Hole Growth Research Articles

The origin of massive compact galaxies: lessons from IllustrisTNG

ABSTRACT We investigate the formation and evolution of z = 0 massive compact galaxies (MCGs) in the IllustrisTNG cosmological simulation. We found that, as in observations, MCGs are mainly old (median age ∼10.8 Gyr), have supersolar metallicities (median log Z/Z⊙ ∼ 0.35), and are α-enhanced (median [α/Fe] ∼ 0.25). The age distribution extends to younger ages, however, and a few MCGs are as young as ∼7 Gyr. In general, MCGs assemble their mass early and accrete low angular momentum gas, significantly increasing their mass while growing their size much slower. A small fraction of MCGs follow another evolutionary path, going through a compaction event, with their sizes shrinking by 40 per cent or more. The accretion of low angular momentum gas leads to enhanced supermassive black hole (SMBH) growth, and MCGs reach the threshold SMBH mass of $\log M_\mathrm{BH}\sim 10^{8.5}\ \mathrm{ M}_\odot$ – when kinetic active galactic nucleus feedback kicks in and quenches the galaxy – earlier than non-compact galaxies. Comparing MCGs to a sample of median-sized quiescent galaxies matched in effective velocity dispersion, we find that their accretion histories are very different. 71 per cent of MCGs do not merge after quenching compared to 37 per cent of median-sized quiescent galaxies. Moreover, tracing these populations back in time, we find that at least a third of median-sized quiescent galaxies do not have a compact progenitor, underscoring that both dry mergers and progenitor bias effects are responsible for the differences in the kinematics and stellar population properties of MCGs and median-sized quiescent galaxies.

Discovery of a radio jet in the Cloverleaf quasar at z = 2.56

ABSTRACT The fast growth of supermassive black holes and their feedback to the host galaxies play an important role in regulating the evolution of galaxies, especially in the early Universe. However, due to cosmological dimming and the limited angular resolution of most observations, it is difficult to resolve the feedback from the active galactic nuclei (AGNs) to their host galaxies. Gravitational lensing, for its magnification, provides a powerful tool to spatially differentiate emission originating from AGN and host galaxy at high-redshifts. Here, we report a discovery of a jet-like radio structure in a strongly lensed starburst quasar, H1413+117 or Cloverleaf at redshift z = 2.56, based on observational data at optical, submillimetre, and radio wavelengths. With both parametric and non-parametric lens models and with reconstructed images in the source plane, we find a well-separated, kpc-scaled, single-sided radio jet located at projected ${\sim }1.2\, \mathrm{kpc}$ to the north-west of the host galaxy in the source plane. This could indicate the co-existence of feedback from the AGN by both wind and jet in the Cloverleaf quasar.

A Census of WISE-selected Dual and Offset AGNs Across the Sky: New Constraints on Merger-driven Triggering of Obscured AGNs

Pairs of galaxies hosting active galactic nuclei (AGNs) are powerful probes of merger-driven supermassive black hole (SMBH) growth as they can resolve individual AGNs and trace mergers over a large range of physical separations. To exploit this on a large scale for the first time for both obscured and unobscured AGNs, we use the photometric redshifts of AGNs selected by the Wide-field Infrared Survey Explorer (WISE) to find probabilistic pairs (<100 kpc separations) across the sky, along with a comparison sample of inactive galaxy pairs. Our final sample of integrated pair probabilities yields 198 AGN–AGN pairs (dual AGNs) and 2767 AGN–galaxy pairs (offset AGNs) with uniformly measured AGN and host galaxy physical properties. We find the fraction of galaxy pairs hosting WISE AGNs is dominated by offset AGNs and is significantly elevated above that of inactive galaxies for large host stellar masses. We show how the AGN merger fraction directly increases with AGN extinction for both offset and dual AGNs, with up to ∼40% of heavily obscured AGNs found in galaxy pairs. Elevated AGN merger fractions coincide with increased host specific star formation rates that suggest merger-driven coevolution of galaxies and SMBHs. Among dual AGNs, the most rapid SMBH growth may occur within the less-massive galaxy. Relative to stochastic mechanisms, mergers produce an excess of AGNs at increasingly smaller separations, especially for obscured AGNs (up to a factor of ∼5), and are augmented by correlated triggering. Finally, this excess is stronger than for lower-luminosity optically selected AGNs, regardless of the AGN obscuration level.

A Candidate Dual QSO at Cosmic Noon

We report the discovery of a candidate dual QSO at z = 1.889, a redshift that is in the era known as “cosmic noon” where most of the universe’s black hole and stellar mass growth occurred. The source was identified in Hubble Space Telescope WFC3/IR images of a dust-reddened QSO that showed two closely separated point sources at a projected distance of 0.″26, or 2.2 kpc. This red QSO was targeted for imaging to explore whether red QSOs are hosted by merging galaxies. We subsequently obtained a spatially resolved Space Telescope Imaging Spectrograph spectrum of the system, covering the visible spectral range, and verifying the presence of two distinct QSO components. We also obtained high-resolution radio continuum observations with the Very Long Baseline Array at 1.4 GHz (21 cm L band) and found two sources coincident with the optical positions. The sources have similar black hole masses, bolometric luminosities, and radio-loudness parameters. However, their colors and reddenings differ significantly. The redder QSO has a higher Eddington ratio, consistent with previous findings. We consider the possibility of gravitational lensing and find that it would require extreme and unlikely conditions. If confirmed as a bona fide dual QSO, this system would link dust reddening to galaxy and supermassive black hole mergers, opening up a new population in which to search for samples of dual active galactic nuclei.

Revisiting the Properties of X-Ray Active Galactic Nuclei in the SSA22 Protocluster: Normal Supermassive Black Hole and Host-galaxy Growth for AGNs in a z = 3.09 Overdensity

We analyze the physical properties of eight X-ray-selected active galactic nuclei (AGNs) and one candidate protoquasar system (ADF22A1) in the z = 3.09 SSA22 protocluster by fitting their X-ray-to-IR spectral energy distributions (SEDs) using our SED-fitting code, Lightning (https://www.github.com/rafaeleufrasio/lightning). We recover star formation histories (SFHs) for seven of these systems which are well fit by composite stellar population plus AGN models. We find indications that four out of nine of the SSA22 AGN systems we study have host galaxies below the main sequence, with SFR/SFRMS ≤ −0.4. The remaining SSA22 systems, including ADF22A1, are consistent with obscured supermassive black hole (SMBH) growth in star-forming galaxies. We estimate the SMBH accretion rates and masses, and compare the properties and SFHs of the nine protocluster AGN systems with X-ray-detected AGN candidates in the Chandra Deep Fields (CDF), finding that the distributions of SMBH growth rates, star formation rates (SFRs), SMBH masses, and stellar masses for the protocluster AGNs are consistent with field AGNs. We constrain the ratio between the sample-averaged SSA22 SMBH mass and CDF SMBH mass to <1.41. While the AGNs are located near the density peaks of the protocluster, we find no statistically significant trends between the AGN or host-galaxy properties and their location in the protocluster. We interpret the similarity of the protocluster and field AGN populations together with existing results as suggesting that the protocluster and field AGNs coevolve with their hosts in the same ways, while AGN-triggering events are more likely in the protocluster.

The Most Obscured AGNs in the XMM-SERVS Fields

We perform X-ray spectral analyses to derive the characteristics (e.g., column density, X-ray luminosity) of ≈10,200 active galactic nuclei (AGNs) in the XMM-Spitzer Extragalactic Representative Volume Survey, which was designed to investigate the growth of supermassive black holes across a wide dynamic range of cosmic environments. Using physical torus models (e.g., Borus02) and a Bayesian approach, we uncover 22 representative Compton-thick (CT; N H > 1.5 × 1024 cm−2) AGN candidates with good signal-to-noise ratios as well as a large sample of 136 heavily obscured AGNs. We also find an increasing CT fraction (f CT) from low (z < 0.75) to high (z > 0.75) redshift. Our CT candidates tend to show hard X-ray spectral shapes and dust extinction in their spectral energy distribution fits, which may shed light on the connection between AGN obscuration and host-galaxy evolution.

Hidden cooling flows in clusters of galaxies – III. Accretion on to the central black hole

ABSTRACT Recently, we have uncovered hidden cooling flows (HCFs) in the X-ray spectra of the central brightest galaxies of 11 clusters, 1 group, and 2 elliptical galaxies. Here, we report such flows in a further 15 objects, consisting of 8 clusters, 3 groups, 3 ellipticals, and 1 Red Nugget. The mass cooling rates are about $1\hbox{$\hbox{$\rm \, {\rm M}_{\odot }$}{\rm \, yr}^{-1}\, $}$ in the ellipticals, 2 to $20\hbox{$\hbox{$\rm \, {\rm M}_{\odot }$}{\rm \, yr}^{-1}\, $}$ in the groups, and 20 to $100\hbox{$\hbox{$\rm \, {\rm M}_{\odot }$}{\rm \, yr}^{-1}\, $}$ in regular clusters. The Red Nugget, MRK 1216, has an HCF of $10\hbox{$\hbox{$\rm \, {\rm M}_{\odot }$}{\rm \, yr}^{-1}\, $}$. We review the fate of the cooled gas and investigate how some of it might accrete on to the central black hole. The gas is likely to be very cold and to have fragmented into low-mass stars and smaller objects before being swallowed whole, with little luminous output. If such a scenario is correct and operates at a few $\hbox{$\hbox{$\rm \, {\rm M}_{\odot }$}{\rm \, yr}^{-1}\, $}$ then such objects may host the fastest growing black holes in the low-redshift Universe. We briefly discuss the relevance of HCF to the growth of early galaxies and black holes.

Observability of low-luminosity AGNs in the early Universe with JWST

ABSTRACT Active galactic nuclei (AGNs) in the early Universe are thought to be prominent sources of energy and ionizing photons that affected the growth of their host galaxy and their environment. However, it is still unclear how the supermassive black holes (SMBHs) that fuel these AGNs grew to the observed high masses already at high redshifts. Observations of high-redshift SMBH progenitors or lower luminosity AGNs will thus help characterize the evolution of SMBHs and their impact on the surroundings. With the launch of the JWST, fainter objects at high redshifts can now be detected, including lower luminosity AGNs. We assess the observability of such low-luminosity AGNs, using the cosmological simulation code gizmo to provide a realistic environment for black hole growth in the early Universe. Soon after the first stars are born in the simulation run, we insert stellar-remnant black hole seeds of various initial masses, between 300 and 104 M⊙, at the centre of a dark matter halo and follow their growth until z ∼ 6. Such stellar black hole seeds placed in a typical high-z environment do not significantly accrete and grow to reach masses that can be observed with the JWST under conditions of standard Bondi–Hoyle accretion, as energy input from stellar feedback and chaotic dynamics prevent efficient gas accretion on to the black holes. To be observed with the JWST, rarer but still physically feasible growth regimes, involving Eddington or super-Eddington accretion, would be required. Alternatively, AGN observability may be boosted under even rarer conditions of extreme gravitational lensing.

Quasars and the Intergalactic Medium at Cosmic Dawn

Quasars at cosmic dawn provide powerful probes of the formation and growth of the earliest supermassive black holes (SMBHs) in the Universe, their connections to galaxy and structure formation, and the evolution of the intergalactic medium (IGM) at the epoch of reionization (EoR). Hundreds of quasars have been discovered in the first billion years of cosmic history, with the quasar redshift frontier extended to z ∼ 7.6. Observations of quasars at cosmic dawn show the following: ▪The number density of luminous quasars declines exponentially at z &gt; 5, suggesting that the earliest quasars emerge at z ∼ 10; the lack of strong evolution in their average spectral energy distribution indicates a rapid buildup of the active galactic nucleus environment.▪Billion-solar-mass black holes (BHs) already exist at z &gt; 7.5; they must form and grow in less than 700 Myr, by a combination of massive early BH seeds with highly efficient and sustained accretion.▪The rapid quasar growth is accompanied by strong star formation and feedback activity in their host galaxies, which show diverse morphological and kinetic properties, with typical dynamical mass lower than that implied by the local BH/galaxy scaling relations.▪Hi absorption in quasar spectra probes the tail end of cosmic reionization at z ∼ 5.3–6 and indicates the EoR midpoint at 6.9 &lt; z &lt; 7.6, with large spatial fluctuations in IGM ionization. Observations of heavy element absorption lines suggest that the circumgalactic medium also experiences evolution in its ionization structure and metal enrichment during the EoR.

On the growth of supermassive black holes formed from the gravitational collapse of fermionic dark matter cores

ABSTRACT Observations support the idea that supermassive black holes (SMBHs) power the emission at the centre of active galaxies. However, contrary to stellar-mass BHs, there is a poor understanding of their origin and physical formation channel. In this article, we propose a new process of SMBH formation in the early Universe that is not associated with baryonic matter (massive stars) or primordial cosmology. In this novel approach, SMBH seeds originate from the gravitational collapse of fermionic dense dark matter (DM) cores that arise at the centre of DM haloes as they form. We show that such a DM formation channel can occur before star formation, leading to heavier BH seeds than standard baryonic channels. The SMBH seeds subsequently grow by accretion. We compute the evolution of the mass and angular momentum of the BH using a geodesic general relativistic disc accretion model. We show that these SMBH seeds grow to ∼109–$10^{10} \, \mathrm{M}_\odot$ in the first Gyr of the lifetime of the Universe without invoking unrealistic (or fine-tuned) accretion rates.

Evolution of the mass relation between supermassive black holes and dark matter halos across the cosmic time

ABSTRACT A positive observational proof suggests that most galaxies contain a central supermassive black hole (SMBH) with mass in the range of 106 M⊙–1010 M⊙. It is suggested that the mass of SMBHs is proportionally related to that of the dark matter (DM) halo, even at z = 6. This implies that these SMBHs could coevolve with the host DM halos. Here, we investigate the mass evolution of SMBHs in a hierarchical structure formation by building halo merger trees using the extended Press–Schechter formalism. An SMBH with a mass that follows various power-law relations with the DM halo mass is assigned as an initial condition. Assuming that the mass growth of all black holes is due to mergers, we obtain the relation between SMBH and DM halo masses at the present epoch. By requiring that the mass of the SMBHs at z = 0 should not be greater than the currently observed SMBH-DM halo mass relation, a lower bound on the mass of the DM halo that can contain a SMBH can be imposed at z = 6 as Mlim &amp;gt; 3.6 × 1010 M⊙ × (1.4 − n)2.3, where n is the power-law index of the SMBH-DM halo mass relation at z = 6. Because we only consider mergers for the mass evolution of SMBHs, this model is simplistic and should underestimate the mass of SMBHs relative to the mass of the DM halo at the present epoch. Our work aims to constrain the SMBH-DM mass relation at z = 6 and not build a new model to explain the observations

Effect of surface energy anisotropy on hole growth in a single-crystalline thin film: A phase-field study

Prediction of the temporal evolution of a pre-existing hole on a solid-state thin film has important implications for self-organized nanoscale pattern formation. In this work, we employ a three-dimensional phase-field model to elucidate the mechanism of corner instability during capillary-driven hole growth in a single-crystalline free-standing thin film. We perform a systematic study to demonstrate the effect of crystalline anisotropy in surface energy, surface diffusivity, and film thickness on hole growth. Our simulations reveal that the instability during hole growth arises due to saturation of the rim height at the corner of the hole that is directly related to the arc length of the corner, specified by the anisotropy in surface energy. Our investigation further reveals the presence of a time-invariant shape of the corner with the onset of corner instability.

Obscured AGN enhancement in galaxy pairs at cosmic noon: evidence from a probabilistic treatment of photometric redshifts

ABSTRACT Observations of the nearby universe reveal an increasing fraction of active galactic nuclei (AGNs) with decreasing projected separation for close galaxy pairs, relative to control galaxies. This implies galaxy interactions play a role in enhancing AGN activity. However, the picture at higher redshift is less established, partly due to limited spectroscopic redshifts. We combine spectroscopic surveys with photometric redshift probability distribution functions for galaxies in the CANDELS and COSMOS surveys, to produce the largest ever sample of galaxy pairs used in an AGN fraction calculation for cosmic noon (0.5 &amp;lt; z &amp;lt; 3). We present a new technique for assessing galaxy pair probability (based on line-of-sight velocities ±1000 km s−1) from photometric redshift posterior convolutions and use these to produce weighted AGN fractions. Over projected separations 5–100 kpc, we find no evidence for enhancement, relative to isolated control galaxies, of X-ray (LX &amp;gt; 1042 erg s−1) or infrared-selected AGN in major (mass ratios up to 4:1) or minor (4:1 to 10:1) galaxy pairs. However, defining the most obscured AGN as those detected in the infrared but not in X-rays, we observe a trend of increasing obscured AGN enhancement at decreasing separations. The peak enhancement, relative to isolated controls, is a factor of 2.08 ± 0.61 for separations &amp;lt;25 kpc. Our simulations with mock data, indicates this could be a lower limit of the true enhancement. If confirmed with improved infrared imaging (e.g. with JWST) and redshifts (e.g. with forthcoming multi-object spectrograph surveys), this would suggest that galaxy interactions play a role in enhancing the most obscured black hole growth at cosmic noon.

Polarimetry of the potential binary supermassive black hole system in J1430+2303

Context. The growth of supermassive black holes (SMBHs) through merging has long been predicted but its detection remains elusive. However, a promising target has been discovered in the Seyfert-1 galaxy J1430+2303, where two SMBHs may be about to merge. Aims. If a binary system truly lies at the center of J1430+2303, the usual symmetry expected from pole-on views in active galactic nuclei (AGNs) responsible for the observed low (≤1%) optical linear polarization in the continuum of these objects is expected to be broken. This should lead to higher-than-usual polarization degrees, together with time-dependent variations of the polarization signal. Methods. We used the specialized photopolarimeters RoboPol mounted on the 1.3 m telescope at the Skinakas Observatory and the Alhambra Faint Object Spectrograph and Camera (ALFOSC) mounted on the 2.56 m Nordic Optical Telescope (NOT) at the “Roque de los Muchachos” Observatory to measure the B-, V-, R-, and I-band polarization of J1430+2303. Observations were complemented using the FORS2 spectropolarimeter mounted on the VLT to acquire 3500−8650 Å polarized spectra. We compared our set of observations to Monte Carlo radiative-transfer predictions to look for the presence of a SMBH binary. Results. The observed linear continuum polarization of J1430+2303 in the V and R bands is ∼0.4% with an associated polarization angle of slightly larger than 0°. We detected no significant changes in polarization or photometry between May, June, and July of 2022. In addition, there is no significant difference between the polarization of Hα and the polarization of the continuum. A single SMBH at the center of an AGN model is able to reproduce the observed spectrum and polarization, while the binary hypothesis is rejected with a probability of ∼85%. Conclusions. The low degree of continuum polarization, the lack of variability in photometry and polarization over three months, and the absence of Hα polarization different than that of the continuum tend to indicate that J1430+2303 is a standard Seyfert-1 AGN whose nuclear inclination is 24−31° according to our model.

The Stellar Mass–Black Hole Mass Relation at z ∼ 2 down to Determined by HETDEX

We investigate the stellar mass–black hole mass () relation with type 1 active galactic nuclei (AGNs) down to , corresponding to a ≃ −21 absolute magnitude in rest-frame ultraviolet, at z = 2–2.5. Exploiting the deep and large-area spectroscopic survey of the Hobby–Eberly Telescope Dark Energy Experiment (HETDEX), we identify 66 type 1 AGNs with ranging from 107–1010 M ⊙ that are measured with single-epoch virial method using C iv emission lines detected in the HETDEX spectra. of the host galaxies are estimated from optical to near-infrared photometric data taken with Spitzer, the Wide-field Infrared Survey Explorer, and ground-based 4–8 m class telescopes by CIGALE spectral energy distribution (SED) fitting. We further assess the validity of SED fitting in two cases by host-nuclear decomposition performed through surface brightness profile fitting on spatially resolved host galaxies with the James Webb Space Telescope/NIRCam CEERS data. We obtain the relation covering the unexplored low-mass ranges of , and conduct forward modeling to fully account for the selection biases and observational uncertainties. The intrinsic relation at z ∼ 2 has a moderate positive offset of 0.52 ± 0.14 dex from the local relation, suggestive of more efficient black hole growth at higher redshift even in the low-mass regime of . Our relation is inconsistent with the suppression at the low- regime predicted by recent hydrodynamic simulations at a 98% confidence level, suggesting that feedback in the low-mass systems may be weaker than those produced in hydrodynamic simulations.

Wet compaction to a blue nugget: a critical phase in galaxy evolution

ABSTRACT We utilize high-resolution cosmological simulations to reveal that high-redshift galaxies tend to undergo a robust ‘wet compaction’ event when near a ‘golden’ stellar mass of $\sim \!\!10^{10}\, \rm M_\odot$ . This is a gaseous shrinkage to a compact star-forming phase, a ‘blue nugget’ (BN), followed by central quenching of star formation to a compact passive stellar bulge, a ‘red nugget’ (RN), and a buildup of an extended gaseous disc and ring. Such nuggets are observed at cosmic noon and seed today’s early-type galaxies. The compaction is triggered by a drastic loss of angular momentum due to, e.g. wet mergers, counter-rotating cold streams, or violent disc instability. The BN phase marks drastic transitions in the galaxy structural, compositional, and kinematic properties. The transitions are from star forming to quenched inside-out, from diffuse to compact with an extended disc or ring and a stellar envelope, from dark matter to baryon central dominance, from prolate to oblate stellar shape, from pressure to rotation support, from low to high metallicity, and from supernova to AGN feedback. The central black hole growth, first suppressed by supernova feedback when below the golden mass, is boosted by the compaction, and the black hole keeps growing once the halo is massive enough to lock in the supernova ejecta.

Enhanced power of gravitational waves and rapid coalescence of black hole binaries through k -essence dark energy accretion

We consider the accretion of dark energy by constituent black holes in binary formations during the present epoch of the Universe. In the context of an observationally consistent dark energy model, we evaluate the growth of black holes' masses due to accretion. However, the accretion rate may turn out to be too high if this model is naively applied to supermassive black holes. We show that the accretion leads to faster circularization of the binary orbits. We compute the average power of the gravitational waves emitted from binaries, which exhibits a considerable enhancement due to the effect of growth of masses as a result of accretion. This in turn, leads to a significant reduction of the coalescence time of the binaries. We present examples pertaining to various choices of the initial masses of the black holes in the stellar mass range and above, in order to clearly establish a possible observational signature of dark energy in the emerging era of gravitational wave astronomy.

Key Science Goals for the Next-Generation Event Horizon Telescope

The Event Horizon Telescope (EHT) has led to the first images of a supermassive black hole, revealing the central compact objects in the elliptical galaxy M87 and the Milky Way. Proposed upgrades to this array through the next-generation EHT (ngEHT) program would sharply improve the angular resolution, dynamic range, and temporal coverage of the existing EHT observations. These improvements will uniquely enable a wealth of transformative new discoveries related to black hole science, extending from event-horizon-scale studies of strong gravity to studies of explosive transients to the cosmological growth and influence of supermassive black holes. Here, we present the key science goals for the ngEHT and their associated instrument requirements, both of which have been formulated through a multi-year international effort involving hundreds of scientists worldwide.

Adiabatically compressed wave dark matter halo and intermediate-mass-ratio inspirals

The adiabatic growth of a central massive black hole could compress the surrounding dark matter halo, leading to a steeper profile of the dark matter halo. This phenomenon is called adiabatic compression. We investigate the adiabatic compression of wave dark matter - a light bosonic dark matter candidate with its mass smaller than a few eV. Using the adiabatic theorem, we show that the adiabatic compression leads to a much denser wave dark matter halo similar to the particle dark matter halo in the semiclassical limit. The compressed wave halo differs from that of the particle halo near the center where the semiclassical approximation breaks down, and the central profile depends on dark matter and the central black hole mass as they determine whether the soliton and low angular momentum modes can survive over the astrophysical time scale without being absorbed by the black hole. Such a compressed profile has several astrophysical implications. As one example, we study the gravitational waves from the inspiral between a central intermediate-mass black hole and a compact solar-mass object within the wave dark matter halo. Due to the enhanced mass density, the compressed wave dark matter halo exerts stronger dynamical friction on the orbiting object, leading to the dephasing of the gravitational waves. The pattern of dephasing is distinctive from that of inspirals in the particle dark matter halo because of the difference in density profile and because of the relatively suppressed dynamical friction force, originating from the wave nature of dark matter. We investigate the prospects of future gravitational wave detectors, such as Laser Interferometer Space Antenna, and identify physics scenarios where the wave dark matter halo can be reconstructed from gravitational wave observations.

Constraints on the Cosmological Coupling of Black Holes from the Globular Cluster NGC 3201

Globular clusters are among the oldest stellar populations in the Milky Way; consequently, they also host some of the oldest known stellar-mass black holes, providing insight into black hole formation and evolution in the early (z ≳ 2) universe. Recent observations of supermassive black holes in elliptical galaxies have been invoked to suggest the possibility of a cosmological coupling between astrophysical black holes and the surrounding expanding universe, offering a mechanism for black holes to grow over cosmic time and potentially explaining the origin of dark energy. In this paper, I show that the mass functions of the two radial velocity black hole candidates in NGC 3201 place strong constraints on the cosmologically coupled growth of black holes. In particular, the amount of coupling required to explain the origin of dark energy would either require both NGC 3201 black holes to be nearly face on (a configuration with probability of at most 10−4) or one of the BHs would need to have formed with a mass below that of the most massive neutron stars (2.2 M ⊙). This emphasizes that these and other detached black hole–star binaries can serve not only as laboratories for compact object and binary astrophysics but as constraints on the long-term evolution of astrophysical black holes.