1 ASTROMETRIC ASTROMETRIC [RAmin RAmax DECmin DECmax] [/MAGNITUDE Mlim] [/EPOCH date] [/OUTPUT File] [/EQUINOX date] Searches and plots all astrometric stars of magnitude less than Mlim (brighter than Mlim) in the (RA,DEC) box specified by RAmin RAmax DECmin DECmax (if present; otherwise, in the current Greg box provided that the coordinate system is equatorial). The current marker type is used and the size depends on the current marker size and on the star magnitude. Proper motions are included to represent the sky at the date specified in the /EPOCH option if present, at the current day otherwise. The stars are precessed to the equinox specified by option /EQUINOX if present, and otherwise to the equinox defined in variable G_EPOCH. If option /OUTPUT is present, star positions, magnitudes, spectral types and names are written in the specified file (which defaults to user terminal). NOTES: - Palomar/SRC Survey Schmidt Plates (POSS#I) are squares of size 35.56 cm (14 inches) with a scale of 67.14 Arcsec. per mm. - ESO Survey Plates are squares of size 30 cm with a scale of 67.6 Arcsec. per mm. If you want to make overlays, do not forget the /EXACT option in command HARDCOPY/PLOT ... 1 GSC GSC [RAmin RAmax DECmin DECmax] [/MAGNITUDE Mlim] [/EPOCH date] [/OUTPUT File Ident] [/MERGE] Search and plots all stars in the Guide Star Catalog with magnitude less than Mlim (brighter than Mlim) in the (RA,DEC) box specified by RAmin RAmax DECmin DECmax (if present, and in the current Greg box otherwise, provided that the coordinate system is equatorial). Please note that the very brightest stars (V<6) have only been added at version 1.1 and will be missing if you are using GSC version 1.0. Most of them can be obtained by using the ASTROM command. The current marker type is used and the size depends on the current marker size and on the star magnitude. No proper motion is applied as this information is not available in versions 1.x of the GSC catalog. The /EPOCH option is therefore not used. If option /EQUINOX is present, the stars are precessed to the equinox it specifies. They are otherwise precessed to the equinox of the map, as defined in variable G_EPOCH. If option /OUTPUT is present, star positions and magnitudes with their error estimates, are written in the specified file (which defaults to user terminal), together with some ancillary Guide Star Catalog information (original plate, multiplicity flag,...). The presence of the second argument, Ident, will generate an identification number for each star in the output file, and plot this number near the star's position on the graphic display. Useful for identification purposes. The list of information stored in the file is located under subtopic Format If option /MERGE is present, multiple detections of objects on overlapping plates are merged (by simple averaging). Individual entries are otherwise plotted and listed. NOTES: - Palomar/SRC Survey Schmidt Plates (POSS#I) are squares of size 35.56 cm (14 inches) with a scale of 67.14 Arcsec. per mm. - ESO Survey Plates are squares of size 30 cm with a scale of 67.6 Arcsec. per mm. If you want to make overlays, do not forget the /EXACT option in command HARDCOPY/PLOT ... 2 FORMAT Format of table lines is ([i4],I5,F9.5,F9.5,F5.1,F5.2,F4.2,I2,I1,A4,A1) for * [optional star Ident number] * ID within region * RA (degrees) * DEC (degrees) * Position error (arc seconds) * Magnitude * Magnitude error * Magnitude band * Classification * Plate ID * Multiplicity flag 1 HEADER HEADER [Image_Name] /EXTREMA Compute the extrema of the current or specified image, and update the header accordingly. HEADER /UPDATE Update the header of the current image, for example after modifications to the G_* header variables have been made. The header variables are G_NDIM Number of dimensions G_DIM[4] Image dimensions G_CONVERT[3,4] Conversion formula (Ref, Val, Inc for each axis) G_BLANK[2] Blanking and tolerance G_MAX Maximum value G_MIN Minimum value G_EXTREMA Zero (0) if no extrema defined G_WHERE[2,4] Pixel of maximum and minimum G_UNITi Units of axis i G_UNIT Units of map G_COORD System coordinates G_SOURCE Source name G_EPOCH Epoch of coordinates G_RA Right Ascension (of Object) G_DEC Declination (of Object) G_LII Galactic longitude (of Object) G_BII Galactic latitude (of Object) G_PTYP Projection Type (0:none,1:Gnomonic,2:Orthographic, 3:Azimuthal,4:Stereographic,5:Lambert,6:Aitoff,7:Radio). Warning: these codes are subject to change without notice. G_XAXI The first axis of projection (1,2,3 or 4) G_YAXI The second axis of projection (1,2,3 or 4) G_A0 Position of projection center for axis G_XAXI (R.A. or LII) G_D0 Position of projection center for axis G_YAXI (DEC. or BII) G_ANGLE Angle of projection (East of North) G_LINE Line name G_FREQRES Frequency resolution G_RESTFRE Signal rest frequency G_FREQOFF Image rest frequency G_VELRES Velocity resolution G_VELOFF Velocity of reference channel G_PA Position angle of beam G_MINOR Minor axis size of beam G_MAJOR Major axis size of beam G_BEAM Size of RESOLUTION section (0 or 3) HEADER [Image_Name] [/OUTPUT FIle_Name] Give the Header of the current or specified Image, on the screen or in the specified output file. Provided you have write access to the image and nobody else is already using it, the header may be editted if the terminal is a VT100 compatible. The keys of the VT100 keypad have the same meaning as in EDT: +--------+--------+--------+--------+ | enter | | | Del L | | edit | | | | +--------+--------+--------+--------+ | print | | | Del W | | header| | | | +--------+--------+--------+--------+ | Advance| Backup | | Del C | | | | | | +--------+--------+--------+--------+ | Word | Eol | Char | | | | | | Enter | +--------+--------+--------+ | | Line | |(Update)| | | | | +-----------------+--------+--------+ To edit a field, press the GOLD (PF1) key. To compute MAXIMA and MINIMA of current image, strike ENTER key. Strike <^Z> to exit. The header will be automatically updated if any modification has been made. 1 IMAGE IMAGE [Filename] [/PLANE I1 I2] [/SUBSET Imin Imax Jmin Jmax] [/WRITE] Read the GDF map Filename. The default image extension is .GDF This command defines the image found in given file as the new current image. Projection, system and extremas are also defined if needed. Unless options are present, the first plane of the image becomes the new Regular Grid array in GreG. The /PLANE I1 I2 option allows to define part of a more than 2- Dimensional image as the regular grid array. A file name should not be specified if you want to select a new plane in the current image. The /SUBSET Imin Imax Jmin Jmax option allows to load only a subset of the input image or image plane. Again, a file name should be specified only to change the input image. The /WRITE option allows you to map the image writeable (instead of Readonly by default), a prerequisite to use some functions (e.g. KILL which kills pixels). The mapped image is then non-shareable by other users... You can combine /PLANE and /SUBSET options. 1 IRAS IRAS Band [Ramin Ramax Decmin Decmax] [/FLUX Threshold] [/SIZE Flux_value] Plots a marker at the position of all IRAS point sources detected at band Band (specified by its wavelength in microns 12, 25, 60 or 100) in the area defined by Ramin, Ramax (in hours), Decmin, Decmax (in degrees). If the option /FLUX is given, only sources with a flux greater than Threshold will be select. If the option /SIZE is given, the marker size will be proportional to the logarithm of the flux (sources with a flux equal to Flux_value having the current marker size as specified by SET MARKER command). The current marker type is used. Command IRAS completely ignores the current GreG box to select the IRAS point sources, but the markers will be clipped in this box when plotted. Hence, it is up to the user to ensure that the system is EQUATORIAL and that the projection area (specified by command LIMITS and PROJECTION) reasonably matches the selection area specified in command IRAS. 1 KILL KILL KILL calls the interactive cursor. Recognised keys are: - V to give the value of the pixel - K to give the current blanking value to the pixel - I to interpolate the value from the neighbour pixels. - E to exit from interactive cursor mode Any other key is ignored. 1 Language GRAPHIC\ Language Summary ASTROMETRIC : Plots astrometric star positions (for finding charts) HEADER : Give the Header of the current Image. IMAGE [Filename]: Read the GDF map Filename. Default extension is .GDF IRAS Band : Select and plot IRAS sources of a given band KILL : Kills pixels. PSC_IRAS : Get characteristics of IRAS point source REGRESSION [Val]: Computes regression lines SPECTRUM : Extract a spectrum from an image (to plot it). 1 PSC_IRAS [ALL\]PSC_IRAS [Ra. Dec.] [/OUTPUT Filename] [/LOOK Around] Find IRAS characteristics of point sources around the specified position. If no position is given, it calls the interactive cursor, and uses the returned coordinates to look for all IRAS sources around this point. The value Around (argument of option /LOOK) is the size of the search area in arc minutes (default 1). The result depends whether the full compact catalog is on line or not. - If not, the fluxes of the sources found in the search box are typed on the screen. - If it is on line, full information about the sources is either typed on the screen, or written on the file specified by the argument Filename of option /OUTPUT. In addition, a binary output file (whose name is PSCSUB.TAB) is produced. This binary file is suited for later processing by the Point Source Catalog software. The same files (formatted and binary) are used for multiple use of this command (unless the Filename is explicitely changed). 2 FORMAT The listing produced by PSC_IRAS or the IRAS command has the following format : Right Ascension Sexagesimal notation in Hours Declination Sexagesimal notation in Degrees Lii (Degrees) Bii (Degrees) Semi-Major axis of position uncertainty ellipsis ( Arc Seconds Semi-Minor axis of position uncertainty ellipsis 95 confidence) Position Angle of the uncertainty ellipsis. (Degrees from North) Number of Hour confirmations Number of LRS spectra Type of LRS spectra Variability flag Discrepant flux flag Confusion flux flag Number of nearby hour confirmed point sources Number of nearby week confirmed point sources High source density bin flag CIRR1 Cirrus flag 1 CIRR2 Cirrus flag 2 CIRR3 100 micron sky brightness (MJy/Sr) Number of identifications Type of identifications For each flux (12, 25, 60 100 microns) Flux (Jy) Flux quality (1 upper limit, 2 poor, 3 good) Calibration uncertainty (%) Signal to noise ratio multiplied by 10 Point source correlation coefficient Number of hour confirmed small extended sources Number of week confirmed small extended sources Identifications (one line per identification) Name Catalog dependant informations Catalog name 1 REGRESSION REGRESSION Nmin [/RANGE [X Xmin Xmax] [Y Ymin Ymax]] Computes linear regressions in a image which is the correlation of two coincident images. The regression lines Y = A * X + B and X = A'* Y + B' are computed assuming the weight of any (X,Y) is the value of the pixel at X,Y. Nmin is the minimum pixel value considered as significant. 1 SPECTRUM SPECTRUM I [J [K]] Extract a spectrum from an image according to the following numbering : Spectrum (l) = Image (l,i,j,k) for a 4-dimensional image. The spectrum is loaded into the X,Y buffers of GreG. It can be processed later by the standard commands LIMITS, CONNECT, CURVE and so on.