1. Introduction to Spitzer and some applications Data products Pipelines Preliminary work K. Nilsson, J.M. Castro Cerón, J.P.U. Fynbo, D.J. Watson, J. Hjorth and A.L. Aguilar Minor

2. - launched 25 August 2003; Cape Cañaveral, Florida (USA) - 2.5 year mission (nominal length; 5+ expected) - 0.85 m telescope - 3 cryogenically cooled science instruments (< 5.5 K) - wavelengths:imaging/photometry 3 – 180  m spectroscopy 5 – 40  m spectrophotometry50 – 100  m - diffraction limit:6.5  m

4. Instrumentation IRAC: InfraRed Array Camera - provides images at 3.6, 4.5, 5.8 and 8.0  m - dual band imaging via dichroic beamsplitters IRS: InfraRed Spectrograph - low resolution: 5.2 to 38.0  m - high resolution 9.9 to 37.2  m MIPS: Multiband Imaging Photometer for Spitzer - photometry, super resolution imaging and efficient mapping - three wavelengths centred near 24, 70 and 160  m - low resolution spectrography: 55 to 95  m

5. Observation planning SPOT: a publicly available software package used by Spitzer observers to plan observations and submit proposals. Data archive LEOPARD: a publicly available software package used to download data.

6. Data products RAW - unprocessed data packaged into a FITS format - calibration data is also provided BCD (basic calibrated data) - single frame FITS format data products - removal of known instrumental signatures necessary (dark subtraction, multiplexer bleed, detector linearisation, flat fielding and cosmic ray detection) - calibrated in scientifically useful units Post BCD - in each wavelength this processing yields corrected images co-added into a mosaic and a list of extracted point sources

7. Pipelines RAW -> BCD - no pipeline is publicly available at this time - SSC pipe linked to many external libraries/modules - will not work outside SSC - user is alone BCD -> Post BCD - publicly available - made up of several modules (Perl scripts) - Linux and/or Solaris

8. Post BCD modules (IRAC ch1/2(3/4)) COSMETIC FIX - fixes two artifacts present in IRAC *multiplexer bleeding: enhanced output level pixels trailing a bright spot *column pull down: intensity reduction of the signal at ~35,000 DN - optional background subtraction FLAT FIELD CORRECTION - creates a flat field for one set and applies it to images in the set BACKGROUND MATCHING/OVERLAP - cumulative pixel by pixel difference between overlapping areas for all pairs is minimised with respect to unknown constant offsets of the input - interpolation is linear -> offset is conserved

9. POINTING REFINEMENT - improves the pointing provided by the on-board star tracker by minimising discrepancies between positions of point sources matched in each pair of images - relative (self consistent images) or absolute (usually 2MASS) MOSAICING (with/out outlier detection) - interpolation and co-addition of input images onto a common grid - area overlap interpolation is performed - drizzle interpolation is implemented - correction for optical distortion in the input images is applied during interpolation ASTRONOMICAL POINT SOURCE EXTRACTION - multi-frame and single-frame point source extraction - for multi-frame, the extraction is performed on co-added image

10. BANDMERGING - reads two to seven input ASCII table files of single band point source information and produces a list of band combinations

11. A) -0.8233 ± 0.0072 -0.8144 ± 0.0069 B) 0.9156 ± 0.0328 0.8956 ± 0.0328 C) 1.7675 ± 0.0612 1.6675 ± 0.0621 OURS SSC D) 1.3682 ± 0.1080 1.2661 ± 0.1055 E) 0.7336 ± 0.0428 0.7116 ± 0.0401 F) 1.2188 ± 0.0471 1.1800 ± 0.0442

12. GRB hosts: faint, blue sub-mm galaxies

14. Ly  -selection of high redshift galaxies

15. GOODS – Great Observatories Origins Deep Survey Joint effort of NASA, ESO, ESA, NOAO... ”Great observatories”: Spitzer, HST, VLT, CXO, XMM... Goal is to ”study galaxy formation and evolution over a wide range of redshifts and cosmic look-back time”. Two fields with deep observations: HDF-N and CDF- S (and HUDF).

16. HST vs. Spitzer – the battle of giants