J/MNRAS/514/640 Dual AGN in the Horizon-AGN simulation (Volonteri+, 2022)
Dual AGN in the Horizon-AGN simulation and their link to galaxy and
massive black hole mergers, with an excursus on multiple AGN.
Volonteri M., Pfister H., Beckmann R., Dotti M., Dubois Y., Massonneau W.,
Musoke G., Tremmel M.
<Mon. Not. R. Astron. Soc. 514, 640-656 (2022)>
=2022MNRAS.514..640V 2022MNRAS.514..640V (SIMBAD/NED BibCode)
ADC_Keywords: Models ; Active gal. nuclei
Keywords: methods: numerical - galaxies: active
Abstract:
The occurrence of dual active galactic nuclei (AGN) on scales of a few
tens of kpc can be used to study merger-induced accretion on massive
black holes (MBHs) and to derive clues on MBH mergers, using dual AGN
as a parent population of precursors. We investigate the properties of
dual AGN in the cosmological simulation HAGN. We create catalogs of
dual AGN selected with distance and luminosity criteria, plus
sub-catalogs where further mass cuts are applied. We divide the sample
into dual AGN hosted in different galaxies, on the way to a merger,
and into those hosed in one galaxy, after the galaxy merger has
happened. We find that the most luminous AGN in a pair has higher
Eddington ratio and mass than the general AGN population, but that the
relation between MBH and galaxy mass is similar to that of all AGN.
The typical mass ratio of galaxy mergers associated to dual AGN is
0.2, with mass loss in the smaller galaxy decreasing the mass ratio as
the merger progresses. The connection between dual AGN and MBH mergers
is weaker. Between 30 and 80 per cent of dual AGN with separations
between 4 and 30∼kpc can be matched to an ensuing MBH merger. The dual
AGN fraction increases with redshift and with separation threshold,
although above 50∼kpc the increase of multiple AGN limits that of
duals. Multiple AGN are generally associated with massive halos, and
mass loss of satellites shapes the galaxy-halo relation.
Description:
We build our simulated dual AGN catalog using the cosmological
simulation Horizon-AGN. It has a volume of (140)3 comoving Mpc and
it includes galaxy formation physics (cooling, star formation, stellar
feedback) and MBH physics (accretion, thermal and kinetic AGN
feedback, drag force from gas, MBH mergers). Two families of dual AGN
catalogs are produced: "all" dual AGN and "pure" dual AGN. The
difference is that in the "pure" sample multiple AGN are first
removed, for instance a triple AGN system is not considered as the
combination of 3 separate dual AGN. In the "all" sample a triple AGN
system is counted as 3 separate dual AGN. In the "all" catalogs, one
can build sub-samples with different luminosity/distance cuts based on
the general catalog. In the "pure" catalogs, one cannot simply apply
new thresholds, because any different cuts would modify the multiple
AGN population and therefore as a consequence the "pure" dual AGNs. In
the paper all results are shown for the "pure" sample and a separate
analysis is performed on multiple AGN. The analysis is performed at
redshifts z=0, z=0.5, z=1, z=1.5, z=2, z=2.5, z=3.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 82 119 List of simulated catalogs
files/* . 119 Individual simulated catalogs
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 32 A32 --- FileName Name of the file with simulated catalog
in subdirectory files
35- 39 I5 --- Nlines Number of line in the simulated catalog
41- 44 A4 --- Type [All Pure] "all" dual AGN or "pure" dual AGN
46- 48 F3.1 --- z Redshift
50- 51 I2 kpc Dist Upper distance value (1)
53- 54 I2 [10-7W] Lum Lower log Luminosity value (2)
56- 82 A27 --- Title Title of the simulated catalog
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Note (1): Computed within a spherical radius, in proper (not comoving) kpc.
Note (2): In the file name the luminosity is expressed as the decimal
logarithmic scale of the luminosity in units of erg/s, but in the catalog the
luminosity is expressed in W. Luminosity is calculated as L=0.1*dM/dt*c2.
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Byte-by-byte Description of file: files/*
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Bytes Format Units Label Explanations
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1- 6 F6.4 --- z Redshift
8- 13 I6 --- IDBH1 ID of the BH of the brighter AGN (1)
15- 22 F8.5 [Msun] logMBH1 log10 of mass of the BH in the brighter AGN
25- 35 E11.5 W Lum1 Luminosity of the BH in the brighter AGN
38- 48 E11.5 --- fedd1 Eddington ratio of the BH in the brighter AGN
50- 55 I6 --- IDGAL1 ID of the galaxy hosting the brighter AGN (2)
57- 64 F8.5 [Msun] logMGAL1 log10 of mass of the galaxy hosting the
brighter AGN
68- 81 E14.8 kpc x1 x position of the brighter AGN (3)
85- 98 E14.8 kpc y1 y position of the brighter AGN (3)
102-115 E14.8 kpc z1 z position of the brighter AGN (3)
117-122 I6 --- IDBH2 ID of the BH of the fainter AGN (1)
125-131 F7.5 [Msun] logMBH2 log10 of mass of the BH in the fainter AGN
134-144 E11.5 W Lum2 Luminosity of the BH in the fainter AGN
147-157 E11.5 --- fedd2 Eddington ratio of the BH in the fainter AGN
159-164 I6 --- IDGAL2 ID of the galaxy hosting the fainter AGN (2)
166-173 F8.5 [Msun] logMGAL2 log10 of mass of the galaxy hosting the
fainter AGN
178-191 E14.8 kpc x2 x position of the fainter AGN (3)
195-208 E14.8 kpc y2 y position of the fainter AGN (3)
212-225 E14.8 kpc z2 z position of the fainter AGN (3)
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Note (1): the ID of MBHs is conserved, a MBH with a given ID could appear in
files at multiple redshifts, and it is the same MBH (its mass would increase
by accretion and mergers).
Note (2): the ID of galaxies is not conserved, a galaxy with a given ID in a
file at one redshift is generally not the galaxy with the same ID
at a different redshift.
Note (3): position in the simulation box expressed in proper kpc.
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Acknowledgements:
Marta Volonteri, martav(at)iap.fr
(End) Marta Volonteri [IAP, France], Patricia Vannier [CDS] 02-May-2022