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<jats:title>Abstract</jats:title> <jats:p>Recent developments in (sub)millimeter facilities have drastically changed the amount of information obtained from extragalactic spectral scans. In this paper, we present a feature extraction technique using principal component analysis (PCA) applied to arcsecond-resolution (1.″0–2.″0 = 72–144 pc) spectral scan data sets for the nearby type-2 Seyfert galaxy NGC 1068, using Band 3 of the Atacama Large Millimeter/submillimeter Array. We apply PCA to 16 well-detected molecular line intensity maps convolved to a common 150 pc resolution. In addition, we include the [S <jats:sc>iii</jats:sc>]/[S <jats:sc>ii</jats:sc>] line ratio and [C <jats:sc>i</jats:sc>] <jats:sup>3</jats:sup> <jats:italic>P</jats:italic> <jats:sub>1</jats:sub>–<jats:sup>3</jats:sup> <jats:italic>P</jats:italic> <jats:sub>0</jats:sub> maps in the literature, both of whose distributions show a remarkable resemblance to that of a kiloparsec-scale biconical outflow from the central active galactic nucleus. We identify two prominent features: (1) central concentration at the circumnuclear disk (CND) and (2) two peaks across the center that coincide with the biconical outflow peaks. The concentrated molecular lines in the CND are mostly high-dipole molecules (e.g., H<jats:sup>13</jats:sup>CN, HC<jats:sub>3</jats:sub>N, and HCN). Line emissions from molecules known to be enhanced in an irradiated interstellar medium, CN, C<jats:sub>2</jats:sub>H, and HNC, show similar concentrations and extended components along the bicone, suggesting that molecule dissociation is a dominant chemical effect of the cold molecular outflow of this galaxy. Although further investigation should be made, this scenario is consistent with the faintness or absence of emission lines from CO isotopologues, CH<jats:sub>3</jats:sub>OH, and N<jats:sub>2</jats:sub>H<jats:sup>+</jats:sup> in the outflow, which are easily destroyed by dissociating photons and electrons.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We formulate a parameterized model of embedded protostellar disks and test its ability to estimate disk properties by fitting dust-continuum observations. The main physical assumptions of our model are motivated by a recent theoretical study of protostellar disk formation; these assumptions include that the disk should be marginally gravitationally unstable, and that the dominant dust heating mechanism is internal accretion heating instead of external protostellar irradiation. These assumptions allow our model to estimate reliably the disk mass even when the observed emission is optically thick and to determine self-consistent disk (dust) temperatures. Using our model to fit multiwavelength observations of 163 disks in the VANDAM Orion survey, we find that the majority (57%) of this sample can be fit well by our model. Using our model, we produce new estimates of Orion protostellar disk properties. We find that these disks are generally warm and massive, with a typical star-to-disk mass ratio <jats:inline-formula> <jats:tex-math> <?CDATA ${M}_{{\rm{d}}}/{M}_{\star }={ \mathcal O }(1)$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">d</mml:mi> </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>=</mml:mo> <mml:mi mathvariant="italic"></mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:mn>1</mml:mn> <mml:mo stretchy="false">)</mml:mo> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac7b94ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> in Class 0/I. We also discuss why our estimates differ from those in previous studies and the implications of our results on disk evolution and fragmentation.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We study a step-like transition in the value of the effective Planck mass (or effective gravitational constant) on cosmological scales prior to recombination. We employ cosmic microwave background, baryon acoustic oscillations, and Type Ia supernova data and find they are sufficient to strongly constrain our implementation of the effective field theory of dark energy and modified gravity, used to model the transition, to a limited parameter space. The data prefer a ∼5% shift in the value of the effective Planck mass (&lt;10% at 2<jats:italic>σ</jats:italic>) prior to recombination. This Transitional Planck Mass (TPM) model is free to undergo its transition at any point over multiple decades of scale factor prior to recombination, <jats:inline-formula> <jats:tex-math> <?CDATA ${\mathrm{log}}_{10}(a)=-{5.32}_{-0.72}^{+0.96}$?> </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:mo stretchy="false">(</mml:mo> <mml:mi>a</mml:mi> <mml:mo stretchy="false">)</mml:mo> <mml:mo>=</mml:mo> <mml:mo>−</mml:mo> <mml:msubsup> <mml:mrow> <mml:mn>5.32</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.72</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.96</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac80fdieqn1.gif" xlink:type="simple" /> </jats:inline-formula> (68% confidence level). This lowers the sound horizon at last scattering, which increases the Hubble constant to 71.09 ± 0.75 km s<jats:sup>−1</jats:sup> Mpc<jats:sup>−1</jats:sup> with a combination of local measurements as prior and to <jats:inline-formula> <jats:tex-math> <?CDATA ${69.22}_{-0.86}^{+0.67}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>69.22</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.86</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.67</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac80fdieqn2.gif" xlink:type="simple" /> </jats:inline-formula> km s<jats:sup>−1</jats:sup> Mpc<jats:sup>−1</jats:sup> when the prior is excluded. The TPM model improves <jats:italic>χ</jats:italic> <jats:sup>2</jats:sup> with respect to ΛCDM by Δ<jats:italic>χ</jats:italic> <jats:sup>2</jats:sup> = −23.72 with the <jats:italic>H</jats:italic> <jats:sub>0</jats:sub> prior and Δ<jats:italic>χ</jats:italic> <jats:sup>2</jats:sup> = −4.8 without the prior. The model allows for both <jats:italic>H</jats:italic> <jats:sub>0</jats:sub> &gt; 70 kms<jats:sup>−1</jats:sup> Mpc<jats:sup>−1</jats:sup> and <jats:italic>S</jats:italic> <jats:sub>8</jats:sub> &lt; 0.80 simultaneously with lower values of <jats:italic>S</jats:italic> <jats:sub>8</jats:sub> due to a reduction in the matter density Ω<jats:sub> <jats:italic>m</jats:italic> </jats:sub> to offset the increase in <jats:italic>H</jats:italic> <jats:sub>0</jats:sub> relative to ΛCDM. While this is a particular modified gravity model, studying other variants of modified gravity may be a productive path for potentially resolving cosmological tensions while avoiding the need for a cosmological constant.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We study the initiation of thermonuclear detonations in tidally disrupted white dwarf stars by intermediate-mass (10<jats:sup>3</jats:sup> <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>) black holes. The length scales required to resolve the initiation mechanism are not easily reached in 3D, so instead we have devised 2D proxy models, which, together with a logarithmic gridding strategy, can adequately capture detonation wave fronts as material undergoes simultaneous compression and stretching from tidal forces. We consider 0.15 and 0.6 <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub> white dwarf stars parameterized by tidal strengths in the range <jats:italic>β</jats:italic> = 4–23. High spatial resolution elucidates the manner and conditions leading to thermonuclear detonation, linking the initiation sequence to stellar composition and tidal strength. All of our models suffer sustained detonations triggered by a combination of adiabatic compression, mild thermonuclear preconditioning, and collisional heating, in degrees depending primarily on tidal strength. We find that many diagnostics, such as temperature, total released energy, and iron-group products, are fairly well converged (better than 10%) at resolutions below 10 km along the scale height of the orbital plane. The exceptions are intermediate-mass transients like calcium, which remain uncertain up to factors of 2, even at 1 km resolution.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Mounting evidence suggests that luminous fast blue optical transients (LFBOTs) are powered by a compact object, launching an asymmetric and fast outflow responsible for the radiation observed in the ultraviolet, optical, infrared, radio, and X-ray bands. Proposed scenarios aiming to explain the electromagnetic emission include an inflated cocoon, surrounding a jet choked in the extended stellar envelope. Alternatively, the observed radiation may arise from the disk formed by the delayed merger of a black hole with a Wolf–Rayet star. We explore the neutrino production in these scenarios, i.e., internal shocks in a choked jet and interaction between the outflow and the circumstellar medium (CSM). If observed on axis, the choked jet provides the dominant contribution to the neutrino fluence. Intriguingly, the IceCube upper limit on the neutrino emission inferred from the closest LFBOT, AT2018cow, excludes a region of the parameter space otherwise allowed by electromagnetic observations. After correcting for the Eddington bias on the observation of cosmic neutrinos, we conclude that the emission from an on-axis choked jet and CSM interaction is compatible with the detection of two track-like neutrino events observed by the IceCube Neutrino Observatory in coincidence with AT2018cow, and otherwise considered to be of atmospheric origin. While the neutrino emission from LFBOTs does not constitute the bulk of the diffuse background of neutrinos observed by IceCube, the detection prospects of nearby LFBOTs with IceCube and the upcoming IceCube-Gen2 are encouraging. Follow-up neutrino searches will be crucial for unraveling the mechanism powering this emergent transient class.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The origin of organic compounds detected in meteorites and comets, some of which could have served as precursors of life on Earth, remains an open question. The aim of the present study is to make one more step in revealing the nature and composition of organic materials of extraterrestrial particles by comparing infrared spectra of laboratory-made refractory organic residues to spectra of cometary particles returned by the Stardust mission, interplanetary dust particles, and meteorites. Our results reinforce the idea of a pathway for the formation of refractory organics through energetic and thermal processing of molecular ices in the solar nebula. There is also the possibility that some of the organic material had formed already in the parental molecular cloud before it entered the solar nebula. The majority of the IR “organic” bands of the studied extraterrestrial particles can be reproduced in the spectra of the laboratory organic residues. We confirm the detection of water, nitriles, hydrocarbons, and carbonates in extraterrestrial particles and link it to the formation location of the particles in the outer regions of the solar nebula. To clarify the genesis of the species, high-sensitivity observations in combination with laboratory measurements like those presented in this paper are needed. Thus, this study presents one more piece of the puzzle of the origin of water and organic compounds on Earth and motivation for future collaborative laboratory and observational projects.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The radio galaxy M87 is the central dominant galaxy of the Virgo Cluster. Very high-energy (VHE, ≳0.1 TeV) emission from M87 has been detected by imaging air Cherenkov telescopes. Recently, marginal evidence for VHE long-term emission has also been observed by the High Altitude Water Cherenkov Observatory, a gamma-ray and cosmic-ray detector array located in Puebla, Mexico. The mechanism that produces VHE emission in M87 remains unclear. This emission originates in its prominent jet, which has been spatially resolved from radio to X-rays. In this paper, we construct a spectral energy distribution from radio to gamma rays that is representative of the nonflaring activity of the source, and in order to explain the observed emission, we fit it with a lepto-hadronic emission model. We found that this model is able to explain nonflaring VHE emission of M87 as well as an orphan flare reported in 2005.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The origins of the GeV gamma rays from nearby radio galaxies are unknown. Hadronic emission from magnetically arrested disks (MADs) around central black holes is proposed as a possible scenario. Particles are accelerated in a MAD by magnetic reconnection and stochastic turbulence acceleration. We pick out the 15 brightest radio galaxies in the GeV band from The Fourth Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope, Data Release 2 and apply the MAD model. We find that we can explain the data in the GeV bands by the MAD model if the accretion rate is lower than 0.1% of the Eddington rate. For a higher accretion rate, GeV gamma rays are absorbed by two-photon interaction due to copious low-energy photons. If we assume another proposed prescription of the electron-heating rate by magnetic reconnection, the MAD model fails to reproduce the GeV data for the majority of our sample. This indicates that the electron-heating rate is crucial. We also apply the MAD model to Sagittarius A* (Sgr A*) and find that GeV gamma rays observed at the Galactic center do not come from the MAD of Sgr A*. We estimate the cosmic ray (CR) intensity from Sgr A*, but it is too low to explain the high-energy CR intensity on Earth.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We have reviewed the first year of observations of the Solar X-ray Monitor (XSM) on board Chandrayaan-2 and the available multiwavelength observations to complement the XSM data, focusing on the Solar Dynamics Observatory AIA and Hinode XRT and EIS observations. XSM has provided disk-integrated solar spectra in the 1–15 keV energy range, observing a large number of microflares. We present an analysis of multiwavelength observations of AR 12759 during its disk crossing. We use a new radiometric calibration of EIS to find that the quiescent active region (AR) core emission during its disk crossing has a distribution of temperatures and chemical abundances that does not change significantly over time. An analysis of the XSM spectra confirms the EIS results and shows that the low first ionization potential (FIP) elements are enhanced compared to their photospheric values. The frequent microflares produced by the AR did not affect the abundances of the quiescent AR core. We also present an analysis of one of the flares it produced, SOL2020-04-09T09:32. The XSM analysis indicates isothermal temperatures reaching 6 MK. The lack of very high-<jats:italic>T</jats:italic> emission is confirmed by AIA. We find excellent agreement between the observed XSM spectrum and the one predicted using an AIA DEM analysis. In contrast, the XRT Al-poly/Be-thin filter ratio gives lower temperatures for the quiescent and flaring phases. We show that this is due to the sensitivity of this ratio to low temperatures, as the XRT filter ratios predicted with a DEM analysis based on EIS and AIA give values in good agreement with the observed ones.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Two ultra-diffuse galaxies in the same group, NGC1052-DF2 and NGC1052-DF4, have been found to have little or no dark matter and to host unusually luminous globular cluster populations. Such low-mass diffuse objects in a group environment are easily disrupted and are expected to show evidence of tidal distortions. In this work, we present deep new imaging of the NGC1052 group, obtained with the Dragonfly Telephoto Array, to test this hypothesis. We find that both galaxies show strong position-angle twists and are significantly more elongated at their outskirts than in their interiors. The group’s central massive elliptical NGC1052 is the most likely source of these tidal disturbances. The observed distortions imply that the galaxies have a low total mass or are very close to NGC1052. Considering constraints on the galaxies’ relative distances, we infer that the dark matter halo masses of these galaxies cannot be much greater than their stellar masses. Calculating pericenters from the distortions, we find that the galaxies are on highly elliptical orbits, with a ratio of pericenter to present-day radius <jats:italic>R</jats:italic> <jats:sub>peri</jats:sub>/<jats:italic>R</jats:italic> <jats:sub>0</jats:sub> ∼ 0.1 if the galaxies are dark matter–free and <jats:italic>R</jats:italic> <jats:sub>peri</jats:sub>/<jats:italic>R</jats:italic> <jats:sub>0</jats:sub> ∼ 0.01 if they have a normal dark halo. Our findings provide strong evidence, independent of kinematic constraints, that both galaxies are dark matter–deficient. Furthermore, the similarity of the tidal features in NGC1052-DF2 and NGC1052-DF4 strongly suggests that they arose at comparable distances from NGC1052. In Appendix A, we describe <jats:monospace>sbcontrast</jats:monospace>, a robust method for determining the surface brightness limits of images.</jats:p>