Stellar AGB evolution and its impact on galaxy

spectrophotometric properties at low and high redshift: an updated

view

Alberto BuzzoniINAF – Oss. Astronomico di Bologna, Italy

UV evolutionary paths for (old) low-mass

stars

Dorman et al. (1993)

Core mass

Renzini & Buzzoni (1986)

EHB stars

Brown et al. (1999)

Castellani et al. (2006)

Buson et al. (2006)

Low ZHigh Z

Vassiliadis & Wood ‘94

Dorman et al. ‘93

(high-mass) MS

Back-in-time HB evolution

Buzzoni (1989)

Brown et al. (2000)

HB temperature distribution

galPN LN /

Buzzoni, Arnaboldi & Corradi (2006)

The puzzling problem of

Planetary Nebulae

Weidemann

(2000)

galPN LN / PNe and galaxy environment

UV enhanced UV poor

Probing AGB extension

Mass loss & SB

magnitudes

Reimers’s law GM

LRM

“Unconventional” fates

AGB deployment and UV upturn

(when infrared speaks to ultraviolet)

No PNe

No PNe

Buzzoni & Gonzàlez-Lòpezlira (2007) data compilation from Cantiello et al.

(2003)

Toward a unitary picture?

O’Connell (1999)

UV enhanced

UV poor

Metal richMetal poor

Globular clustersAGB ~ RGB

[Fe/H] lowest (« -0.5 dex)η highest (0.4-0.5)Core mass low (~0.54 Mo)HB bluePN poor rate

Metal-rich GCs & dE’sAGB >> RGB

[Fe/H] intermediate (< 0.0 dex)η lowest (0.0-0.1 ?)Core mass highest (~0.65 Mo)HB redPN yes “standard” rate

EllipticalsAGB > RGB

[Fe/H] highest (> 0.0 dex)η low (0.1-0.3 ?)Core mass lowest (<0.52 Mo)HB blue due to metal-rich PN poor rate

Spiral galaxiesAGB >> RGB

η VERY high (»1.5 ?)Core mass highest (0.7-0.8 Mo)HB redPN yes “standard” rateUV enhanced? yes but due to young