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Are large language models (LLMs) biased towards text generated by LLMs over text authored by humans, leading to possible anti-human bias? Utilizing a classical experimental design inspired by employment discrimination studies, we tested widely-used LLMs, including GPT-3.5 and GPT4, in binary-choice scenarios. These involved LLM-based agents selecting between products and academic papers described either by humans or LLMs under identical conditions. Our results show a consistent tendency for LLM-based AIs to prefer LLM-generated content. This suggests the possibility of AI systems implicitly discriminating against humans, giving AI agents an unfair advantage., Comment: 8 pages, 1 figure

When attempting to understand the behavior of an executable, a binary analyst can make use of many different techniques. These include program slicing, dynamic instrumentation, binary-level rewriting, symbolic execution, and formal verification, all of which can uncover insights into how a piece of machine code behaves. As a result, there is no one-size-fits-all binary analysis tool, so a binary analysis researcher will often combine several different tools. Sometimes, a researcher will even need to design new tools to study problems that existing frameworks are not well equipped to handle. Designing such tools from complete scratch is rarely time- or cost-effective, however, given the scale and complexity of modern instruction set architectures. We present Macaw, a modular framework that makes it possible to rapidly build reliable binary analysis tools across a range of use cases. Over a decade of development, we have used Macaw to support an industrial research team in building tools for machine code-related tasks. As such, the name "Macaw" refers not just to the framework itself, but also a suite of tools that are built on top of the framework. We describe Macaw in depth and describe the different static and dynamic analyses that it performs, many of which are powered by an SMT-based symbolic execution engine. We put a particular focus on interoperability between machine code and higher-level languages, including binary lifting from x86 to LLVM, as well verifying the correctness of mixed C and assembly code.

We analyzed images of every northern hemisphere Sd galaxy listed in the Third Reference Catalogue of Bright Galaxies (RC3) with a relatively face-on inclination ($\theta\leq30{\deg}$). Specifically, we measured the spiral arms' winding angle, $\phi$, in 85 galaxies. We applied a novel black hole mass planar scaling relation involving the rotational velocities (from the literature) and pitch angles of each galaxy to predict central black hole masses. This yielded 23 galaxies, each having at least a 50% chance of hosting a central intermediate-mass black hole (IMBH), $10^2$1.22% of bright galaxies ($B_{\rm T}\lesssim15.5$ mag) in the local Universe host an IMBH (i.e., the "occupation fraction"), which implies a number density $>$$4.96\times10^{-6}$ Mpc$^{-3}$ for central IMBHs. Finally, we observe that Sd galaxies exhibit an unexpected diversity of properties that resemble the general population of spiral galaxies, albeit with an enhanced signature of the eponymous prototypical traits (i.e., low masses, loosely wound spiral arms, and smaller rotational velocities)., Comment: Unedited manuscript (30 pages, 5 figures, and 1 table) accepted by The Astrophysical Journal on June 7, 2024

We present the High-$z$ Evolution of Large and Luminous Objects (HELLO) project, a set of more than 30 high-resolution hydrodynamical cosmological simulations aimed to study Milky Way analogues ($M_\star\sim10^{10-11}$ $\mathrm{M}_\odot$) at high redshift, namely at $z=3.6$ (age $\sim$ 1.7 Gyr) and $z=2$ (age $\sim$ 3.3 Gyr). The HELLO project features an updated scheme for chemical enrichment and the addition of local photoionization feedback processes. Independently of redshift and stellar mass, all galaxies follow a similar evolutionary path: (i) first a smooth progression along the star formation main sequence, where galaxies grow in both stellar mass and size, (ii) a (short) period of intense star formation, which causes a contraction phase in the stellar size, until the galaxies reach their peak star formation rate (SFR), during this period we also witness a significant black hole growth, and (iii) the onset of declining SFRs, which is due to a mix of gas consumption, stellar feedback, and AGN feedback, but with AGN feedback still being subdominant with respect to stellar feedback for energy deposition. The exact phase in which a galaxy in our mass range can be found at a given redshift is set by its gas reservoir and assembly history. Finally, our galaxies are in excellent agreement with several various scaling relations observed with the Hubble Space Telescope and the James Webb Space Telescope, and hence can be used to provide the theoretical framework to interpret current and future observations from these facilities and shed light on the transition from star-forming to quiescent galaxies., Comment: 22 pages, 16 figures, 3 tables, submitted to MNRAS

Our knowledge of supermassive black holes (SMBHs) and their relation to their host galaxies is still limited, and there are only around 150 SMBHs that have their masses directly measured and confirmed. Better black hole mass scaling relations will help us reveal the physics of black holes, as well as predict black hole masses that are not yet measured. Here, we apply symbolic regression, combined with random forest to those directly-measured black hole masses and host galaxy properties, and find a collection of higher-dimensional (N-D) black hole mass scaling relations. These N-D black hole mass scaling relations have scatter smaller than any of the existing black hole mass scaling relations. One of the best among them involves the parameters of central stellar velocity dispersion, bulge-to-total ratio, and density at the black hole's sphere-of-influence with an intrinsic scatter of $\epsilon=0.083\,\ \text{dex}$, significantly lower than $\epsilon \sim 0.3\,\ \text{dex}$ for the M-$\sigma$ relation. These relations will inspire black hole physics, test black hole models implemented in simulations, and estimate unknown black hole masses on an unprecedented precision., Comment: 9 pages, 3 figures, accepted by NeurIPS 2023 workshop on Machine Learning and the Physical Sciences

Supermassive black holes (SMBHs) are tiny in comparison to the galaxies they inhabit, yet they manage to influence and coevolve along with their hosts. Evidence of this mutual development is observed in the structure and dynamics of galaxies and their correlations with black hole mass ($M_\mathrm{BH}$). For our study, we focus on relative parameters that are unique to only disk galaxies. As such, we quantify the structure of spiral galaxies via their logarithmic spiral-arm pitch angles ($\phi$) and their dynamics through the maximum rotational velocities of their galactic disks ($v_\mathrm{max}$). In the past, we have studied black hole mass scaling relations between $M_\mathrm{BH}$ and $\phi$ or $v_\mathrm{max}$, separately. Now, we combine the three parameters into a trivariate $M_\mathrm{BH}$-$\phi$-$v_\mathrm{max}$ relationship that yields best-in-class accuracy in prediction of black hole masses in spiral galaxies. Because most black hole mass scaling relations have been created from samples of the largest SMBHs within the most massive galaxies, they lack certainty when extrapolated to low-mass spiral galaxies. Thus, it is difficult to confidently use existing scaling relations when trying to identify galaxies that might harbor the elusive class of intermediate-mass black holes (IMBHs). Therefore, we offer our novel relationship as an ideal predictor to search for IMBHs and probe the low-mass end of the black hole mass function by utilizing spiral galaxies. Already with rotational velocities widely available for a large population of galaxies and pitch angles readily measurable from uncalibrated images, we expect that the $M_\mathrm{BH}$-$\phi$-$v_\mathrm{max}$ fundamental plane will be a useful tool for estimating black hole masses, even at high redshifts., Comment: Unedited manuscript (12 pages & 4 figures), accepted for publication by The Astrophysical Journal Letters on September 15, 2023

We present an analysis of the pitch angle distribution function (PADF) for nearby galaxies and its resulting black hole mass function (BHMF) via the well-known relationship between pitch angle and black hole mass. Our sample consists of a subset of 74 spiral galaxies from the Carnegie-Irvine Galaxy Survey with absolute $B$-band magnitude $\mathfrak{M}_{B}>-19.12$ mag and luminosity distance $D_{\mathrm{L}} \leq 25.4$ Mpc, which is an extension of a complementary set of 140 more luminous ($\mathfrak{M}_{B}\leq-19.12$ mag) late-type galaxies. We find the PADFs of the two samples are, somewhat surprisingly, not strongly dissimilar; a result that may hold important implications for spiral formation theories. Our data show a distinct bimodal population manifest in the pitch angles of the Sa-Sc types and separately the Scd-Sm types, with Sa-Sc types having tighter spiral arms on average. Importantly, we uncover a distinct bifurcation of the BHMF, such that the Sa-Sc galaxies typically host so-called "supermassive" black holes ($M_{\bullet}\gtrsim10^6\,\mathrm{M_{\odot}}$), whereas Scd-Sm galaxies accordingly harbor black holes that are "less-than-supermassive" ($M_{\bullet}\lesssim10^6\,\mathrm{M_{\odot}}$). It is amongst this latter population of galaxies where we expect fruitful bounties of elusive intermediate-mass black holes (IMBHs), through which a better understanding will help form more precise benchmarks for future generations of gravitational wave detectors., Comment: 39 pages, 17 figures, to be published in Universe

This research investigates analytical and quantitative methods for simulating elevator optimizations. To maximize overall elevator usage, we concentrate on creating a multiple-user positive-sum system that is inspired by agent-based game theory. We define and create basic "Dumbwaiter" models by attempting both the Spatial Process Approach and the Gibbs Random Field Approach. These two mathematical techniques approach the problem from different points of view: the spatial process can give an analytical solution in continuous space and the Gibbs Random Field provides a discrete framework to flexibly model the problem on a computer. Starting from the simplest case, we target the assumptions to provide concrete solutions to the models and develop a "Multi-Dumbwaiter System". This paper examines, evaluates, and proves the ultimate success of such implemented strategies to design the basic elevator's optimal policy; consequently, not only do we believe in the results' practicality for industry, but also their potential for application., Comment: 14 pages

The near-absence of compact massive quiescent galaxies in the local Universe implies a size evolution since $z\sim2.5$. It is often theorised that such `red nuggets' have evolved into today's elliptical (E) galaxies via an E-to-E transformation. We examine an alternative scenario in which a red nugget develops a rotational disc through mergers and accretion, say, at $1\lesssim z\lesssim2$, thereby cloaking the nugget as the extant bulge/spheroid component of a larger, now old, galaxy. We have performed detailed, physically-motivated, multi-component decompositions of a volume-limited sample of 103 massive ($M_*/\rm M_{\odot} \gtrsim 1\times 10^{11}$) galaxies within 110\,Mpc. Among our 28 galaxies with existing elliptical classifications, we found that 18 have large-scale discs, and two have intermediate-scale discs, and are reclassified here as lenticulars (S0) and elliculars (ES). The local spheroid stellar mass function, size-mass diagram and bulge-to-total ($B/T$) flux ratio are presented. We report lower-limits for the volume number density of compact massive spheroids, $n_\mathrm{c,Sph}\sim (0.17$-$1.2) \times 10^{-4}\,\rm Mpc^{-3}$, based on different definitions of `red nuggets' in the literature. Similar number densities of local compact massive bulges were reported by de la Rosa et al. using automated two-component decompositions and their existence is now abundantly clear with our multi-component decompositions. We find disc-cloaking to be a salient alternative for galaxy evolution. In particular, instead of an E-to-E process, disc growth is the dominant evolutionary pathway for at least low-mass ($1\times10^{10}

The Laser Interferometer Space Antenna (LISA) will be a transformative experiment for gravitational wave astronomy, and, as such, it will offer unique opportunities to address many key astrophysical questions in a completely novel way. The synergy with ground-based and space-born instruments in the electromagnetic domain, by enabling multi-messenger observations, will add further to the discovery potential of LISA. The next decade is crucial to prepare the astrophysical community for LISA's first observations. This review outlines the extensive landscape of astrophysical theory, numerical simulations, and astronomical observations that are instrumental for modeling and interpreting the upcoming LISA datastream. To this aim, the current knowledge in three main source classes for LISA is reviewed; ultracompact stellar-mass binaries, massive black hole binaries, and extreme or intermediate mass ratio inspirals. The relevant astrophysical processes and the established modeling techniques are summarized. Likewise, open issues and gaps in our understanding of these sources are highlighted, along with an indication of how LISA could help making progress in the different areas. New research avenues that LISA itself, or its joint exploitation with upcoming studies in the electromagnetic domain, will enable, are also illustrated. Improvements in modeling and analysis approaches, such as the combination of numerical simulations and modern data science techniques, are discussed. This review is intended to be a starting point for using LISA as a new discovery tool for understanding our Universe.

Building upon three late-type galaxies in the Virgo cluster with both a predicted black hole mass of less than $\sim$10$^5$ M$_{\odot}$ and a centrally-located X-ray point-source, we reveal 11 more such galaxies, more than tripling the number of active intermediate-mass black hole candidates among this population. Moreover, this amounts to a 36$\pm$8% X-ray detection rate (despite the sometimes high, X-ray-absorbing, HI column densities), compared to just 10$\pm$5% for (the largely HI-free) dwarf early-type galaxies in the Virgo cluster. The expected contribution of X-ray binaries from the galaxies' inner field stars is negligible. Moreover, given that both the spiral and dwarf galaxies contain nuclear star clusters, the above inequality appears to disfavor X-ray binaries in nuclear star clusters. The higher occupation, or rather detection, fraction among the spiral galaxies may instead reflect an enhanced cool gas/fuel supply and Eddington ratio. Indeed, four of the 11 new X-ray detections are associated with known LINERs or LINER/HII composites. For all (four) of the new detections for which the X-ray flux was strong enough to establish the spectral energy distribution in the Chandra band, it is consistent with power-law spectra. Furthermore, the X-ray emission from the source with the highest flux (NGC 4197: $L_X \approx 10^{40}$ erg s$^{-1}$) suggests a non-stellar-mass black hole if the X-ray spectrum corresponds to the `low/hard state'. Follow-up observations to further probe the black hole masses, and prospects for spatially resolving the gravitational spheres-of-influence around intermediate-mass black holes, are reviewed in some detail., Comment: To appear in ApJ (accepted Sep. 2021)

Galaxies can grow through their mutual gravitational attraction and subsequent union. While orbiting a regular high-surface-brightness galaxy, the body of a low-mass galaxy can be stripped away. However, the stellar heart of the infalling galaxy, if represented by a tightly-bound nuclear star cluster, is more resilient. From archival Hubble Space Telescope images, we have discovered a red, tidally-stretched star cluster positioned ~5 arcseconds (~400 pc in projection) from, and pointing toward the center of, the post-merger spiral galaxy NGC 4424. The star cluster, which we refer to as `Nikhuli', has a near-infrared luminosity of (6.88+/-1.85)x10^6 L_{solar,F160W} and likely represents the nucleus of a captured/wedded galaxy. Moreover, from our Chandra X-ray Observatory image, Nikhuli is seen to contain a high-energy X-ray point source, with L_{0.5-8 keV} = 6.31^{+7.50}_{-3.77}x10^{38} erg/s (90% confidence). We argue that this is more likely to be an active massive black hole than an X-ray binary. Lacking an outward-pointing comet-like appearance, the stellar structure of Nikhuli favors infall rather than the ejection from a gravitational-wave recoil event. A minor merger with a low-mass early-type galaxy may have sown a massive black hole, aided an X-shaped pseudobulge, and be sewing a small bulge. The stellar mass and the velocity dispersion of NGC 4424 predict a central black hole of (0.6-1.0)x10^5 M_solar, similar to the expected intermediate-mass black hole in Nikhuli, and suggestive of a black hole supply mechanism for bulgeless late-type galaxies. We may potentially be witnessing black hole seeding by capture and sinking, with a nuclear star cluster the delivery vehicle., Comment: To appear in ApJ (accepted 21 September 2021)

This paper is the fourth in a series presenting (galaxy morphology, and thus galaxy formation)-dependent black hole mass, $M_{\rm BH}$, scaling relations. We have used a sample of 119 galaxies with directly-measured $M_{\rm BH}$ and host spheroid parameters obtained from multi-component decomposition of, primarily, $3.6\,\mu$m Spitzer images. Here, we investigate the correlations between $M_{\rm BH}$ and the projected luminosity density $\mu$, the projected stellar mass density $\Sigma$, and the deprojected (internal) stellar mass density $\rho$, for various spheroid radii. We discover the predicted $M_{\rm BH}$--$\mu_{\rm 0,sph}$ relation and present the first $M_{\rm BH}$--$\mu_{\rm e, sph}$ and $M_{\rm BH}$--$\rho_{\rm e,int, sph}$ diagrams displaying slightly different (possibly curved) trends for early- and late-type galaxies (ETGs and LTGs) and an offset between ETGs with (fast-rotators, ES/S0) and without (slow-rotators, E) a disk. The scatter about various $M_{\rm BH}$--$\langle\Sigma\rangle_{\rm R,sph}$ (and $\langle\rho\rangle_{\rm r,sph}$) relations is shown to systematically decrease as the enclosing aperture (and volume) increases, dropping from 0.69~dex when using the spheroid \enquote{compactness}, $\langle\Sigma\rangle_{\rm 1kpc,sph}$, to 0.59~dex when using $\langle\Sigma\rangle_{\rm 5kpc,sph}$. We also reveal that $M_{\rm BH}$ correlates with the internal density, $\rho_{\rm soi,sph}$, at the BH's sphere-of-influence radius, such that core-S\'ersic (high S\'ersic index, $n$) and (low-$n$) S\'ersic galaxies define different relations with total rms scatters 0.21~dex and 0.77~dex, respectively.(Abridged), Comment: 27 pages, 12 figures, 2 tables, submitted to ApJ

Recent X-ray observations by Jiang et al. have identified an active galactic nucleus (AGN) in the bulgeless spiral galaxy NGC 3319, located just $14.3\pm1.1\,$Mpc away, and suggest the presence of an intermediate-mass black hole (IMBH; $10^2\leq M_\bullet/\mathrm{M_{\odot}}\leq10^5$) if the Eddington ratios are as high as 3 to $3\times10^{-3}$. In an effort to refine the black hole mass for this (currently) rare class of object, we have explored multiple black hole mass scaling relations, such as those involving the (not previously used) velocity dispersion, logarithmic spiral-arm pitch angle, total galaxy stellar mass, nuclear star cluster mass, rotational velocity, and colour of NGC 3319, to obtain ten mass estimates, of differing accuracy. We have calculated a mass of $3.14_{-2.20}^{+7.02}\times10^4\,\mathrm{M_\odot}$, with a confidence of 84% that it is $\leq$$10^5\,\mathrm{M_\odot}$, based on the combined probability density function from seven of these individual estimates. Our conservative approach excluded two black hole mass estimates (via the nuclear star cluster mass, and the fundamental plane of black hole activity $\unicode{x2014}$ which only applies to black holes with low accretion rates) that were upper limits of $\sim$$10^5\,{\rm M}_{\odot}$, and it did not use the $M_\bullet\unicode{x2013}L_{\rm 2-10\,keV}$ relation's prediction of $\sim$$10^5\,{\rm M}_{\odot}$. This target provides an exceptional opportunity to study an IMBH in AGN mode and advance our demographic knowledge of black holes. Furthermore, we introduce our novel method of meta-analysis as a beneficial technique for identifying new IMBH candidates by quantifying the probability that a galaxy possesses an IMBH., Comment: Original unedited manuscript (19 pages & 7 figures), accepted for publication by the Publications of the Astronomical Society of Australia, May 7, 2021

For 123 local galaxies with directly-measured black hole masses ($M_{\rm BH}$), we provide the host spheroid's S\'ersic index ($\rm n_{sph}$), effective half-light radius ($\rm R_{e,sph}$), and effective surface brightness ($\mu_e$), obtained from careful multi-component decompositions, and we use these to derive the morphology-dependent $M_{\rm BH}$--$\rm n_{sph}$ and $M_{\rm BH}$--$\rm R_{e,sph}$ relations. We additionally present the morphology-dependent $M_{\rm *,sph}$--$\rm n_{sph}$ and $M_{\rm *,sph}$--$\rm R_{e,sph}$ relations. We explored differences due to: early-type galaxies (ETGs) versus late-type galaxies (LTGs); S\'ersic versus core-S\'ersic galaxies; barred versus non-barred galaxies; and galaxies with and without a stellar disk. We detect two different $M_{\rm BH}$--$\rm n_{sph}$ relations due to ETGs and LTGs with power-law slopes $3.95\pm0.34$ and $2.85\pm 0.31$. We additionally quantified the correlation between $M_{\rm BH}$ and the spheroid's central concentration index, which varies monotonically with the S\'ersic index. Furthermore, we observe a single, near-linear $M_{\rm *,sph}$--$\rm R_{e,sph}^{1.08\pm 0.04}$ relation for ETGs and LTGs, which encompasses both classical and alleged pseudobulges. In contrast, ETGs and LTGs define two distinct $M_{\rm BH}$--$\rm R_{e,sph}$ relations with $\Delta_{\rm rms|BH}\sim\rm 0.60~dex$ (cf.\ $\sim$0.51~dex for the $M_{\rm BH}$--$\sigma$ relation and $\sim$0.58~dex for the $M_{\rm BH}$--$M_{\rm *,sph}$ relation), and the ETGs alone define two steeper $M_{\rm BH}$--$\rm R_{e,sph}$ relations, offset by $\sim$1~dex in the $\log M_{\rm BH}$-direction, depending on whether they have a disk or not and explaining their similar offset in the $M_{\rm BH}$--$M_{\rm *,sph}$ diagram. This trend holds using $10 \%$, $50 \%$, or $90 \%$ radii.(Abridged), Comment: 30 pages, 14 figures

Stationary Density Wave Theory predicts the existence of an age gradient across the spiral arms with a phase crossing at the co-rotation radius. Using star formation history (SFH) maps of 12 nearby spiral galaxies derived from \textsc{LIGHTNING} \citep{Eufracio:2017}, a spectral energy distribution (SED) fitting procedure, and by using \textsc{Spirality} \citep{Shield:2015} a \textsc{MATLAB}-based code which plots synthetic spiral arms over \textsc{FITS} images, we have found a gradual decrement in pitch angles with increasing age, thus providing us with evidence in favour of the Stationary Density Wave Theory. We have also used azimuthal offsets of spatially resolved stellar clusters in 3 LEGUS galaxies to observe age trends.

Owing to the small energy differences between its polymorphs, MoTe2 can access a full spectrum of electronic states, from the 2H semiconducting state to the 1T semimetallic state, and from the Td Weyl semimetallic state to the superconducting state in the 1T and Td phase at low temperature. Thus, it is a model system for phase transformation studies as well as quantum phenomena such as the quantum spin Hall effect and topological superconductivity. Careful studies of MoTe2 and its potential applications require large area MoTe2 thin films with high crystallinity and thickness control. Here, we present cm2 scale synthesis of 2H MoTe2 thin films with layer control and large grains that span several microns. Layer control is achieved by controlling the initial thickness of the precursor MoOx thin films, which are deposited on sapphire substrates by atomic layer deposition and subsequently tellurized. Despite the van der Waals epitaxy, the precursor-substrate interface is found to critically determine the uniformity in thickness and grain size of the resulting MoTe2 films: MoTe2 grown on sapphire show uniform films while MoTe2 grown on amorphous SiO2 substrates form islands. This synthesis strategy decouples the layer control from the variabilities of growth conditions for robust growth results, and is applicable to grow other transition metal dichalcogenides with layer control., Comment: 6 figure