A new Population Synthesis Code for NS/BH Binaries

Transcription

1 A new Population Synthesis Code for NS/BH Binaries StarBurst Matthias Kruckow PhD supervisor: Thomas Tauris Argelander-Institut für Astronomie Rheinischen Friedrich-Wilhelms-Universität Bonn 30 th November 2015

2 Outline Outline 1 The Code 2 Parameter Studies 3 Gravitational Wave Mergers 4 Outlook M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

3 Aim Aim predict event rates of NS/BH binaries M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

4 Aim Aim predict event rates of NS/BH binaries gravitational merger rates SN rates M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

5 Aim Aim predict event rates of NS/BH binaries gravitational merger rates SN rates get distributions of binaries in mass, semi-major axis, eccentricity,... at various points in the evolution M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

6 Structure Flowchart initialize and read in parameters M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

7 Structure Flowchart initialize and read in parameters read in tables M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

8 Structure Flowchart initialize and read in parameters read in tables initialize system M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

9 Structure Flowchart initialize and read in parameters read in tables initialize system check for next evolutionary phase M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

10 Structure Flowchart initialize and read in parameters read in tables initialize system check for next evolutionary phase apply current evolutionary phase M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

11 Structure Flowchart initialize and read in parameters read in tables initialize system check for next evolutionary phase apply current evolutionary phase system is merged/disrupted or all components are compact remnants analyze system, save/print data and delete system next phase M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

12 Structure Flowchart initialize and read in parameters read in tables initialize system next system check for next evolutionary phase apply current evolutionary phase system is merged/disrupted or all components are compact remnants analyze system, save/print data and delete system all systems calculated print population synthesis output next phase M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

13 Structure Flowchart initialize and read in parameters read in tables initialize system next system check for next evolutionary phase apply current evolutionary phase system is merged/disrupted or all components are compact remnants analyze system, save/print data and delete system all systems calculated print population synthesis output next phase delete values and free space M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

14 Structure Differences to Other Binary Population Synthesis Codes very fast low statistical errors allow to estimate systematic errors caused by the input parameters credits: T. Tauris M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

15 Structure Differences to Other Binary Population Synthesis Codes very fast low statistical errors allow to estimate systematic errors caused by the input parameters interpolate stellar evolutionary tables possibility to easily use other or update stellar evolutionary tables can account for structure of the star without detailed integration, e.g. via pre calculated λ-values credits: T. Tauris M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

16 Structure Differences to Other Binary Population Synthesis Codes very fast low statistical errors allow to estimate systematic errors caused by the input parameters interpolate stellar evolutionary tables possibility to easily use other or update stellar evolutionary tables can account for structure of the star without detailed integration, e.g. via pre calculated λ-values case BB RLO according to Tauris et al changes number of surviving systems by > 1 dex credits: T. Tauris M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

17 Parameter Studies Stable RLO and CE Events counts of events/total number of systems Stable RLO vs. CE Case A-C: qlimit 1.2 stable RLO: total case A case B/C case BB 1.0 q= Mdonor Maccretor CE: total case A case B/C case BB credits: ESO qlimit M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

18 Parameter Studies Stable RLO and CE Events Stable RLO vs. CE Case A-C: q limit counts of events/total number of systems stable RLO: total case A case B/C case BB q limit larger q limit more stable RLO, less CE CE: total case A case B/C case BB M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

19 Parameter Studies Formation rate Interpolate λ-values for CE: α TH λ λ = G M Menv R E bind E bind = E grav + α TH E int formation rate per yr in MW λ G λ B 2 λ G α TH NS-NS NS-BH BH-NS BH-BH M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

20 Parameter Studies Formation rate Interpolate λ-values for CE: α TH λ larger λ less systems merge in CE formation rate per yr in MW λ G λ B 2 λ G α TH NS-NS NS-BH BH-NS BH-BH M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

21 Gravitational Wave Mergers Histograms of Gravitational Wave Mergers Counts counts of systems NS-NS NS-BH BH-NS BH-BH time until graviational wave merger in yr M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

22 Gravitational Wave Mergers Histograms of Gravitational Wave Mergers Counts counts of systems NS-NS NS-BH BH-NS BH-BH system count fraction NSNS % NSBH % BHNS % BHBH % time until graviational wave merger in yr M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

23 Gravitational Wave Mergers Histograms of Gravitational Wave Mergers Normalised counts of systems/total number of systems NS-NS NS-BH BH-NS BH-BH system count fraction NSNS % NSBH % BHNS % BHBH % time until graviational wave merger in yr M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

24 Gravitational Wave Mergers Gravitational Wave Mergers Rates Merger Rate in the MW gravitational wave merger rate per yr in MW NS-NS NS-BH BH-NS BH-BH α IMF M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

25 Gravitational Wave Mergers Gravitational Wave Mergers Rates Merger Rate in the MW gravitational wave merger rate per yr in MW NS-NS NS-BH BH-NS BH-BH α IMF less steep IMF more NS or BH progenitors M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10

26 Outlook Goals get reliable merger rates in MW like galaxy detections rate for LIGO distance to host galaxy at merger most probable formation channel most important parameters on rates calibration using earlier evolutionary phases, like HMXBs predictions for characteristics of NS-NS Binaries (P orb, e, P spin,...) M. Kruckow (AIfA - Uni Bonn) New Pop. Synth. Code for NS/BH Binaries November 30, / 10