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<jats:title>Abstract</jats:title> <jats:p>We carry out a comparative analysis of the relation between the mass of supermassive black holes (BHs) and the stellar mass of their host galaxies at 0.2 &lt; <jats:italic>z</jats:italic> &lt; 1.7 using well-matched observations and multiple state-of-the-art simulations (e.g., MassiveBlackII, Horizon-AGN, Illustris, TNG, and a semianalytic model). The observed sample consists of 646 uniformly selected Sloan Digital Sky Survey quasars (0.2 &lt; <jats:italic>z</jats:italic> &lt; 0.8) and 32 broad-line active galactic nuclei (AGNs; 1.2 &lt; <jats:italic>z</jats:italic> &lt; 1.7) with imaging from Hyper Suprime-Cam (HSC) for the former and Hubble Space Telescope (HST) for the latter. We first add realistic observational uncertainties to the simulation data and then construct a simulated sample in the same manner as the observations. Over the full redshift range, our analysis demonstrates that all simulations predict a level of intrinsic scatter of the scaling relations comparable to the observations that appear to agree with the dispersion of the local relation. Regarding the mean relation, Horizon-AGN and TNG are in closest agreement with the observations at low and high redshift (<jats:italic>z</jats:italic> ∼ 0.2 and 1.5, respectively), while the other simulations show subtle differences within the uncertainties. For insight into the physics involved, the scatter of the scaling relation, seen in the SAM, is reduced by a factor of two and closer to the observations after adopting a new feedback model that considers the geometry of the AGN outflow. The consistency in the dispersion with redshift in our analysis supports the importance of both quasar- and radio-mode feedback prescriptions in the simulations. Finally, we highlight the importance of increasing the sensitivity (e.g., using the James Webb Space Telescope), thereby pushing to lower masses and minimizing biases due to selection effects.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>It is important to understand the cycle of baryons through the circumgalactic medium (CGM) in the context of galaxy formation and evolution. In this study, we forecast constraints on the feedback processes heating the CGM with current and future Sunyaev–Zeldovich (SZ) observations. To constrain these processes, we use a suite of cosmological simulations, the Cosmology and Astrophysics with MachinE Learning Simulations (CAMELS). CAMELS varies four different feedback parameters of two previously existing hydrodynamical simulations, IllustrisTNG and SIMBA. We capture the dependences of SZ radial profiles on these feedback parameters with an emulator, calculate their derivatives, and forecast future constraints on these feedback parameters from upcoming experiments. We find that for a galaxy sample similar to what would be obtained with the Dark Energy Spectroscopic Instrument at the Simons Observatory, all four feedback parameters can be constrained (some within the 10% level), indicating that future observations will be able to further restrict the parameter space for these subgrid models. Given the modeled galaxy sample and forecasted errors in this work, we find that the inner SZ profiles contribute more to the constraining power than the outer profiles. Finally, we find that, despite the wide range of parameter variation in active galactic feedback in the CAMELS simulation suite, we cannot reproduce the thermal SZ signal of galaxies selected by the Baryon Oscillation Spectroscopic Survey as measured by the Atacama Cosmology Telescope.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The cosmic web contains filamentary structure on a wide range of scales. On the largest scales, superclustering aligns multiple galaxy clusters along intercluster bridges, visible through their thermal Sunyaev–Zel’dovich signal in the cosmic microwave background. We demonstrate a new, flexible method to analyze the hot gas signal from multiscale extended structures. We use a Compton <jats:italic>y</jats:italic>-map from the Atacama Cosmology Telescope (ACT) stacked on redMaPPer cluster positions from the optical Dark Energy Survey (DES). Cutout images from the <jats:italic>y</jats:italic>-map are oriented with large-scale structure information from DES galaxy data such that the superclustering signal is aligned before being overlaid. We find evidence of an extended quadrupole moment of the stacked <jats:italic>y</jats:italic> signal at the 3.5<jats:italic>σ</jats:italic> level, demonstrating that the large-scale thermal energy surrounding galaxy clusters is anisotropically distributed. We compare our ACT × DES results with the Buzzard simulations, finding broad agreement. Using simulations, we highlight the promise of this novel technique for constraining the evolution of anisotropic, non-Gaussian structure using future combinations of microwave and optical surveys.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We determine the detection limits of the search for dwarf galaxies in the Pan-Andromeda Archaeological Survey (PAndAS) using the algorithm developed by the PAndAS team. The recovery fractions of artificial dwarf galaxies are, as expected, a strong function of physical size and luminosity and, to a lesser extent, distance. We show that these recovery fractions vary strongly with location in the surveyed area because of varying levels of contamination from both the Milky Way foreground stars and the stellar halo of Andromeda. We therefore provide recovery fractions that are a function of size, luminosity, and location within the survey on a scale of ∼1 × 1 deg<jats:sup>2</jats:sup> (or ∼14 × 14 kpc<jats:sup>2</jats:sup>). Overall, the effective surface brightness for a 50% detection rate ranges between 28 and 30 mag arcsec<jats:sup>−2</jats:sup>. This is in line with expectations for a search that relies on photometric data that are as deep as the PAndAS survey. The derived detection limits are an essential ingredient on the path to constraining the global properties of Andromeda’s system of satellite dwarf galaxies and, more broadly, to providing constraints on dwarf galaxy formation and evolution in a cosmological context.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We report high-precision X-ray monitoring observations in the 0.4–10 keV band of the luminous, long-period colliding wind binary Eta Carinae, up to and through its most recent X-ray minimum/periastron passage in 2020 February. Eta Carinae reached its observed maximum X-ray flux on 2020 January 7, at a flux level of 3.30 ×10<jats:sup>−10</jats:sup> ergs s<jats:sup>−1</jats:sup> cm<jats:sup>−2</jats:sup>, followed by a rapid plunge to its observed minimum flux, 0.03 × 10<jats:sup>−10</jats:sup> ergs s<jats:sup>−1</jats:sup> cm<jats:sup>−2</jats:sup>, near 2020 February 17. The NICER observations show an X-ray recovery from the minimum of only ∼16 days, the shortest X-ray minimum observed so far. We provide new constraints for the “deep” and “shallow” minimum intervals. Variations in the characteristic X-ray temperatures of the hottest observed X-ray emission indicate that the apex of the wind–wind “bow shock” enters the companion’s wind acceleration zone about 81 days before the start of the X-ray minimum. There is a steplike increase in column density just before the X-ray minimum, probably associated with the presence of dense clumps near the shock apex. During the recovery and after, the column density shows a smooth decline, which agrees with previous <jats:italic>N</jats:italic> <jats:sub> <jats:italic>H</jats:italic> </jats:sub> measurements made by Swift at the same orbital phase, indicating that the changes in the mass-loss rate are only a few percent over the two cycles. Finally, we use the variations in the X-ray flux of the outer ejecta seen by NICER to derive a kinetic X-ray luminosity of the ejecta of ∼10<jats:sup>41</jats:sup> ergs s<jats:sup>−1</jats:sup> near the time of the “Great Eruption.”</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Common envelope evolution (CEE) physics plays a fundamental role in the formation of binary systems, such as merging stellar gravitational wave sources, pulsar binaries, and Type Ia supernovae. A precisely constrained CEE has become more important in the age of large surveys and gravitational wave detectors. We use an adiabatic mass-loss model to explore how the total energy of the donor changes as a function of the remnant mass. This provides a more self-consistent way to calculate the binding energy of the donor. For comparison, we also calculate the binding energy through integrating the total energy from the core to the surface. The outcome of CEE is constrained by total energy conservation at the point at which both components’ radii shrink back within their Roche lobes. We apply our results to 142 hot subdwarf binaries. For shorter orbital period hot subdwarf B stars (sdBs), the binding energy is highly consistent. For longer orbital period sdBs in our samples, the binding energy can differ by up to a factor of 2. The common envelope (CE) efficiency parameter <jats:italic>β</jats:italic> <jats:sub>CE</jats:sub> becomes smaller than <jats:italic>α</jats:italic> <jats:sub>CE</jats:sub> for the final orbital period <jats:inline-formula> <jats:tex-math> <?CDATA ${\mathrm{log}}_{10}{P}_{\mathrm{orb}}/\mathrm{days}\gt -0.5$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>log</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> </mml:msub> <mml:msub> <mml:mrow> <mml:mi>P</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>orb</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy="true">/</mml:mo> </mml:mrow> <mml:mi>days</mml:mi> <mml:mo>&gt;</mml:mo> <mml:mo>−</mml:mo> <mml:mn>0.5</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac75d3ieqn1.gif" xlink:type="simple" /> </jats:inline-formula>. We also find the mass ratios <jats:inline-formula> <jats:tex-math> <?CDATA ${\mathrm{log}}_{10}q$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>log</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> </mml:msub> <mml:mi>q</mml:mi> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac75d3ieqn2.gif" xlink:type="simple" /> </jats:inline-formula> and CE efficiency parameters <jats:inline-formula> <jats:tex-math> <?CDATA ${\mathrm{log}}_{10}{\alpha }_{\mathrm{CE}}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>log</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> </mml:msub> <mml:msub> <mml:mrow> <mml:mi>α</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>CE</mml:mi> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac75d3ieqn3.gif" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math> <?CDATA ${\mathrm{log}}_{10}{\beta }_{\mathrm{CE}}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>log</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> </mml:msub> <mml:msub> <mml:mrow> <mml:mi>β</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>CE</mml:mi> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac75d3ieqn4.gif" xlink:type="simple" /> </jats:inline-formula> linearly correlate in sdBs, similarly to the findings of De Marco et al. for post-AGB binaries.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Chemical processes on the surface of icy grains play an important role in the chemical evolution in molecular clouds. In particular, reactions involving nonenergetic hydrogen atoms accreted from the gaseous phase have been extensively studied. These reactions are believed to effectively proceed only on the surface of the icy grains; thus, molecules embedded in the ice mantle are not considered to react with hydrogen atoms. Recently, Tsuge et al. suggested that nonenergetic hydrogen atoms can react with CO molecules even in ice mantles via diffusive hydrogenation. This investigation was extended to benzene and naphthalene molecules embedded in amorphous solid water (ASW) in the present study, which revealed that a portion of these molecules could be fully hydrogenated in astrophysical environments. The penetration depths of nonenergetic hydrogen atoms into porous and nonporous ASW were determined using benzene molecules to be &gt;50 and ∼10 monolayers, respectively (1 monolayer ≈ 0.3 nm).</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Dense gas is important for galaxy evolution and star formation. Optically thin dense-gas tracers, such as isotopologues of HCN, HCO<jats:sup>+</jats:sup>, etc., are very helpful in diagnosing the excitation conditions of dense molecular gas. However, previous studies of optically thin dense-gas tracers mostly focused on the average properties of galaxies as a whole, due to limited sensitivity and angular resolution. M82, a nearby prototype starburst galaxy, offers a unique case for spatially resolved studies with single-dish telescopes. With the IRAM 30 m telescope, we observed the <jats:italic>J</jats:italic> = 1 → 0 transition of H<jats:sup>13</jats:sup>CN, HC<jats:sup>15</jats:sup>N, H<jats:sup>13</jats:sup>CO<jats:sup>+</jats:sup>, HN<jats:sup>13</jats:sup>C, H<jats:sup>15</jats:sup>NC, and SiO <jats:italic>J</jats:italic> = 2 → 1, HC<jats:sub>3</jats:sub>N <jats:italic>J</jats:italic> = 10 → 9, and H<jats:sub>2</jats:sub>CO <jats:italic>J</jats:italic> = 2 → 1 toward five positions along the major axis of M82. The intensity ratios of <jats:italic>I</jats:italic>(HCN)/<jats:italic>I</jats:italic>(H<jats:sup>13</jats:sup>CN) and <jats:italic>I</jats:italic>(HCO<jats:sup>+</jats:sup>)/<jats:italic>I</jats:italic>(H<jats:sup>13</jats:sup>CO<jats:sup>+</jats:sup>) show a significant spatial variation along the major axis, with lower values in the central region than those on the disk, indicating higher optical depths in the central region. The optical depths of HCO<jats:sup>+</jats:sup> lines are found to be systematically higher than those of HCN lines at all positions. Furthermore, we find that the <jats:sup>14</jats:sup>N/<jats:sup>15</jats:sup>N ratios have an increasing gradient from the center to the outer disk.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Spider pulsars are compact binary systems composed of a millisecond pulsar and a low-mass companion. The relativistic magnetically dominated pulsar wind impacts onto the companion, ablating it and slowly consuming its atmosphere. The interaction forms an intrabinary shock, a proposed site of particle acceleration. We perform global fully kinetic particle-in-cell simulations of the intrabinary shock, assuming that the pulsar wind consists of plane-parallel stripes of alternating polarity and that the shock wraps around the companion. We find that particles are efficiently accelerated via shock-driven reconnection. We extract first-principles synchrotron spectra and light curves, which are in good agreement with X-ray observations: (1) the synchrotron spectrum is nearly flat, <jats:italic>F</jats:italic> <jats:sub> <jats:italic>ν</jats:italic> </jats:sub> ∝ const; (2) when the pulsar spin axis is nearly aligned with the orbital angular momentum, the light curve displays two peaks, just before and after the pulsar eclipse (pulsar superior conjunction), separated in phase by ∼0.8 rad; (3) the peak flux exceeds the one at the inferior conjunction by a factor of 10.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We demonstrate the potential of line-intensity mapping to place constraints on the initial mass function (IMF) of Population III stars via measurements of the mean He <jats:sc>ii</jats:sc> 1640 Å/H<jats:italic>α</jats:italic> line-intensity ratio. We extend the <jats:monospace>21cmFAST</jats:monospace> code with modern high-redshift galaxy-formation and photoionization models, and estimate the line emission from Population II and Population III galaxies at redshifts 5 ≤ <jats:italic>z</jats:italic> ≤ 20. In our models, mean ratio values of He <jats:sc>ii</jats:sc>/H <jats:italic>α</jats:italic> ≳ 0.1 indicate top-heavy Population III IMFs with stars of several hundred solar masses, reached at <jats:italic>z</jats:italic> ≳ 10 when Population III stars dominate star formation. A next-generation space mission with capabilities moderately superior to those of CDIM will be able to probe this scenario by measuring the He <jats:sc>ii</jats:sc> and H<jats:italic>α</jats:italic> fluctuation power spectrum signals and their cross-correlation at high significance up to <jats:italic>z</jats:italic> ∼ 20. Moreover, regardless of the IMF, a ratio value of He <jats:sc>ii</jats:sc>/H<jats:italic>α</jats:italic> ≲ 0.01 indicates low Population III star formation and, therefore, it signals the end of the period dominated by this stellar population. However, a detection of the corresponding He <jats:sc>ii</jats:sc> power spectrum may be only possible for top-heavy Population III IMFs or through cross-correlation with the stronger H<jats:italic>α</jats:italic> signal. Finally, ratio values of 0.01 ≲ He <jats:sc>ii</jats:sc>/H<jats:italic>α</jats:italic> ≲ 0.1 are complex to interpret because they can be driven by several competing effects. We discuss how various measurements at different redshifts and the combination of the line-intensity ratio with other probes can assist in constraining the Population III IMF in this case.</jats:p>