High Impact Parameter Research Articles

The MUSE Ultra Deep Field (MUDF). VI. The Relationship between Galaxy Properties and Metals in the Circumgalactic Medium

We present initial results associating galaxies in the Multi-Unit Spectroscopic Explorer (MUSE) Ultra Deep Field (MUDF) with gas seen in absorption along the line of sight to two bright quasars in this field to explore the dependence of metals in the circumgalactic medium (CGM) on galaxy properties. The MUDF includes ∼140 hr of Very Large Telescope (VLT)/MUSE data and 90 orbits of Hubble Space Telescope (HST)/G141M grism observations alongside VLT/Ultraviolet and Visual Echelle Spectrograph spectroscopy of the two quasars and several bands of HST imaging. We compare the metal absorption around galaxies in this field as a function of impact parameter, azimuthal angle, and galaxy metallicity across redshifts 0.5 < z < 3.2. Due to the depth of our data and a large field of view, our analysis extends to low stellar masses (<107 M ⊙) and high impact parameters (>600 kpc). We find a correlation between the absorber equivalent width and the number of nearby galaxies, but do not detect a significant anticorrelation with the impact parameter. Our full sample does not show any significant change in absorber incidence as a function of azimuthal angle. However, we do find a bimodality in the azimuthal angle distribution of absorption at small impact parameters (<2 r vir) and around highly star-forming galaxies, possibly indicating disk-like accretion and biconical outflows. Finally, we do not detect any systematic deviation from the fundamental metallicity relation among galaxies with detected absorption. This work is limited by gaps in the wavelength coverage of our current data; broader-wavelength observations with the James Webb Space Telescope will allow us to unlock the full potential of the MUDF for studying the CGM.

Ringdown amplitudes of nonspinning eccentric binaries

Closed-form expressions for the ringdown complex amplitudes of nonspinning unequal-mass binaries in arbitrarily eccentric orbits are presented. They are built upon 237 numerical simulations contained within the RIT catalog, through the parameterisation introduced in [Phys. Rev. Lett. 132 (2024) 101401]. Global fits for the complex amplitudes, associated to linear quasinormal mode frequencies of the dominant ringdown modes, are obtained in a factorised form immediately applicable to any existing quasi-circular model. Similarly to merger amplitudes, ringdown ones increase by more than 50% compared to the circular case for high impact parameters (medium eccentricities), while strongly suppressed in the low impact parameter (highly eccentric) limit. Such reduction can be explained by a transition between an “orbital-type” and an “infall-type” dynamics. The amplitudes (phases) fits accuracy lies around a few percent (deciradians) for the majority of the dataset, comparable to the accuracy of current state-of-the-art quasi-circular ringdown models, and well within current statistical errors of current LIGO-Virgo-Kagra ringdown observations. These expressions constitute another building block towards the construction of complete general relativistic inspiral-merger-ringdown semi-analytical templates, and allow to extend numerically-informed spectroscopic analyses beyond the circular limit. Such generalisations are key to achieve accurate inference of compact binaries astrophysical properties, and tame astrophysical systematics within observational investigations of strong-field general relativistic dynamics.

Imaging Spin-Orbit Excitation of Yttrium through High-Energy Collisions with Rare Gas Atoms.

The energy required for spin-orbit excitation plays a critical role in understanding translational-to-electronic energy conversion, particularly in chemical reactions involving changes in spin states. This is particularly important for transition metal atoms possessing d-orbitals, which result in multiple spin-orbit split energy levels at low energies. The accurate identification and characterization of spin-orbit transitions in such species require advanced experimental techniques and theoretical support. In this study, the spin-orbit excited collisions of Y(2D3/2) with rare gas atoms Ne, Ar, and Kr leading to Y(2D5/2) were observed using laser-ablated crossed-beam and time-sliced ion velocity mapping imaging techniques. Through a comparison of the forward angular distributions of Y(2D3/2) to the backward and sideway scattering distributions of Y(2D5/2) from elastic and inelastic collisions of Y(2D) with rare gas atoms, this study reveals that the spin-orbit electronic excitation occurs with high collision energy and low impact parameters from backward and sideway collisions. The effectiveness of the spin-orbit excitation process is strongly dependent on the collision energy or temperature, suggesting that energy requirements of the process have to be considered in chemical reactions involving changes in spin states.

Life Cycle Greenhouse Gas Emissions of CO2-Enabled Sedimentary Basin Geothermal.

The expansion of renewable energy and the large-scale deployment of carbon dioxide (CO2) capture and storage (CCS) can decarbonize the power sector. The use of CO2 to extract geothermal heat from naturally porous and permeable sedimentary basins to generate electricity (CO2-plume geothermal (CPG) system) presents an opportunity to simultaneously generate renewable energy and geologically store CO2. In this study, we estimate the life cycle greenhouse gas (GHG) impacts of CPG systems through 12 scenarios in which CPG systems are combined with one of six CO2 sources (e.g., bioenergy with carbon capture and storage (BECCS) and iron and steel facilities) and operate in two geological settings. We find the life cycle GHG emissions of CPG systems ranging from -0.25 to -6.18 kg CO2eq/kWh. CPG systems can achieve the highest emissions reductions when utilizing the CO2 captured from BECCS. We evaluate uncertainty through a Monte Carlo simulation, demonstrating consistent net reductions in life cycle emissions and a local, one-parameter-at-a-time sensitivity analysis that identifies the CO2 capture capacity as the high-impact parameter of the results. Through the production of electricity, CPG systems can provide additional environmental benefits to the deployment of large-scale CCS.

Assessment of tuberculosis transmission probability in three Thai prisons based on five dynamic models.

This study aimed to assess and compare the probability of tuberculosis (TB) transmission based on five dynamic models: the Wells-Riley equation, two Rudnick & Milton-proposed models based on air changes per hour (ACH) and liters per second per person (L/s/p), the model proposed by Issarow et al, and the Applied Susceptible-Exposed-Infected-Recovered (SEIR) TB transmission model. This study also aimed to determine the impact of model parameters on such probabilities in three Thai prisons. A cross-sectional study was conducted using data from 985 prison cells. The TB transmission probability for each cell was calculated using parameters relevant to the specific model formula, and the magnitude of the model agreement was examined by Spearman's rank correlation and Bland-Altman plot. Subsequently, a multiple linear regression analysis was conducted to investigate the influence of each model parameter on the estimated probability. Results revealed that the median (Quartiles 1 and 3) of TB transmission probability among these cells was 0.052 (0.017, 0.180). Compared with the pioneered Wells-Riley's model, the remaining models projected discrepant TB transmission probability from less to more commensurate to the degree of model modification from the pioneered model as follows: Rudnick & Milton (ACH), Issarow et al., and Rudnick & Milton (L/s/p), and the applied SEIR models. The ventilation rate and number of infectious TB patients in each cell or zone had the greatest impact on the estimated TB transmission probability in most models. Additionally, the number of inmates in each cell, the area per person in square meters, and the inmate turnover rate were identified as high-impact parameters in the applied SEIR model. All stakeholders must urgently address these influential parameters to reduce TB transmission in prisons. Moreover, further studies are required to determine their relative validity in accurately predicting TB incidence in prison settings.

NUMERICAL INVESTIGATION OF OFF-CENTER COLLISION BETWEEN TWO EQUAL-SIZED WATER DROPLETS

Droplet collision is a basic phenomenon in numerous natural and industrial processes, while the understanding of collision dynamics is still lacking. In this work, a numerical investigation of the offcenter collision of two equal-sized water droplets is performed with the Weber number of 14 to 196 and impact parameter of 0 to 0.8. The incompressible Navier-Stokes equations are solved by the finite volume method. The volume of fluid (VOF) method and adaptive mesh technique are used to capture the gas-liquid interface. First, by comparing with reliable published experimental data, the reliability of the numerical results is verified. Then, the shape evolution for coalescence, reflexive separation, and stretching separation is described in detail. The effect of the Weber number and impact parameter on the collision of two equal-sized water droplets is analyzed. Moreover, the analysis of the surface energy and kinetic energy is conducted for the collision process. Furthermore, the dimensions of ligament and bridge for high-impact parameter stretching separation are presented quantitatively. Finally, the collision outcome for the simulation cases in this work is depicted and discussed. This work is helpful for fundamentally understanding the mechanism of collision dynamics of droplets, as well as applying the droplet collision model to related processes.

Study on the Effect of Parameter Sensitivity on Engine Optimization Results

The effects of six control parameters, intake valve opening timing (IVO), exhaust valve opening timing (EVO), compression ratio (CR), engine speed, intake temperature, and intake pressure on engine output power, indicated specific fuel consumption (ISFC), and nitrogen oxides (NOx) emissions, are analyzed through engine simulation. The six parameters were categorized into two groups based on the degree of influence: high influence (EVO, speed and intake pressure) and low influence (CR, IVO and intake temperature). The relationship between these two groups of parameters and power, ISFC and NOx emissions was explored. Optimization was carried out for each of the two groups of parameters, and the optimization of the high impact parameters resulted in a higher diversity and wider distribution of the solution set. On the other hand, the optimization of the low-impact parameters resulted in a more concentrated distribution of the solution set, while better reflecting the trade-off between the optimization objectives. For the optimal solutions for both sets of parameters, the high-impact parameters provided significant optimization performance compared to the standard operating conditions. Although power and ISFC were optimized, the optimal solution for the low-impact parameter performed poorly with a significant increase in NOx emissions. Therefore, the parameters should be evaluated for optimization using high impact parameters to improve engine performance.

Differential Cross Sections for Pair-Correlated Rotational Energy Transfer in NO(A2Σ+) + N2, CO, and O2: Signatures of Quenching Dynamics.

A crossed molecular beam, velocity-map ion-imaging apparatus has been used to determine differential cross sections (DCSs), as a function of collider final internal energy, for rotationally inelastic scattering of NO(A2Σ+, v = 0, j = 0.5f1) with N2, CO, and O2, at average collision energies close to 800 cm-1. DCSs are strongly forward scattered for all three colliders for all observed NO(A) final rotational states, N'. For collisions with N2 and CO, the fraction of NO(A) that is scattered sideways and backward increases with increasing N', as does the internal rotational excitation of the colliders, with N2 having the highest internal excitation. In contrast, the DCSs for collisions with O2 are essentially only forward scattered, with little rotational excitation of the O2. The sideways and backward scattering expected from low-impact-parameter collisions, and the rotational excitation expected from the orientational dependence of published van der Waals potential energy surfaces (PESs), are absent in the observed NO(A) + O2 results. This is consistent with the removal of these short-range scattering trajectories via facile electronic quenching of NO(A) by O2, in agreement with the literature determination of the coupled NO-O2 PESs and the associated conical intersections. In contrast, collisions at high-impact parameter that predominately sample the attractive van der Waals minimum do not experience quenching and are inelastically forward scattered with low rotational excitation.

Short-term electricity load forecasting based on a novel data preprocessing system and data reconstruction strategy

Accurate forecasting of the electricity load plays a crucial role in the decision-making and operation of the smart grid. The characteristics of load series such as non-stationarity, non-linearity, and multiple-seasonality make such prediction a challenging task. In this study, a novel combined prediction model based on a feed-forward neural network (FNN) is established to address these challenges. A novel multi-step data preprocessing (DP) system is developed, which comprehensively eliminates the undesirable characteristics in electricity load data by identifying outliers, correcting outliers, and smoothing the data. Random forest is used to select high-impact parameters for electricity load to eliminate irrelevant variables. Moreover, a strategy combining seasonal-trend decomposition based on loess (STL) and Hodrick-Prescott (HP) filtering has been developed. STL is utilized to decompose the load series for exploring the inherent connection between electricity load trends and seasonal variations, while HP is employed to reconstruct the residual series, enabling a more in-depth exploration of the latent trend characteristics. The accuracy of the proposed framework was evaluated using publicly available datasets. The proposed DP-HSTL-FNN model achieved the lowest root mean square error (4.11 KW) and the coefficient of determination (R2) was closest to 1, demonstrating the highest predictive accuracy and reliable performance among all compared models. The results validate the significant advantage of the novel DP system in improving the quality of complex datasets, while confirming the potential of the data reconstruction strategy in enhancing prediction accuracy. Therefore, this novel model can be effectively applied in short-term electricity load forecasting for smart grids.

A hybrid forecasting method for cooling load in large public buildings based on improved long short term memory

Air conditioning system in large public buildings have great potential for energy saving. In order to improve the operational efficiency of the air conditioning system, it is crucial to establish an accurate and effective cooling load forecasting model. This paper proposes a hybrid model based on random forest-improved sparrow search algorithm-long short term memory (RF-ISSA-LSTM) for forecasting the cooling load of large public buildings. Firstly, random forest (RF) is used to select high-impact parameters for building cooling load and reduce the dimensionality of the original input data. Secondly, three strategies are introduced to improve the location update in different stages of the sparrow search algorithm (ISSA), and then an ISSA-optimized LSTM forecasting model is established. Finally, two case studies are selected to evaluate the predictive performance of the model in detail. The experimental results show that the mean average percentage error (MAPE) and root mean square error (RMSE) of the RF-ISSA-LSTM model predicting the cooling load for these two buildings are 0.6072%, 3.3552 and 0.7939%, 4.4227, respectively. Compared with other neural network models, the RF-ISSA-LSTM model has higher prediction accuracy and shorter running time. Meanwhile, with the reduced training sample size, the RF-ISSA-LSTM model can still effectively predict the cooling load, which indicates its strong generalization ability. Therefore, this work is enlightening and the proposed hybrid prediction model can serve as a technical tool to support the energy efficiency management of large public buildings.

4D scale-dependent Schwarzschild-AdS/dS black holes: study of shadow and weak deflection angle and greybody bounding

We investigate the shadow, deflection angle, and the greybody bounding of a Schwarzschild-AdS/dS black hole in scale-dependent gravity. We used the EHT data to constrain the parameter epsilon. We have found that within the 1sigma level of uncertainty, epsilon M_0 ranges at 10^{-11} - 10^{-16} orders of magnitude for Sgr. A*, and 10^{-11} - 10^{-17} for M87*. Using these parameters, we explored how the shadow radius behaves as perceived by a static observer. Using the known parameters for Sgr. A* and M87*, we found different shadow cast behavior near the cosmological horizon even if the same scaling parameters were used. We explored the deflection angle {hat{alpha }} in the weak field limit for both massive and null particles, in addition to the effect of finite distances using the non-asymptotically flat version of the Gauss-Bonnet theorem. We have found that the {hat{alpha }} strongly depends on massive particles. Tests on epsilon’s effect using Sgr. A* is only along points of low impact parameters. For M87*, only the scaled BH in AdS type can be tested at high impact parameters at the expense of very low value for {hat{alpha }}. We study the rigorous bound on the greybody factor for scalar field emitted from black holes in the theory and show the bound on the transmission probability. The effects of the scale-dependent gravity on the greybody factors are investigated, and the results indicate that the bound on the greybody factor in this case is less than the bound for the Schwarzschild black hole.

CMS Phase-2 Inner Tracker Upgrade

The HL-LHC conditions of instantaneous peak luminosity up to 7.5x1034 cm-2s-1 and an integrated luminosity of the order of 300 fb-1/year is expected to result in 1 MeV neutron equivalent fluence of 2.3 x 1016 neq/cm2 and a total ionizing dose (TID) of 12 MGy (1.2 Grad) at the center of the CMS Experiment, where its innermost component, the Phase-2 Pixel Detector will be installed. This detector has to survive the above radiation dose, handle hit rates of 3.2 GHz/cm2 in the layers closest to the beam line, be able to track and separate particles in extremely dense collisions, deal with a pileup of 140-200 collisions per bunch crossing and have a high impact parameter resolution. This translates into a highly granular detector design with thinner sensors and smaller pixels, and a faster and more radiation hard electronics compared to the Phase-1 detector. This contribution reviews the Phase-2 upgrade of the (silicon-based) CMS Inner Tracker focusing on the features of the detector layout and on developments of pixelated devices.

Neutron stars colliding with binary companions: formation of hypervelocity stars, pulsar planets, bumpy superluminous supernovae and Thorne–Żytkow objects

ABSTRACT We perform three-dimensional (3D) hydrodynamical simulations of new-born neutron stars (NSs) colliding with main-sequence binary companions after a supernova explosion. Based on those hydrodynamical models, we construct a semi-analytical formula that describes the drag force inside stars with steep density gradients. We then compute the outcome of NS–companion collisions over a wide range of parameters using the semi-analytical formula. Depending on the direction and magnitude of the natal kick, we find that the collision may lead to various outcomes. For relatively fast kicks and high impact parameters, the NS may penetrate the companion star envelope without merging. By allowing the NS to plunge through their companions, the companion can be accelerated to have runaway velocities up to ∼10 per cent above the theoretical upper limit considered in classical binary disruption scenarios. The NS can capture and carry away up to a few per cent of the companion envelope as it escapes, which may form pulsar planets or cause outflows through accretion to heat the ejecta from inside and power the supernova light curve. For lower impact parameters, the NS will directly merge with the companion and form a Thorne–Żytkow object. In intermediate cases, the NS penetrates the companion envelope several times before merging, possibly causing multiple bumps in the supernova light curve like in SN2015bn and SN2019stc.

Exploring compact binary merger host galaxies and environments with zELDA

ABSTRACT Compact binaries such as double neutron stars or a neutron star paired with a black hole, are strong sources of gravitational waves during coalescence and also the likely progenitors of various electromagnetic phenomena, notably short-duration gamma-ray bursts (SGRBs), and kilonovae. In this work, we generate populations of synthetic binaries and place them in galaxies from the large-scale hydrodynamical galaxy evolution simulation, eagle. With our zELDA code, binaries are seeded in proportion to star formation rate, and we follow their evolution to merger using both the bpass and cosmic binary stellar evolution codes. We track their dynamical evolution within their host galaxy potential, to estimate the galactocentric distance at the time of the merger. Finally, we apply observational selection criteria to allow comparison of this model population with the legacy sample of SGRBs. We find a reasonable agreement with the redshift distribution (peaking at 0.5 &amp;lt; z &amp;lt; 1), host morphologies, and projected galactocentric offsets (modal impact parameter ≲10 kpc). Depending on the binary simulation used, we predict $\sim 16\!-\!35{{\ \rm per\ cent}}$ of SGRB events would appear ‘host-less’, i.e. sources that merge with high impact parameters or have hosts fainter than the detection limit (H &amp;gt; 26).

AutoDSE: Enabling Software Programmers to Design Efficient FPGA Accelerators

Adopting FPGA as an accelerator in datacenters is becoming mainstream for customized computing, but the fact that FPGAs are hard to program creates a steep learning curve for software programmers. Even with the help of high-level synthesis (HLS) , accelerator designers still have to manually perform code reconstruction and cumbersome parameter tuning to achieve optimal performance. While many learning models have been leveraged by existing work to automate the design of efficient accelerators, the unpredictability of modern HLS tools becomes a major obstacle for them to maintain high accuracy. To address this problem, we propose an automated DSE framework— AutoDSE —that leverages a bottleneck-guided coordinate optimizer to systematically find a better design point. AutoDSE detects the bottleneck of the design in each step and focuses on high-impact parameters to overcome it. The experimental results show that AutoDSE is able to identify the design point that achieves, on the geometric mean, 19.9× speedup over one CPU core for MachSuite and Rodinia benchmarks. Compared to the manually optimized HLS vision kernels in Xilinx Vitis libraries, AutoDSE can reduce their optimization pragmas by 26.38× while achieving similar performance. With less than one optimization pragma per design on average, we are making progress towards democratizing customizable computing by enabling software programmers to design efficient FPGA accelerators.

The TESS–Keck Survey. VI. Two Eccentric Sub-Neptunes Orbiting HIP-97166

Abstract We report the discovery of HIP-97166b (TOI-1255b), a transiting sub-Neptune on a 10.3 day orbit around a K0 dwarf 68 pc from Earth. This planet was identified in a systematic search of TESS Objects of Interest for planets with eccentric orbits, based on a mismatch between the observed transit duration and the expected duration for a circular orbit. We confirmed the planetary nature of HIP-97166b with ground-based radial-velocity measurements and measured a mass of M b = 20 ± 2 M ⊕ along with a radius of R b = 2.7 ± 0.1 R ⊕ from photometry. We detected an additional nontransiting planetary companion with M c sini = 10 ± 2 M ⊕ on a 16.8 day orbit. While the short transit duration of the inner planet initially suggested a high eccentricity, a joint RV-photometry analysis revealed a high impact parameter b = 0.84 ± 0.03 and a moderate eccentricity. Modeling the dynamics with the condition that the system remain stable over &gt;105 orbits yielded eccentricity constraints e b = 0.16 ± 0.03 and e c &lt; 0.25. The eccentricity we find for planet b is above average for the small population of sub-Neptunes with well-measured eccentricities. We explored the plausible formation pathways of this system, proposing an early instability and merger event to explain the high density of the inner planet at 5.3 ± 0.9 g cc−1 as well as its moderate eccentricity and proximity to a 5:3 mean-motion resonance.

Inertial stretching separation in binary droplet collisions

Binary droplet collisions exhibit a wide range of outcomes, including coalescence and stretching separation, with a transition between these two outcomes arising for high Weber numbers and impact parameters. Our experimental study elucidates the effect of viscosity on this transition, which we show exhibits inertial (viscosity-independent) behaviour over an order-of-magnitude-wide range of Ohnesorge numbers. That is, the transition is not always shifted towards higher impact parameters by increasing droplet viscosity, as it might be thought from the existing literature. Moreover, we provide compelling experimental evidence that stretching separation only arises if the length of the coalesced droplet exceeds a critical multiple of the original droplet diameters (3.35). Using this as a criterion, we provide a simple but robust model (without any arbitrarily chosen free parameters) to predict the coalescence/stretching-separation transition.

Inelastic collision dynamics of oriented NO molecules with Kr atoms

Building on our previous work on NO + Ar, this paper presents a complete set of orientation measurements and quantum mechanical calculations for the NO + Kr collision system, including both spin-orbit conserving and changing collisions, and both side-on (x-axis) and end-on (z-axis) orientations. While many of the trends observed in the oriented differential and integral scattering distributions, as well as in the spin-orbit branching fractions, are similar to the ones seen previously for NO + Ar, a direct comparison with the Ar data reveals subtle differences in the scattering dynamics, which we rationalise with the more extended attractive regions on the NO + Kr potential energy surfaces. High-impact parameter collisions that lead to low scattering angles in the spin-orbit conserving manifold are particularly sensitive to the topology in the attractive parts of the potential, whereas more impulsive, low-impact parameter trajectories, which sample the repulsive parts of the potential, produce very similar features in the oriented differential cross sections for the Ar and Kr systems, especially for spin-orbit changing collisions.

Sensitivity analysis of the SWAP (Soil-Water-Atmosphere-Plant) model under different nitrogen applications and root distributions in saline soils

Sensitivity analysis is important for determining the parameters in the model calibration process. In our study, a variance-based global sensitivity analysis (extended Fourier amplitude sensitivity test, EFAST) was applied to an agro-hydrological model (the SWAP (Soil-Water-Atmosphere-Plant model) model). The sensitivities of 20 parameters belonging to 4 categories (soil hydraulics, solute transport, root water uptake, and environmental stresses) for the simulated accumulated transpiration, dry matter (DM), and yield of sunflowers were analyzed under three nitrogen application rates (N1, N2, and N3), four salinity levels (S1, S2, S3, and S4), and three root distributions (R1, R2, and R3). The results indicated that for predominantly loamy soils, the high-impact parameters for accumulated transpiration, DM, and yield were the soil hydraulic parameters (α and n), critical stress index for compensatory root water uptake (ωc), the salt level at which salt stress starts (Pi), the decline of root water uptake above Pi (SSF), residual water content (θr), saturated water content (θs), and relative uptake of solutes by roots (TSCF). We also found that nitrogen application did not change the order of the parameter impacts on accumulated transpiration, DM, and yield. However, TSCF replaced α as the highest-impact parameter for the accumulated transpiration, DM, and yield at high salinity levels (S2 and S3). Furthermore, α was also the highest-impact parameter for DM and yield under different root distributions, but the highest-impact parameters for transpiration were ωc, α, and θs under R1, R2, and R3, respectively. Nitrogen application could be neglected when considering the interactive effects of nitrogen application, salinity level, and root distribution on the transpiration, DM, and yield. Additionally, the mean values and uncertainties of the transpiration, DM, and yield were similar in all scenarios, except S3, which showed a sharp decrease in the mean values. We suggest determining the above eight parameters (α, n, ωc, Pi, SSF, θr, θs, and TSCF) and the saturated vertical hydraulic conductivity (KS) based on rigorous calibrations with direct or indirect local measurements using economical methods (e.g., a literature review), with limited observations for other parameters when using the SWAP model and other similar agro-hydrological models.

TOI 564 b and TOI 905 b: Grazing and Fully Transiting Hot Jupiters Discovered by TESS

Abstract We report the discovery and confirmation of two new hot Jupiters discovered by the Transiting Exoplanet Survey Satellite (TESS): TOI 564 b and TOI 905 b. The transits of these two planets were initially observed by TESS with orbital periods of 1.651 and 3.739 days, respectively. We conducted follow-up observations of each system from the ground, including photometry in multiple filters, speckle interferometry, and radial velocity measurements. For TOI 564 b, our global fitting revealed a classical hot Jupiter with a mass of M J and a radius of R J. Also a classical hot Jupiter, TOI 905 b has a mass of M J and radius of R J. Both planets orbit Sun-like, moderately bright, mid-G dwarf stars with V ∼ 11. While TOI 905 b fully transits its star, we found that TOI 564 b has a very high transit impact parameter of , making it one of only ∼20 known systems to exhibit a grazing transit and one of the brightest host stars among them. Therefore, TOI 564 b is one of the most attractive systems to search for additional nontransiting, smaller planets by exploiting the sensitivity of grazing transits to small changes in inclination and transit duration over a timescale of several years.