Open Questions in the Globular Cluster - Galaxy Connection Markus Kissler-Patig March 6th, 2006 Markus Kissler-Patig (ESO)

Gobular Culsters Systems in the 80s… GCLF Specific frequency Structure Colour and metallicity Formation scenarios Pre-galactic In proto-galaxy In mergers Harris & Racine, ARA&A 1979 Harris, ARA&A1991 March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) The first conference on GC Systems: "Harlow-Shapley Symposium" 1986 Cambridge, MA March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) Questions of the 80s The Milky Way globular cluster system (kinematics, chemistry, ages) Local Group GCS (intermediate ages, peculiarities of integrated colours) Distant Galaxies out to Coma (colours, first kinematics) Some links to stellar populations of the host galaxies, but no real attempts to strongly constrain galaxy formation and evolution March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) Questions of the 80s W.E.Harris March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) 1992 Santa Cruz, CA March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) The 1992 questions… Characterizing the Local Group Systems (Do bulge clusters belong to the bulge, relation to other stellar populations, …) 1 out of 10 sections: "Extragalactic Globular Cluster Systems" 1 out of 10 sections: "The Formation and Evolution of Globular Cluster Systems within the Context of their parent Galaxies" incl. Ashman & Zepf 'Merging and Interacting Galaxies: Sites of Globular Cluster Formation' March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) Ashman & Zepf March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) The next decade Observational rush on GCS with HST/WFPC2 From mid-90s on: spectroscopy with 10m class telescopes Our favourite "Galaxy Formation and Evolution / Early-type Galaxies / Stellar Population" Conferences hosted a 'Globular Cluster Systems' section Various attempts to declare/refine scenarios of GCS formation March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) The results of the 90s Buzz-word: Bi-modal distribution Characterization of the main two (red/blue) sub-populations Lots of controversy whether mergers are responsible for the bi-modality (Hierarchical merging is most fashionable) First spectroscopy shows GCs in early-type galaxies to be very similar to the Milky Way ones, with exceptions… (intermediate ages, high /Fe) March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) 2001 Pucon March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) 2002 Garching March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) What are the Open Questions? March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) Understanding our tools: individual GCs Measurements of integrated properties GC systems in the nearby universe Galaxy formation and evolution March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) Understanding our tools: individual GCs Measurements of integrated properties GC systems in the nearby universe Galaxy formation and evolution March 6th, 2006 Markus Kissler-Patig (ESO)

Birth and death of star clusters The dissolution of massive star clusters starts to be understood (although it is a complex problem) The formation process, especially under various environmental conditions, is still very poorly studied this prevents us from making detailed predictions on GC system formation Approach the star formation community ('Star and Star Cluster Formation' meeting?) March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) The evolution of stars Continue the excellent work on more detailed isochrones Solve the 2nd parameter problem and understand horizontal branches censured Serenelli & Weiss 2005 March 6th, 2006 Markus Kissler-Patig (ESO)

Individual Globular Clusters Understand the star cluster formation: From giant molecular cloud, to star cluster, to old globular cluster Model (calibrate) in more detail the 'difficult' stellar evolutionary phases: Horizontal branches, AGBs March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) Understanding our tools: individual GCs Measurements of integrated properties GC systems in the nearby universe Galaxy formation and evolution March 6th, 2006 Markus Kissler-Patig (ESO)

Measuring integrated properties: imaging Jordan et al. 2005 Larsen et al. 2005 March 6th, 2006 Markus Kissler-Patig (ESO)

Measuring integrated properties: spectroscopy Puzia et al. 2005 Larsen et al. 2005 March 6th, 2006 Markus Kissler-Patig (ESO)

Measuring integrated properties Both Photometry as well as spectroscopy of the integrated light of extra-galactic globular clusters are difficult measurements! Badly calibrated data only add noise to our understanding (e.g. systematics not understood or detected; data not properly put on Lick system; …) March 6th, 2006 Markus Kissler-Patig (ESO)

Interpreting integrated properties Hempel et al. 2005 Peng et al. 2005, See Yoon's talk tonight March 6th, 2006 Markus Kissler-Patig (ESO)

Interpreting integrated properties Lamers et al. 2006 Korn et al. 2005 March 6th, 2006 Markus Kissler-Patig (ESO)

Integrated properties Difficult measurements: measure carefully Difficult interpretation: Do not over-interpret, consider all possibilities Support the population synthesis modellers March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) Understanding our tools: individual GCs Measurements of integrated properties GC systems in the nearby universe Galaxy formation and evolution March 6th, 2006 Markus Kissler-Patig (ESO)

Bi-modality - where are we? Lots of ideas - but still no clue Bi?-modality is blue + lots of different reds Bi-modality is myth: an artifact of the colour-metallicity conversion Bi-modality is natural and due to [Buzz word: re-ionization, down-sizing, … N.B. 'mergers' is out] Why are the metallicity distributions of the stars and GCs different? G.Harris et al. 1999 March 6th, 2006 Markus Kissler-Patig (ESO)

Sequence of Events / Chemical History Pre-/Proto-/Post-Galactic formation: What are the relative ages of GCs Can we track the formation environment? Are GCs connected via a common chemical enrichment history? Do star clusters trace the star formation? What does connect star and star cluster formation? De Angeli et al. 2005 March 6th, 2006 Markus Kissler-Patig (ESO)

GCs in Ellipticals = GCs in Spirals? We assume that GC in Ellipticals are similar to the GCs in Spirals What are the evidences? Similar colours and spectroscopic indices Same fundamental plane What are the consequences? Compare data to SSPs / models calibrated locally Suffer from local 'prejudices' NGC 5128 W.E.Harris et al. 2002 McLaughlin 2000 March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) Understanding our tools: individual GCs Measurements of integrated properties GC systems in the nearby universe Galaxy formation and evolution March 6th, 2006 Markus Kissler-Patig (ESO)

GCs: Clues to Galaxy Formation and Evolution? Lots of literature: most of it is only qualitative, describes incomplete scenarios, rather assembly of GCS than galaxy formation/evolution GCs can probably constrain the star formation history well In order to constrain the assembly / merger history, we need to confront them with (unavailable?) galaxy formation / evolution models Beasley et al. 2002, 2003 March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) Taken from a talk by Simon D.M. White, Venice 2003 March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) SUMMARY Open Questions? There are many… Some of my favourites: How to get from a GMC to a GC? What parameters drive the CMDs? Are the GCs in ellipticals similar to the ones in spirals? (interpreting integrated properties) How is GC formation linked to star formation in galaxies? To do: Increase the interactions with the star formation and galaxy formation and evolution communities Better interplay with good models March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) The good news: We will get some of the answers this week March 6th, 2006 Markus Kissler-Patig (ESO)

Markus Kissler-Patig (ESO) ADVERTISMENT SALE: Excellent Students and Ex-Students Thomas Puzia Maren Hempel Nate Bastian Marcelo Mora Daniela Villegas On the Job Market Sold out Coming soon… ADVERTISMENT March 6th, 2006 Markus Kissler-Patig (ESO)