Distinguishing source populations. with LIGO/VIRGO

Transcription

1 Modest18, Santorini, Greece, June 27, 2018 Distinguishing source populations Bence Kocsis Eotvos University with LIGO/VIRGO GALNUC team members postdoc: Yohai Meiron, Alexander Rasskazov, Hiromichi Tagawa phd: László Gondán, Gergely Máthé, Ákos Szölgyén msc: Ádám Takács, Barnabás Deme, Kristóf Jakovác external collaborators: Ryan O Leary (Colorado), Zoltan Haiman, Imre Bartos (Columbia), Bao-Minh Hoang, Smadar Naoz (UCLA), Giacomo Fragione (Jerusalem), Idan Ginzburg (CFA), Manuel Arca-Sedda (ZAH) Teruaki Suyama (Tokyo), Suichiro Yokoyama, Takahiro Tanaka (Kyoto) Scott Tremaine (IAS)

2 Source populations Field stellar binary evolution galactic field binaries (talks by Michela Mapelli, Mario Spera) galactic field triples (talk by Silvia Toonen) Dynamical channel globular clusters (talks by Abbas Askar, Carl Rodriguez, Giacomo Fragione) galactic nuclei (talks by Bao-Minh Hoang, Alexander Rasskazov, Akos Szolgyen) open clusters (talk by Sambaran Banderjee) dark matter halos, primordial black holes Hydrodynamical channel Weak/failed supernova fallback (poster by Hiromichi Tagawa) Active galactic nuclei

3 Tagawa, Saitoh, Kocsis 2018, PRL Fallback driven merger ejected gas t=0 yr CO 2 CO 1

4 Fallback driven merger t=0 yr Y [AU] CO 2 ejected gas CO 1 N-body/SPH simulation (3D) Ideal gas EOS v(r)=vmax r/rmax Tagawa, Saitoh, Kocsis 2018, PRL Initial condition: studies of fallback accretion e.g. Zampieri et al. 1998, Batta etal X [AU]

5 Fallback driven merger MCO1=MCO2=5M Mgas,ini=5.4M Y [AU] rotating clockwise Tagawa, Kocsis, Saitoh, 2018, PRL X [AU]

6 Distinguishing LIGO/VIRGO sources Rate of mergers (see also talk by Michela Mapelli) Mass (see also talk by Michela Mapelli) Distance (see also talk by Michela Mapelli) Spins, spin direction (see talk by Carl Rodriguez) Eccentricity Host environment 1. Absolute rates? 2. Distribution of rates? 3. Direct detection of smoking gun signatures

7 Absolute rates Currently observed value: Gpc -3 yr -1 (powerlaw mass distribution prior, Abbott PRL ) galactic field binaries: Gpc -3 yr -1 (Belczynski+ 2016, Kruczkow+ 2018) galactic field triples: 2-25 Gpc -3 yr -1 (Silsbee & Tremaine 2017; Antonini, Toonen, Hamers 2017; Rodriguez & Antonini 2018) globular clusters: 5-15 Gpc -3 yr -1 (Rodriguez+ 2016,2017; Askar+ 2016; Fragione & Kocsis 2018) galactic nuclei: 1-15 Gpc -3 yr -1 (O Leary+ 2009, Antonini & Perets 2012, Antonini+ 2018, Hoang+ 2018) dark matter halos: Gpc -3 yr -1 primordial black holes (exotic) (Bird+ 2016, Ali-Haimud+ 2017, Sasaki+ 2016)

8 Upper limits on absolute rates Currently observed value: Gpc -3 yr -1 (powerlaw mass distribution prior, Abbott PRL ) Assume 100% of BHs merge at most once in a Hubble time BHs from stars with m>20m Sun, dn/dm ~ m % of stars turns into BHs globular clusters: R < 38 Gpc -3 yr % of stellar mass, stars with n ~ 0.8 Mpc -3 galactic nuclei: R < 30 Gpc -3 yr % of stellar mass, 10 7 stars with n ~ 0.02 Mpc -3

9 Distinguishing LIGO/VIRGO sources Rate of mergers Mass Distance Spins Spin direction Eccentricity Host environment 1. Absolute rates? 2. Distribution of rates? 3. Direct detection of smoking gun signatures

10 probability of merger [arbitrary scale] Mass distribution for globular clusters Monte Carlo and Nbody simulations 7% Robust statement (independent of IMF): heavy objects merge more often M^4 Second generation mergers: 7% O Leary, Meiron, Kocsis (see also Rodriguez+ 17, 18, Askar+ 17, 18)

11 Mass distribution for different processes universal diagnostic: independent of the mass function Given: How can we eliminate the unknown f(m)? Kocsis, Suyama, Takahiro, Yokoyama 2018; Gondan, Kocsis, Raffai, Frei 2018

12 Mass distribution for different processes universal diagnostic: independent of the mass function Given: How can we eliminate the unknown f(m)? = 4 in globular clusters (*needs revision) = for GW capture binaries in galactic nuclei = 1. 4 for GW capture binaries in collisionless systems = 1 for PBH binaries formed in early universe ~100 sources are needed to measure to integer accuracy Kocsis, Suyama, Takahiro, Yokoyama 2018; Gondan, Kocsis, Raffai, Frei 2018

13 Distance (redshift) distribution Evolving globular clusters in host galaxies Field binaries Depends on how globular clusters evolve in host galaxies TALK BY GIACOMO FRAGIONE TALK BY MICHELA MAPELLI Fragione and Kocsis 2018

14 Eccentricity measurement Unique features: Newtonian: 1PN frequency upper harmonics amplitude modulation due to apsidal precession each frequency harmonic splits to a triplet 2.5PN accelerated inspiral rate (mostly at low characteristic frequency) time-dependent eccentricity Gondán, Kocsis, Raffai, Frei (2018a,b)

15 Kocsis and Levin (2012) 3.5PN numerical simulation, numerical FFT of GW signal

16 / (D/100Mpc) Gondán, Kocsis, Raffai, Frei (2018a) / (D/100Mpc) Eccentricity measurement accuracy with LIGO+VIRGO+KAGRA Fisher matrix analysis (stationary phase approximation, random binary sky position and orientation, neglecting spin effects) measurement accuracy of initial eccentricity at last stable orbit pericenter distance / mass pericenter distance / mass

17 eccentricity O Leary, Kocsis, Loeb (2009); see also Rodriguez+ 2016, Gondan+ 2018, Samsing 2017 Eccentricity distribution for GW capture binaries pericenter distance / mass Velocity dispersion maximum initial pericenter distance r p /M eccentricity at merger

18 Gondán, Kocsis, Raffai, Frei (2018b) Eccentricity distribution for GW capture sources shows mass segregation eccentricity at last stable orbit radial distribution of mergers shows mass segregation

19 Gondán, Kocsis, Raffai, Frei (2018a,b) Eccentricity distribution for GW capture sources shows mass segregation cf. measurement accuracy De LSO ~ M Sun +30M 1Gpc Eccentricty distribution at 10Hz eccentricity at last stable orbit

20 Samsing & D Orazio (2018) see also Rodriguez Eccentricity distribution for globular cluster sources

21 Arca-Sedda, Li, Kocsis (2018a) Eccentricity distribution for non-hierarchical triples Eccentricty distribution at different GW frequencies

22 How to directly identify environment from GWs

23 Meiron, Kocsis, Loeb 2017 SMBH/AGN source with LIGO Doppler phase shift Detection SNR

24 Meiron, Kocsis, Loeb 2017 SMBH/AGN source with LIGO+LISA see also Sesana (2016), Inayoshi+ (2017) LISA+LIGO coincident detection of triple inspiral LIGO detection of GW mass loss LISA detection of GW mass loss Later: LIGO detection of merger (if stellar-mass triple) Test of general relativity

25 Kocsis 2013, Gondan & Kocsis in prep. GW amplitude Deflection angle (deg) GW echos GW rays are deflected around supermassive black holes Echo amplitude depends on distance to SMBH and deflection angle SMBH LIGO source GW echo arrives in

26 Take-away Discriminate LIGO sources using 2D mass distribution 4 for globular clusters for galactic nuclei 1 for primordial black holes Eccentricity measurable at design sensitivity Delta e ~ 0.01 at 1Gpc eccentricity vs mass distribution needed for all astrophysical channels Smoking gun signatures to identify sources in galactic nuclei Doppler phase GW echo for a few percent of these Fallback driven mergers new channel for field binaries too wide for common envelope

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28 Source populations

29 Mergers in active galactic nuclei Bartos There are large amounts of gas at the centers of 1% of galaxies (AGN). 29

30 Mergers in active galactic nuclei <10Myr Bartos Get captured by the disk 31

31 Mergers in active galactic nuclei <10Myr <1Myr Bartos and then quickly merge due to dynamical friction on the gas 32

32 Bartos, Kocsis, Haiman, Marka 2017 Stone, Metzger, Haiman 2017 Mergers in active galactic nuclei <10Myr <1Myr Event rate: 1 Gpc -3 yr event/yr (LIGO)

33 intermediate mass black holes Theory Observational constraints Formation Early universe: collapse of the first stars (Madau & Reese 01) Globular clusters runaway collisions (Portegies Zwart &McMillan 02) mergers of stellar mass black holes (Miller & Hamilton 02) dynamical friction IMBH deposited in the galactic center In accretion disks (Goodman & Tan 04, McKernan+ 12, 14; Leigh+) ~ 50 IMBHs within 10 pc ~ 8,000 IMBHs within 1kpc Fragione, Ginzburg, Kocsis 2017 Yu & Tremaine (2003) Gualandris & Merritt (2009)

34 Option 5: Dark matter halo 10x more mass than in stars primordial mass black holes? Rates match if 100% of dark matter is in 30 Msun single BHs (Bird et al 2016) RULED OUT BY OBSERVATION OF a GLOBULAR CLUSTER IN A DWARF GALAXY (Brandt+17) 0.1% of dark matter is in primordial binary BHs after inflation (Sasaki et al 2016) 30 Msun primordial BHs form when T ~ 30 MeV (Carr 1975) standard model does not have any phase transitions at this temperature