Presentation on theme: "The Local Universe Survey (LUS) IAAIACINAOEUAM J.M. VilchezJ.M. Rodríguez Espinosa R. TerlevichA. I. Díaz Jorge IglesiasC. Muñoz TuñónD. RosaM. Mollá (Ciemat)"— Presentation transcript:
The Local Universe Survey (LUS) IAAIACINAOEUAM J.M. VilchezJ.M. Rodríguez Espinosa R. TerlevichA. I. Díaz Jorge IglesiasC. Muñoz TuñónD. RosaM. Mollá (Ciemat) A. López AguerriO. Vega J. Mendez AbreuD. Mayya L. Rodríguez E. Terlevich E. Bertone A. Bressan
LUS LUS aims to study the formation and evolution of galaxies – Determine the spatial distribution of the properties of the ionised gas and recent star formation – Determine the spatial distribution of the properties of the evolved stellar populations Local Universe Galaxies carry themselves the memory of its formation and evolution (e.g. Heavens et al., Nature 2004; R. González Delgado, this morning talk!)
LUS: The Goals Trace the star formation history of individual galaxies in the sample Produce high-resolution BPT-diagram analysis Map the metallicity/age distribution in disc galaxies Study Compact Star Clusters in the nuclear and circumnuclear regions of normal galaxies Study Feedback: the interaction between massive stars and the ISM Detect and quantify the diffuse ionized gas in the sample galaxies Study Star-formation in low-density environments
The Sample All galaxies inside a volume of 3.5 Mpc Plus all irregulars and spirals within a volume of 11 Mpc Plus a sample of Virgo Galaxies 224 Galaxies in Total
LUS strategy Map the sample galaxies in both a number of selected emission lines plus continuum The lines selected are Lick indices motivated Use Galex, SDSS, 2Mass & Spitzer BB photometry The logistics is dictated by the need to cover most relevant lines and continuum feature sparing observing time Use the OSIRIS TF and BB for the observation Preliminary results show that to achieve our goals we require narrow band images with photometric accuracy < 5%...
What we have so far 6 hours Verification Time 6 hours on Spain-Mex. 9 hours Spain-Mex. M101 Field SEM101 Field SWNGC 5949 BB: u,i BB: u, g, r, i TF: Hα + [NII] (6528,6548,6568,6588,660 8,6628,6648,6668) TF: Hα (6572, 6533) TF: [NII] (6593, 6617) TF: [SII] (6696,6716,6736,6756,677 6,6796,6816) TF: [SII] (6726, 6702) [SII] (6740, 6716) (planned) TF:[ SIII] (9056,9076,9096,9116,913 6,9156,9176) TF: [SIII] (9082, 9110) (planned)
M101 region Hα
M101 region SII
The LUS Pipeline (IRAF based) Pre-reduction: bias, flat, and trim Each chip treated individually Cosmic Ray and Bad Pixel Masking (pending) Alignment of the images: geomap, geotran and imcombine Create a Weight image by combining 1 – 0 fake images using the same dithering pattern as for the real images PSF-Matching before stacking (pending) Astrometry and creation of a single image: ccxymatch, ccmap, imcombine, mkpattern, ccsetwcs, wregister (applied to the images and the weight)
Example: NGC 5949
LUS Pipeline: Step II Flux calibrate using the S 3 Method: Select isolated SLOAN stars Use the SEGUE spectroscopic data base to fit the observed SEDs (http://segue.uchicago.edu/) Use best Spectra to find the conversion between counts and flux in the NB TF images
NGC 5949 SLOAN Id K factor Hα Image (λc=6572 Å, Δλ=12 Å) J e-17 J e-17 J e-17 J e-17 J e-17 J e-17 J e-17 J e-17 J e-17 = ( )e-17 erg s -1 cm -2 /count s -1 Photometric Error~ 6%!
Full Monochromatic Ha Image of M101 - SW
Summary LUS intends to disentangle the individual history of each galaxy of a large sample of local galaxies – Each galaxy carries its history in its stellar populations Using the large FoV of OSIRIS and its TF capability So far we are working with preliminary data & optimising the strategy Depend heavily on the availability of the Blue TF Preliminary data looks promising