J/A+A/673/A120 Black hole mergers with Obelisk simulation (Dong-paez+, 2023)
Black hole mergers as tracers of spinning massive black hole and galaxy populations in the OBELISK simulation. Multi-messenger study of merging massive black holes in the OBELISK simulation: Gravitational waves, electromagnetic counterparts, and their link to galaxy and black-hole populations.
Dong-Paez C.A., Volonteri M., Beckmann R.S., Dubois Y., Trebitsch M.,
Mangiagli A., Vergani S.D., Webb N.A.
<Astron. Astrophys., 673, A120 (2023); 676, A2 (2023)>
=2023A&A...673A.120D 2023A&A...673A.120D (SIMBAD/NED BibCode)
+2023A&A...676A...2D 2023A&A...676A...2D
ADC_Keywords: Models ; Black holes ; QSOs ; Redshifts
Keywords: quasars: supermassive black holes - galaxies: evolution -
methods: numerical - gravitational waves
Abstract:
Massive black hole (BH) mergers will be key targets of future
gravitational wave and electromagnetic observational facilities. In
order to constrain BH evolution with the information extracted from BH
mergers, one must take into account the complex relationship between
the population of merging BHs and the global BH population. We
analysed the high-resolution cosmological radiation-hydrodynamics
simulation OBELISK, run to redshift z=3.5, to study the properties of
the merging BH population, and its differences with the underlying
global BH population in terms of BH and galaxy properties. In
post-processing, we calculated dynamical delays between the merger in
the simulation at the resolution limit and the actual coalescence well
below the resolution scale. We find that merging BHs are hosted in
relatively massive galaxies with stellar mass M*≳109M☉. Given
that galaxy mass is correlated with other BH and galaxy properties, BH
mergers tend to also have a higher total BH mass and higher BH
accretion rates than the global population of main BHs. These
differences generally disappear if the merger population is compared
with a BH population sampled with the same galaxy mass distribution as
merger hosts. Galaxy mergers can temporarily boost the BH accretion
rate and the host's star formation rate, which can remain active at
the BH merger if sub-resolution delays are not taken into account.
When dynamical delays are taken into account, the burst has generally
faded by the time the BHs merge. BH spins are followed
self-consistently in the simulation under the effect of accretion and
BH mergers. We find that merging BHs have higher spins than the global
population, but similar or somewhat lower spins compared to a
mass-matched sample. For our sample, mergers tend to decrease the spin
of the final BH remnant.
Massive black-hole (BH) mergers are predicted to be powerful sources
of low-frequency gravitational waves (GWs). Coupling the detection of
GWs with an electromagnetic (EM) detection can provide key information
about merging BHs and their environments as well as cosmology. We
study the high-resolution cosmological radiation-hydrodynamics
simulation OBELISK, run to redshift z=3.5, to assess the GW and
EM detectability of high-redshift BH mergers, modelling spectral
energy distribution and obscuration. For EM detectability, we further
consider sub-grid dynamical delays in postprocessing. We find that
most of the merger events can be detected by LISA, except for
high-mass mergers with very unequal mass ratios. Intrinsic binary
parameters are accurately measured, but the sky localisation is poor
generally. Only ∼40% of these high-redshift sources have a sky
localisation better than 10deg2. Merging BHs are hard to detect in
the restframe UV since they are fainter than the host galaxies, which
at high redshift are star-forming. A significant fraction, 15-35%,
of BH mergers instead outshine the galaxy in X-rays, and about
5-15% are sufficiently bright to be detected with sensitive
X-ray instruments. If mergers induce an Eddington-limited brightening,
up to 30% of sources can become observable. The transient flux change
originating from such a brightening is often large, allowing
4-20% of mergers to be detected as EM counterparts. A fraction, 1-30%,
of mergers are also detectable at radio frequencies. Transients are
found to be weaker for radio-observable mergers. Observable merging
BHs tend to have higher accretion rates and masses and are overmassive
at a fixed galaxy mass with respect to the full population. Most
EM-observable mergers can also be GW-detected with LISA, but their sky
localisation is generally poorer. This has to be considered when using
EM counterparts to obtain information about the properties of merging
BHs and their environment.
Description:
A catalogue listing the BH mergers in the Obelisk simulation.
Numerical mergers refer to mergers occurring in the simulation. The
criterion for a numerical merger is that the BHs are closer than four
times the resolution. Delayed mergers are BH mergers including
sub-grid dynamical evolution in post-processing (see Paper I,
2023A&A...673A.120D 2023A&A...673A.120D). Only the delayed mergers occurring before the
end of the simulation are considered. mergers that occur. Paper I
provides a more detailed description of the data. We provide
redshifts, BH masses and accretion rates, host galaxy masses,
rest-frame (unobscured) luminosity in the X-rays and 1500 Angstrom
(for the remnant BH and the host galaxy) and spins. The BH
luminosities are calculated both using the accretion rates measured in
the simulation and assuming the Eddington accretion rate. The BH
luminosities are calculated assuming a Novikov-Thorne disk with a
power-law corona. The optical to X-ray normalisations are taken from
fits to Done et al. (2012MNRAS.420.1848D 2012MNRAS.420.1848D) and Dong et al.
(2012ApJ...761...73D 2012ApJ...761...73D). The galaxy X-ray luminosities are estimated
using the scaling relation in Fornasini et al., 2018ApJ...865...43F 2018ApJ...865...43F,
Cat. J/ApJ/865/43. The galaxy 1500Å luminosities are computed by
applying the Bpass v2.2.1 SED (Eldridge et al., 2017PASA...34...58E 2017PASA...34...58E ;
Stanway & Eldridge, 2018MNRAS.479...75S 2018MNRAS.479...75S) to the stellar particles,
based on their age and metallicity.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
numeric.dat 178 878 Numerical mergers
delayed.dat 109 129 Delayed mergers
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Byte-by-byte Description of file: numeric.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 E10.5 --- z Redshift
12- 21 E10.5 Msun M1 Mass of the primary BH
23- 32 E10.5 Msun M2 Mass of the secondary BH
34- 43 E10.5 --- fEdd1 Accretion rate normalised to the Eddington
rate for the primary
45- 54 E10.5 --- fEdd2 Accretion rate normalised to the Eddington
rate for the secondary
56- 65 E10.5 --- fEddrem Accretion rate normalised to the Eddington
rate for the remnant BH
67- 76 E10.5 Msun Mstar Host galaxy mass
78- 87 E10.5 10-7W L1500A ? Remnant BH luminosity (nu*Lnu) at 1500Å
rest-frame
89- 98 E10.5 10-7W LX Integrated remnant BH luminosity in the range
0.5-10eV rest-frame
100-109 E10.5 10-7W L1500AEdd ? Luminosity at at 1500Å rest-frame
assuming Eddington accretion rate
111-120 E10.5 10-7W LXEdd Integrated luminosity 0.5-10eV rest-frame
assuming Eddington accretion rate
122-131 E10.5 10-7W L1500Agal Galaxy luminosity at 1500Å rest-frame
133-142 E10.5 10-7W LXgal Integrated (X-ray binary) galaxy luminosity
in the range 0.5-10eV rest-frame
144-154 E11.5 --- a1 [-1/1] Primary spin
156-166 E11.5 --- a2 [-1/1] Secondary spin
168-178 E11.5 --- arem [-1/1] Remnant spin
--------------------------------------------------------------------------------
Byte-by-byte Description of file: delayed.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 E10.5 --- z Redshift
12- 21 E10.5 Msun Mrem Mass of the remnant BH
23- 32 E10.5 --- fEddrem Accretion rate normalised to the Eddington
rate for the remnant BH
34- 43 E10.5 Msun Mstar Host galaxy mass
45- 54 E10.5 10-7W L1500A ? Remnant BH luminosity (nu*Lnu) at 1500Å
rest-frame
56- 65 E10.5 10-7W LX Integrated remnant BH luminosity in the range
0.5-10eV rest-frame
67- 76 E10.5 10-7W L1500AEdd Luminosity at at 1500Å rest-frame assuming
Eddington accretion rate
78- 87 E10.5 10-7W LXEdd Integrated luminosity 0.5-10eV rest-frame
assuming Eddington accretion rate
89- 98 E10.5 10-7W L1500Agal Galaxy luminosity at 1500Å rest-frame
100-109 E10.5 10-7W LXgal Integrated galaxy (X-ray binary) luminosity
in the range 0.5-10eV rest-frame
--------------------------------------------------------------------------------
Acknowledgements:
Chi An Dong-Paez, chiandongpaez(at)gmail.com
References:
Dong-Paez et al., Paper I, 2023A&A...673A.120D 2023A&A...673A.120D
Dong-Paez et al., Paper II, 2023A&A...676A...2D 2023A&A...676A...2D
(End) Patricia Vannier [CDS] 28-Feb-2024