SExtractor Draft - METU Astrophysics

9OBJECTS-OBJECTSAPERTURESSEGMENTATION– detected objects,– background-subtracted image withdetected objects blanked,– MAG APER and MAG AUTO integrationlimits,– display patches corresponding topixels attributed to each object.CLEAN — boolean If true, a “cleaning” of the catalogueis done before being written to disk.CLEAN PARAM — float Efficiency of “cleaning”.DEBLEND MINCONT — float Minimum contrast parameter for deblending.DEBLEND NTHRESH — integer Number of deblending sub-thresholds.DETECT MINAREA — integer Minimum number of pixels abovethreshold triggering detection.DETECT THRESH — floats (n ≤ 2) Detection threshold. 1 argument:(ADUs or relative to Background RM-S, see THRESH TYPE). 2 arguments: µ(mag.arcsec −2 ), Zero-point (mag).DETECT TYPE CCD keyword Type of device that produced the image:CCD– linear detector like CCDs or NIC-MOS,PHOTO– photographic scan.FILTER — boolean If true, filtering is applied to the databefore extraction.FILTER NAME — string Name of the file containing the filterdefinition.FILTER THRESH floats (n ≤ 2) Lower and higher thresholds (in backgroundstandard deviations) for a pixelto be considered in filtering (usedfor retina-filtering only).FITS UNSIGNED N boolean Force 16-bit FITS input data to be interpretedas unsigned integers.FLAG IMAGE flag.fits strings (n ≤ 4) File name(s) of the “flag-image(s)”.FLAG TYPE OR keyword Combination method for flags on thesame object:OR– arithmetical OR,AND– arithmetical AND,MIN– minimum of all flag values,MAX– maximum of all flag values,MOST– most common flag value.GAIN float “Gain” (conversion factor ine − /ADU) used for error estimates ofCCD magnitudes .INTERP MAXXLAG 16 integers (n ≤ 2) Maximum x gap (in pixels) allowed ininterpolating the input image(s).INTERP MAXYLAG 16 integers (n ≤ 2) Maximum y gap (in pixels) allowed ininterpolating the input image(s).