Please enter the IRAS source name that you want to search for LRS spectra, and select the format in which you wish to receive the data: either the values as raw text, a postscript plot, a gif plot, or a jpeg plot. The gif file is displayed, the other plots will likely be sent in file form.
At the end of ISO mission a series of spectra of standard stars were taken with the SWS instrument even though the detectors were warming up. These were reduced and presented as an Atlas by Vandenbussche et al. (2002). I obtained the reduced spectra from Bart Vandenbussche, and these can be accessed at the ISO Post-helium Atlas Plotting Page.
These spectra cover from about 2.35 to about 4.1 microns. For an atlas of full range ISO SWS spectra see just below.
Greg Sloan carried out an autoamtic reduction of all ISO SWS01 spectra taken during the mission. Although the reduction sometimes fails (usually this is seen in the form of negative offsets of the short wavelength part of the spectrum) it usually gives a reasonable result. One can get any of these spectra from the ISO SWS01 Atlas Plotting Page.
This page is an HTML interface to some programs for the extraction of the IRAS LRS spectra of objects. The form below allows you to enter the name of an IRAS source (i.e. 18095+2704 or 17584+6638A) and then submit a query. If the source named has an LRS spectrum it is either returned as a text file, where one has the wavelength in microns and the associated wavelength flux density value in Watts/square meter/micron in two columns, as "corrected raw text", where the calibration correction is applied (see below) and the values are wavelength*flux density as in the plots, or as a plot, which is of wavelength*flux density in Watts/square meter versus the wavelength in microns. Thus the plot is different from the ascii data values; this is due to the custom of plotting the spectra in the wavelength*flux density form which dates back to the original publication of the LRS Atlas by Olnon and Raymond (1983).
There are a few sources which have LRS spectra extracted and in the database which do not have IRAS names because some error occurred in the IRAS sky survey, or because the source is extended. The two famous examples of this are NML Cyg and the Egg Nebula. These spectra can be accessed with the names "NML Cyg" and "Egg Nebula" respectively. Other such sources are "V407Cyg" and "V3811Sgr". All other sources need to be searched for by the IRAS name in the Point Source Catalogue. Some of the 11000+ sources in the database have bad LRS data or no data at all: a "spectrum" of all zero values indicates that the source was looked for but there was no data, as opposed to a source for which no LRS search has been made yet where a message would be returned that the source was not found in the database.
The data returned or plotted here is usually as extracted from the LRS database; the correction of the absolute calibration as in Volk and Cohen (1989; Astron.J., 98, 1918) and Cohen, Walker, and Witteborn (1992; Astron.J., 104, 2030) has not been applied to the data values unless you specify the "corrected raw data" option. The set of correction factors from the latter paper represent the best way to fix the original LRS calibration (which assumes that Alpha Tau has a spectrum like a 10000 K blackbody at these wavelengths, missing an SiO band in the spectrum near 8 microns to cause a problem with the calibration).
When the "corrected raw text" option is chosen, the corrections from Cohen, Walker, and Witteborn (1992) are applied to the values. This is then the "best" LRS data. The plots are still NOT corrected for this.
Also please note that while the relative shape of the LRS spectrum is usually O.K., the absolute level need not match the IRAS 12 micron flux density from the photometry or other spectral data. No attempt at proper absolute calibration was carried out in the original data reduction.
Please enter the IRAS source name that you want to search for LRS spectra, and select the format of the data in which you wish to receive the data: either the raw text, postscript plot, gif, or jpeg.
This page was developed by Rae Yip (ryip@cco.caltech.edu) and I would like to thank him for his work on the form interface; I wish that I could take the time to learn about all this stuff but so far I have had too many more immediate things to work on. So I farmed the task to Rae and he has done a very good job on it.