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<jats:title>Abstract</jats:title> <jats:p>We explore the connection between the kinematics, structures and stellar populations of massive galaxies at 0.6 &lt; <jats:italic>z</jats:italic> &lt; 1.0 using the fundamental plane (FP). Combining stellar kinematic data from the Large Early Galaxy Astrophysics Census (LEGA-C) survey with structural parameters measured from deep Hubble Space Telescope imaging, we obtain a sample of 1419 massive (<jats:inline-formula> <jats:tex-math> <?CDATA $\mathrm{log}({M}_{* }/{M}_{\odot })\gt 10.5$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>log</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>*</mml:mo> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy="true">/</mml:mo> </mml:mrow> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>⊙</mml:mo> </mml:mrow> </mml:msub> <mml:mo stretchy="false">)</mml:mo> <mml:mo>&gt;</mml:mo> <mml:mn>10.5</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabf1e7ieqn1.gif" xlink:type="simple" /> </jats:inline-formula>) galaxies that span a wide range in morphology, star formation activity, and environment, and therefore is representative of the massive galaxy population at <jats:italic>z</jats:italic> ∼ 0.8. We find that quiescent and star-forming galaxies occupy the parameter space of the <jats:italic>g</jats:italic>-band FP differently and thus have different distributions in the dynamical mass-to-light ratio (<jats:italic>M</jats:italic> <jats:sub>dyn</jats:sub>/<jats:italic>L</jats:italic> <jats:sub> <jats:italic>g</jats:italic> </jats:sub>), largely owing to differences in the stellar age and recent star formation history, and to a lesser extent, the effects of dust attenuation. In contrast, we show that both star-forming and quiescent galaxies lie on the same mass FP at <jats:italic>z</jats:italic> ∼ 0.8, with a comparable level of intrinsic scatter about the plane. We examine the variation in <jats:italic>M</jats:italic> <jats:sub>dyn</jats:sub>/<jats:italic>M</jats:italic> <jats:sub>*</jats:sub> through the thickness of the mass FP, finding no significant residual correlations with stellar population properties, Sérsic index, or galaxy overdensity. Our results suggest that, at fixed size and velocity dispersion, the variations in <jats:italic>M</jats:italic> <jats:sub>dyn</jats:sub>/<jats:italic>L</jats:italic> <jats:sub> <jats:italic>g</jats:italic> </jats:sub> of massive galaxies reflect an approximately equal contribution of variations in <jats:italic>M</jats:italic> <jats:sub>*</jats:sub>/<jats:italic>L</jats:italic> <jats:sub> <jats:italic>g</jats:italic> </jats:sub>, and variations in the dark matter fraction or initial mass function.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>A recent observational study suggests that the occurrence of hot Jupiters (HJs) around solar-type stars is correlated with stellar clustering. We study a new scenario for HJ formation, called “Flyby Induced High-e Migration,” that may help explain this correlation. In this scenario, stellar flybys excite the eccentricity and inclination of an outer companion (giant planet, brown dwarf, or low-mass star) at large distance (10–300 au), which then triggers high-e migration of an inner cold Jupiter (at a few astronomical units) through the combined effects of von Zeipel–Lidov–Kozai (ZLK) eccentricity oscillation and tidal dissipation. Using semianalytical calculations of the effective ZLK inclination window, together with numerical simulations of stellar flybys, we obtain the analytic estimate for the HJ occurrence rate in this formation scenario. We find that this “flyby induced high-e migration” could account for a significant fraction of the observed HJ population, although the result depends on several uncertain parameters, including the density and lifetime of birth stellar clusters, and the occurrence rate of the “cold Jupiter + outer companion” systems.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Stars can either be formed in or captured by the accretion disks in active galactic nuclei (AGNs). These AGN stars are irradiated and subject to extreme levels of accretion, which can turn even low-mass stars into very massive ones (<jats:italic>M</jats:italic> &gt; 100<jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>) whose evolution may result in the formation of massive compact objects (<jats:italic>M</jats:italic> &gt; 10<jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>). Here we explore the spins of these AGN stars and the remnants they leave behind. We find that AGN stars rapidly spin up via accretion, eventually reaching near-critical rotation rates. They further maintain near-critical rotation even as they shed their envelopes, become compact, and undergo late stages of burning. This makes them good candidates to produce high-spin massive black holes, such as the ones seen by LIGO-Virgo in GW 190521g, as well as long gamma-ray bursts and the associated chemical pollution of the AGN disk.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The radio galaxy 1321+045 is a rare example of a young, compact steep-spectrum source located in the center of a <jats:italic>z</jats:italic> = 0.263 galaxy cluster. Using a combination of Chandra, VLBA, VLA, MERLIN, and IRAM 30 m observations, we investigate the conditions that have triggered this outburst. We find that the previously identified 5 kpc scale radio lobes are probably no longer powered by the active galactic nucleus, which seems to have launched a new ∼20 pc jet on a different axis, likely within the last few hundred years. We estimate the enthalpy of the lobes to be <jats:inline-formula> <jats:tex-math> <?CDATA ${8.48}_{-3.56}^{+6.04}\times {10}^{57}\,\mathrm{erg}$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabf6c6ieqn1.gif" xlink:type="simple" /> </jats:inline-formula>, only sufficient to balance cooling in the surrounding 16 kpc for ∼9 Myr. The properties of the cluster’s intracluster medium (ICM) are similar to those of rapidly cooling nearby clusters, with a low central entropy (8.6<jats:inline-formula> <jats:tex-math> <?CDATA ${}_{-1.4}^{+2.2}$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabf6c6ieqn2.gif" xlink:type="simple" /> </jats:inline-formula> keV cm<jats:sup>2</jats:sup> within 8 kpc), short central cooling time (390<jats:inline-formula> <jats:tex-math> <?CDATA ${}_{-150}^{+170}$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabf6c6ieqn3.gif" xlink:type="simple" /> </jats:inline-formula> Myr), and <jats:italic>t</jats:italic> <jats:sub>cool</jats:sub>/<jats:italic>t</jats:italic> <jats:sub>ff</jats:sub> and <jats:italic>t</jats:italic> <jats:sub>cool</jats:sub>/<jats:italic>t</jats:italic> <jats:sub>eddy</jats:sub> ratios indicative of thermal instability out to ∼45 kpc. Despite previous detection of H<jats:italic>α</jats:italic> emission from the brightest cluster galaxy, our IRAM 30 m observations do not detect CO emission in either the (1–0) or (3–2) transitions. We place 3<jats:italic>σ</jats:italic> limits on the molecular gas mass of <jats:italic>M</jats:italic> <jats:sub>mol</jats:sub> ≤ 7.7 × 10<jats:sup>9</jats:sup> <jats:italic> M</jats:italic> <jats:sub>⊙</jats:sub> and ≤5.6 × 10<jats:sup>9</jats:sup> <jats:italic> M</jats:italic> <jats:sub>⊙</jats:sub> from the two lines respectively. We find indications of a recent minor cluster merger that has left a ∼200 kpc tail of stripped gas in the ICM, and probably induced sloshing motions.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The bulk propagation speed of GeV-energy cosmic rays is limited by frequent scattering off hydromagnetic waves. Most galaxy evolution simulations that account for this confinement assume the gas is fully ionized and cosmic rays are well coupled to Alfvén waves; however, multiphase density inhomogeneities, frequently underresolved in galaxy evolution simulations, induce cosmic-ray collisions and ionization-dependent transport driven by cosmic-ray decoupling and elevated streaming speeds in partially neutral gas. How do cosmic rays navigate and influence such a medium, and can we constrain this transport with observations? In this paper, we simulate cosmic-ray fronts impinging upon idealized, partially neutral clouds and lognormally distributed clumps, with and without ionization-dependent transport. With these high-resolution simulations, we identify cloud interfaces as crucial regions where cosmic-ray fronts can develop a stairstep pressure gradient sufficient to collisionlessly generate waves, overcome ion–neutral damping, and exert a force on the cloud. We find that the acceleration of cold clouds is hindered by only a factor of a few when ionization-dependent transport is included, with additional dependencies on magnetic field strength and cloud dimensionality. We also probe how cosmic rays sample the background gas and quantify collisional losses. Hadronic gamma-ray emission maps are qualitatively different when ionization-dependent transport is included, but the overall luminosity varies by only a small factor, as the short cosmic-ray residence times in cold clouds are offset by the higher densities that cosmic rays sample.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Terrestrial planets with large water inventories are likely ubiquitous and will be among the first Earth-sized planets to be characterized with upcoming telescopes. It has previously been argued that waterworlds—particularly those possessing more than 1% H<jats:sub>2</jats:sub>O—experience limited melt production and outgassing due to the immense pressure overburden of their overlying oceans, unless subject to high internal heating. But an additional, underappreciated obstacle to outgassing on waterworlds is the high solubility of volatiles in high-pressure melts. Here, we investigate this phenomenon and show that volatile solubilities in melts probably prevent almost all magmatic outgassing from waterworlds. Specifically, for Earth-like gravity and oceanic crust composition, oceans or water ice exceeding 10–100 km in depth (0.1–1 GPa) preclude the exsolution of volatiles from partial melt of silicates. This solubility limit compounds the pressure overburden effect as large surface oceans limit both melt production and degassing from any partial melt that is produced. We apply these calculations to Trappist-1 planets to show that, given current mass and radius constraints and implied surface water inventories, Trappist-1f and -1g are unlikely to experience volcanic degassing. While other mechanisms for interior-surface volatile exchange are not completely excluded, the suppression of magmatic outgassing simplifies the range of possible atmospheric evolution trajectories and has implications for interpretation of ostensible biosignature gases, which we illustrate with a coupled model of planetary interior–climate–atmosphere evolution.</jats:p>