The IRAF V2.11 upgrade for OpenVMS running on the VAX and the DEC Alpha is now available from our network archives on iraf.noao.edu in the /iraf/v211/VMS7/ directory. The README file in this directory contains details pertaining to the release. With the VMS/IRAF release IRAF V2.11 is now available for all currently supported IRAF platforms including SunOS and Solaris, Dec Alpha systems running Digital Unix V4.0, Hewlett-Packard systems running HP-UX 10.20, SGI IRIX, IBM AIX, and PC-IRAF platforms including Slackware Linux V3.3, Red Hat Linux V5.0, and FreeBSD V2.2.5.
A few sites have received Solaris 7 and have been asking about IRAF support. We have only recently received our copy of Solaris 7 at NOAO; it will be installed on a local system for IRAF support sometime in February. Early reports from the field suggest that the existing Sun/IRAF V2.11 release will work under Solaris 7, but we have not yet tested this. A V2.11 patch this spring will provide full support for Solaris 7, as well as other enhancements, such as the Y2K fixes mentioned below, support for the upcoming science GUIs release, and some early elements of Open IRAF (e.g. improved host execution facilities). A new version of X11IRAF is also planned.
The next major system upgrade will be the upcoming PC-IRAF release, which will upgrade PC-IRAF platform support as well as provide the latest V2.11 patches. FreeBSD support will be upgraded to FreeBSD 3.0 or later, Slackware Linux to V3.6 or later, and RedHat Linux to 5.2 or later (these are the versions we are currently running here). New support for Solaris x86 (using Solaris 7) and Macintosh Linux is planned for this release. We have been planning to use MkLinux DR3 for the Macintosh Linux port, but there has been some discussion with users recently regarding whether this is the best platform for us to support, or whether we should use LinuxPPC instead. The problem is that Apple is terminating support for MkLinux. However, the Linux community is expected to take over support for MkLinux; there is talk of expanded coordination of MkLinux and the only other Linux variant for the Mac, LinuxPPC. Our inclination is to port to MkLinux as planned, since this is what a number of us have already bought and installed, but the matter is still under consideration and a final decision has not yet been made. Mac users are encouraged to contact us concerning your preferences.
As reported in the last issue of this Newsletter we do not expect any major Y2K-related problems with IRAF. A few minor Y2K problems nonetheless exist and an IRAF V2.11 patch will need to be installed before January 2000 to correct these problems. This patch will also add support for the new FITS DATE-OBS (date and time) format; we are making these changes to IRAF now. A fully Y2K compliant release of IRAF for all supported platforms is slated for the V2.11 patch planned for the spring of 1999. More details about IRAF and the Y2K problem are available on the Web page http://iraf.noao.edu/projects/y2k, which will be updated as the Y2K project progresses.
Support for sinc interpolation was added to the 2D image interpolation routines. Support for drizzle resampling was added to both the 2D and 1D image interpolation routines. The sinc interpolant preserves the high frequency information in the resampled images more accurately than polynomial-based interpolants, although at the expense of greater execution times. The drizzle resampling algorithm can be used to enhance the resolution of dithered images in some circumstances. All the appropriate IMAGES package tasks were upgraded to support the new resampling options.
A spectroscopic exposure time calculator task called spectime has been written. Given an input spectrum in absolute flux units or a reference flux value and blackbody temperature for a blackbody spectrum, it applies atmosphere, telescope, spectrograph, and detector efficiencies to estimate detector photon counts and signal-to-noise ratios (S/N) for the spectrum. One can ask for an exposure time to reach a particular S/N at a reference wavelength or obtain the S/N for a specified exposure time. The expected detector counts and S/N as a function of wavelengths covered by the spectroscopic observation are graphically displayed.
The spectime task is written as a general tool. All calibration information is specified in a set of calibration files. These files can be in a system database, in the user's directory, or a combination of both (allowing users to edit and override system tables). The optical components that can be included cover most types of spectrographs, including long slit, fiber, and echelle instruments. The task is in the final stages of development. It will be used as the engine for a NOAO/SCOPE proposal preparation tool and will be available on the Web. It will also be made available as an IRAF add-on task and eventually in new releases of the IRAF system.
An interesting new project we are just starting is a data reduction pipeline for the NOAO Mosaic imager. This will capture raw Mosaic data as it is acquired on the mountain and automatically carry it through a number of stages of processing at various locations, eventually producing offline archives at NOAO of both the raw and processed data, as well as an online archive of the processed data to be maintained off site. This project is interesting not only for the scientific capability it will provide for wider access to Mosaic data, but as a major step towards data archiving at NOAO, and as a testbed for developing IRAF software for automated data reductions and the Open IRAF facilities for component-based processing. The archive pipeline will be implemented as an extension of the existing Mosaic DHS and developmental Open IRAF facilities.
Members of the IRAF group attended the Astronomical Data Analysis Software and Systems (ADASS) Conference in Urbana, Illinois in early November. The following papers were presented at the conference on current IRAF projects:
The papers will appear in a future volume of the Astronomical Society of the Pacific Conference Series.
For further information about the IRAF project please see the IRAF Web pages at http://iraf.noao.edu/ or send email to iraf@noao.edu. The adass.iraf newsgroups (available on USENET or via a moderated mailing list which you can subscribe to by filling out a form on the IRAF Web page) provide timely information on IRAF developments and are available for the discussion of IRAF related issues.
Doug Tody, Jeannette Barnes