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Welcome to the Orion HST Images directory. This directory contains the following files: mosaicf502.fits mosaicf547.fits mosaicf656.fits mosaicf658.fits mosaiccolor.tiff pltsolballf547 fov*f*.fits EROf*.fits GO5469PCf*.fits GO5469WFf*.fits The mosaic*.fits files are fits format images, each containing a single Orion image. The f... designation indications which WFPC2 filter was used. f502 is the F502N [OIII] filter, f547 is the F547M narrow V filter, f656 is the F656N Halpha filter, and f658 is the F658N [NII] filter. The normalization is to the exposure times in the program GO 5085, i.e. f656n(200S), f658n(500s), f502n(200s), f547m(50s). These images are not purely the targeted emission-line because they all contain some contribution from the continuum and sometimes nearby lines. The method of calibration and separation of the components of the signal are described in a paper by C. R. O'Dell and T. Doi (1999 PASP, 111, 1316-1320). The images are each a composite of multiple pointings by the WFPC2 camera. Each pointing produced a four part single image through the STSDAS task wmosaic from cosmic ray cleaned sets of of individual CCD frames. The different wmosaic images were then combined using the imcombine task after orienting the central wmosaic images to north up, then pasting on the outer wmosaic images by using stars in overlapping zones for getting the relative orientations. The resulting mosaic images are 4999x5999 pixels. The data files are big, each being 114.4MB. The creation of these images are described in C. R. O'Dell and S.-K. Wong 1996,AJ,11,846. The relation of the x,y values to the RA and DEC is the same for all the fits images. The calculation of x,y values from known RA and DEC can be done with the STSDAS task (stsdas.analysis.gasp) "eqxy" while conversion from x,y to RA and DEC is done with task "xyeq". The parameter configuration for each is copied below: Image Reduction and Analysis Facility PACKAGE = gasp TASK = xyeq iminfo = no Is there an input image image = Input image name coeffile= pltsolballf547 Input astrometic solution file xyfile = STDIN Input (x,y) file name pix_cent= iraf X,Y origin: iraf(1,1); dss(1.5,1.5); cos(0.5,0. xcolnum = 1 X pixel column number ycolnum = 2 Y pixel column number nskip = 0 Number of lines to skip in xy file (origina= no) Use original plate solution? (new = no) Use new plate solution? (cdmatx = no) Use CD matrix values? (ra_hour= yes) Display RA in h
Ⓜ️s? (ra_form= %12.2h) Output format for RA (dec_for= %12.2h) Output format for DEC (mode = al) Image Reduction and Analysis Facility PACKAGE = gasp TASK = eqxy iminfo = no Is there an input image image = Input image name coeffile= pltsolballf547 Input astrometic solution f rdfile = STDIN Input (ra,dec) file name pix_cent= iraf X,Y origin: iraf[1,1]; dss[1.5,1.5]; cos[.5,.5] rcolnum = 1 ra column number dcolnum = 2 dec column number nskip = 0 Number of lines to skip in rd file (origina= no) Use original plate solution? (new = no) Use new plate solution? (cdmatx = no) Use CD matrix values? (ra_hour= yes) Are RA values in h Ⓜ️s? (xformat= %12.2h) Output format for X (yformat= %12.2h) Output format for Y (mode = al) The mosaiccolor.tiff is a full resolution color image made from mosaic658(Red), mosaicf656(Green), and mosaicf502(Blue) using logarithmic display of intensity. The image is big, i.e. 49.8MB. The fov*f*.fits images are WFPC2 cosmic ray cleaned images prior to being turned into a mosaic using task wmosaic. These are the highest spatial resolution images. Each file contains the four CCD images separately with the PC 0.0455"/pixel first, followed by the 0.0996"/pixel WFC images. The fov* indicates which pointing from program GO 5085 is meant. To determine the field of view, look at Figure 1 of O'Dell & Wong 1996. The fields are drawn, but not numbered there. The cartoon below shows the numbering. fov10 fov3 fov4 fov1 GO 5469 fov5 ERO5193 fov2 fov7 fov8 fov6 fov9 The ERO5193f*.fits files are were generated with wmosaic from the cosmic-ray event cleaned images described in O'Dell & Wong 1996 and analyzed in the publication C. R. O'Dell & Z. Wen 1994,ApJ,436,194. Their single pointing is also shown in O'Dell & Wong's Figure 1 and the position is in the above cartoon. The GO5469PCf*.fits images are mosaics of images in the PC (CCD#1) images from program GO 5469. It employed 4 slightly different pointings and used relatively short exposures and extended the usual list of filters to also include F631N (isolating the [OI] 6300 and [SIII] 6312 lines) and F673N (isolating the [SII] doublet at 6717+6731). Because of the shifting required to aligh the images, the resolution is slightly degraded from an individual PC image. The pointings are shown in the above cartoon and O'Dell and Wong's Figure 1. The GO5469WFf*.fits images are mosaics of images from program GO 5469 at a scale of 0.0996"/pixel processed similarly to the PC images described above. These images were used in the article C. R. O'Dell 1998,AJ,115,263. If you have questions, please direct them to Bob O'Dell at "email@example.com". Bon Appetit!