum (68% upper confidence limit)
	brems_kt	double	keV	temperature (kT) of the best fitting absorbed bremsstrahlung model spectrum to the source region aperture PI spectrum
	brems_kt_lolim	double	keV	temperature (kT) of the best fitting absorbed bremsstrahlung model spectrum to the source region aperture PI spectrum (68% lower confidence limit)
	brems_kt_hilim	double	keV	temperature (kT) of the best fitting absorbed bremsstrahlung model spectrum to the source region aperture PI spectrum (68% upper confidence limit)
	brems_kt_rhat	double		temperature (kT) convergence criterion of the best fitting absorbed bremsstrahlung model spectrum to the source region aperture PI spectrum
	brems_nh	double	N HI atoms 1020 cm-2	NH column density of the best fitting absorbed bremsstrahlung model spectrum to the source region aperture PI spectrum
	brems_nh_lolim	double	N HI atoms 1020 cm-2	NH column density of the best fitting absorbed bremsstrahlung model spectrum to the source region aperture PI spectrum (68% lower confidence limit)
	brems_nh_hilim	double	N HI atoms 1020 cm-2	NH column density of the best fitting absorbed bremsstrahlung model spectrum to the source region aperture PI spectrum (68% upper confidence limit)
	brems_nh_rhat	double		NH column density convergence criterion of the best fitting absorbed bremsstrahlung model spectrum to the source region aperture PI spectrum
	brems_norm	double		amplitude of the best fitting absorbed bremsstrahlung model spectrum to the source region aperture PI spectrum
	brems_norm_lolim	double		amplitude of the best fitting absorbed bremsstrahlung model spectrum to the source region aperture PI spectrum (68% lower confidence limit)
	brems_norm_hilim	double		amplitude of the best fitting absorbed bremsstrahlung model spectrum to the source region aperture PI spectrum (68% upperer confidence limit)
	brems_norm_rhat	double		amplitude convergence criterion of the best fitting absorbed bremsstrahlung model spectrum to the source region aperture PI spectrum
	brems_stat	double		χ2 statistic per degree of freedom of the best fitting absorbed bremsstrahlung model spectrum to the source region aperture PI spectrum
	flux_apec	double	ergs s-1 cm-2	net integrated 0.5-7.0 keV energy flux of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum
	flux_apec_lolim	double	ergs s-1 cm-2	net integrated 0.5-7.0 keV energy flux of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum (68% lower confidence limit)
	flux_apec_hilim	double	ergs s-1 cm-2	net integrated 0.5-7.0 keV energy flux of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum (68% upper confidence limit)
	apec_kt	double	keV	temperature (kT) of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum
	apec_kt_lolim	double	keV	temperature (kT) of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum (68% lower confidence limit)
	apec_kt_hilim	double	keV	temperature (kT) of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum (68% upper confidence limit)
	apec_kt_rhat	double		temperature (kT) convergence criterion of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum
	apec_abund	double		abundance of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum
	apec_abund_lolim	double		abundance of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum (68% lower confidence limit)
	apec_abund_hilim	double		abundance of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum (68% upper confidence limit)
	apec_abund_rhat	double		abundance convergence criterion of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum
	apec_z	double		redshift of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum
	apec_z_lolim	double		redshift of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum (68% lower confidence limit)
	apec_z_hilim	double		redshift of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum (68% upper confidence limit)
	apec_z_rhat	double		redshift convergence criterion Redshift of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum
	apec_nh	double	N HI atoms 1020 cm-2	NH column density of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum
apec_nh_lolim	double	N HI atoms 1020 cm-2	NH column density of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum (68% lower confidence limit)
apec_nh_hilim	double	N HI atoms 1020 cm-2	NH column density of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum (68% upper confidence limit)
apec_nh_rhat	double		NH column density convergence criterion of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum
apec_norm	double		amplitude of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum
apec_norm_lolim	double		amplitude of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum (68% lower confidence limit)
apec_norm_hilim	double		amplitude of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum (68% upperer confidence limit)
apec_norm_rhat	double		amplitude convergence criterion of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum
apec_stat	double		χ2 statistic per degree of freedom of the best fitting absorbed APEC model spectrum to the source region aperture PI spectrum
Source Variability	var_index	integer[6]		intra-observation Gregory-Loredo variability index in the range [0, 10]: indicates whether the source region photon flux is constant within an observation (highest value across all stacked observations) for each science energy band
	var_prob	double[6]		intra-observation Gregory-Loredo variability probability (highest value across all stacked observations) for each science energy band
	ks_prob	double[6]		intra-observation Kolmogorov-Smirnov test variability probability (highest value across all observations) for each science energy band
	kp_prob	double[6]		intra-observation Kuiper's test variability probability (highest value across all stacked observations) for each science energy band
	var_sigma	double[6]	counts s-1	flux variability standard deviation, calculated from an optimally-binned light curve for each science energy band
	var_mean	double[6]	counts s-1	flux variability mean value, calculated from an optimally-binned light curve for each science energy band
	var_min	double[6]	counts s-1	flux variability minimum value, calculated from an optimally-binned light curve for each science energy band
	var_max	double[6]	counts s-1	flux variability maximum value, calculated from an optimally-binned light curve for each science energy band
Source Timing Information	livetime	double	s	effective single observation exposure time, after applying the good time intervals and the deadtime correction factor; vignetting and dead area corrections are NOT applied
Source Instrument Information	detector	string		detector elements over which the background region bounding box dithers during the observation: HRC-I, HRC-S, or ACIS-<n>, where <n> is string of the CCD Ids (e.g. "ACIS-78"); see the ACIS focal plane figure in the POG.