Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title> <jats:p>One of the key properties of any binary is its viewing angle (i.e., inclination), <jats:italic>θ</jats:italic> <jats:sub>obs</jats:sub>. In binary neutron star (BNS) mergers it is of special importance due to the role that it plays in the measurement of the Hubble constant, <jats:italic>H</jats:italic> <jats:sub>0</jats:sub>. The opening angle of the jet that these mergers launch, <jats:italic>θ</jats:italic> <jats:sub> <jats:italic>j</jats:italic> </jats:sub>, is also of special interest. Following the detection of the first BNS merger, GW170817, there were numerous attempts to estimate these angles using the afterglow light curve, finding a wide range of values. Here we provide a simple formula for the ratio <jats:italic>θ</jats:italic> <jats:sub>obs</jats:sub>/<jats:italic>θ</jats:italic> <jats:sub> <jats:italic>j</jats:italic> </jats:sub> based on the afterglow light curve and show that this is the only quantity that can be determined from the light curve alone. Our result explains the inconsistency of the values found by the various studies of GW170817 that were largely driven by the different priors taken in each study. Among the additional information that can be used to estimate <jats:italic>θ</jats:italic> <jats:sub>obs</jats:sub> and <jats:italic>θ</jats:italic> <jats:sub> <jats:italic>j</jats:italic> </jats:sub>, the most useful is a VLBI measurement of the afterglow image superluminal motion. An alternative is an identification of the afterglow transition to the subrelativistic phase. These observations are possible only for mergers observed at small viewing angles, whose afterglow is significantly brighter than the detector’s threshold. We discuss the implications of these results to measurements of <jats:italic>H</jats:italic> <jats:sub>0</jats:sub> using GW observations. We show that while the viewing angle will be measured only in a small fraction of future BNS mergers, it can significantly reduce the uncertainty in <jats:italic>H</jats:italic> <jats:sub>0</jats:sub> in each one of these events, possibly to a level of 4%–5%.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Over 4000 exoplanets have been identified and thousands of candidates are to be confirmed. The relations between the characteristics of these planetary systems and the kinematics, Galactic components, and ages of their host stars have yet to be well explored. To address these questions, we conduct a research project, dubbed Planets Across Space and Time (PAST). To do this, one of the key steps is to accurately characterize the planet host stars. In this paper, Paper I of the PAST series, we revisit the kinematic method for classification of Galactic components and extend the applicable range of velocity ellipsoid from ∼100 pc to ∼1500 pc from the Sun in order to cover most known planet hosts. Furthermore, we revisit the age–velocity dispersion relation (AVR), which allows us to derive kinematic ages with a typical uncertainty of 10–20% for an ensemble of stars. Applying the above revised methods, we present a catalog of kinematic properties (i.e., Galactic positions, velocities, and the relative membership probabilities among the thin disk, thick disk, Hercules stream, and the halo) as well as other basic stellar parameters for 2174 host stars of 2872 planets by combining data from Gaia, LAMOST, APOGEE, RAVE, and the NASA exoplanet archive. The revised kinematic method and AVR, as well as the stellar catalog of kinematic properties and ages, lay the foundation for future studies of exoplanets in space and time in the Galactic context.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We present the results of a search for MeV-scale electron antineutrino events in KamLAND coincident with the 60 gravitational wave events/candidates reported by the LIGO/Virgo collaboration during their second and third observing runs. We find no significant coincident signals within a ±500 s timing window from each gravitational wave and present 90% C.L. upper limits on the electron antineutrino fluence between 10<jats:sup>8</jats:sup> and 10<jats:sup>13</jats:sup> cm<jats:sup>−2</jats:sup> for neutrino energies in the energy range of 1.8–111 MeV.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>In order to shed light on how galactic properties depend on the intergalactic medium (IGM) environment traced by the Ly<jats:italic>α</jats:italic> forest, we observationally investigate the IGM–galaxy connection using the publicly available 3D IGM tomography data (CLAMATO) and several galaxy catalogs in the COSMOS field. We measure the cross-correlation function (CCF) for 570 galaxies with spec-<jats:italic>z</jats:italic> measurements and detect a correlation with the IGM up to 50 <jats:italic>h</jats:italic> <jats:sup>−1</jats:sup> comoving Mpc. We show that galaxies with stellar masses of 10<jats:sup>9</jats:sup>−10<jats:sup>10</jats:sup> <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub> are the dominant contributor to the total CCF signal. We also investigate CCFs for several galaxy populations: Ly<jats:italic>α</jats:italic> emitters (LAEs), H<jats:italic>α</jats:italic> emitters (HAEs), [O <jats:sc>iii</jats:sc>] emitters (O3Es), active galactic nuclei (AGNs), and submillimeter galaxies (SMGs), and we detect the highest signal in AGNs and SMGs at large scales (<jats:italic>r</jats:italic> ≥ 5 <jats:italic>h</jats:italic> <jats:sup>−1</jats:sup> Mpc), but in LAEs at small scales (<jats:italic>r</jats:italic> &lt; 5 <jats:italic>h</jats:italic> <jats:sup>−1</jats:sup> Mpc). We find that they live in various IGM environments—HAEs trace the IGM in a similar manner to the continuum-selected galaxies, but LAEs and O3Es tend to reside in higher-density regions. Additionally, LAEs’ CCF is flat up to <jats:italic>r</jats:italic> ∼ 3 <jats:italic>h</jats:italic> <jats:sup>−1</jats:sup> Mpc, indicating that they tend to avoid the highest-density regions. For AGNs and SMGs, the CCF peak at <jats:italic>r</jats:italic> = 5−6 <jats:italic>h</jats:italic> <jats:sup>−1</jats:sup> Mpc implies that they tend to be in locally lower-density regions. We suspect that it is due to the photoionization of IGM <jats:sc>H i</jats:sc> by AGNs, i.e., the proximity effect.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>A distance-deviation consistency and model-independent method to test the cosmic distance–duality relation (CDDR) is provided. This method is worthy of attention for two reasons. First, a distance-deviation consistency method is used to pair subsamples: instead of pairing subsamples with redshift deviations smaller than a value of, say, <jats:inline-formula> <jats:tex-math> <?CDATA $\left|{\rm{\Delta }}z\right|\lt 0.005$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabc9bfieqn1.gif" xlink:type="simple" /> </jats:inline-formula>. The redshift deviation between subsamples decreases with the redshift to ensure the distance deviation stays the same. The method selects more subsamples at high redshift, up to <jats:italic>z</jats:italic> = 2.16, and provides 120 subsample pairs. Second, the model-independent method involves the latest data set of 1048 SNe Ia and 205 strong gravitational lensing systems (SGLS), which are used to obtain the luminosity distances <jats:italic>D</jats:italic> <jats:sub> <jats:italic>L</jats:italic> </jats:sub> and the ratio of angular diameter distance <jats:italic>D</jats:italic> <jats:sub> <jats:italic>A</jats:italic> </jats:sub>, respectively. With the model-independent method, parameters of the CDDR, the SNe Ia light curve, and the SGLS are fitted simultaneously. The result shows that <jats:inline-formula> <jats:tex-math> <?CDATA $\eta ={0.047}_{-0.151}^{+0.190}$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabc9bfieqn2.gif" xlink:type="simple" /> </jats:inline-formula> and CDDR is validated at the 1<jats:italic>σ</jats:italic> confidence level in the form of <jats:inline-formula> <jats:tex-math> <?CDATA $\tfrac{{D}_{L}}{{D}_{A}}{\left(1+z\right)}^{-2}=1+\eta z$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabc9bfieqn3.gif" xlink:type="simple" /> </jats:inline-formula>.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>High-redshift Ly<jats:italic>α</jats:italic> blobs (LABs) are an enigmatic class of objects that have been the subject of numerous observational and theoretical investigations. It is of particular interest to determine the dominant power sources for their luminosity, as direct emission from H <jats:sc>ii</jats:sc> regions, cooling gas, and fluorescence due to the presence of active galactic nuclei (AGNs) can all contribute significantly. In this paper, we present the first theoretical model to consider all of these physical processes in an attempt to develop a model for the origin of LABs. This is achieved by combining a series of high-resolution cosmological zoom-in simulations with ionization and Ly<jats:italic>α</jats:italic> radiative transfer models. We find that massive galaxies display a range of Ly<jats:italic>α</jats:italic> luminosities and spatial extents (which strongly depend on the limiting surface brightness used) over the course of their lives, though regularly exhibit luminosities and sizes consistent with observed LABs. The model LABs are typically powered from a combination of recombination in star-forming galaxies, as well as cooling emission from gas associated with accretion. When AGNs are included in the model, the fluorescence caused by active galactic nucleus-driven ionization can be a significant contributor to the total Ly<jats:italic>α</jats:italic> luminosity as well. Within our modeled mass range, there are no obvious threshold physical properties that predict the appearance of LABs, and only weak correlations of the luminosity with the physical properties of the host galaxy. This is because the emergent Ly<jats:italic>α</jats:italic> luminosity from a system is a complex function of the gas temperature, ionization state, and Ly<jats:italic>α</jats:italic> escape fraction.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We compare the radial profiles of the specific star formation rate (sSFR) in a sample of 169 star-forming galaxies in close pairs with those of mass-matched control galaxies in the SDSS-IV MaNGA survey. We find that the sSFR is centrally enhanced (within one effective radius) in interacting galaxies by ∼0.3 dex and that there is a weak sSFR suppression in the outskirts of the galaxies of ∼0.1 dex. We stack the difference profiles for galaxies in five stellar-mass bins in the range log(<jats:italic>M</jats:italic>/<jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>) = 9.0–11.5 and find that the sSFR enhancement has no dependence on the stellar mass. The same result is obtained when comparison galaxies are matched to each paired galaxy in both stellar mass and redshift. In addition, we find that the sSFR enhancement is elevated in pairs with nearly equal masses and closer projected separations, in agreement with previous work based on single-fiber spectroscopy. We also find that the sSFR offsets in the outskirts of the paired galaxies are dependent on whether the galaxy is the more-massive or less-massive companion in the pair. The more-massive companion experiences zero to a positive sSFR enhancement, while the less-massive companion experiences sSFR suppression in their outskirts. Our results illustrate the complex tidal effects on star formation in closely paired galaxies.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Using recently acquired Hubble Space Telescope NIR observations (<jats:italic>J</jats:italic>, Pa<jats:italic>β</jats:italic>, and <jats:italic>H</jats:italic> bands) of the nearby galaxy NGC 1313, we investigate the timescales required by a young star cluster to emerge from its natal cloud. We search for extincted star clusters, potentially embedded in their natal cloud as either (1) compact sources in regions with high H<jats:italic>α</jats:italic>/Pa<jats:italic>β</jats:italic> extinctions or (2) compact H <jats:sc>ii</jats:sc> regions that appear as point-like sources in the Pa<jats:italic>β</jats:italic> emission map. The NUV–optical–NIR photometry of the candidate clusters is used to derive their ages, masses, and extinctions via a least-<jats:italic>χ</jats:italic> <jats:sup>2</jats:sup> spectral energy distribution broad- and narrowband fitting process. The 100 clusters in the final samples have masses in the range <jats:inline-formula> <jats:tex-math> <?CDATA ${\mathrm{log}}_{10}(M/{M}_{\odot })=2.5\mbox{--}3.5$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabe0b5ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> and moderate extinctions, <jats:italic>E</jats:italic>(<jats:italic>B</jats:italic> − <jats:italic>V</jats:italic>) ≲ 1.0 mag. Focusing on the young clusters (0–6 Myr), we derive a weak correlation between extinction and age of the clusters. Almost half of the clusters have low extinctions, <jats:italic>E</jats:italic>(<jats:italic>B</jats:italic> − <jats:italic>V</jats:italic>) &lt; 0.25 mag, already at very young ages (≤3 Myr), suggesting that dust is quickly removed from clusters. A stronger correlation is found between the morphology of the nebular emission (compact, partial or absent, both in H<jats:italic>α</jats:italic> and Pa<jats:italic>β</jats:italic>) and cluster age. Relative fractions of clusters associated with a specific nebular morphology are used to estimate the typical timescales for clearing the natal gas cloud, resulting in between 3 and 5 Myr, ∼1 Myr older than what was estimated from NUV–optical-based cluster studies. This difference hints at a bias for optical-only-based studies, which James Webb Space Telescope will address in the coming years.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The doublet and quartet potential energy surfaces for the P + SO → PO + S reaction are explored using the highly accurate explicit correlation multireference configuration interaction method, and the reaction is found to be thermodynamically favorable, with an exothermicity value of 70.5 kJ mol<jats:sup>−1</jats:sup>. The electronic structure, spectra, and bond dissociation energies of the intermediates involved in the reaction, such as SPO, PSO, and SOP, are calculated using high-level quantum chemistry methods. An explanation of the nondetection of the diatomic SP is proposed. At pressures relevant to astrochemistry, the reaction is overwhelmingly bimolecular, with a predicted rate coefficient of 2.1 × 10<jats:sup>−10</jats:sup> (<jats:italic>T</jats:italic>/300)<jats:sup>−0.23</jats:sup> cm<jats:sup>3</jats:sup> molecule<jats:sup>−1</jats:sup> s<jats:sup>−1</jats:sup>. The results from this study are expected to aid in the spectroscopic detection of these new species in the laboratory and the interstellar medium.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>2-aminooxazole (2AO), a N-heterocyclic molecule, has been proposed as an intermediate in prebiotic syntheses. It has been demonstrated that it can be synthesized from small molecules such as cyanamide and glycoaldehyde, which are present in interstellar space. The aim of this work is to provide infrared (IR) spectra, in the solid phase for conditions typical of astrophysical environments and to estimate its stability toward UV photons and cosmic rays. IR (4000–600 cm<jats:sup>−1</jats:sup>) absorption spectra at 20 K, 180 K, and 300 K, IR band strengths, and room-temperature UV (120–250 nm) absorption spectra are given for the first time for this species. Destruction cross sections of ≈9.5 10<jats:sup>−18</jats:sup> cm<jats:sup>2</jats:sup> and ≈2 10<jats:sup>−16</jats:sup> cm<jats:sup>2</jats:sup> were found in the irradiation at 20 K of pure 2AO and 2AO:H2O ices with UV (6.3–10.9 eV) photons or 5 keV electrons, respectively. These data were used to estimate half-life times for the molecule in different environments. It is estimated that 2AO could survive UV radiation and cosmic rays in the ice mantles of dense clouds beyond cloud collapse. In contrast, it would be very unstable on the surface of cold solar system bodies like Kuiper Belt objects, but the molecule could still survive within dust grain agglomerates or cometesimals.</jats:p>