instituto de astrofÍsica de canarias alexandre vazdekis
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INSTITUTO DE ASTROFÍSICA DE CANARIAS Alexandre Vazdekis. MAGPOP ACTIVITY AT IAC. MAGPOP Mid-Term Review. La Palma, 7-8/12/2006. M. Balcells, C. Carretero, J. Cenarro, J.L. Cervantes, A. de Lorenzo-Cáceres, AV. Stellar population model developments. - PowerPoint PPT PresentationTRANSCRIPT
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