=================================================== SSGSS Data Release Version 1.0 =================================================== The Spitzer SDSS Galaxy Spectroscopic Survey (SSGSS) is a Cycle-3 Spitzer program to acquire 5 to 40 micron mid-infrared spectroscopy of a representative sample of galaxies from SDSS, selected for having full prior photometric coverage from the UV to the far-IR. The full SSGSS sample includes 101 star forming galaxies from the SWIRE/Lockman Hole region. These galaxies were selected from those with full SDSS, GALEX and IRAC (4 channel) and MIPS (24 and 70 micron) photometry, with a 5.8 micron surface brightness limit of 0.75 MJy/sr and a 24 micron flux limit of 1.5 mJy. These data represent the first public data release of the full SSGSS sample. The dataset includes short-low and long-low IRS spectroscopy for the full sample, and short-high IRS spectroscopy for a subsample of the 33 brightest galaxies. The characteristics of these data are: Instrument: IRS Modules: SL1, SL2, LL1, LL2, SH Resolution: Low Res: R~57-127 Hi Res: R~600 Exposure time per pointing: Low Res: 487.6 sec Hi Res: 975.17 sec Observation dates: Low Res: 12-10-2006 to 12-17-2006 Hi Res: 11-18-2006, 10-12-2006, and 11-12-2006 The file sets are named as follows: 1. SSGSS_[#]_[SL/LL]_[A/B]_[1 to 4].fits The uncombined short-low (SL) or long-low (LL) spectra for galaxy number [#], in the SL2/LL2 (A) or SL1/LL1 (B) order, for slit positions 1 to 4. 2. SSGSS_[#]_[SL/LL]_[A/B]_Comb.fits The combined short-low (SL) or long-low (LL) spectrum for galaxy number [#], in the SL2/LL2 (A) or SL1/LL1 (B) order. 3. SSGSS_[#]_[SL/LL].fits The combined short-low (SL) or long-low (LL) spectrum for galaxy number [#], with the two orders concatenated. 4. SSGSS_[#]_SL-LL.fits The concatenated short-low and long-low spectrum for galaxy number [#]. 5. SSGSS_[#]_lores.fits The concatenated short-low and long-low spectrum for galaxy number [#]. Order overlap regions are combined by weighted mean and channel overlap regions are combined by either a cut or weighted mean. 6. SSGSS_[#]_SH.fits The short-high spectrum for galaxy number [#]. Order overlap regions are not combined 7. SSGSS_[#]_hires.fits The short-high spectrum for galaxy number [ID]. Order overlap regions are combined by weighted mean. The spectra are stored in fits format and contain structures with the following tags: WAVE (all file sets): Wavelength in micrometers FLUX (all file sets): Flux in Janskys ERROR (all file sets): Error in the flux ORDER (all file sets): Order number BITFLAG (all file sets): Bit-flags generated by SPICE. In the case of combined files (all but file set 1), the bit flag of the first position is used ORDERFLAG (file sets 1, 2, 3, 4, 6): 1 for regions in which order overlap occurs, 0 otherwise. CHANNELFLAG (file set 5): Set to 1, 2, 3, or 4 for channels: short-low right, short-low left, long-low right, and long-low left respectively. For channel overlap regions combined by weighted mean, CHANNELFLAG is set to the mean of the two flags. For example, the long-low right and long-low level combined overlap region is set to 3.5. Note: ORDER appears after BITFLAG in spectra from file set 1. These data and the SSGSS project in general are described in full in: Schiminovich, D. et al. (2008), in prep Further information may also be found at the SSGSS home page: http://astro.columbia.edu/ssgss Additional information on the data reduction process, including definition of BITFLAG values can be found in the SPICE GUI help tool: http://ssc.spitzer.caltech.edu/postbcd/spice.html =================================================== SSGSS team contacts: David Schiminovich, Ben Johnson, Matt O'Dowd ds@astro.columbia.edu, bjohnson@astro.columbia.edu, matt@astro.columbia.edu April 2008 Edited by J. Howell, IRSA, January 2009 change log: standard terminology for IRS orders, added ORDER to list of columns, added note that ORDER and BITFLAG columns are in reverse order in one file set.