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<jats:title>Abstract</jats:title> <jats:p>We perform the first three-dimensional radiation hydrodynamical simulations that investigate the growth of intermediate-mass BHs (IMBHs) embedded in massive self-gravitating, dusty nuclear accretion disks. We explore the dependence of mass accretion efficiency on the gas metallicity <jats:italic>Z</jats:italic> and mass injection at super-Eddington accretion rates from the outer galactic disk <jats:inline-formula> <jats:tex-math> <?CDATA ${\dot{M}}_{\mathrm{in}}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mover accent="true"> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>̇</mml:mo> </mml:mrow> </mml:mover> </mml:mrow> <mml:mrow> <mml:mi>in</mml:mi> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabcfc2ieqn1.gif" xlink:type="simple" /> </jats:inline-formula>, and we find that the central BH can be fed at rates exceeding the Eddington rate only when the dusty disk becomes sufficiently optically thick to ionizing radiation. In this case, mass outflows from the disk owing to photoevaporation are suppressed, and thus a large fraction (≳40%) of the mass injection rate can feed the central BH. The conditions are expressed as <jats:inline-formula> <jats:tex-math> <?CDATA ${\dot{M}}_{\mathrm{in}}\gt 2.2\times {10}^{-1}\,{\text{}}{M}_{\odot }$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mover accent="true"> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>̇</mml:mo> </mml:mrow> </mml:mover> </mml:mrow> <mml:mrow> <mml:mi>in</mml:mi> </mml:mrow> </mml:msub> <mml:mo>&gt;</mml:mo> <mml:mn>2.2</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> <mml:mspace width="0.25em" /> <mml:mtext mathvariant="italic" /> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>⊙</mml:mo> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabcfc2ieqn2.gif" xlink:type="simple" /> </jats:inline-formula> <jats:inline-formula> <jats:tex-math> <?CDATA ${\mathrm{yr}}^{-1}{(1+Z/{10}^{-2}{\text{}}{Z}_{\odot })}^{-1}({c}_{{\rm{s}}}/10$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msup> <mml:mrow> <mml:mi>yr</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> <mml:msup> <mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:mn>1</mml:mn> <mml:mo>+</mml:mo> <mml:mi>Z</mml:mi> <mml:mrow> <mml:mo stretchy="true">/</mml:mo> </mml:mrow> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> <mml:mspace width="0.25em" /> <mml:mtext mathvariant="italic" /> <mml:msub> <mml:mrow> <mml:mi>Z</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>⊙</mml:mo> </mml:mrow> </mml:msub> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> <mml:mo stretchy="false">(</mml:mo> <mml:msub> <mml:mrow> <mml:mi>c</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">s</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy="true">/</mml:mo> </mml:mrow> <mml:mn>10</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabcfc2ieqn3.gif" xlink:type="simple" /> </jats:inline-formula> <jats:inline-formula> <jats:tex-math> <?CDATA $\mathrm{km}\,{{\rm{s}}}^{-1})$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>km</mml:mi> <mml:mspace width="0.25em" /> <mml:msup> <mml:mrow> <mml:mi mathvariant="normal">s</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> <mml:mo stretchy="false">)</mml:mo> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabcfc2ieqn4.gif" xlink:type="simple" /> </jats:inline-formula>, where <jats:italic>c</jats:italic> <jats:sub>s</jats:sub> is the sound speed in the gaseous disk. With increasing numerical resolution, vigorous disk fragmentation reduces the disk surface density, and dynamical heating by formed clumps makes the disk geometrically thicker. As a result, the photoevaporative mass-loss rate rises and thus the critical injection rate increases for fixed metallicity. This process enables super-Eddington growth of BHs until the BH mass reaches <jats:inline-formula> <jats:tex-math> <?CDATA ${M}_{\mathrm{BH}}\sim {10}^{7\mbox{--}8}\,{\text{}}{M}_{\odot }$?> </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>BH</mml:mi> </mml:mrow> </mml:msub> <mml:mo>∼</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mn>7</mml:mn> <mml:mo>–</mml:mo> <mml:mn>8</mml:mn> </mml:mrow> </mml:msup> <mml:mspace width="0.25em" /> <mml:mtext mathvariant="italic" /> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>⊙</mml:mo> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabcfc2ieqn5.gif" xlink:type="simple" /> </jats:inline-formula>, depending on the properties of the host dark-matter halo and metal-enrichment history. In the assembly of protogalaxies, seed BHs that form in overdense regions with a mass variance of 3–4<jats:italic>σ</jats:italic> at <jats:italic>z</jats:italic> ∼ 15–20 are able to undergo short periods of rapid growth and transit into the Eddington-limited growth phase afterward to be supermassive BHs observed at <jats:italic>z</jats:italic> &gt; 6–7.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We assemble a large set of 2–10 GHz radio flux density measurements and upper limits of 294 different supernovae (SNe), from the literature and our own and archival data. Only 31% of SNe were detected. We characterize the SN radio lightcurves near the peak using a two-parameter model, with <jats:italic>t</jats:italic> <jats:sub>pk</jats:sub> being the time to rise to a peak and <jats:italic>L</jats:italic> <jats:sub>pk</jats:sub> the spectral luminosity at that peak. Over all SNe in our sample at <jats:italic>D</jats:italic> &lt; 100 Mpc, we find that <jats:italic>t</jats:italic> <jats:sub>pk</jats:sub> = 10<jats:sup>1.7±0.9</jats:sup> days and that <jats:italic>L</jats:italic> <jats:sub>pk</jats:sub> = 10<jats:sup>25.5±1.6</jats:sup> erg s<jats:sup>−1</jats:sup> Hz<jats:sup>−1</jats:sup>, and therefore that generally 50% of SNe will have <jats:italic>L</jats:italic> <jats:sub>pk</jats:sub> &lt; 10<jats:sup>25.5</jats:sup> erg s<jats:sup>−1</jats:sup> Hz<jats:sup>−1</jats:sup>. These <jats:italic>L</jats:italic> <jats:sub>pk</jats:sub> values are ∼30 times lower than those for only detected SNe. Types Ib/c and II (excluding IIn’s) have similar mean values of <jats:italic>L</jats:italic> <jats:sub>pk</jats:sub> but the former have a wider range, whereas Type IIn SNe have ∼10 times higher values with <jats:italic>L</jats:italic> <jats:sub>pk</jats:sub> = 10<jats:sup>26.5±1.1</jats:sup> erg s<jats:sup>−1</jats:sup> Hz<jats:sup>−1</jats:sup>. As for <jats:italic>t</jats:italic> <jats:sub>pk</jats:sub>, Type Ib/c have <jats:italic>t</jats:italic> <jats:sub>pk</jats:sub> of only 10<jats:sup>1.1±0.5</jats:sup> days while Type II have <jats:italic>t</jats:italic> <jats:sub>pk</jats:sub> = 10<jats:sup>1.6±1.0</jats:sup> and Type IIn the longest timescales with <jats:italic>t</jats:italic> <jats:sub>pk</jats:sub> = 10<jats:sup>3.1±0.7</jats:sup> days. We also estimate the distribution of progenitor mass-loss rates, <jats:inline-formula> <jats:tex-math> <?CDATA $\dot{M}$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabccd9ieqn1.gif" xlink:type="simple" /> </jats:inline-formula>, and find that the mean and standard deviation of <jats:inline-formula> <jats:tex-math> <?CDATA ${\mathrm{log}}_{10}(\dot{M}/[{M}_{\odot }\,{\mathrm{yr}}^{-1}])$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabccd9ieqn2.gif" xlink:type="simple" /> </jats:inline-formula> are −5.4 ± 1.2 (assuming <jats:italic>v</jats:italic> <jats:sub>wind</jats:sub> = 1000 km s<jats:sup>−1</jats:sup>) for Type Ib/c SNe, and −6.9 ± 1.4 (assuming <jats:italic>v</jats:italic> <jats:sub>wind</jats:sub> = 10 km s<jats:sup>−1</jats:sup>) for Type II SNe excluding Type IIn.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>In this contribution, we achieve the primary goal of the active galactic nucleus (AGN) <jats:sc>STORM</jats:sc> campaign by recovering velocity–delay maps for the prominent broad emission lines (Ly<jats:italic>α</jats:italic>, C <jats:sc>iv</jats:sc>, He <jats:sc>ii</jats:sc>, and H<jats:italic>β</jats:italic>) in the spectrum of NGC 5548. These are the most detailed velocity–delay maps ever obtained for an AGN, providing unprecedented information on the geometry, ionization structure, and kinematics of the broad-line region. Virial envelopes enclosing the emission-line responses show that the reverberating gas is bound to the black hole. A stratified ionization structure is evident. The He <jats:sc>ii</jats:sc> response inside 5–10 lt-day has a broad single-peaked velocity profile. The Ly<jats:italic>α</jats:italic>, C <jats:sc>iv</jats:sc>, and H<jats:italic>β</jats:italic> responses extend from inside 2 to outside 20 lt-day, with double peaks at ±2500 km s<jats:sup>−1</jats:sup> in the 10–20 lt-day delay range. An incomplete ellipse in the velocity–delay plane is evident in H<jats:italic>β</jats:italic>. We interpret the maps in terms of a Keplerian disk with a well-defined outer rim at <jats:italic>R</jats:italic> = 20 lt-day. The far-side response is weaker than that from the near side. The line-center delay <jats:inline-formula> <jats:tex-math> <?CDATA $\tau =(R/c)(1-\sin i)\approx 5$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>τ</mml:mi> <mml:mo>=</mml:mo> <mml:mo stretchy="false">(</mml:mo> <mml:mi>R</mml:mi> <mml:mrow> <mml:mo stretchy="true">/</mml:mo> </mml:mrow> <mml:mi>c</mml:mi> <mml:mo stretchy="false">)</mml:mo> <mml:mo stretchy="false">(</mml:mo> <mml:mn>1</mml:mn> <mml:mo>−</mml:mo> <mml:mi>sin</mml:mi> <mml:mi>i</mml:mi> <mml:mo stretchy="false">)</mml:mo> <mml:mo>≈</mml:mo> <mml:mn>5</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabce60ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> days gives the inclination <jats:italic>i</jats:italic> ≈ 45°. The inferred black hole mass is <jats:italic>M</jats:italic> <jats:sub>BH</jats:sub> ≈ 7 × 10<jats:sup>7</jats:sup> <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>. In addition to reverberations, the fit residuals confirm that emission-line fluxes are depressed during the “BLR Holiday” identified in previous work. Moreover, a helical “Barber-Pole” pattern, with stripes moving from red to blue across the C <jats:sc>iv</jats:sc> and Ly<jats:italic>α</jats:italic> line profiles, suggests azimuthal structure rotating with a 2 yr period that may represent precession or orbital motion of inner-disk structures casting shadows on the emission-line region farther out.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We study the relationship between molecular gas and dust in the California Molecular Cloud over an unprecedented dynamic range of cloud depth (<jats:italic>A</jats:italic> <jats:sub>V</jats:sub> = 3–60 mag). We compare deep Herschel-based measurements of dust extinction with observations of the <jats:sup>12</jats:sup>CO, <jats:sup>13</jats:sup>CO, and C<jats:sup>18</jats:sup>O <jats:italic>J</jats:italic> = 2 − 1 lines on sub-parsec scales across the cloud. We directly measure the ratio of CO integrated intensity to dust extinction to derive the CO <jats:italic>X</jats:italic>-factor at over 10<jats:sup>5</jats:sup> independent locations in the cloud. Confirming an earlier study, we find that no single <jats:sup>12</jats:sup>CO <jats:italic>X</jats:italic>-factor can characterize the molecular gas in the cold (<jats:italic>T</jats:italic> <jats:sub>dust</jats:sub> ≤ 20) regions of the cloud that account for most of its mass. We are able to derive a single-valued <jats:italic>X</jats:italic>-factor for all three CO isotopologues in the warm (<jats:italic>T</jats:italic> <jats:sub>dust</jats:sub> &gt; 25 K) material that is spatially coincident with an H <jats:sc>ii</jats:sc> region surrounding the star LkH<jats:italic>α</jats:italic> 101. We derive the LTE CO column densities for <jats:sup>13</jats:sup>CO and C<jats:sup>18</jats:sup>O since we find both lines are relatively optically thin. In the warm cloud material, CO is completely in the gas phase and we are able to recover the total <jats:sup>13</jats:sup>CO and C<jats:sup>18</jats:sup>O abundances. Using CO abundances and deep Herschel observations, we measure lower bounds to the freeze-out of CO onto dust across the whole cloud, finding some regions having CO depleted by a factor of &gt;20. We construct the first maps of depletion that span the extent of a giant molecular cloud. Using these maps we identify 75 depletion-defined cores and discuss their physical nature.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>In this work, we report on observations with the Neutron Star Interior Composition Explorer of the known neutron star X-ray transient XTE J1739–285. We observed the source in 2020 February and March, finding it in a highly active bursting state. Across a 20 day period, we detected 32 thermonuclear X-ray bursts, with an average burst recurrence time of <jats:inline-formula> <jats:tex-math> <?CDATA ${2.0}_{-0.3}^{+0.4}\,\mathrm{hr}$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabd54bieqn1.gif" xlink:type="simple" /> </jats:inline-formula>. A timing and spectral analysis of the ensemble of X-ray bursts reveals homogeneous burst properties, evidence for short-recurrence time bursts, and the detection of a 386.5 Hz burst oscillation candidate. The latter is especially notable, given that a previous study of this source claimed a 1122 Hz burst oscillation candidate. We did not find any evidence of variability near 1122 Hz and instead find that the 386.5 Hz oscillation is the more prominent signal of the two burst oscillation candidates. Hence, we conclude it is unlikely that XTE J1739–285 has a submillisecond rotation period.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We derive dynamical parameters for a large sample of 446 <jats:italic>r</jats:italic>-process-enhanced (RPE) metal-poor stars in the halo and disk systems of the Milky Way, based on data releases from the <jats:italic>R</jats:italic>-Process Alliance, supplemented by additional literature samples. This sample represents more than a 10-fold increase in size relative to that previously considered by Roederer et al. and, by design, covers a larger range of <jats:italic>r</jats:italic>-process-element enrichment levels. We test a number of clustering analysis methods on the derived orbital energies and other dynamical parameters for this sample, ultimately deciding on application of the <jats:monospace>HDBSCAN</jats:monospace> algorithm, which obtains 30 individual chemodynamically tagged groups (CDTGs); 21 contain between 3 and 5 stars, and 9 contain between 6 and 12 stars. Even though the clustering was performed solely on the basis of their dynamical properties, the stars in these CDTGs exhibit <jats:italic>statistically significant similarities</jats:italic> in their metallicity ([Fe/H]), carbonicity ([C/Fe]), and neutron-capture element ratios ([Sr/Fe], [Ba/Fe], and [Eu/Fe]). These results demonstrate that the RPE stars in these CDTGs have likely experienced common chemical-evolution histories, presumably in their parent satellite galaxies or globular clusters, prior to being disrupted into the Milky Way’s halo. We also confirm the previous claim that the orbits of the RPE stars preferentially exhibit pericentric distances that are substantially lower than the present distances of surviving ultrafaint dwarf and canonical dwarf spheroidal galaxies, consistent with the disruption hypothesis. The derived dynamical parameters for several of our CDTGs indicate their association with previously known substructures, dynamically tagged groups, and RPE groups.</jats:p>