INSTITUTO DE ASTROFÍSICA DE CANARIAS

Alexandre Vazdekis

MAGPOP ACTIVITY AT IAC

MAGPOP Mid-Term Review

M. Balcells, C. Carretero, J. Cenarro, J.L. Cervantes, A. de Lorenzo-Cáceres, AV

M. Balcells, C. Carretero, J. Cenarro, J.L. Cervantes, A. de Lorenzo-Cáceres, AV

La Palma, 7-8/12/2006

2A. VazdekisInstituto de Astrofísica de Canarias

Stellar population model developments

~1000 stars (Sánchez-Blázquez etal.2006; Cenarro etal.2006)

High S/N (>100) flux calibrated spectra Spectral range: 3500–7500Å at 2.3Å (FWHM) Unprecedented stellar parameter coverage

12.5Gyr[M/H]=0.0

tt zz+

UCMGroninge

n

+UCM

Groningen

3A. VazdekisInstituto de Astrofísica de Canarias

Models and methodology

Some examples of fits to ITP-MAGPOP dwarfs:

4A. VazdekisInstituto de Astrofísica de Canarias

New optimized indices…for obtaining accurate stellar population parameters

An optimized Hβ age indicator that is virtually free from metallicity and abundance ratios effects

Cervantes-Rodriguez et al. (2007)

5A. VazdekisInstituto de Astrofísica de Canarias

Cleaning absorption lines from nebular emission.

… to obtain accurate age estimates.

Alternative approach based on the use of model SSP spectra to fit the full spectrum including several Balmer lines

de Lorenzo-Cáceres et al. (2007)

6A. VazdekisInstituto de Astrofísica de Canarias

Abundance ratios and environment

Carretero et al. (2004,2006)

Shorter formation timescales in more massive clusters

Mg C,N Fe

time

CN abundance ratio correlates with Lx, which traces cluster mass:

CN abundance ratio correlates with Lx, which traces cluster mass:

Timescales are shorter than 1Gyr in all galaxy clusters for intermediate/massive ellipticals

7A. VazdekisInstituto de Astrofísica de Canarias

Stellar populations of Extragalactic Globular Clusters

GCs are fossils of the main star-forming GCs are fossils of the main star-forming events in the Universeevents in the Universe

Most GCs are found to be old Galaxy formation/assembly should happen at high zSome youngish GCs are consistent with being old hosting BHB and/or blue straggler starsDetailed analysis of abundance ratios:

-Two subpopulations of MR GCs with different [Mg/Fe] and [C/Fe] values-Strong CN overabundance-Intriguing C-N anticorrelation for MR GCs Consequence of the CNO cycle?

HST/ACS

NGC1407

Cenarro et al. (2007)

8A. VazdekisInstituto de Astrofísica de Canarias

B,K counts: constrain E formation epoch

Confirm knee in K counts, K=17.5Gardner-style number count modelsSimultaneously reproduce number counts in Groth, U, B, Ks

Cristóbal-Hornillos et al. 2003; Eliche-Moral et al (2006)

Late zf=1.5 for ellipticals gives knee in Ks counts Ks~17.5Implies mean age 9 Gyr, consistent with independent results.

Balcells, David Cristóbal-Hornillos, Carmen Eliche-Moral, Mercedes Prieto

9A. VazdekisInstituto de Astrofísica de Canarias

Bulges 0.3<z<1 are red

Bulge-disk galaxies in Groth, GOODS-N:

o “Bulge galaxies” have a Red Sequence in bulge colors (R=0.2” ~ 1.5 kpc)

o Bulge colors scale with disk colors, and with global colors, same as in local Universe

U-B rest-frame BULGE colors, bulges vs no-bulges

U-B rest-frame nuclear colors vs GLOBAL colors

Lilian Domínguez & BalcellsLilian Domínguez & Balcells