Geneviève Parmentier

Transcription

1 Heidelbeg Joint Astonomical Colloquium, 19 Octobe 2010 Splinte Bonn, 15 Septembe 2010 Sta Clustes as Cucial Taces of Galaxy Evolution and Pobes into Sta Fomation Geneviève Pamentie Agelande-Institut füf Astonomie Rheinische Fiedich-Wilhelms Univesität t Bonn

2 Sta Clustes: Fast Facts! "#$%$& ' Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 2 /

3 A Vital Diagnostic Tool: the Age-Mass Diagam Cluste mass vs cluste age fo a sample of 1,000 clustes in the Lage Magellanic Cloud Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 3 /

4 Age-Mass Diagam and Size-of-Sample Effect ( ) *" )*& ( + ) "+ )& dn 2 m dm dn m d log m 1 log(dn/dlogm) t=20my t=2gy (100 moe SCs if CFR=cst) log(m) Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 4 /

5 Age-Mass Diagam - Do Not Tust You Eyes: 1/2 Cluste mass vs cluste age fo a sample of 1,000 clustes in the Lage Magellanic Cloud Size-of-Sample Effect Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 5 /

6 dn/dlogm Lage Magellanic Cloud cluste sample: Fading limit log (m [m 0 ]) log (m [m 0 ]) 6

7 dn/dlogm Lage Magellanic Cloud cluste sample: Fading limit t dis 4 = 1Gy log (m [m 0 ]) log (m [m 0 ]) Completeness limit: M v =-4.7 7

8 Age-Mass Diagam - Do Not Tust You Eyes: 2/2 Cluste mass vs cluste age fo a sample of 1,000 clustes in the Lage Magellanic Cloud Size-of-Sample Effect Evolutionay fading: fo a given mass, olde clustes ae fainte Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 8 /

9 Age-Mass Diagam - Do Not Tust You Eyes: 2/2 Cluste mass vs cluste age fo a sample of 1,000 clustes in the Lage Magellanic Cloud Highe SFR Impoved detection limit Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 9 /

10 Cluste mass vs cluste age fo a sample of 1,000 clustes in the Lage Magellanic Cloud Complete sample 100% completeness limit: Mv=-4.7 At a given age: the lowe the mass, the moe incomplete the sample 10

11 Sta Clustes: Fast Facts! "#$%$& ' 11 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 11 /

12 Secula Evol.: Caving a Tunove in the ICMF Modelling of Secula Evolution: Fig.17 in Pamentie & de Gijs (2008), based on the models of Baumgadt & Makino (2003) and Lames et al (2005) Vetical scaling is abitay 75My 300My dn/dlogm Quicke Slowe 1Gy 5Gy log (m [M 0 ]) log (m [M 0 ]) 12 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 12 /

13 dn/dlogm t dis 4 = 1Gy log (m [m 0 ]) log (m [m 0 ]) Completeness limit: Mv=

14 Bound Cluste Fomation Histoy and Cluste Dissolution Time-Scale in the LMC Pamentie & de Gijs 2008 log (dn/dt [My -1 ]) 50My 1.5Gy Mass atio : 0.50 Numbe atio: 0.03 Pedicted Bound CFR t 4 dis = 1Gy t 4 dis = 8Gy Obseved age distibution log ( age [y] ) Secula evolution modelling Bound Cluste Fomation Histoy fom the obseved cluste age distibution 14 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 14 /

15 Cluste Mass Functions: mass vesus numbe Powe - Law Mass Function: dn dm m 2 dn/dm,! - ".#/0 & 1! - ".!2% +)&.!$ low- and high-mass clustes equally contibute to the total mass (sta clustes) α m Numbes: 90% 9% 0.9% 0.09% logm log(m) Masses: 25% 25% 25% 25% 15 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 15 /

16 Gas-Embedded Cluste Fomation Histoy: the next step... log (dn/dt [My -1 ]) Violent elaxation Violent elaxation modelling: (Gas-embedded) CFR SFR Secula evolution modelling: (Bound) CFR log ( age [y] ) 16 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 16 /

17 Violent Relaxation (VR): Obsevable Signatues And Pime Paametes Effects of Gas expulsion - VIOLENT RELAXATION Cluste expansion Cluste infant weight-loss and infant motality Obsevable Impints upon Sta Cluste Systems : Cluste mass distibution, Cluste age distibution, Cluste adius distibution, Ratio of the total mass in clustes to the total stella mass in gas-embedded clustes Inta-Cluste Gas-Expulsion and Violent Relaxation Pime paametes: (e.g. Baumgadt & Koupa 2007) - SFE in cluste-foming molecula s - Gas expulsion time-scale: τ GExp /τ coss - Impact of extenal tidal field (envionment) time See also Adams (2000), Vespeini et al (2009), Geye & Buket (2001) 17 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 17 /

18 Violent Relaxation: Cluste Mass Functions Time-Evolution of Cluste Mass Functions: What obseves tell modelles Log [dn/dlog m] CMF 50My ( = -2.0) CMF 3My ( = -2.0) Infant motality/ weight-loss dn dm m 2 dn d logm m 1 log m [M o ] m ( of VR) = F m ( at Gas Exp) cluste end bound cluste 18 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 18 /

19 cluste SFE and Cluste Mass Functions m ( end of VR) = F ( SFE) SFE m bound F bound ( SFE ε ). F bound Instantaneous gas emoval, weak tf impact. SFE 19 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 19 /

20 F bound GExp / coss SFE ε, τ τ and Cluste Mass Functions GExp coss Constant adius: Moe massive s have - a deepe potential well - a slowe gas-expulsion t-s - can suvive despite a low SFE of, say, 20% dn/dlogm coss log ( m [M o ] ) Pamentie, Goodwin et al. (2008) 20 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 20 /

21 Tidal Field Impact and Cluste Mass Functions t τ coss, τ GExp SFE ε,, τ coss half mass tidal Weak t.f. impact Half-mass adius half-mass Cicula velocity of iso-t potential V c Galactocentic distance D gal tidal Embedded cluste mass m ecl Stong t.f. impact Limiting tidal adius : tidal G m = 2V ecl 2 c 1/ 3 D 2 / 3 gal, with m = ecl SFE. m 21 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 21 /

22 Half-mass adius to tidal adius atio 1pc = m = pc M o 1/ m = pc M o 1/ 3 half mass m δ 4100 tidal m 1/ 3 ecl m 1/ 3 half mass tidal m δ 1/ 3 22 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 22 /

23 F bound and Tidal Field Impact 2 1/ m 1pc = 0.30 = pc M o m = pc M o 1/ 3 Pamentie & Koupa (in pess) Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 23 /

24 The m - Diagam as a Diagnostic Tool m = pc M o m = pc M o = pc 1/ 2 1/ 3 Extenal tidal field stength: (V c, D gal ) h/t in [log(),log(m)] h/t < 0.05: tf does not matte (does not necessaily imply weak tf!) h/t > 0.15: cluste suvivability demands long τ GExp /τ coss and high SFE tf impact impedes cl. suvivability As if no extenal tf 24 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 24 /

25 Tidal Field Impact and Cluste Mass Functions: Pobing the cluste-foming mass-adius elation Cluste infant weight-loss is mass-independent, the shape of the cluste mass function does not evolve duing VR log (dn/dlogm) Ecl.MF CMF F bound log(m) 4100 Constant Volume Density Coes: mass-independent infant weight-loss m = pc M o 1/ 3 25 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 25 /

26 Tidal Field Impact and Cluste Mass Functions dn/dlogm SFE=0.40 D gal =5kpc F bound log ( m [M o ] ) Constant Suface Density Coes: When moe massive means moe vulneable... Σ : 1pc m = M o 1/ 2 26 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 26 /

27 Galaxy Sta Fomation Histoies: even a long jouney stats with one single footstep... log (dn/dt [My -1 ]) F bound τ GExp SFE ε,, τ coss half mass tidal Violent elaxation modelling: (Gas-embedded) CFR SFR Secula evolution modelling: (Bound) CFR log ( age [y] ) 27 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 27 /

28 Coe mass-adius elations: obsevations Muelle+02 Density pofiles: (,m 1E4 cm -3 Coe mass-adius diagam: impint of - measuement method, o of - cluste-fomation physics? when picking-up obs data ead (pat of) the pape o?? Limited baseline in cluste-foming mass Lack of high-mass data 28 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 28 /

29 Coe mass-adius elations: so what...? Ca GMC (Yonekua+05) Oion B (Aoyama+01) - Red cicles: C 18 O s showing signs of SF activity C 18 O 29 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 29 /

30 Coe mass-adius elations: so what...? Ca GMC (Yonekua+05) Oion B (Aoyama+01) C 18 O - Red cicles: C 18 O s showing signs of SF activity - Most of them also host a clump at 1E5 cm -3 (H 13 CO + ) SF takes place in egions whee the density is highe than a theshold, i.e. only in the densest egions of C 18 O s 30 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 30 /

31 Coe mass-adius elations: so what...? Ca GMC (Yonekua+05) Oion B (Aoyama+01) C 18 O - Red cicles: C 18 O s showing signs of SF activity - Most of them also host a clump at 1E5 cm -3 (H 13 CO + ) SF takes place in egions whee the density is highe than a theshold, i.e. only in the densest egions of C 18 O s Why? Efficient decay of tubulence (Klessen 2003) Consequence: the local SFE must be measued ove the cluste volume, not ove the whole C 18 O H 13 CO + obsevations suggest: Constant volume density cluste-foming s, which lead to mass-independent infant weight-loss (t.f. impact), as suggested by obsevations Pamentie & Koupa (in pess) 31 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 31 / * * * * * *

32 Conclusions Popeties of young sta cluste systems shap insights into the clusteed mode of sta fomation sta fomation conditions detemine what mass faction clustes lose as they age infomation needed to econstuct galaxy SFH time-vaiations? (e.g. metallicity) SFH Even a long jouney stats with a one sinle step Oiental saying Most exciting yeas ae still to come: HERSCHEL, ALMA, log (dn/dt [My -1 ]) Obseved age distibution of LMC sta clustes log ( age [y] ) 32 Geneviève Pamentie - Bonn Agelande-Institut fü Astonomie 32 /