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We investigate the impact of binary orbital motions on the dynamical modeling of dwarf galaxies with intrinsic line-of-sight velocity dispersions ( σ v r ) of 1–9 km s−1. Using dwarf galaxies from the auriga level-2 and level-3 simulations, we apply the Jeans Anisotropic Multi-Gaussian Expansion modeling to tracer stars before and after including binaries to recover the dynamical masses. The recovered total masses within the half-mass radius of tracers, M (< r half), are always inflated due to binary motions, with greater inflations occurring for smaller σ v r . However, many dwarf galaxies experience central density deflated due to binary motions, with little dependence on σ v r . This is due to the negative radial gradients in the velocity dispersion profiles, with the fractional inflation in σ v r due to binaries more significant in outskirts. An extreme binary fraction of 70% can lead to central density deflation of up to 10%–20% at 3 km s−1 < σ v r < 8 km s−1, with M (< r half) inflated by 4% at 9 km s−1 and up to 15% at 3 km s−1. A lower binary fraction of 36% leads to similar deflations, with the inflations decreasing to approximately 10% at 3 km s−1 and becoming statistically insignificant. The choice of binary orbit distribution models does not result in significant differences, and observational errors tend to slightly weaken the deflations in the recovered central density. Two observations separated by 1 yr to exclude binaries lead to almost zero inflations/deflations for a binary fraction of 36% over 3 km s−1 < σ v r < 9 km s−1. For σ v r ∼ 1 km s−1 to 3 km s−1, a binary fraction of 70% (36%) still results in 60% (30%) to 10% (1%) of inflations in M (< r half), even with two-epoch observation. [ABSTRACT FROM AUTHOR]

Based on independent shear measurements using the Dark Energy Camera Legacy Survey/DR8 imaging data, we measure the weak lensing signals around isolated central galaxies (ICGs) from Sloan Digital Sky Survey/DR7 at z ∼ 0.1. The projected stellar mass density profiles of satellite galaxies are further deduced, using photometric sources from the Hyper Suprime-cam survey. The signals of ICGs + their extended stellar halos are taken from Wang et al. All measurements are compared with predictions by the IllustrisTNG300-1 simulation. We find, overall, a good agreement between observation and TNG300. In particular, a correction to the stellar mass of massive observed ICGs is applied based on the calibration of He et al., which brings a much better agreement with TNG300 predicted lensing signals at log 10 M * / M ⊙ > 11.1. In real observation, red ICGs are hosted by more massive dark matter halos and have more satellites and more extended stellar halos than blue ICGs at fixed stellar mass. However, in TNG300 there are more satellites around blue ICGs at fixed stellar mass, and the outer stellar halos of red and blue ICGs are similar. The stellar halos of TNG galaxies are more extended compared with real observed galaxies, especially for blue ICGs with log 10 M * / M ⊙ > 10.8. We find the same trend for TNG100 galaxies and for true halo central galaxies. The tensions between TNG and real galaxies indicate that satellite disruptions are stronger in TNG. In both TNG300 and observation, satellites approximately trace the underlying dark matter distribution beyond 0.1 R 200, but the fraction of total stellar mass in TNG300 does not show the same radial distribution as real galaxies. [ABSTRACT FROM AUTHOR]

Mock member stars for 28 dwarf galaxies are constructed from the cosmological auriga simulation, which reflects the dynamical status of realistic stellar tracers. Axisymmetric Jeans Anisotropic Multi-Gaussian Expansion (jam) modeling is applied to 6000 star particles for each system to recover the underlying matter distribution. The stellar or dark matter component individually is poorly recovered, but the total profile is constrained more reasonably. The mass within the half-mass radius of tracers is recovered the tightest, and the mass between 200 and 300 pc, M (200–300 pc), is an unbiasedly constrained ensemble, with a scatter of 0.167 dex. If using 2000 particles and only line-of-sight velocities with typical errors, the scatter in M (200–300 pc) is increased by ∼50%. Quiescent Saggitarius dSph–like systems and star-forming systems with strong outflows show distinct features, with M (200–300 pc) mostly underestimated for the former, and likely overestimated for the latter. The biases correlate with the dynamical status, which is a result of contraction motions due to tidal effects in quiescent systems or galactic winds in star-forming systems, driving them out of equilibrium. After including Gaia DR3 proper motion errors, we find proper motions can be as useful as line-of-sight velocities for nearby systems at < ∼60 kpc. By extrapolating the actual density profiles and the dynamical constraints down to scales below the resolution, we find the mass within 150 pc can be an unbiasedly constrained ensemble, with a scatter of ∼0.255 dex. We show that the contraction of member stars in nearby systems is detectable based on Gaia DR3 proper motion errors. [ABSTRACT FROM AUTHOR]

Using photometrically selected galaxies from the Hyper Suprime-Cam (HSC) survey, we measure the stellar-mass density profiles for satellite galaxies around isolated central galaxies (ICGs) from SDSS/DR7 at z ∼ 0.1. By stacking HSC images, we also measure the projected stellar-mass density profiles for ICGs and their stellar halos. The total mass distributions are further measured from HSC weak-lensing signals. ICGs dominate within ∼0.15 times the halo virial radius (0.15 R200). The stellar mass versus total mass fractions drop with the increase in projected distance up to ∼0.15 R200, beyond which they are less than 1% while staying almost constant. The integrated stellar mass in satellites is proportional to the virial mass of the host halo, M200, for ICGs more massive than 1010.5M⊙, i.e., M*,sat ∝ M200, whereas the relation between the stellar mass of ICGs + stellar halos and M200 is close to. Below 1010.5M⊙, the change in M200 is much slower with the decrease in M*,ICG+diffuse. At fixed stellar mass, red ICGs are hosted by more massive dark matter halos and have more satellites. At M200 ∼ 1012.7M⊙, both M*,sat and the fraction of stellar mass in satellites versus total stellar mass, fsat, tend to be marginally higher around blue ICGs. fsat increases with the increase in both M*,ICG+diffuse and M200, and scales more linearly with M200. We provide best-fitting relations to M200 versus M*,ICG+diffuse, M*,sat or M*,ICG+diffuse + M*,sat, and to fsat versus M200 or M*,ICG+diffuse, for red and blue ICGs separately. [ABSTRACT FROM AUTHOR]

To enhance contact resonance atomic force microscopy (CR-AFM) and harmonic AFM imaging simultaneously, we design a multifunctional cantilever. Precise tailoring of the cantilever's dynamic properties is realized by either mass-removing or mass-adding. As prototypes, focused ion beam drilling or depositing is used to fabricate the optimized structures. CR-AFM subsurface imaging on circular cavities covered by a piece of highly oriented pyrolytic graphite validates the improved CR frequency to contact stiffness sensitivity. The detectable subsurface depth and cavity radius increase accordingly by using the multifunctional cantilever. At the same time, the free resonance frequency of the second mode is tuned to an integer multiple of the fundamental one. Harmonic AFM imaging on polystyrene and low-density polystyrene mixture shows the improved harmonic amplitude contrast and signal strength on the two material phases. The multifunctional cantilever can be extended to enhance other similar AFM operation modes and it has potential applications in relevant fields such as mechanical characterization and subsurface imaging. [ABSTRACT FROM AUTHOR]

Improvement of contact resonance atomic force microscopy (CR-AFM) frequency sensitivity at a high contact stiffness condition and subsequent enhancement of its subsurface imaging capability were demonstrated by adding an additional mass on the cantilever backside near the free end. The influence of mass and its position on the CR-AFM performances was analytically investigated by using a simplified cantilever vibration model and further compared with finite element analysis. Theoretical results and FEA simulations showed good agreement and they could provide a general guide on the cantilever's modification by attaching a proper mass to improve the CR-AFM capability. As a prototype, a Pt micro-disc with precisely controlled size and position on the cantilever, which served as the attached mass, was deposited by utilizing focused ion beam. The improvement of frequency sensitivity was verified through CR spectroscopy and subsurface imaging on cavities having pre-determined diameters and covered with highly oriented pyrolytic graphite flakes. Compared with the original unmodified cantilever, obvious enhancement of CR-AFM subsurface nano-imaging was obtained. The mass-attached cantilever can benefit characterizing sample's mechanical properties and enhancing subsurface imaging based on tip-generated stress. [ABSTRACT FROM AUTHOR]

Magnetic force microscopy (MFM) has become one of the most important instruments for characterizing magnetic materials with nanoscale spatial resolution. When analyzing magnetic particles by MFM, calibration of the magnetic tips using reference magnetic nanoparticles is a prerequisite due to similar orientation and dimension of the yielded magnetic fields. However, in such a calibration process, errors caused by extra electrostatic interactions will significantly affect the output results. In this work, we evaluate the magnetic moment and dipole radius of the MFM tip on Fe3O4 nanoparticles by considering the associated electrostatic force. The coupling of electrostatic contribution on the measured MFM phase is eliminated by combining MFM and Kelvin probe force microscopy together with theoretical modeling. Numerical simulations and experiments on nickel nanoparticles demonstrate the effectiveness of decoupling. Results show that the calibrated MFM tip can enable a more accurate analysis of micro-and-nano magnetism. In addition, a fast and easy calibration method by using bimodal MFM is discussed, in which the acquisition of multiple phase shifts at different lift heights is not required. [ABSTRACT FROM AUTHOR]

We estimate the Milky Way (MW) halo properties using satellite kinematic data including the latest measurements from Gaia DR2. With a simulation-based 6D phase-space distribution function (DF) of satellite kinematics, we can infer halo properties efficiently and without bias, and handle the selection function and measurement errors rigorously in the Bayesian framework. Applying our DF from the EAGLE simulation to 28 satellites, we obtain an MW halo mass of and a concentration of with the prior based on the M–c relation. The inferred mass profile is consistent with previous measurements but with better precision and reliability due to the improved methodology and data. Potential improvement is illustrated by combining satellite data and stellar rotation curves. Using our EAGLE DF and best-fit MW potential, we provide much more precise estimates of the kinematics for those satellites with uncertain measurements. Compared to the EAGLE DF, which matches the observed satellite kinematics very well, the DF from the semi-analytical model based on the dark-matter-only simulation Millennium II (SAM-MII) over-represents satellites with small radii and velocities. We attribute this difference to less disruption of satellites with small pericenter distances in the SAM-MII simulation. By varying the disruption rate of such satellites in this simulation, we estimate a ∼5% scatter in the inferred MW halo mass among hydrodynamics-based simulations. [ABSTRACT FROM AUTHOR]

We propose a versatile and accurate method to estimate the halo mass and concentration from the kinematics of satellite galaxies. We construct the 6D phase-space distribution function of satellites from a cosmological simulation based on the similarity of internal dynamics for different halos. Within the Bayesian statistical framework, not only can we efficiently infer the halo mass and concentration, we can also treat various observational effects, including the selection function, incomplete data, and measurement errors, in a rigorous and straightforward manner. Through tests with mock samples, we show that our method is valid and accurate, as well as more precise than pure steady-state methods. It can constrain the halo mass to within ∼20% using only 20 tracers and has a small intrinsic uncertainty of ∼10%. In addition to the clear application to the Milky Way and similar galaxies, our method can be extended to galaxy groups or clusters. [ABSTRACT FROM AUTHOR]

Evolutionary game theory is one of the key paradigms behind many scientific disciplines from science to engineering. Previous studies proposed a strategy updating mechanism, which successfully demonstrated that the scale-free network can provide a framework for the emergence of cooperation. Instead, individuals in random graphs and small-world networks do not favor cooperation under this updating rule. However, a recent empirical result shows the heterogeneous networks do not promote cooperation when humans play a prisoner’s dilemma. In this paper, we propose a strategy updating rule with payoff memory. We observe that the random graphs and small-world networks can provide even better frameworks for cooperation than the scale-free networks in this scenario. Our observations suggest that the degree heterogeneity may be neither a sufficient condition nor a necessary condition for the widespread cooperation in complex networks. Also, the topological structures are not sufficed to determine the level of cooperation in complex networks. [ABSTRACT FROM AUTHOR]