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Current versions: low-resolution=LR7 / high-resolution=HR1

Important announcements (Full news & updates here)
- 2017 Jul 14: Partially-extended source flux calibration is now provided for tapered column extractions
- 2016 Nov 23: CASSIS now stands for "Combined Atlas of Sources with Spitzer IRS spectra. New URL to CASSIS: cassis.sirtf.com
- 2015 Jun 25: First release for high-resolution (HR1)! See accompanying published paper
- 2015 Jun 25: LR7 released. See Technical Note.
- 2014 Feb 26: LR6 released. See Technical Note.
- 2013 Mar 26: LR5 released. See Technical Note.
- 2011 Aug 15: CASSIS released ("LR4"). See accompanying published paper

CASSIS is the Combined Atlas of Sources with Spitzer IRS Spectra.

It provides to the community the low-resolution (R~60-127) and high-resolution (R~600) spectra of the Infrared Spectrograph (IRS) instrument on board the Spitzer Space Telescope.

A dedicated spectral extraction pipeline has been developed which performs optimal extraction for point-like sources and a regular extraction for partially extended sources.

CASSIS includes the spectra of all the observations performed in staring mode (single source or cluster) with the low-resolution and high-resolution modules.

Several parameters are determined during the pipeline processing such as the source extent, a quantitative detection level, and a redshift if one can be associated uniquely through the NASA Extragalactic Database (NED).

CASSIS was developed by the IRS Science Team, which was established by J.R. Houck, P.I. of the Spitzer/IRS instrument.

CASSIS is now hosted by the Department of Physics and Astronomy at the University of Rochester.

From the IOC (In Orbit Checkout) to the end of the cryogenic mission, the IRS team developed extraction techniques and data reduction and analysis tools. Two software tools were provided to the community:
- SMART (Spectroscopic Modeling Analysis and Reduction Tool) (Higdon et al. 2004; Lebouteiller et al. 2010), allowing the reduction and analysis of data at the 2D level (detector images: cleaning, exposure combining, etc...) or 1D level (spectra: defringing, line fitting, etc...).
- AdOpt (Advanced Optimal extraction) (Lebouteiller et al. 2010), a tool within SMART performs optimal extraction on low-resolution data using a super-sampled point spread function. AdOpt enables the extraction of multiple/blended sources, sources with complex background emission, and sources shifted in the dispersion direction.

These tools have been extensively used to produce the CASSIS pipeline and atlas, and every IRS team member, current and former, played a role in their current status.

Tools & Links : IRS pocket guide IRS handbook IRSA server SMART page IRS data analysis tools Publications using CASSIS Acronyms