Stefan Uttenthaler: Tc in Bulge and Field AGB Stars This talk mainly deals with two papers: "Technetium and the third dredge up in AGB stars I.: Field stars" Lebzelter & Hron, 2003, A&A 411, 533 – 542 "Technetium and the third dredge up in AGB stars II.: Bulge stars" Uttenthaler et al., in preparation for A&A Paper I: Stars in solar neighborhood, good HIPPARCOS parallaxes Spectra from UVES, KPNO, AAT Paper II: Bulge stars in PG3 b  -10°, l = 0° Spectra taken with UVES/VLT ESO: Hans-Ulrich Käufl Vienna (A): Bernhard Aringer Thomas Lebzelter Josef Hron Michael Lederer Michael Gorfer Besançon (F): Mathias Schultheis Perugia (I): Maurizio Busso

Δ SRV □ Mira ▲/■ with Tc Sample selection using K 0 vs. log(P) relation Near-IR photometry from ESO measurements Schultheis), 2MASS & DENIS, Periods from Wesselink Ph.D. K 0 – log(P) relation from Glass & Schultheis, 2003 Two stars outside the "allowed" range!

Using MACHO light curve and data from Plaut (1971) we get new periods for 2 uncertain cases → everything fine now! All objects are in the BULGE! Sample selection using K 0 vs. log(P) relation Δ SRV □ Mira ▲/■ with Tc

Observed and synthetic spectra around Tc lines R=50000 obs with UVES/VLT in 2000 (blue and red arm) All 3 lines in observed range are identified 4297 Å Line is blended by Cr line Problems with model spectra: Too high contrast between lines and "continuum" points! 4238 Å4262 Å4297 Å

Observed and synthetic spectra around Tc lines 4238 Å4262 Å4297 Å R=50000 obs with UVES/VLT in 2000 (blue and red arm) All 3 lines in observed range are identified 4297 Å Line is blended by Cr line Problems with model spectra: Too high contrast between lines and "continuum" points! 4238 Å4262 Å4297 Å

Used to distinguish between "Tc yes" and "Tc no" Ratios of lines 4238 Å and 4262 Å are best suited for this distinction! Flux ratios

Tc possible! Model spectrum with [Tc/H] = Model spectrum without Tc Used to distinguish between "Tc yes" and "Tc no" Ratios of lines 4238 Å and 4262 Å are best suited for this distinction! Flux ratios

M bol vs. (J – K) 0 diagram, I. M bol from BCK(J – K) (Kerschbaum et al., in prep.) All stars with Tc above 3DUP luminosity limit Luminosity limiy estimated from luminosity of a 1.5 M sun model when 3DUP sets in → M bol = -3.9

M bol vs. (J – K) 0 diagram, II. M bol "corrected" for depth induced scatter (from period luminosity diagram): "Tc yes" stars form upper envelope! Isochrones from Girardi et al., 2000 (+ "our" (J – K)/T eff calibration) do not reach up to the observed peak luminosity!! → younger (3 Gyr) = more massive stars in the bulge?? 1.5 M sol required for 3DUP! Tc poss.

Bulge stars vs. field stars Percentage of stars above the luminosity limit with Tc: Field: 10/50 = 0.20 Bulge: 3/21 = /19 = 0.21 ??  probably no difference! Bright "Tc no" stars: a) Massive stars with eroded envelope (mass loss)? b) Low mass stars observed at high-luminosity phase of TP Lebzelter & Hron 2003, field stars:

Are there AGB stars which have had 3DUP some time ago, but all Tc has decayed by now (case a)? To solve this question: ● Determine s-element abundances in the atmospheres :-( Model spectra are not yet good enough for this But: qualitative information on Nb content helps! → Will be worked out on Monday, 8 a.m.! ● Measure C/O and 12 C/ 13 C ratios of the stars :-( ISAAC/VLT observing time was not granted :-/ Maybe DDT observations?

Take care with abbreviations! HB = Horizontal Branch ?? HB = Hof Bräu ?? Hofbräuhaus, Munich

CRIRES, or: "The Last will be the First" CRyogenic Infra-Red Echelle Spectrograph Last instrument of the first generation Basic characteristics: 1 – 5  m R=100,000 VLT UT1, Nasmyth A slit: 0.1"  50" 4  1024  1024 InSb /70 coverage etc., see

CRIRES, or: "The Last will be the First" Current status: All subsystems are tested, final lab tests of the whole system, all specifications are met April 2006: commissioning of warm parts at the telescope June 2006: commissioning of the rest August 2006: science verification, 2 nd commissioning What can CRIRES do for research on AGB stars? ● All AGBs out to the bulge & the brightest in the MCs observable ● Atmospheric dynamics, especially in C stars ● Temperature structure pinned down ● Improved chemical and isotopic abundances ● Born-again AGB and Post-AGB stars: narrow nebular lines resolved, kinematics from velocity along the slit ● etc.

(CO2) (H2O) (N2)