the local universe survey (lus)

The Local Universe Survey (LUS)IAA IAC INAOE UAM

J.M. Vilchez J.M. Rodríguez Espinosa

R. Terlevich A. I. Díaz

Jorge Iglesias C. Muñoz Tuñón D. Rosa M. Mollá (Ciemat)

A. López Aguerri O. Vega

J. Mendez Abreu D. 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 far6 hours Verification Time 6 hours on Spain-Mex. 9 hours Spain-Mex.

M101 Field SE M101 Field SW NGC 5949BB: u,i BB: u,i BB: u, g, r, i

TF: Hα + [NII] (6528,6548,6568,6588,6608,6628,6648,6668)

TF: Hα + [NII] (6528,6548,6568,6588,6608,6628,6648,6668)

TF: Hα (6572, 6533)TF: [NII] (6593, 6617)

TF: [SII] (6696,6716,6736,6756,6776,6796,6816)

TF: [SII] (6696,6716,6736,6756,6776,6796,6816)

TF: [SII] (6726, 6702)[SII] (6740, 6716) (planned)

TF:[ SIII] (9056,9076,9096,9116,9136,9156,9176)

TF:[ SIII] (9056,9076,9096,9116,9136,9156,9176)

TF: [SIII] (9082, 9110) (planned)

M101

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 S3 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 factorHα Image (λc=6572 Å, Δλ=12 Å)

J152726.30+644617.1 1.67239e-17J152731.33+644205.4 1.34703e-17J152737.48+644402.0 1.56477e-17J152738.39+644750.6 1.64536e-17J152739.92+644643.4 1.56409e-17J152744.18+644339.9 1.61065e-17J152748.74+644825.6 1.53437e-17J152825.81+644514.3 1.52459e-17J152834.75+644643.5 1.60957e-17

< K Factor > = (1.56 +- 0.095)e-17 erg s-1cm-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