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<jats:title>Abstract</jats:title> <jats:p>We present the distance-calibrated spectral energy distribution (SED) of the d/sdL7 SDSS J14162408+1348263A (J1416A) and an updated SED for SDSS J14162408+1348263B (J1416B). We also present the first retrieval analysis of J1416A using the Brewster retrieval code base and the second retrieval of J1416B. We find that the primary is best fit by a nongray cloud opacity with a power-law wavelength dependence but is indistinguishable between the type of cloud parameterization. J1416B is best fit by a cloud-free model, consistent with the results from Line et al. Most fundamental parameters derived via SEDs and retrievals are consistent within 1<jats:italic>σ</jats:italic> for both J1416A and J1416B. The exceptions include the radius of J1416A, where the retrieved radius is smaller than the evolutionary model-based radius from the SED for the deck cloud model, and the bolometric luminosity, which is consistent within 2.5<jats:italic>σ</jats:italic> for both cloud models. The pair’s metallicity and carbon-to-oxygen ratio point toward formation and evolution as a system. By comparing the retrieved alkali abundances while using two opacity models, we are able to evaluate how the opacities behave for the L and T dwarf. Lastly, we find that relatively small changes in composition can drive major observable differences for lower-temperature objects.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>In the universe’s most massive galaxies, active galactic nucleus (AGN) feedback appears to limit star formation. The accumulation of cold gas near the central black hole fuels powerful AGN outbursts, keeping the ambient medium in a state marginally unstable to condensation and formation of cold gas clouds. However, the ability of that mechanism to self-regulate may depend on numerous environmental factors, including the depth of the potential well and the pressure of the surrounding circumgalactic medium (CGM). Here we present a suite of numerical simulations, with halo mass ranging from 2 × 10<jats:sup>12</jats:sup> <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub> to 8 × 10<jats:sup>14</jats:sup> <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>, exploring the dependence of AGN feedback on those environmental factors. We include the spatially extended mass and energy input from the massive galaxy’s old stellar population capable of sweeping gas out of the galaxy if the confining CGM pressure is sufficiently low. Our simulations show that this feedback mechanism is tightly self-regulating in a massive galaxy with a deep central potential and low CGM pressure, permitting only small amounts of multiphase gas to accumulate and allowing no star formation. In a similar-mass galaxy with shallower central potential and greater CGM pressure the feedback mechanism is more episodic, producing extended multiphase gas and allowing small rates of star formation (∼0.1 <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub> yr<jats:sup>−1</jats:sup>). At the low-mass end, the mechanism becomes implausibly explosive, perhaps because the CGM initially has no angular momentum, which would have reduced the amount of condensed gas capable of fueling feedback.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Recent discussions about supernova magnitude evolution have raised doubts about the robustness of the late-universe acceleration. In a previous letter, Huang did a null test of the cosmic acceleration by using a Parameterization based on the cosmic Age (PAge), which covers a broad class of cosmological models including the standard Λ cold dark matter model and its many extensions. In this work, we continue to explore the cosmic expansion history with the PAge approximation. Using baryon acoustic oscillations (<jats:italic>without</jats:italic> a CMB prior on the acoustic scale), gravitational strong lens time delay, and passively evolving early galaxies as cosmic chronometers, we obtain  ≳ 4<jats:italic>σ</jats:italic> detections of cosmic acceleration for both flat and nonflat PAge universes. In the nonflat case, we find a novel ≳3<jats:italic>σ</jats:italic> tension between the spatial curvatures derived from baryon acoustic oscillations and strong lens time delay. Implications and possible systematics are discussed.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We present a large sample of 2.5–38 <jats:italic>μ</jats:italic>m galaxy spectra drawn from a cross-archival comparison in the AKARI–Spitzer Extragalactic Spectral Survey, and investigate a subset of 113 star-forming galaxies with prominent polycyclic aromatic hydrocarbon (PAH) emission spanning a wide range of star formation properties. With AKARI’s extended 2.5–5 <jats:italic>μ</jats:italic>m wavelength coverage, we self-consistently model for the first time <jats:italic>all</jats:italic> PAH emission bands using a modified version of <jats:sc>Pahfit</jats:sc>. We find <jats:italic>L</jats:italic> <jats:sub> <jats:sc>PAH</jats:sc> 3.3</jats:sub>/<jats:italic>L</jats:italic> <jats:sub> <jats:sc>IR</jats:sc> </jats:sub> ∼ 0.1%, and the 3.3 <jats:italic>μ</jats:italic>m PAH feature contributes ∼1.5%–3% to the total PAH power—somewhat less than earlier dust models have assumed. We establish a calibration between 3.3 <jats:italic>μ</jats:italic>m PAH emission and star formation rate, but also find regimes where it loses reliability, including at high luminosity and low metallicity. The 3.4 <jats:italic>μ</jats:italic>m aliphatic emission and a broad plateau feature centered at 3.47 <jats:italic>μ</jats:italic>m are also modeled. As the PAH feature with the shortest wavelength, the one at 3.3 <jats:italic>μ</jats:italic>m is susceptible to attenuation, leading to differences of a factor of ∼3 in the inferred star formation rate at high obscuration with different assumed attenuation geometries. Surprisingly, <jats:italic>L</jats:italic> <jats:sub> <jats:sc>PAH</jats:sc> 3.3</jats:sub>/<jats:italic>L</jats:italic> <jats:sub>Σ <jats:sc>PAH</jats:sc> </jats:sub> shows no sign of decline at high luminosities, and the low-metallicity dwarf galaxy II Zw 40 exhibits an unusually strong 3.3 <jats:italic>μ</jats:italic>m band; both results suggest either that the smallest PAHs are better able to survive under intense radiation fields than presumed, or that PAH emission is shifted to shorter wavelengths in intense and high-energy radiation environments. A photometric surrogate for 3.3 <jats:italic>μ</jats:italic>m PAH luminosity using JWST/NIRCam is provided and found to be highly reliable at low redshift.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Helioseismic inferences of large-scale flows in the solar interior necessitate accounting for the curvature of the Sun, both in interpreting systematic trends introduced in measurements as well as the sensitivity kernel that relates photospheric measurements to subsurface flow velocities. Additionally, the inverse problem that relates measurements to model parameters needs to be well posed to obtain accurate inferences, which necessitates a sparse set of parameters. Further, the sensitivity functions need to be computationally easy to evaluate. In this work, we address these issues by demonstrating that the sensitivity kernels for flow velocities may be computed efficiently on the basis of vector spherical harmonics. We are also able to account for line-of-sight projections in Doppler measurements, as well as center-to-limb differences in line-formation heights. We show that given the assumed spherical symmetry of the background model, it is often cheap to simultaneously compute the kernels for pairs of observation points that are related by a rotation. Such an approach is therefore particularly well suited to inverse problems for large-scale flows in the Sun, such as meridional circulation.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We report the observational findings of the Sh2-112 H <jats:sc>ii</jats:sc> region by using the multiwavelength data analysis ranging from optical to radio wavelengths. This region is powered by the massive O8V-type star BD +45 3216. The surface density distribution and minimum spanning tree analyses of the young stellar object (YSO) candidates in the region reveal their groupings toward the western periphery of the H <jats:sc>ii</jats:sc> region. A GMRT radio continuum emission peak is found toward the northwest boundary of the H <jats:sc>ii</jats:sc> region and is investigated as a compact/ultracompact H <jats:sc>ii</jats:sc> region candidate powered by a B0–B0.5-type star. Toward the southwest direction, a prominent curved rim-like structure is found in the H<jats:italic>α</jats:italic> image and GMRT radio continuum maps, where the H<jats:sub>2</jats:sub> and <jats:sup>13</jats:sup>CO emission is also observed. These results suggest the existence of the ionized boundary layer (IBL) on the surface of the molecular cloud. This IBL is found to be overpressured with respect to the internal pressure of the surrounding molecular cloud. This implies that the shocks are propagating/propagated into the molecular cloud, and the young stars identified within it are likely triggered due to the massive star. It is also found that this region is ionization-bounded toward the west and density-bounded toward the east. Based on the distribution of the ionized gas, molecular material, and YSO candidates, we propose that the Sh2-112 H <jats:sc>ii</jats:sc> region is a good candidate for the blister-type H <jats:sc>ii</jats:sc> region that has been evolved on the surface of a cylindrical molecular cloud.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The physical mechanism driving mass ejection during a nova eruption is still poorly understood. Possibilities include ejection in a single ballistic event, a common-envelope interaction, a continuous wind, or some combination of these processes. Here, we present a study of 12 Galactic novae, for which we have premaximum high-resolution spectroscopy. All 12 novae show the same spectral evolution. Before optical peak, they show a slow P Cygni component. After peak, a fast component quickly arises, while the slow absorption remains superimposed on top of it, implying the presence of at least two physically distinct flows. For novae with high-cadence monitoring, a third, intermediate-velocity component is also observed. These observations are consistent with a scenario where the slow component is associated with the initial ejection of the accreted material and the fast component with a radiation-driven wind from the white dwarf. When these flows interact, the slow flow is swept up by the fast flow, producing the intermediate component. These colliding flows may produce the <jats:italic>γ</jats:italic>-ray emission observed in some novae. Our spectra also show that the transient heavy-element absorption lines seen in some novae have the same velocity structure and evolution as the other lines in the spectrum, implying an association with the nova ejecta rather than a preexisting circumbinary reservoir of gas or material ablated from the secondary. While this basic scenario appears to qualitatively reproduce multiwavelength observations of classical novae, substantial theoretical and observational work is still needed to untangle the rich diversity of nova properties.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Thanks to the observational and simulation works, the importance of the nonideal magnetohydrodynamic (MHD) effects, i.e., Hall effect, ohmic resistivity, and ambipolar diffusion, have been well established at various stages of cloud evolution. To get a comparison between the Hall effect with other effects, we aim to model the time evolution of a rotating filamentary molecular cloud during the isothermal/polytropic collapse phase in the presence of the Hall drift. Three components of the velocity vector are investigated when the angular momentum is fully coupled with the magnetic field at large radii of a filament. For this purpose, the nonideal MHD equations in the self-similar formalism are considered at large radii of a molecular cloud where the magnetic field evolution is affected by the Hall drift. Then, the connection between the self-similar approach with the observational data from the filamentary clouds is examined to get a realistic model. Due to the existence of Hall drift, the significant changes on the rotation of the cloud can be seen when the cloud switches from the isothermal collapse phase to the polytropic collapse phase. Also, the results of this model are useful in the study of the multiple star formation process as well as the initial conditions for driving the outflows during the collapse of the filamentary clouds. Finally, we found that there are some conditions for the comparability of the Hall effect with the ambipolar diffusion in the outer regions of the clouds.</jats:p>