GR1 – Pipeline and advanced data description

1. Pipeline Overview.. 1

2. Pipeline Products. 2

3. Spectral Data Product Files. 4

4. Source Extraction. 8

5. Primary Object Catalog - Merged FUV+NUV Catalog (mcat file) 9

6. Pipeline Products Gallery. 20

7. GALEX Image Artifacts. 29

1. Pipeline Overview

The GALEX data pipeline converts GALEX satellite telemetry data and any necessary corollary data into calibrated images, spectra, and catalogs. The GALEX Science Operations Center (SOC) receives satellite telemetry data and ingestpipe unpacks it into time-tagged photon lists, instrument/SC housekeeping, and satellite aspect information. From these data sets, orbpipe generates images, spectra, and source catalogs.

Astrometric modules rta (for rectify, transform and aspect) and deltaphot correct the photon positions for detector and optical distortions, and determine an aspect solution using star positions from the time-tagged photon data. The astrometric refinement process is diagrammed below.

A photometric module simplemap accumulates the photons into count and intensity maps and sextra extracts sources from images. A spectroscopic module galexspac uses image source catalog inputs to extract spectra of these sources from the multiple slitless grism observations.

2. Pipeline Products

Data from each single-orbit visit stored in a single directory in the GALEX file system. The directory path has the following format:

<ROOT>/<proc ver>/<tile>/<obs mode>/<product>/<image>/<try>/.

An example path and filename is:

Path: <root>/01-vsn/10330-AISCHV2_381_40554/d/00-visits/0002-img/03-try/

Filename: AISCHV2_381_40554_0002_sv12-xd-mcat.fits

This path contains the pipeline processing version number, a tile identification string, instrument observing mode (direct, grism, opaque; represented by d, g, o, in each case preceded by the wavelength, data product type (single visit, multiple visit), and the pipeline processing try. Additionally, a unique source ID tag is generated by the pipeline that uniquely encodes both the path information and the source number from merged source and spectra catalogs.

All of the pipeline products are described in the table below.

Table 3.1– Pipeline Products Summary (the most significant files are in bold)

Filename Suffix	File type	Description
Low-level pipeline products		Photon and housekeeping files
-asp.rec	Binary record	Satellite attitude solution. Raw S/C pointing data.
-asprta.rec	Binary record	Refined spacecraft attitude solution (using bright stars in the FOV).
-rtastar.fits	FITS binary table	Star catalog for attitude refinement: info. on stars used for S/C pointing solution vs. time.
-scst.fits	FITS binary table	Spacecraft state file: S/C status values.
Images		Maps and associated files
-[n or f][d or g]-cnt.fits	FITS image	Count map (J2000) in counts (photons) per pixel, corrected for image position and dither.
-[n or f][d or g]-exp.fits	FITS image	Exposure map (J2000). An image of time spent observing within the GALEX FOV (w/o response correction).
-[n or f][d or g]-intbgsub.fits	FITS image	Background-subtracted intensity map (J2000). Note: "-intbgsub" equals "-int" minus "-skybg".
-[n or f][d or g]-int.fits	FITS image	Intensity map (J2000). GALEX FOV image in counts per sec. per pixel, corrected for relative response.
-[n or f][d or g]-movie.fits	FITS image cube	Time-slice count maps (J2000). Multiple images of the raw detector within selected segments of time (not corrected for S/C motion).
-[n or f][d or g]-rr.fits	FITS image	Low resolution relative response (J2000). A low resolution version of "rrhr". (Provided only for rrhr and beyond.)
-[n or f][d or g]-skybg.fits	FITS image	Sky background image (J2000).
-[n or f][d or g]-wt.fits	FITS image	Weight/threshold image (J2000). FOV image used by Sextractor for thresholding sources. Pixels with values > 1 have a flux above the detection threshold.
Grism-specific files		Spectral 1-D arrays or 2-D images
-[n or f]g-gsax.fits	FITS binary table	Spectral extraction parameter information for each source
-[n or f]g-pri.fits	FITS binary table	Image strips for each source from a single visit
-[n or f]g-prc.fits	FITS binary table	Image strips (combined) for each source from multiple visits
-[n or f]g-prm.fits	FITS binary table	Image strips (median) for each source from multiple visits
-[n or f]g-gsp.fits	FITS binary table	Spectral data for each extracted source vs. wavelength
-xg-gsp.fits	FITS binary table	Spectral data for each extracted source vs. wavelength (both bands)
Quality assurance (QA)		QA file description
-x[d or g]-int_2color*.jpg	FITS binary table	JPEG images of the field.
*.ps	postscript text	Various postscript plots.
-[n or f]d-dphcent.txt	ASCII text	Aspect refinement QA data .
-[n or f]d-gauss*.txt	ASCII text	Gaussian filter used by Sextractor.
-[n or f]d-sexcols.txt	ASCII text	Sextractor catalog columns.
-[n or f]d-sexparams.txt	ASCII text	Parameter file used by Sextractor.
-[n or f]d-sexnnw.txt	ASCII text	Neural network parameter file used by Sextractor.
*stats.txt	ASCII text	Various QA statistics.
-[n or f]d-cat.ds9reg	ASCII text	ds9 region file: ellipses of sources listed in the -[n or f] d-c at.fits file. [Note: a ds9 region file is a file of ellipse parameters used by the image viewing program "DS9". These parameters include the RA, Dec, major and minor axes and position angle of the major axis.]
-fd-ncat.ds9reg	ASCII text	ds9 region file: ellipses of sources listed in the -fd-ncat. fit s file.
-nd-fcat.ds9reg	ASCII text	ds9 region file: ellipses of sources listed in the -nd-fcat. fit s file.
_getmask-[n or f]d-cat.ds9reg	ASCII text	ds9 region file: Objects ignored in estimating background flux.
rtastar.ds9reg	ASCII text	ds9 region file: ellipses of bright stars from rtastar.fit s file used in the attitude solution (aspect correction).
Catalogs		FUV, NUV and merged catalogs
-[n or f]d-cat.fits	FITS binary table	Sextractor catalogs for images. Table of objects extracted by GALEX reduction pipeline. The table contains positions, flux, magnitude, and major/minor axes.
-[n or f]d-[f or n]cat.fits	FITS binary table	NUV (FUV) extractions using FUV (NUV) positions; the latter are taken from the FUV (NUV) source catalog "fd
-xd-mcat.fits	FITS binary table	Merged source catalog. Band-merged table of extracted objects. Contains all objects contained in "[n or f]d-cat.fits" matched to the best candidate. The table contains positions, flux, magnitude, and major/minor axes. By definition, it contains all data from the two single-band catalogs.
Flags		Artifact flag information
-[n or f][d or g]-flags.fits	FITS image	Artifact Flag image (J2000). Identifies predetermined regions which may introduce systematic errors in data extraction. These artifact regions are caused mainly by reflections of nearby bright stars.
-[n or f]d-flagstar.fits	FITS binary table	Star catalog for flagging. List of known bright stars used to determine artifact regions.

3. Spectral Data Product Files

The spectral data product files are stored in binary FITS format, but they are GALEX-specific. The formats of these files are described below:

-pri.fits

This file contains the image strips for individual exposures for each spectral-extracted source. The photon data, response, and masking images are recorded for each source. Masking for the image strip is stored in the response image (neighbor masking) and the photon data image (other masking) as negative numbers. Spectral response variations with position (column) are stored in the response image in the final row. These images contain the total accumulated photon data for each source for a given single visit or exposure.

Each source has its own FITS header unit. The order of the image strips is identical to the order of sources in the catalog given in the (root)-gsax.fits file for those sources which are actually extracted. A catalog source is an extracted source if the "flag” column value in the -gsax.fits table is either 2 or 3.

First Header Unit: Includes grism position angle, total exposure time, total number of spectrally extracted sources (ECOUNT), field center, and other extraction parameters.

Second through “N" Header Unit: Accumulated image strips for photon data and response for any of N-1 sources in the field of view.

The header card portion of each of these units defines the image dimensions (PRI_NC,PRI_NR). The scale is nominally 1 arcsecond per pixel in both the spatial and dispersion directions. The header key words also include the blue limit offset in arcseconds (ARCSEC1) relative to the object center (undeviated) position, which is used to derive the wavelength scale. The image strips typically cover multiple grism orders, e.g. 1st, 2nd, and 0th. The image data is stored as 2-byte integers, which can be scaled to true data values using the header key words DATZERO, DATSCALE, RSPZERO, and RSPSCALE.

-prc.fits

This file contains the combined or summed image strips for multiple exposures for each spectral-extracted source. The format is the same as for the pri files, except that masking has been applied before summing. That is, all masked pixels in the individual (pri) image strips were set to zero before summing.

First Header Unit: Contains the filenames of all *-pri.fits which have been combined, their respective grism angles, observation times, spacecraft roll angles, visits, and eclipse numbers.

Second through "N" Header Unit: Accumulated image strips for photon data and response for any of N-1 sources in the field of view.

-prm.fits

This file contains the medianed image strips for multiple exposures for each spectral-extracted source. The format is the same as for the pri files, except that masked pixels have been ignored by the median value calculation.

First Header Unit: Contains the filenames of all *-pri.fits which have been medianed, as well as other information.

Second through "N" Header Unit: Accumulated image strips for photon data and response for any of N-1 sources in the field of view.

-gsax.fits

General information (binary FITS table). This file contains parameter information, as well as a source list table including extraction parameters for each source. This source list catalog is created on the first exposure and read in and used for each subsequent exposure. This file also contains a table of data for each accumulated exposure.

First Header Unit: Header key words contain various extraction parameters for ``galaxspac" (spectral accumulation program). These include the number of sources in the catalog (NUMSOURC) and the number of these sources which were actually extracted (ECOUNT); the difference is the number of sources used for masking purposes only. Also included are the field RA,Dec origin (RAO,DECO), the masking parameters, and the total exposure time accumulated (TOTTIME).

Second Header Unit: Extracted source list. This contains a source catalog of all the sources which have been extracted and used for masking. The table column "flag" indicates whether a source was extracted (2 or 3). The table includes the RA,Dec positions, global IDs, direct image FUV and NUV flux rates, direct image FWHMs, and extraction parameters (object and background widths and length of the spectrum) for each source.

Third Header Unit: Accumulated exposures (orbits) list. This contains a catalog of all the photon data sets added into the image strips. This includes all the *-pri.fits filenames, grism angles, field offsets used (x, y, twist (rotation) relative to the direct image source positions), exposure times, and reduction dates.

-xsp.fits

These are labeled *-fg-xsp.fits and *-ng-xsp.fits for each band. As in the -prc.fits and -pri.fits files, each header unit is a separate extracted source. These are "raw" spectral extractions which no flux or wavelength calibration. The units are photons per second per arcsecond. Each source has its own FITS header unit, in the same order as the data occur in the -pri.fits file.

First Header Unit: Contains various parameters and values.

Second through ``N" Header Unit: Spectra for each source and its computed Poisson error. Spectra are given in photons/second/pixel vs. offset arcsecond (which is the position relative to object center or undeviated or undispersed position).

-gsp.fits

There are three gsp files for each spectrum: *-fg-gsp, *-ng-gsp, and *-xg-gsp. The first two are calibrated spectra for NUV and FUV, rebinned onto a linear wavelength scale. The third is the conjoined spectrum of the first two files. The fg-gsp and ng-gsp files are for most purposes rendered obsolete by the xg-gsp file.

First Header Unit: Each file consists of a short primary header with information such as the number of spectra in the file "ECOUNT".

Second Header Unit: Each row of this table gives spectral information (fluxes, associated errors, etc.) for an astronomical object. These rows are listed in order of their appearance in the extracted source catalog in the (root)-gsax.fits file. However, "masking" sources appearing in the gsax file are not extracted as spectra and thus not included in the gsp file listing.

Two of the vector entries (obj and objerr) are for a simple (summation) extraction of the primary grism orders (1st for NUV and 2nd for FUV). Two vectors (objs and objserr) are for a summation extraction of the secondary grism orders (2nd for NUV and 3rd for FUV). One vector (objmdn) is the extraction from the median image strip (-prm.fits) and is only filled for coadded (multiple exposure) data. Finally, two vectors (opx,opxerr) are reserved for optimal extraction but are not currently used. The units for these are photons per second per centimeter squared per Angstrom. Since the dispersion is linear, the zero point and dispersion of the wavelength scale are given as table entries.

4. Background Determination and Source Extraction

See Background_determination_and_source_extraction_for_GALEX_data.pdf, in the GR1 documentation.

5. Primary Object Catalog - Merged FUV+NUV Catalog (mcat file)

The merged object catalog is the final catalog product from the GALEX data pipeline. It contains the full complement of source extractions from both the FUV and NUV images. The columns of the mcat file fall into the following major categories:

· Observation description

o Contains global object ID, pipeline version, image tile number, observation type, optics wheel position, image product type, pipeline re-run (try) number, band, mcat ID, subvisit number and leg number (where applicable)

· Band merger output quantities and flags

o Includes merged position in Equatorial and Galactic coordinates, extinction E(B-V) from Schlegel maps, and calibrated fluxes, magnitudes and errors. “Calibrated” currently means that values have been converted to AB magnitudes. Four additional columns contain FUV fluxes extracted at NUV detection positions, NUV fluxes extracted at FUV detection positions and their errors. These are useful for any study that is best performed using identical aperture photometry in each band (e.g. for colors, photometric redshifts)

· Neighbor properties

o Includes neighbor count and total flux out to three radii (currently set to 5”, 10” and 30”), closest neighbor distance, PA and nuv and fuv mag.

· Derived quantities and map levels at merged output position

o Includes extractions from pipeline-generated maps at the position of the detected source. Sky background [counts s^-1 pixel^-1], artifact [flag value], weight [exposure-relative response product], contrast [dimensionless] and masked pixel counts [number] values are given for each source.

· Sextractor output columns from FUV image extractions

· Sextractor output columns from NUV image extractions

o Please consult the Sextractor manual and Sextractor for Dummies for definitions of these outputs

Catalog Fields

Table 3.2 Merged Object Catalog (-xd-mcat.fits). For more detailed descriptions of the first 85 columns, see GR1_Column_descriptions_for_-xd-mcat.fits.htm in the GR1 documentation.

Name	Col	Format	Unit	Definition
Object ID and orbpipe info
ggoid_hex	1	16A	string	Hex string of Galex Global Object ID
ggoid_dec	2	20A	string	Decimal string of Galex Global Object ID
ggoid	3	2J	number	Galex Global Object ID
vsn	4	1J	number	Version number
tilenum	5	1J	number	Tile number
type	6	1J	number	Obs.type (0=single,1=multi)
ow	7	1J	number	Optics wheel (1=drct,2=grsm,3=opaq)
prod	8	1J	number	Product number (_visits,_main,etc.)
img	9	1J	number	image number (exposure# for _visits)
try	10	1J	number	Try number (processing attempt number)
band	11	1J	number	Band number (1=nuv,2=fuv,3=both)
id	12	1J	number	Merged ID.
subvisit	13	1I	number	Sub-visit number for AIS
leg	14	1I	number	Planned leg number for AIS
Merged object quantities
alpha_j2000	15	1D	degrees	Merged Right Ascension(degrees).
delta_j2000	16	1D	degrees	Merged Declination (degrees).
prob	17	1E	probability	Chi-squared probability of match.
sep	18	1E	arcseconds	Separation between band positions.
E_bv	19	1E	number	E(B-V) Galactic Reddening.
glon	20	1E	degrees	Galactic longitude in degrees.
glat	21	1E	degrees	Galactic latitude in degrees.
primary	22	1J	number	Primary source flag
fov_radius	23	1E	degrees	distance from center of FOV in degrees
nuv_det_x	24	1E	value	NUV detector X position
nuv_det_y	25	1E	value	NUV detector Y position
fuv_det_x	26	1E	value	FUV detector X position
fuv_det_y	27	1E	value	FUV detector Y position
chkobj_type	28	1J	number	Astrometry check type
chkobj_id	29	1J	number	Astrometry check ID
chkobj_r	30	1E	degrees	Astrometry check radius in degrees
chkobj_pa	31	1E	degrees	Astrometry check position angle in degrees
misc_flags	32	1J	value	Miscellaneous flags
nuv_flux	33	1E	flux	NUV calibrated flux (micro Jansky)
nuv_fluxerr	34	1E	flux	NUV calibrated flux error
nuv_mag	35	1E	mag	NUV calibrated magnitude
nuv_magerr	36	1E	mag	NUV calibrated magnitude error
fuv_flux	37	1E	flux	FUV calibrated flux (micro Jansky)
fuv_fluxerr	38	1E	flux	FUV calibrated flux error
fuv_mag	39	1E	mag	FUV calibrated magnitude
fuv_magerr	40	1E	mag	FUV calibrated magnitude error
nuv_fcat_flux	41	1E	flux	NUV calibrated flux using FUV catalog position
nuv_fcat_fluxerr	42	1E	flux	Error for nuv_fcat_flux
fuv_ncat_flux	43	1E	flux	FUV calibrated flux using NUV catalog position
fuv_ncat_fluxerr	44	1E	flux	Error for fuv_ncat_flux
Nearest neighbor
nuv_nc_r1	45	1I	number	NUV neighbor count out to radius R1
nuv_nc_r2	46	1I	number	NUV neighbor count out to radius R2
nuv_nc_r3	47	1I	number	NUV neighbor count out to radius R3
fuv_nc_r1	48	1I	number	FUV neighbor count out to radius R1
fuv_nc_r2	49	1I	number	FUV neighbor count out to radius R2
fuv_nc_r3	50	1I	number	FUV neighbor count out to radius R3
nuv_nf_r1	51	1E	flux	NUV neighbor flux out to radius R1
nuv_nf_r2	52	1E	flux	NUV neighbor flux out to radius R2
nuv_nf_r3	53	1E	flux	NUV neighbor flux out to radius R3
fuv_nf_r1	54	1E	flux	FUV neighbor flux out to radius R1
fuv_nf_r2	55	1E	flux	FUV neighbor flux out to radius R2
fuv_nf_r3	56	1E	flux	FUV neighbor flux out to radius R3
cn_radius	57	1E	arcseconds	Closest neighbor radius in arcseconds
cn_pa	58	1E	degrees	Closest neighbor position angle in degrees
cn_mag_nuv	59	1E	mag	Closest neighbor NUV magnitude
cn_mag_fuv	60	1E	mag	Closest neighbor FUV magnitude
Image/detection map values
nuv_skybg	61	1E	flux	NUV sky background (photons/sec/sq.arcsec) (at
fuv_skybg	62	1E	flux	FUV sky background (photons/sec/sq.arcsec) (at
nuv_weight	63	1E	seconds	NUV effective exposure (response) (mdn near sou
fuv_weight	64	1E	seconds	FUV effective exposure (response) (mdn near sou
nuv_thres	65	1E	sigmas	NUV threshold sigmas (int-bg)/wt)
fuv_thres	66	1E	sigmas	FUV threshold sigmas (int-bg)/wt)
nuv_contrast	67	1E	ratio	NUV ratio of min to max response near source
fuv_contrast	68	1E	ratio	FUV ratio of min to max response near source
nuv_maskpix	69	1J	number	NUV number of masked pixels near source
fuv_maskpix	70	1J	number	FUV number of masked pixels near source
nuv_artifact	71	1J	number	NUV artifact flag (logical OR near source)
fuv_artifact	72	1J	number	FUV artifact flag (logical OR near source)
Band merger QA
nuv_ambg	73	1J	number	NUV ambiguity flag.
fuv_ambg	74	1J	number	FUV ambiguity flag.
nuv_nc	75	1J	number	NUV number of candidates.
fuv_nc	76	1J	number	FUV number of candidates.
nuv_cid1	77	1J	number	First candidate for NUV source(FUV IDs)
fuv_cid1	78	1J	number	First candidate for FUV source(NUV IDs)
nuv_cid2	79	1J	number	Second candidate for NUV source(FUV IDs)
fuv_cid2	80	1J	number	Second candidate for FUV source(NUV IDs)
nuv_cid3	81	1J	number	Third candidate for NUV source(FUV IDs)
fuv_cid3	82	1J	number	Third candidate for FUV source(NUV IDs)
sourcepa	83	1E	degrees	position angle betw. band sources.
objtype	84	1J	number	0=galaxy,1=star,-1=unknown, etc.
quality	85	1J	number	Quality flag (undefined)
NUV source extraction catalog
NUV_NUMBER	86	1J	value	Running object number
NUV_FLUX_ISO	87	1E	flux	Isophotal flux
NUV_FLUXERR_ISO	88	1E	flux	RMS error for isophotal flux
NUV_MAG_ISO	89	1E	mag	Isophotal magnitude
NUV_MAGERR_ISO	90	1E	mag	RMS error for isophotal magnitude
NUV_FLUX_ISOCOR	91	1E	flux	Corrected isophotal flux
NUV_FLUXERR_ISOCOR	92	1E	flux	RMS error for corrected isophotal flux
NUV_MAG_ISOCOR	93	1E	mag	Corrected isophotal magnitude
NUV_MAGERR_ISOCOR	94	1E	mag	RMS error for corrected isophotal magnitude
NUV_FLUX_APER_1	95	1E	flux	Flux aperture ( 2.000)
NUV_FLUX_APER_2	96	1E	flux	Flux aperture ( 3.000)
NUV_FLUX_APER_3	97	1E	flux	Flux aperture ( 5.000)
NUV_FLUX_APER_4	98	1E	flux	Flux aperture ( 8.000)
NUV_FLUX_APER_5	99	1E	flux	Flux aperture ( 12.000)
NUV_FLUX_APER_6	100	1E	flux	Flux aperture ( 17.000)
NUV_FLUX_APER_7	101	1E	flux	Flux aperture ( 23.000)
NUV_FLUXERR_APER_1	102	1E	flux	Flux error aperture ( 2.000)
NUV_FLUXERR_APER_2	103	1E	flux	Flux error aperture ( 3.000)
NUV_FLUXERR_APER_3	104	1E	flux	Flux error aperture ( 5.000)
NUV_FLUXERR_APER_4	105	1E	flux	Flux error aperture ( 8.000)
NUV_FLUXERR_APER_5	106	1E	flux	Flux error aperture ( 12.000)
NUV_FLUXERR_APER_6	107	1E	flux	Flux error aperture ( 17.000)
NUV_FLUXERR_APER_7	108	1E	flux	Flux error aperture ( 23.000)
NUV_MAG_APER_1	109	1E	mag	Magnitude aperture ( 2.000)
NUV_MAG_APER_2	110	1E	mag	Magnitude aperture ( 3.000)
NUV_MAG_APER_3	111	1E	mag	Magnitude aperture ( 5.000)
NUV_MAG_APER_4	112	1E	mag	Magnitude aperture ( 8.000)
NUV_MAG_APER_5	113	1E	mag	Magnitude aperture ( 12.000)
NUV_MAG_APER_6	114	1E	mag	Magnitude aperture ( 17.000)
NUV_MAG_APER_7	115	1E	mag	Magnitude aperture ( 23.000)
NUV_MAGERR_APER_1	116	1E	mag	Magnitude error aperture ( 2.000)
NUV_MAGERR_APER_2	117	1E	mag	Magnitude error aperture ( 3.000)
NUV_MAGERR_APER_3	118	1E	mag	Magnitude error aperture ( 5.000)
NUV_MAGERR_APER_4	119	1E	mag	Magnitude error aperture ( 8.000)
NUV_MAGERR_APER_5	120	1E	mag	Magnitude error aperture ( 12.000)
NUV_MAGERR_APER_6	121	1E	mag	Magnitude error aperture ( 17.000)
NUV_MAGERR_APER_7	122	1E	mag	Magnitude error aperture ( 23.000)
NUV_FLUX_AUTO	123	1E	flux	Flux within a Kron-like elliptical aperture
NUV_FLUXERR_AUTO	124	1E	flux	RMS error for AUTO flux
NUV_MAG_AUTO	125	1E	mag	Kron-like elliptical aperture magnitude
NUV_MAGERR_AUTO	126	1E	mag	RMS error for AUTO magnitude
NUV_FLUX_BEST	127	1E	flux	Best of FLUX_AUTO and FLUX_ISOCOR
NUV_FLUXERR_BEST	128	1E	flux	RMS error for BEST flux
NUV_MAG_BEST	129	1E	mag	Best of MAG_AUTO and MAG_ISOCOR
NUV_MAGERR_BEST	130	1E	mag	RMS error for MAG_BEST
NUV_FLUX_RADIUS_1	131	1E	pixel	Fraction-of-light radius ( 0.2000)
NUV_FLUX_RADIUS_2	132	1E	pixel	Fraction-of-light radius ( 0.5000)
NUV_FLUX_RADIUS_3	133	1E	pixel	Fraction-of-light radius ( 0.8000)
NUV_FLUX_RADIUS_4	134	1E	pixel	Fraction-of-light radius ( 0.9000)
NUV_FLUX_RADIUS_5	135	1E	pixel	Fraction-of-light radius ( 0.9500)
NUV_ZPMAG	136	1E	mag	NUV zero point magnitude correction.
NUV_KRON_RADIUS	137	1E	pixel	Kron apertures in units of A or B
NUV_BACKGROUND	138	1E	count	Background at centroid position
NUV_THRESHOLD	139	1E	number	Detection threshold above background
NUV_MU_THRESHOLD	140	1E	number	Detection threshold above background
NUV_FLUX_MAX	141	1E	number	Peak flux above background
NUV_MU_MAX	142	1E	number	Peak surface brightness above background
NUV_ISOAREA_IMAGE	143	1E	number	Isophotal area above Analysis threshold
NUV_ISOAREA_WORLD	144	1E	number	Isophotal area above Analysis threshold
NUV_XMIN_IMAGE	145	1J	pixel	Minimum x-coordinate among detected pixels
NUV_YMIN_IMAGE	146	1J	pixel	Minimum y-coordinate among detected pixels
NUV_XMAX_IMAGE	147	1J	pixel	Maximum x-coordinate among detected pixels
NUV_YMAX_IMAGE	148	1J	pixel	Maximum y-coordinate among detected pixels
NUV_X_IMAGE	149	1E	pixel	Object position along x
NUV_Y_IMAGE	150	1E	pixel	Object position along y
NUV_XPEAK_IMAGE	151	1J	count	x-coordinate of the brightest pixel
NUV_YPEAK_IMAGE	152	1J	count	y-coordinate of the brightest pixel
NUV_ALPHA_J2000	153	1D	degrees	Right ascension of barycenter (J2000)
NUV_DELTA_J2000	154	1D	degrees	Declination of barycenter (J2000)
NUV_X2_IMAGE	155	1E	pixel	Variance along x
NUV_Y2_IMAGE	156	1E	pixel	Variance along y
NUV_XY_IMAGE	157	1E	pixel	Covariance between x and y
NUV_X2_WORLD	158	1E	number	Variance along X-WORLD (alpha)
NUV_Y2_WORLD	159	1E	number	Variance along Y-WORLD (delta)
NUV_XY_WORLD	160	1E	number	Covariance between X-WORLD and Y-WORLD
NUV_CXX_IMAGE	161	1E	number	Cxx object ellipse parameter
NUV_CYY_IMAGE	162	1E	number	Cyy object ellipse parameter
NUV_CXY_IMAGE	163	1E	number	Cxy object ellipse parameter
NUV_CXX_WORLD	164	1E	number	Cxx object ellipse parameter (WORLD units)
NUV_CYY_WORLD	165	1E	number	Cyy object ellipse parameter (WORLD units)
NUV_CXY_WORLD	166	1E	number	Cxy object ellipse parameter (WORLD units)
NUV_A_IMAGE	167	1E	number	Profile RMS along major axis
NUV_B_IMAGE	168	1E	number	Profile RMS along minor axis
NUV_A_WORLD	169	1E	number	Profile RMS along major axis (world units)
NUV_B_WORLD	170	1E	number	Profile RMS along minor axis (world units)
NUV_THETA_IMAGE	171	1E	degrees	Position angle (CCW/x)
NUV_THETA_WORLD	172	1E	degrees	Position angle (CCW/world-x)
NUV_THETA_J2000	173	1E	degrees	Position angle (east of north) (J2000)
NUV_ELONGATION	174	1E	number	A_IMAGE/B_IMAGE
NUV_ELLIPTICITY	175	1E	number	1 - B_IMAGE/A_IMAGE
NUV_ERRX2_IMAGE	176	1D	number	Variance of position along x
NUV_ERRY2_IMAGE	177	1D	number	Variance of position along y
NUV_ERRXY_IMAGE	178	1E	number	Covariance of position between x and y
NUV_ERRX2_WORLD	179	1D	number	Variance of position along X-WORLD (alpha)
NUV_ERRY2_WORLD	180	1D	number	Variance of position along Y-WORLD (delta)
NUV_ERRXY_WORLD	181	1E	number	Covariance of position X-WORLD/Y-WORLD
NUV_ERRCXX_IMAGE	182	1E	number	Cxx error ellipse parameter
NUV_ERRCYY_IMAGE	183	1E	number	Cyy error ellipse parameter
NUV_ERRCXY_IMAGE	184	1E	number	Cxy error ellipse parameter
NUV_ERRCXX_WORLD	185	1E	number	Cxx error ellipse parameter (WORLD units)
NUV_ERRCYY_WORLD	186	1E	number	Cyy error ellipse parameter (WORLD units)
NUV_ERRCXY_WORLD	187	1E	number	Cxy error ellipse parameter (WORLD units)
NUV_ERRA_IMAGE	188	1E	number	RMS position error along major axis
NUV_ERRB_IMAGE	189	1E	number	RMS position error along minor axis
NUV_ERRA_WORLD	190	1E	number	World RMS position error along major axis
NUV_ERRB_WORLD	191	1E	number	World RMS position error along minor axis
NUV_ERRTHETA_IMAGE	192	1E	number	Error ellipse position angle (CCW/x)
NUV_ERRTHETA_WORLD	193	1E	number	Error ellipse pos. angle (CCW/world-x)
NUV_ERRTHETA_J2000	194	1E	number	J2000 error ellipse pos. angle (east of north)
NUV_FWHM_IMAGE	195	1E	pixel	FWHM assuming a gaussian core
NUV_FWHM_WORLD	196	1E	deg	FWHM assuming a gaussian core
NUV_FLAGS	197	1I	value	Extraction flags
NUV_CLASS_STAR	198	1E	value	S/G classifier output
FUV source extraction catalog
FUV_NUMBER	199	1J	value	Running object number
FUV_FLUX_ISO	200	1E	flux	Isophotal flux
FUV_FLUXERR_ISO	201	1E	flux	RMS error for isophotal flux
FUV_MAG_ISO	202	1E	mag	Isophotal magnitude
FUV_MAGERR_ISO	203	1E	mag	RMS error for isophotal magnitude
FUV_FLUX_ISOCOR	204	1E	flux	Corrected isophotal flux
FUV_FLUXERR_ISOCOR	205	1E	flux	RMS error for corrected isophotal flux
FUV_MAG_ISOCOR	206	1E	mag	Corrected isophotal magnitude
FUV_MAGERR_ISOCOR	207	1E	mag	RMS error for corrected isophotal magnitude
FUV_FLUX_APER_1	208	1E	flux	Flux aperture ( 2.000)
FUV_FLUX_APER_2	209	1E	flux	Flux aperture ( 3.000)
FUV_FLUX_APER_3	210	1E	flux	Flux aperture ( 5.000)
FUV_FLUX_APER_4	211	1E	flux	Flux aperture ( 8.000)
FUV_FLUX_APER_5	212	1E	flux	Flux aperture ( 12.000)
FUV_FLUX_APER_6	213	1E	flux	Flux aperture ( 17.000)
FUV_FLUX_APER_7	214	1E	flux	Flux aperture ( 23.000)
FUV_FLUXERR_APER_1	215	1E	flux	Flux error aperture ( 2.000)
FUV_FLUXERR_APER_2	216	1E	flux	Flux error aperture ( 3.000)
FUV_FLUXERR_APER_3	217	1E	flux	Flux error aperture ( 5.000)
FUV_FLUXERR_APER_4	218	1E	flux	Flux error aperture ( 8.000)
FUV_FLUXERR_APER_5	219	1E	flux	Flux error aperture ( 12.000)
FUV_FLUXERR_APER_6	220	1E	flux	Flux error aperture ( 17.000)
FUV_FLUXERR_APER_7	221	1E	flux	Flux error aperture ( 23.000)
FUV_MAG_APER_1	222	1E	mag	Magnitude aperture ( 2.000)
FUV_MAG_APER_2	223	1E	mag	Magnitude aperture ( 3.000)
FUV_MAG_APER_3	224	1E	mag	Magnitude aperture ( 5.000)
FUV_MAG_APER_4	225	1E	mag	Magnitude aperture ( 8.000)
FUV_MAG_APER_5	226	1E	mag	Magnitude aperture ( 12.000)
FUV_MAG_APER_6	227	1E	mag	Magnitude aperture ( 17.000)
FUV_MAG_APER_7	228	1E	mag	Magnitude aperture ( 23.000)
FUV_MAGERR_APER_1	229	1E	mag	Magnitude error aperture ( 2.000)
FUV_MAGERR_APER_2	230	1E	mag	Magnitude error aperture ( 3.000)
FUV_MAGERR_APER_3	231	1E	mag	Magnitude error aperture ( 5.000)
FUV_MAGERR_APER_4	232	1E	mag	Magnitude error aperture ( 8.000)
FUV_MAGERR_APER_5	233	1E	mag	Magnitude error aperture ( 12.000)
FUV_MAGERR_APER_6	234	1E	mag	Magnitude error aperture ( 17.000)
FUV_MAGERR_APER_7	235	1E	mag	Magnitude error aperture ( 23.000)
FUV_FLUX_AUTO	236	1E	flux	Flux within a Kron-like elliptical aperture
FUV_FLUXERR_AUTO	237	1E	flux	RMS error for AUTO flux
FUV_MAG_AUTO	238	1E	mag	Kron-like elliptical aperture magnitude
FUV_MAGERR_AUTO	239	1E	mag	RMS error for AUTO magnitude
FUV_FLUX_BEST	240	1E	flux	Best of FLUX_AUTO and FLUX_ISOCOR
FUV_FLUXERR_BEST	241	1E	flux	RMS error for BEST flux
FUV_MAG_BEST	242	1E	mag	Best of MAG_AUTO and MAG_ISOCOR
FUV_MAGERR_BEST	243	1E	mag	RMS error for MAG_BEST
FUV_FLUX_RADIUS_1	244	1E	pixel	Fraction-of-light radius ( 0.2000)
FUV_FLUX_RADIUS_2	245	1E	pixel	Fraction-of-light radius ( 0.5000)
FUV_FLUX_RADIUS_3	246	1E	pixel	Fraction-of-light radius ( 0.8000)
FUV_FLUX_RADIUS_4	247	1E	pixel	Fraction-of-light radius ( 0.9000)
FUV_FLUX_RADIUS_5	248	1E	pixel	Fraction-of-light radius ( 0.9500)
FUV_ZPMAG	249	1E	mag	FUV zero point magnitude correction.
FUV_KRON_RADIUS	250	1E	pixel	Kron apertures in units of A or B
FUV_BACKGROUND	251	1E	count	Background at centroid position
FUV_THRESHOLD	252	1E	number	Detection threshold above background
FUV_MU_THRESHOLD	253	1E	number	Detection threshold above background
FUV_FLUX_MAX	254	1E	number	Peak flux above background
FUV_MU_MAX	255	1E	number	Peak surface brightness above background
FUV_ISOAREA_IMAGE	256	1E	number	Isophotal area above Analysis threshold
FUV_ISOAREA_WORLD	257	1E	number	Isophotal area above Analysis threshold
FUV_XMIN_IMAGE	258	1J	pixel	Minimum x-coordinate among detected pixels
FUV_YMIN_IMAGE	259	1J	pixel	Minimum y-coordinate among detected pixels
FUV_XMAX_IMAGE	260	1J	pixel	Maximum x-coordinate among detected pixels
FUV_YMAX_IMAGE	261	1J	pixel	Maximum y-coordinate among detected pixels
FUV_X_IMAGE	262	1E	pixel	Object position along x
FUV_Y_IMAGE	263	1E	pixel	Object position along y
FUV_XPEAK_IMAGE	264	1J	count	x-coordinate of the brightest pixel
FUV_YPEAK_IMAGE	265	1J	count	y-coordinate of the brightest pixel
FUV_ALPHA_J2000	266	1D	degrees	Right ascension of barycenter (J2000)
FUV_DELTA_J2000	267	1D	degrees	Declination of barycenter (J2000)
FUV_X2_IMAGE	268	1E	pixel	Variance along x
FUV_Y2_IMAGE	269	1E	pixel	Variance along y
FUV_XY_IMAGE	270	1E	pixel	Covariance between x and y
FUV_X2_WORLD	271	1E	number	Variance along X-WORLD (alpha)
FUV_Y2_WORLD	272	1E	number	Variance along Y-WORLD (delta)
FUV_XY_WORLD	273	1E	number	Covariance between X-WORLD and Y-WORLD
FUV_CXX_IMAGE	274	1E	number	Cxx object ellipse parameter
FUV_CYY_IMAGE	275	1E	number	Cyy object ellipse parameter
FUV_CXY_IMAGE	276	1E	number	Cxy object ellipse parameter
FUV_CXX_WORLD	277	1E	number	Cxx object ellipse parameter (WORLD units)
FUV_CYY_WORLD	278	1E	number	Cyy object ellipse parameter (WORLD units)
FUV_CXY_WORLD	279	1E	number	Cxy object ellipse parameter (WORLD units)
FUV_A_IMAGE	280	1E	number	Profile RMS along major axis
FUV_B_IMAGE	281	1E	number	Profile RMS along minor axis
FUV_A_WORLD	282	1E	number	Profile RMS along major axis (world units)
FUV_B_WORLD	283	1E	number	Profile RMS along minor axis (world units)
FUV_THETA_IMAGE	284	1E	degrees	Position angle (CCW/x)
FUV_THETA_WORLD	285	1E	degrees	Position angle (CCW/world-x)
FUV_THETA_J2000	286	1E	degrees	Position angle (east of north) (J2000)
FUV_ELONGATION	287	1E	number	A_IMAGE/B_IMAGE
FUV_ELLIPTICITY	288	1E	number	1 - B_IMAGE/A_IMAGE
FUV_ERRX2_IMAGE	289	1D	number	Variance of position along x
FUV_ERRY2_IMAGE	290	1D	number	Variance of position along y
FUV_ERRXY_IMAGE	291	1E	number	Covariance of position between x and y
FUV_ERRX2_WORLD	292	1D	number	Variance of position along X-WORLD (alpha)
FUV_ERRY2_WORLD	293	1D	number	Variance of position along Y-WORLD (delta)
FUV_ERRXY_WORLD	294	1E	number	Covariance of position X-WORLD/Y-WORLD
FUV_ERRCXX_IMAGE	295	1E	number	Cxx error ellipse parameter
FUV_ERRCYY_IMAGE	296	1E	number	Cyy error ellipse parameter
FUV_ERRCXY_IMAGE	297	1E	number	Cxy error ellipse parameter
FUV_ERRCXX_WORLD	298	1E	number	Cxx error ellipse parameter (WORLD units)
FUV_ERRCYY_WORLD	299	1E	number	Cyy error ellipse parameter (WORLD units)
FUV_ERRCXY_WORLD	300	1E	number	Cxy error ellipse parameter (WORLD units)
FUV_ERRA_IMAGE	301	1E	number	RMS position error along major axis
FUV_ERRB_IMAGE	302	1E	number	RMS position error along minor axis
FUV_ERRA_WORLD	303	1E	number	World RMS position error along major axis
FUV_ERRB_WORLD	304	1E	number	World RMS position error along minor axis
FUV_ERRTHETA_IMAGE	305	1E	number	Error ellipse position angle (CCW/x)
FUV_ERRTHETA_WORLD	306	1E	number	Error ellipse pos. angle (CCW/world-x)
FUV_ERRTHETA_J2000	307	1E	number	J2000 error ellipse pos. angle (east of north)
FUV_FWHM_IMAGE	308	1E	pixel	FWHM assuming a gaussian core
FUV_FWHM_WORLD	309	1E	deg	FWHM assuming a gaussian core
FUV_FLAGS	310	1I	value	Extraction flags
FUV_CLASS_STAR	311	1E	value	S/G classifier output

Primary Header Card for mcat.fits file

FITS Preamble

SIMPLE = T / file does conform to FITS standard

BITPIX = 16 / number of bits per data pixel

NAXIS = 0 / number of data axes

EXTEND = T / FITS dataset may contain extensions

COMMENT FITS (Flexible Image Transport System) format is defined in 'Astronomy

COMMENT and Astrophysics', volume 376, page 359; bibcode: 2001A&A...376..359H

ORIGIN = 'galexmerge.c'

Band Merger Input Files

NUVFILE = '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/CDFS_00-nd-cat.fits' / NUV source catalog file.

FUVFILE = '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/CDFS_00-fd-cat.fits' / FUV source catalog file.

NUVWTFIL= '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/CDFS_00-nd-rrhr.fits' / NUV weight image file.

FUVWTFIL= '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/CDFS_00-fd-rrhr.fits' / FUV weight image file.

NUVCNTFI= '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/CDFS_00-nd-cnt.fits' / NUV count image file.

FUVCNTFI= '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/CDFS_00-fd-cnt.fits' / FUV count image file.

NUVINTFI= '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/CDFS_00-nd-int.fits' / NUV intensity image file.

FUVINTFI= '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/CDFS_00-fd-int.fits' / FUV intensity image file.

NUVLWTFI= '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/CDFS_00-nd-wt.fits' / NUV literal weight (-wt.fits) file.

FUVLWTFI= '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/CDFS_00-fd-wt.fits' / FUV literal weight (-wt.fits) file.

NUVSKYFI= '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/CDFS_00-nd-skybg.fits' / NUV sky background image file.

FUVSKYFI= '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/CDFS_00-fd-skybg.fits' / FUV sky background image file.

NUVFLGFI= '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/CDFS_00-nd-flags.fits' / NUV artifact flags image file.

FUVFLGFI= '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/CDFS_00-fd-flags.fits' / FUV artifact flags image file.

MCHFILE = '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/CDFS_00-nd-cat_mch_rtastar.fits' / RTA star match file.

STARCAT = '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/CDFS_00-rtastar.fits'

RTA (Rectification, Transformation, and Aspect correction) values

NSTAR = 30

NMCH = 30

RMEAN = 0.536157456361519

RMEANSD = 0.0510420409592596

RSTDDEV = 0.279568772144891

RMIN = 0.13556304962726

RMAX = 1.1818926138633

Band Merger Parameters and Output Quantities

NUVS2N = 2. / Minimum S/N for NUV merges.

FUVS2N = 2. / Minimum S/N for FUV merges.

NUVS2NCU= 0. / S/N Cutoff for any NUV sources.

FUVS2NCU= 0. / S/N Cutoff for any FUV sources.

NUVNUM = 29869 / Number of NUV sources.

FUVNUM = 16377 / Number of FUV sources.

SEPLIM = 7. / Maximum separation in arcsec.

PROBLIM = 0. / Minimum probability for matches.

RPOSERR = 0.962917339842493 / Radial position error.

RA_CENT = 53.127785 / RA center for this field.

DEC_CENT= -27.871367 / DEC center for this field.

RAO = 53.127785 / RA center for this field.

DECO = -27.871367 / DEC center for this field.

TOTNUM = 33542 / Total number of sources.

TOTFILL = 12704 / Number of filled sources.

TOTUFN = 17165 / Number of unfilled NUV sources.

TOTUFF = 3673 / Number of unfilled FUV sources.

LRGNUVID= 29870 / Largest NUV ID number plus one.

N_ZPMAG = 20.0823753525469 / NUV Zero Point Magnitude

F_ZPMAG = 18.8170737879193 / FUV Zero Point Magnitude

N_ZPSCAL= 1. / NUV Zero Point Scale Factor

F_ZPSCAL= 1. / FUV Zero Point Scale Factor

CALMAG = 'AUTO ' / Calibration magnitude type

N_CUJ = 33.6539993286133 / NUV scale: pho/sec to micro Janskys

F_CUJ = 107.93399810791 / FUV scale: pho/sec to micro Janskys

R1 = 5. / Neighbor radius limit 1 (arcsec)

R2 = 10. / Neighbor radius limit 2 (arcsec)

R3 = 30. / Neighbor radius limit 3 (arcsec)

N_AMBG0 = 17063 / Number of NUV 0 ambig.

N_AMBG1 = 12704 / Number of NUV 1 ambig.

N_AMBG2 = 0 / Number of NUV 2 ambig.

N_AMBG3 = 102 / Number of NUV 3 ambig.

N_AMBG4 = 0 / Number of NUV 4 ambig.

N_AMBG5 = 0 / Number of NUV 5 ambig.

N_AMBG6 = 0 / Number of NUV 6 ambig.

N_AMBGM6= 0 / Number of NUV -6 ambig.

N_AMBGM1= 0 / Number of NUV -1 ambig.

F_AMBG0 = 3521 / Number of FUV 0 ambig.

F_AMBG1 = 12704 / Number of FUV 1 ambig.

F_AMBG2 = 0 / Number of FUV 2 ambig.

F_AMBG3 = 152 / Number of FUV 3 ambig.

F_AMBG4 = 0 / Number of FUV 4 ambig.

F_AMBG5 = 0 / Number of FUV 5 ambig.

F_AMBG6 = 0 / Number of FUV 6 ambig.

F_AMBGM6= 0 / Number of FUV -6 ambig.

F_AMBGM1= 0 / Number of FUV -1 ambig.

COMMENT AMBG 0: unfilled, no candidates, no ambiguity.

COMMENT AMBG 1: filled, first choice candidates agree, no ambiguity.

COMMENT AMBG 2: filled, first choice matches second choice candidate.

COMMENT AMBG 3: unfilled, first choice taken, no second choice candidate.

COMMENT AMBG 4: filled, second choice matches a first choice candidate.

COMMENT AMBG 5: filled, second choice matches a second choice candidate.

COMMENT AMBG 6: unfilled, first and second taken, no third choice.

COMMENT AMBG -6: unfilled, first and second taken, third choice exists.

COMMENT AMBG -1: unfilled, cleared, unchecked.

COMMENT AMBG -2: not applicable, does not exist, blank.

FILENAME= '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/CDFS_00-xd-mcat.fits'

DIRECTRY= '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/ '

VSN = 1 / Reduction version (high level)

TILENUM = 6051 / Tile number (a.k.a. field or target)

TYPE = 0 / Observation type (0=single,1=multi)

OW = 1 / Optics wheel (1=drct,2=grsm,3=opaq)

PROD = 1 / Reduction product number (type)

IMG = 1 / Image number (exposure or run)

TRY = 4 / Reduction try number (low level)

Common header cards from SExtractor (Source Extractor) Output

EPOCH = 2000.

OBJECT = 'CDFS_00_0037'

CRVAL1 = 53.127785

CRVAL2 = -27.871367

CRPIX1 = 1920.5

CRPIX2 = 1920.5

CDELT1 = -0.000416666666666667

CDELT2 = 0.000416666666666667

CROTA1 = 0.

CROTA2 = 0.

GRELEASE= 'ops-v4_0-RC2'

EQUINOX = 2000.

ECLIPSE = -999

LEG = -999

MPSNPOS = 0

VISIT = -1

SUBVIS = 0

ROLL = -999.

OBS-DATE= '2003-11-09'

OBSDATIM= 'unknown '

TILENAME= 'CDFS_00 '

PLANID = -1

MPSPHASE= 'G1 '

MPSPLAN = 'deep '

MPSTYPE = 'DIS '

AVASPRA = 53.1298646069532

AVASPDEC= -27.8761034951757

AVASPROL= 203.961542187749

AVASPOK = -999.

Aperture information for flux aperture columns

NUM_APER= 7 / Number of apertures.

SXAPER1 = 2. / Aperture #1 in pixels

SXAPER2 = 3. / Aperture #2 in pixels

SXAPER3 = 5. / Aperture #3 in pixels

SXAPER4 = 8. / Aperture #4 in pixels

SXAPER5 = 12. / Aperture #5 in pixels

SXAPER6 = 17. / Aperture #6 in pixels

SXAPER7 = 23. / Aperture #7 in pixels

NUM_FOL = 5 / Number of fraction-of-light radii.

SXFRAC1 = 0.2 / Fraction-of-light radius #1

SXFRAC2 = 0.5 / Fraction-of-light radius #2

SXFRAC3 = 0.8 / Fraction-of-light radius #3

SXFRAC4 = 0.9 / Fraction-of-light radius #4

SXFRAC5 = 0.95 / Fraction-of-light radius #5

General information (may not be applicable)

ABSCAL = ' '

CALINFO = ' '

STATFILE= ' '

ABSPIPE = ' '

PRUNDAT0= ' '

PRUNDAT1= ' '

NLEGS = -999

MPSCOW = ' '

PIPESTAT= -999

HISTORY NUV: HISTORY 14/11/04 21:48 Catalog created

Header card from NUV catalog file Sextractor Output

NEPOCH = 2000.

NOBJECT = 'CDFS_00_0037'

NORIGIN = 'SExtractor'

NCRVAL1 = 53.127785

NCRVAL2 = -27.871367

NCRPIX1 = 1920.5

NCRPIX2 = 1920.5

NCDELT1 = -0.000416666666666667

NCDELT2 = 0.000416666666666667

NCROTA1 = 0.

NCROTA2 = 0.

Sextractor Parameters and Outputs (NUV)

NSXIMASX= 3840 / IMAGE WIDTH (PIXELS) originally SEXIMASX

NSXIMASY= 3840 / IMAGE HEIGHT (PIXELS)

NSXSTRSY= 1024 / STRIP HEIGHT (LINES)

NSXIMABP= -32 / FITS IMAGE BITPIX

NSXPIXS = 1.5 / PIXEL SCALE (ARCSEC)

NSXSFWHM= 5.5 / SEEING FWHM (ARCSEC)

NSXNNWF = 'CDFS_00-nd-sexnnw.txt' / CLASSIFICATION NNW FILENAME

NSXGAIN = 44668.2 / GAIN (IN E- PER ADU)

NSXBKGND= 0. / MEDIAN BACKGROUND (ADU)

NSXBKDEV= 0.0003236696066 / MEDIAN RMS (ADU)

NSXBKTHD= 4.47745806E-05 / EXTRACTION THRESHOLD (ADU)

NSXCONFF= 'CDFS_00-nd-sexparams.txt' / CONFIGURATION FILENAME

NSXDETT = 'CCD ' / DETECTION TYPE

NSXTHLDT= 'SIGMA ' / THRESHOLD TYPE

NSXTHLD = 1. / THRESHOLD

NSXMINAR= 8 / EXTRACTION MINIMUM AREA (PIXELS)

NSXCONV = T / CONVOLUTION FLAG

NSXCONVN= T / CONVOLUTION NORM. FLAG

NSXCONVF= 'CDFS_00-nd-gauss_30_7x7.txt' / CONVOLUTION FILENAME

NSXDBLDN= 32 / NUMBER OF SUB-THRESHOLDS

NSXDBLDC= 0.0001 / CONTRAST PARAMETER

NSXCLN = T / CLEANING FLAG

NSXCLNPA= 1. / CLEANING PARAMETER

NSXCLNST= 32 / CLEANING OBJECT-STACK

NSXAPERD= 0 / APERTURE DIAMETER (PIXELS)

NSXAPEK1= 2.5 / KRON PARAMETER

NSXAPEK2= 2.5 / KRON ANALYSIS RADIUS

NSXAPEK3= 3.5 / KRON MINIMUM RADIUS

NSXSATLV= 999999999. / SATURATION LEVEL (ADU)

NSXMGZPT= 0. / MAGNITUDE ZERO-POINT

NSXMGGAM= 4. / MAGNITUDE GAMMA

NSXBKGSX= 64 / BACKGROUND MESH WIDTH (PIXELS)

NSXBKGSY= 64 / BACKGROUND MESH HEIGHT (PIXELS)

NSXBKGFX= 3 / BACKGROUND FILTER WIDTH

NSXBKGFY= 3 / BACKGROUND FILTER HEIGHT

NSXPBKGT= 'GLOBAL ' / PHOTOM BACKGROUND TYPE

NSXPBKGS= 24 / LOCAL AREA THICKNESS (PIXELS)

NSXPIXSK= 1500000 / PIXEL STACKSIZE (PIXELS)

NSXFBUFS= 1024 / FRAME-BUFFER SIZE (LINES)

NSXISAPR= 0. / ISO-APER RATIO

NSXNDET = 34770 / NB OF DETECTIONS

NSXNFIN = 29869 / NB OF FINAL EXTRACTED OBJECTS

NSXNPARA= 84 / NB OF PARAMETERS PER OBJECT

NUV Image and Exposure Data

NGRELEAS= 'ops-v4_0-RC2'

NCTYPE1 = 'RA---TAN'

NCTYPE2 = 'DEC--TAN'

NEQUINOX= 2000.

NRA_CENT= 53.127785

NDEC_CEN= -27.871367 / originally DEC_CENT

NTWIST = 0.

NECLIPSE= -999

NGRSPA = -999.

NLEG = -999

NMPSNPOS= 0

NVISIT = -1

NSUBVIS = 0

NMINIVIS= 0

NOW = 1

NBAND = 1

NROLL = -999.

NEXPTIME= 44668.2

NEXPSTAR= 1068392837.995 / originally EXPSTART

NEXPEND = 1070755524.985

NOBS-DAT= '2003-11-09' / originally OBS-DATE

NTIME-OB= '15:47:18' / orig:TIME-OBS, was OBS-TIME

NOBSSECS= -1.

NOBSDATI= 'unknown ' / originally OBSDATIM

NTILENAM= 'CDFS_00 ' / originally TILENAME

NTILENUM= 6051

NPLANID = -1

NMPSPHAS= 'G1 ' / originally MPSPHASE

NMPSPLAN= 'deep '

NMPSTYPE= 'DIS '

NIMAGSZX= 3840

NIMAGSZY= 3840

NAVASPRA= 53.1298646069532

NAVASPDE= -27.8761034951757

NAVASPRO= 203.961542187749

NAVASPOK= -999.

NCALPATH= ' '

NFLATFL = ' '

NINTIMAG= '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/CDFS_00-nd-int.fits' / originally INTIMAGE

NPHOFILE= ' '

NNVALIDP= -1 / originally NVALIDPH

NFILTERE= 1 / originally FILTERED

NPSFFWHM= 4.5

NTEDMODE= 1

NSIGTHRE= -999

NABSTHRE= 2

NABSCAL = ' '

NCALINFO= ' '

NSTATFIL= ' '

NABSPIPE= ' '

NPRUNDA0= ' '

NPRUNDA1= ' '

NNLEGS = -999

NMPSCOW = ' '

NPIPESTA= -999

HISTORY FUV: HISTORY 14/11/04 22:00 Catalog created

Header cards from FUV catalog file Sextractor Output

FEPOCH = 2000.

FOBJECT = 'CDFS_00_0037'

FORIGIN = 'SExtractor'

FCRVAL1 = 53.127785

FCRVAL2 = -27.871367

FCRPIX1 = 1920.5

FCRPIX2 = 1920.5

FCDELT1 = -0.000416666666666667

FCDELT2 = 0.000416666666666667

FCROTA1 = 0.

FCROTA2 = 0.

Sextractor Parameters and Outputs (FUV)

FSXIMASX= 3840 / IMAGE WIDTH (PIXELS) originally SEXIMASX

FSXIMASY= 3840 / IMAGE HEIGHT (PIXELS)

FSXSTRSY= 1024 / STRIP HEIGHT (LINES)

FSXIMABP= -32 / FITS IMAGE BITPIX

FSXPIXS = 1.5 / PIXEL SCALE (ARCSEC)

FSXSFWHM= 5. / SEEING FWHM (ARCSEC)

FSXNNWF = 'CDFS_00-fd-sexnnw.txt' / CLASSIFICATION NNW FILENAME

FSXGAIN = 44667.95 / GAIN (IN E- PER ADU)

FSXBKGND= 0. / MEDIAN BACKGROUND (ADU)

FSXBKDEV= 7.131370512E-05 / MEDIAN RMS (ADU)

FSXBKTHD= 4.477483162E-05 / EXTRACTION THRESHOLD (ADU)

FSXCONFF= 'CDFS_00-fd-sexparams.txt' / CONFIGURATION FILENAME

FSXDETT = 'CCD ' / DETECTION TYPE

FSXTHLDT= 'SIGMA ' / THRESHOLD TYPE

FSXTHLD = 1. / THRESHOLD

FSXMINAR= 8 / EXTRACTION MINIMUM AREA (PIXELS)

FSXCONV = T / CONVOLUTION FLAG

FSXCONVN= T / CONVOLUTION NORM. FLAG

FSXCONVF= 'CDFS_00-fd-gauss_30_7x7.txt' / CONVOLUTION FILENAME

FSXDBLDN= 32 / NUMBER OF SUB-THRESHOLDS

FSXDBLDC= 0.0001 / CONTRAST PARAMETER

FSXCLN = T / CLEANING FLAG

FSXCLNPA= 1. / CLEANING PARAMETER

FSXCLNST= 32 / CLEANING OBJECT-STACK

FSXAPERD= 0 / APERTURE DIAMETER (PIXELS)

FSXAPEK1= 2.5 / KRON PARAMETER

FSXAPEK2= 2.5 / KRON ANALYSIS RADIUS

FSXAPEK3= 3.5 / KRON MINIMUM RADIUS

FSXSATLV= 999999999. / SATURATION LEVEL (ADU)

FSXMGZPT= 0. / MAGNITUDE ZERO-POINT

FSXMGGAM= 4. / MAGNITUDE GAMMA

FSXBKGSX= 64 / BACKGROUND MESH WIDTH (PIXELS)

FSXBKGSY= 64 / BACKGROUND MESH HEIGHT (PIXELS)

FSXBKGFX= 3 / BACKGROUND FILTER WIDTH

FSXBKGFY= 3 / BACKGROUND FILTER HEIGHT

FSXPBKGT= 'GLOBAL ' / PHOTOM BACKGROUND TYPE

FSXPBKGS= 24 / LOCAL AREA THICKNESS (PIXELS)

FSXPIXSK= 1500000 / PIXEL STACKSIZE (PIXELS)

FSXFBUFS= 1024 / FRAME-BUFFER SIZE (LINES)

FSXISAPR= 0. / ISO-APER RATIO

FSXNDET = 19913 / NB OF DETECTIONS

FSXNFIN = 16377 / NB OF FINAL EXTRACTED OBJECTS

FSXNPARA= 84 / NB OF PARAMETERS PER OBJECT

FGRELEAS= 'ops-v4_0-RC2'

FUV Image and Exposure Data

FCTYPE1 = 'RA---TAN'

FCTYPE2 = 'DEC--TAN'

FEQUINOX= 2000.

FRA_CENT= 53.127785

FDEC_CEN= -27.871367 / originally DEC_CENT

FTWIST = 0.

FECLIPSE= -999

FGRSPA = -999.

FLEG = -999

FMPSNPOS= 0

FVISIT = -1

FSUBVIS = 0

FMINIVIS= 0

FOW = 1

FBAND = 2

FROLL = -999.

FEXPTIME= 44667.95

FEXPSTAR= 1068392837.995 / originally EXPSTART

FEXPEND = 1070755524.985

FOBS-DAT= '2003-11-09' / originally OBS-DATE

FTIME-OB= '15:47:18' / orig:TIME-OBS, was OBS-TIME

FOBSSECS= -1.

FOBSDATI= 'unknown ' / originally OBSDATIM

FTILENAM= 'CDFS_00 ' / originally TILENAME

FTILENUM= 6051

FPLANID = -1

FMPSPHAS= 'G1 ' / originally MPSPHASE

FMPSPLAN= 'deep '

FMPSTYPE= 'DIS '

FIMAGSZX= 3840

FIMAGSZY= 3840

FAVASPRA= 53.1298645875342

FAVASPDE= -27.8761079159628

FAVASPRO= 203.961523402068

FAVASPOK= -999.

FCALPATH= ' '

FFLATFL = ' '

FINTIMAG= '/home/runes5/fltops/pipe/01-vsn/06051-CDFS_00/d/01-main/0001-img/04&'

CONTINUE '-try/CDFS_00-fd-int.fits' / originally INTIMAGE

FPHOFILE= ' '

FNVALIDP= -1 / originally NVALIDPH

FFILTERE= 1 / originally FILTERED

FPSFFWHM= 4.5

FTEDMODE= 1

FSIGTHRE= -999

FABSTHRE= 2

FABSCAL = ' '

FCALINFO= ' '

FSTATFIL= ' '

FABSPIPE= ' '

FPRUNDA0= ' '

FPRUNDA1= ' '

FNLEGS = -999

FMPSCOW = ' '

FPIPESTA= -999

DATE = '2004-11-15T06:08:10' / file creation date (YYYY-MM-DDThh:mm:ss UT)

END

6. Pipeline Products Gallery

The images below show ds9 snapshots of some of the main pipeline image products. FUV images are on the left, NUV on the right. Specific details can be seen in the magnifier image (upper right), which is providing a zoom around the cursor position (indicated by the white arrow in the image). (Note that the figures are described in the text precedes the image.)

These images have been obtained from the pipeline a single visit to the target M51 (NGA_M51_0001)

Dose Map

The dose map contains photon positions in the instrument frame. The full field of view is 65 mm diameter, or 1.24 degrees in the telescope focal plane. Note that the NUV image frame is rotated 180 degrees from the FUV frame.

Because of the dither motion by the satellite, stars and galaxies move in this frame during an observation (appearing in this image as donuts or smeared objects). Point sources in these images are “detector hot spots” which are masked in further processing.

The four points at the corners of the images are generated by electronic stimulus pulses in the detector system. These are used for calibration of electronic drift and dead time corrections only and do not show up in the final images.

Count Map

The combination of time-tagged photon positions and satellite aspect satellite are used to generate a count map in sky coordinates. This observation was acquired at a roll angle of 90 degrees (measured with respect to the Y axis of the detector/instrument frame), which explains why the image is rotated with respect to the dose maps above.

The image quantities are in units of counts per pixel. Each pixel is 1.5”x1.5”. Note that at the position of the arrow, 50 counts were detected in this exposure.

Relative Response Map

The high resolution relative response map shows the effective normalized instrument response (based on flat field) * exposure (seconds) projected onto the sky. The small annuli are in regions of the detector active area (hot spots) which have been masked in pipeline processing. The annular shape results from the removal of the dither pattern used in pointing during observations.

Over most of the active area, the response varies by less than +/- 20%. The FUV detector shows much larger response variation across the field, particularly on one side where the response drops off significantly.

Intensity map

The intensity map is generated by dividing the count map by the relative response map. The units are in counts / pixel s (normalized effective area*bandwidth), which means that while the image is ‘flattened’ to reflect the true instrument response, the units correspond roughly to counts per second per pixel. At the position of the arrow (highlighted in the magnifier), we detected ~ 0.082 counts/(s normalized EA pixel) in the NUV image. This can easily be converted to a surface brightness using the conversion factors provided in the table above.

Note that in the low response region of the FUV detector, the average level is relatively flat, but the image becomes noisy as expected due to the low throughput in this region.

Sky Background Map

The GALEX pipeline generates a smoothed sky background map which is subtracted from the intensity image prior to the final source extraction processing step. See: Background_determination_and_source_extraction_for_GALEX_data.pdf

Grism Intensity Maps

Intensity maps are also built up in grism mode. The quad image below shows imaging and grism intensity maps of the ELAISS1_00 field. The grism data are from a single visit (and grism rotation).

7. GALEX Image Artifacts

The GALEX optics and detector produce several image artifacts which the pipeline flags to indicate regions where analysis problems may arise. Most image artifacts are observed in the NUV channel due to a bevel on the edge of the NUV window and the abundance of bright stars detected vs. the FUV. The principal artifacts are:

• Bright star halos (both)
• Bright star NUV beveled edge reflections (NUV only)
• Dichroic ghosts (NUV only)
• Detector window ghosts (both)
• Near-field stray light from bright stars

Other artifacts are produced by transient effects. These include

• Unmasked detector hot spots (hot spot masks are updated occasionally as hot spot come and go)
• Satellite transits
• Asteroid motion
• Local flaring of detector count rate caused by South Atlantic Anomaly, solar activity

The pipeline flags possible artifacts for the NUV detector and masks known detector hot spots.

Table 3.3 -- Artifact Gallery

Artifact	Pipeline Flag	Picture [NUV=red/yellow, FUV=blue]
Bright star halo [NUV] Due to diffraction, and electron halo due to proximity focused photocathode.	NONE
Bright star halo [FUV]	NONE
Ghosts—Window & Dichroic The small ghost to the upper right is due to the dichroic beam splitter. It is offset along the detector Y-axis (instrument X-axis) and oblique due to the oblique angle of the beam splitter. The largest (dim red, lower) ghost is due to the 10 mm thick NUV detector window. Detector window ghosts are radially offset due to curvature on the window.
FUV hot spot Normally masked out in pipeline, new hotspots not in database will appear as spiral dither pattern (since hot spots are fixed in detector coordinates and the aspect is corrected to account for the dithered pointing during observations).
NUV Window Bevel Reflection – Edge Ghost The NUV window has a beveled interior surface required to locate the photocathode surface close to the microchannel plate surface. Total internal reflection causes light from stars within 5 arcminutes of the edge to reflect into the field of view. Depending on the exact location of the star, a ghost image can be produced far inside the field of view, as shown in the next image
NUV Window Bevel Reflection – Interior Ghost