An official website of the United States government
Abstract We present radial profiles of luminosity-weighted age (ageL) and ΔΣSFRfor various populations of high- and low-mass central and satellite galaxies in the TNG100 cosmological simulation. Using these profiles, we investigate the impact of intrinsic and environmental factors on the radial distribution of star formation. For both central galaxies and satellites, we investigate the effects of black hole mass, cumulative active galactic nucleus (AGN) feedback energy, morphology, halo mass, and local galaxy overdensity on the profiles. In addition, we investigate the dependence of radial profiles of the satellite galaxies as a function of the redshifts at which they joined their hosts, as well as the net change in star-forming gas mass since the satellites joined their host. We find that high-mass (M*> 1010.5M⊙) central and satellite galaxies show evidence of inside-out quenching driven by AGN feedback. Effects from environmental processes only become apparent in averaged profiles at extreme halo masses and local overdensities. We find that the dominant quenching process for low-mass galaxies (M*< 1010M⊙) is environmental, generally occurring at low halo mass and high local galaxy overdensity for low-mass central galaxies and at high host halo masses for low-mass satellite galaxies. Overall, we find that environmental processes generally drive quenching from the outside-in.
more »
« less
Black Hole Growth, Baryon Lifting, Star Formation, and IllustrisTNG
Abstract Quenching of star formation in the central galaxies of cosmological halos is thought to result from energy released as gas accretes onto a supermassive black hole. The same energy source also appears to lower the central density and raise the cooling time of baryonic atmospheres in massive halos, thereby limiting both star formation and black hole growth, by lifting the baryons in those halos to greater altitudes. One predicted signature of that feedback mechanism is a nearly linear relationship between the central black hole’s mass (MBH) and the original binding energy of the halo’s baryons. We present the increasingly strong observational evidence supporting a such a relationship, showing that it extends up to halos of massMhalo∼ 1014M⊙. We then compare current observational constraints on theMBH–Mhalorelation with numerical simulations, finding that black hole masses in IllustrisTNG appear to exceed those constraints atMhalo< 1013M⊙and that black hole masses in EAGLE fall short of observations atMhalo∼ 1014M⊙. A closer look at IllustrisTNG shows that quenching of star formation and suppression of black hole growth do indeed coincide with black hole energy input that lifts the halo’s baryons. However, IllustrisTNG does not reproduce the observedMBH–Mhalorelation because its black holes gain mass primarily through accretion that does not contribute to baryon lifting. We suggest adjustments to some of the parameters in the IllustrisTNG feedback algorithm that may allow the resulting black hole masses to reflect the inherent links between black hole growth, baryon lifting, and star formation among the massive galaxies in those simulations.
more »
« less
- Award ID(s):
- 2106575
- PAR ID:
- 10480746
- Publisher / Repository:
- DOI PREFIX: 10.3847
- Date Published:
- Journal Name:
- The Astrophysical Journal
- Volume:
- 960
- Issue:
- 1
- ISSN:
- 0004-637X
- Format(s):
- Medium: X Size: Article No. 28
- Size(s):
- Article No. 28
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Abstract We present measurements of black hole masses and Eddington ratios (λEdd) for a sample of 38 bright (M1450< −24.4 mag) quasars at 5.8 ≲z≲ 7.5, derived from Very Large Telescope/X–shooter near–IR spectroscopy of their broad Civand Mgiiemission lines. The black hole masses (on average,MBH∼ 4.6 × 109M⊙) and accretion rates (0.1 ≲λEdd≲ 1.0) are broadly consistent with that of similarly luminous 0.3 ≲z≲ 2.3 quasars, but there is evidence for a mild increase in the Eddington ratio abovez≳ 6. Combined with deep Atacama Large Millimeter/submillimeter Array (ALMA) observations of the [CII] 158μm line from the host galaxies and VLT/MUSE investigations of the extended Lyαhalos, this study provides fundamental clues to models of the formation and growth of the first massive galaxies and black holes. Compared to local scaling relations,z≳ 5.7 black holes appear to be over-massive relative to their hosts, with accretion properties that do not change with host galaxy morphologies. Assuming that the kinematics of theT∼ 104K gas, traced by the extended Lyαhalos, are dominated by the gravitational potential of the dark matter halo, we observe a similar relation between black hole mass and circular velocity as reported forz∼ 0 galaxies. These results paint a picture where the first supermassive black holes reside in massive halos atz≳ 6 and lead the first stages of galaxy formation by rapidly growing in mass with a duty cycle of order unity. The duty cycle needs to drastically drop toward lower redshifts, while the host galaxies continue forming stars at a rate of hundreds of solar masses per year, sustained by the large reservoirs of cool gas surrounding them.more » « less
-
Abstract We investigate the impact of massive primordial black holes (PBHs;mBH ∼ 106M⊙) on the star formation and first galaxy assembly process using high-resolution hydrodynamical simulations fromz= 1100 toz ∼ 9. We find that PBH accretion is self-regulated by feedback, suppressing mass growth unless feedback is weak. PBHs accelerate structure formation by seeding dark matter (DM) halos and gravitationally attracting gas, but strong feedback can delay cooling and suppress star formation. In addition, the presence of baryon-DM streaming creates an offset between the PBH location and the peaks induced in gas density, promoting earlier and more efficient star formation compared to standard ΛCDM. Byz ∼ 10, PBH-seeded galaxies form dense star clusters, with PBH-to-stellar mass ratios comparable to observed high-zactive galactic nuclei like UHZ-1. Our results support PBHs as viable supermassive black hole (SMBH) seeds but do not exclude alternative scenarios. We emphasize that PBH-seeding provides a natural explanation for some of the newly discovered overmassive SMBHs at high redshift, in particular those with extreme ratios of BH-to-dynamical (virial) mass that challenge standard formation channels. Future studies with ultra-deep JWST surveys, the Roman Space Telescope, and radio surveys with facilities such as the Square Kilometre Array and Hydrogen Epoch of Reionization Array will be critical in distinguishing PBH-driven SMBH growth from other pathways.more » « less
-
null (Ed.)ABSTRACT Supermassive black holes (SMBHs) that reside at the centres of galaxies can inject vast amounts of energy into the surrounding gas and are thought to be a viable mechanism to quench star formation in massive galaxies. Here, we study the $$10^{9-12.5}\, \mathrm{M_\odot }$$ stellar mass central galaxy population of the IllustrisTNG simulation, specifically the TNG100 and TNG300 volumes at z = 0, and show how the three components – SMBH, galaxy, and circumgalactic medium (CGM) – are interconnected in their evolution. We find that gas entropy is a sensitive diagnostic of feedback injection. In particular, we demonstrate how the onset of the low-accretion black hole (BH) feedback mode, realized in the IllustrisTNG model as a kinetic, BH-driven wind, leads not only to star formation quenching at stellar masses $$\gtrsim 10^{10.5}\, \mathrm{M_\odot }$$ but also to a change in thermodynamic properties of the (non-star-forming) gas, both within the galaxy and beyond. The IllustrisTNG kinetic feedback from SMBHs increases the average gas entropy, within the galaxy and in the CGM, lengthening typical gas cooling times from $$10\!-\!100\, \mathrm{Myr}$$ to $$1\!-\!10\, \mathrm{Gyr}$$, effectively ceasing ongoing star formation and inhibiting radiative cooling and future gas accretion. In practice, the same active galactic nucleus (AGN) feedback channel is simultaneously ‘ejective’ and ‘preventative’ and leaves an imprint on the temperature, density, entropy, and cooling times also in the outer reaches of the gas halo, up to distances of several hundred kiloparsecs. In the IllustrisTNG model, a long-lasting quenching state can occur for a heterogeneous CGM, whereby the hot and dilute CGM gas of quiescent galaxies contains regions of low-entropy gas with short cooling times.more » « less
-
The baryonic physics shaping galaxy formation and evolution are complex, spanning a vast range of scales and making them challenging to model. Cosmological simulations rely on subgrid models that produce significantly different predictions. Understanding how models of stellar and active galactic nucleus (AGN) feedback affect baryon behavior across different halo masses and redshifts is essential. Using the SIMBA and IllustrisTNG suites from the Cosmology and Astrophysics with MachinE Learning Simulations (CAMELS) project, we explore the effect of parameters governing the subgrid implementation of stellar and AGN feedback. We find that while IllustrisTNG shows higher cumulative feedback energy across all halos, SIMBA demonstrates a greater spread of baryons, quantified by the closure radius and circumgalactic medium (CGM) gas fraction. This suggests that feedback in SIMBA couples more effectively to baryons and drives them more efficiently within the host halo. There is evidence that the different feedback modes are highly interrelated in these subgrid models. The parameters controlling the stellar feedback efficiency significantly impact AGN feedback, as seen in the suppression of black hole mass growth and delayed activation of AGN feedback to higher-mass halos with increasing stellar feedback efficiency in both simulations. Additionally, the AGN feedback efficiency parameters affect the CGM gas fraction at low halo masses in SIMBA, hinting at complex, nonlinear interactions between the AGN and supernova feedback modes. Overall, we demonstrate that stellar and AGN feedback are intimately interwoven, especially at low redshift, due to subgrid implementation, resulting in halo property effects that might initially seem counterintuitive.more » « less
