Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title> <jats:p>Molecular cooling is essential for studying the formation of substructure of dissipative dark-matter halos that may host compact objects such as black holes. Here, we analyze the reaction rates relevant for the formation, dissociation, and transition of hydrogenic molecules while allowing for different values of the physical parameters: the coupling constant, the proton mass, and the electron mass. For all cases, we rescale the reaction rates for the standard molecular hydrogen, so our results are valid as long as the dark matter is weakly coupled and one of the fermions is much heavier than the other. These results will allow a robust numerical treatment of cosmic structure, in particular for minihalos for which molecular cooling is important, in a dissipative dark-matter scenario.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We study the relationship between the morphology and star formation history (SFH) of 361 quiescent galaxies (QGs) at redshift 〈<jats:italic>z</jats:italic> <jats:sub>obs</jats:sub>〉 ≈ 2, with stellar mass <jats:inline-formula> <jats:tex-math> <?CDATA $\mathrm{log}{M}_{* }\geqslant 10.3$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>log</mml:mi> <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:mn>10.3</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac7f43ieqn1.gif" xlink:type="simple" /> </jats:inline-formula>, selected with the UVJ technique. Taking advantage of panchromatic photometry covering the rest-frame UV-to-NIR spectral range ( ≈40 bands), we reconstruct the nonparametric SFH of the galaxies with the fully Bayesian SED fitting code P<jats:sc>rospector</jats:sc>. We find that the half-light radius <jats:italic>R</jats:italic> <jats:sub> <jats:italic>e</jats:italic> </jats:sub>, observed at <jats:italic>z</jats:italic> <jats:sub>obs</jats:sub>, depends on the formation redshift of the galaxies, <jats:italic>z</jats:italic> <jats:sub>form</jats:sub>, and that this relationship depends on <jats:italic>M</jats:italic> <jats:sub>*</jats:sub>. At <jats:inline-formula> <jats:tex-math> <?CDATA $\mathrm{log}{M}_{* }\lt 11$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>log</mml:mi> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>*</mml:mo> </mml:mrow> </mml:msub> <mml:mo>&lt;</mml:mo> <mml:mn>11</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac7f43ieqn2.gif" xlink:type="simple" /> </jats:inline-formula>, the relationship is consistent with <jats:inline-formula> <jats:tex-math> <?CDATA ${R}_{e}\propto {\left(1+{z}_{\mathrm{form}}\right)}^{-1}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>R</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>e</mml:mi> </mml:mrow> </mml:msub> <mml:mo>∝</mml:mo> <mml:msup> <mml:mrow> <mml:mfenced close=")" open="("> <mml:mrow> <mml:mn>1</mml:mn> <mml:mo>+</mml:mo> <mml:msub> <mml:mrow> <mml:mi>z</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>form</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:mfenced> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac7f43ieqn3.gif" xlink:type="simple" /> </jats:inline-formula>, in line with the expectation that the galaxies’ central density depends on the cosmic density at the time of their formation, i.e., the “progenitor effect.” At <jats:inline-formula> <jats:tex-math> <?CDATA $\mathrm{log}{M}_{* }\gt 11$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>log</mml:mi> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>*</mml:mo> </mml:mrow> </mml:msub> <mml:mo>&gt;</mml:mo> <mml:mn>11</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac7f43ieqn4.gif" xlink:type="simple" /> </jats:inline-formula>, the relationship between <jats:italic>R</jats:italic> <jats:sub> <jats:italic>e</jats:italic> </jats:sub> and <jats:italic>z</jats:italic> <jats:sub>form</jats:sub> flattens, suggesting that mergers become increasingly important for the size growth of more massive galaxies after they quenched. We also find that the relationship between <jats:italic>z</jats:italic> <jats:sub>form</jats:sub> and galaxy compactness similarly depends on <jats:italic>M</jats:italic> <jats:sub>*</jats:sub>. While no clear trend is observed for QGs with <jats:inline-formula> <jats:tex-math> <?CDATA $\mathrm{log}{M}_{* }\gt 11$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>log</mml:mi> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>*</mml:mo> </mml:mrow> </mml:msub> <mml:mo>&gt;</mml:mo> <mml:mn>11</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac7f43ieqn5.gif" xlink:type="simple" /> </jats:inline-formula>, lower-mass QGs that formed earlier, i.e., with larger <jats:italic>z</jats:italic> <jats:sub>form</jats:sub>, have larger central stellar-mass surface densities, both within the <jats:italic>R</jats:italic> <jats:sub> <jats:italic>e</jats:italic> </jats:sub> (Σ<jats:sub> <jats:italic>e</jats:italic> </jats:sub>) and central 1 kpc (Σ<jats:sub>1 kpc</jats:sub>), and also larger <jats:italic>M</jats:italic> <jats:sub>1 kpc</jats:sub>/<jats:italic>M</jats:italic> <jats:sub>*</jats:sub>, the fractional mass within the central 1 kpc. These trends between <jats:italic>z</jats:italic> <jats:sub>form</jats:sub> and compactness, however, essentially disappear if the progenitor effect is removed by normalizing the stellar density with the cosmic density at <jats:italic>z</jats:italic> <jats:sub>form</jats:sub>. Our findings highlight the importance of reconstructing the SFH of galaxies before attempting to infer their intrinsic structural evolution.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Dissipative dark matter predicts rich observable phenomena that can be tested with future large-scale structure surveys. As a specific example, we study atomic dark matter, consisting of a heavy particle and a light particle charged under a dark electromagnetism. In particular, we calculate the cosmological evolution of atomic dark matter focusing on dark recombination and dark molecule formation. We have obtained the relevant interaction rate coefficients by rescaling the rates for normal hydrogen, and evolved the abundances for ionized, atomic, and molecular states using a modified version of <jats:sans-serif>Recfast++</jats:sans-serif> (which we have released publicly at <jats:inline-formula> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac75e4ill1.gif" xlink:type="simple" /> </jats:inline-formula> <jats:xref ref-type="fn" rid="apjac75e4fn1a"> <jats:sup>a</jats:sup> </jats:xref> <jats:fn id="apjac75e4fn1a"> <jats:label> <jats:sup>a</jats:sup> </jats:label> <jats:p> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="https://github.com/jamesgurian/RecfastJulia" xlink:type="simple">https://github.com/jamesgurian/RecfastJulia</jats:ext-link> </jats:p> </jats:fn>). We also provide an analytical approximation for the final abundances. We then calculate the effects of atomic dark matter on the linear power spectrum, which enter through a dark photon diffusion and dark acoustic oscillations. At formation time, the atomic dark matter model suppresses halo abundances on scales smaller than the diffusion scale, just as warm dark matter models suppress the abundance below the free-streaming scale. The subsequent evolution with radiative cooling, however, will alter the halo mass function further.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We investigate the metal species associated with the Ly<jats:italic>α</jats:italic> forest in eBOSS quasar spectra. Metal absorption lines are revealed in stacked spectra from cross-correlating the selected Ly<jats:italic>α</jats:italic> absorbers in the forest and the flux fluctuation field. Up to 13 metal species are identified as being associated with relatively strong Ly<jats:italic>α</jats:italic> absorbers (those with flux fluctuations − 1.0 &lt; <jats:italic>δ</jats:italic> <jats:sub>Ly<jats:italic>α</jats:italic> </jats:sub> &lt; − 0.6 and with a neutral hydrogen column density of ∼ 10<jats:sup>15−16</jats:sup> cm<jats:sup>−2</jats:sup>) over the absorber redshift range of 2 &lt; <jats:italic>z</jats:italic> <jats:sub>abs</jats:sub> &lt; 4. The column densities of these species decrease toward higher redshift and for weaker Ly<jats:italic>α</jats:italic> absorbers. From modeling the column densities of various species, we find that the column density pattern suggests contributions from multiple gas components, both in the circumgalactic medium (CGM) and the intergalactic medium (IGM). While the low-ionization species (e.g., C <jats:sc>ii</jats:sc>, Si <jats:sc>ii</jats:sc>, and Mg <jats:sc>ii</jats:sc>) can be explained by high-density, cool gas (<jats:italic>T</jats:italic> ∼ 10<jats:sup>4</jats:sup> K) from the CGM, the high-ionization species may reside in low-density or high-temperature gas in the IGM. The measurements provide inputs for modeling the metal contamination in the Ly<jats:italic>α</jats:italic> forest baryon acoustic oscillation measurements. Comparisons with metal absorptions in high-resolution quasar spectra and hydrodynamic galaxy formation simulations can further elucidate the physical conditions of these Ly<jats:italic>α</jats:italic> absorbers.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Dark matter that is dissipative may cool sufficiently to form compact objects, including black holes. Determining the abundance and mass spectrum of those objects requires an accurate model of the chemistry relevant for the cooling of the dark matter gas. Here we introduce a chemistry tool for dark matter, DarkKROME, an extension of the KROME software package. DarkKROME is designed to include all atomic and molecular processes relevant for dark matter with two unequal-mass fundamental fermions, interacting via a massless-photon-mediated <jats:italic>U</jats:italic>(1) force. We use DarkKROME to perform one-zone collapse simulations and study the evolution of temperature–density phase diagrams for various dark sector parameters. DarkKROME is publicly available at <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="https://bitbucket.org/mtryan83/darkkrome" xlink:type="simple">https://bitbucket.org/mtryan83/darkkrome</jats:ext-link>.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We demonstrate that future radius measurements of the NICER mission have the potential to reveal the existence of a strong phase transition in dense neutron star matter by confirming the existence of so-called twin stars, compact star configurations with the same mass but different radii. The latest radius constraints from NICER for the pulsars J0740+6620 as well as J0030+0451 are discussed using relativistic mean field equations of state with varying stiffness, connected with a first-order phase transition to quark matter. We show that twin star solutions are compatible with the new radius constraint but are located at radii <jats:italic>below</jats:italic> the present constraints from NICER, serving as a smoking gun for a strong phase transition in neutron star matter. This scenario is realized if a strong phase transition takes place in neutron stars of the first branch with masses above 2 <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We analyze a 7.4 hr XMM-Newton light curve of the cataclysmic variable Swift J0503.7−2819, previously classified using optical periods as an intermediate polar (IP) with an orbital period of 0.0567 days. A photometric signal at 975 s, previously suggested to be the spin period, is not present in X-rays and is readily understood as a quasiperiodic oscillation. The X-ray light curve instead shows clear behavior of a highly asynchronous polar or stream-fed IP. It can be described by either of two scenarios: one that switches between one-pole and two-pole accretion, and another in which accretion alternates fully between two poles. The spin periods in these two models are 0.0455 days and 0.0505 days, respectively. The spin frequency <jats:italic>ω</jats:italic> is thus either 24% faster or 12% faster than the orbital frequency Ω, and the corresponding beat period between spin and orbit is 0.231 days or 0.462 days. Brief absorption events seen in the light curve are spaced in a way that may favor the longer spin and beat periods. These periods are confirmed and refined using data from the Transiting Exoplanet Survey Satellite and the Asteroid Terrestrial-impact Last Alert System. The short beat cycle of Swift J0503.7−2819 makes it well-suited to resolving this common dilemma, which amounts to deciding whether the main signal in the power spectrum is <jats:italic>ω</jats:italic> or 2<jats:italic>ω</jats:italic> − Ω.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Type-I X-ray burst oscillations are powered by thermonuclear energy released on the neutron star (NS) surface in low-mass X-ray binaries (LMXBs), where the burst oscillation frequencies are close to the NS spin rates. In this work, we report the detection of oscillation at 584.65 Hz during the cooling tail of type-I X-ray bursts observed from the accreting NS LMXB 4U 1730–22 on 2022 March 20, by the Neutron star Interior Composition Explorer telescope. The oscillation signal showed a strong Leahy power, <jats:italic>P</jats:italic> <jats:sub>m</jats:sub> ∼ 54.04, around 584.65 Hz, which has single-trial and multiple-trial confidence levels of 7.05<jats:italic>σ</jats:italic> and 4.73<jats:italic>σ</jats:italic>, respectively. The folded pulse profile of the oscillation in the 0.2–10 keV band showed a sinusoidal shape with the fractional rms amplitude of (8.0 ± 1.1)%. We found the oscillation frequency showed insignificant upward drifting, i.e., less than 0.3 Hz, during the cooling tail, similar to the behavior appearing in accreting millisecond X-ray pulsars (AMXP), and indicate the source could be an AMXP spinning at 1.71 ms.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The physics behind the ionization structure of outflows from black holes is yet to be fully understood. Using archival observations with the Chandra/HETG gratings over the past two decades, we measured an absorption measure distribution for a sample of outflows in nine active galactic nuclei (AGNs), namely the dependence of outflow column density, <jats:italic>N</jats:italic> <jats:sub>H</jats:sub>, on the ionization parameter, <jats:italic>ξ</jats:italic>. The slope of <jats:inline-formula> <jats:tex-math> <?CDATA $\mathrm{log}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>log</mml:mi> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac7c6bieqn1.gif" xlink:type="simple" /> </jats:inline-formula> <jats:italic>N</jats:italic> <jats:sub>H</jats:sub> versus <jats:inline-formula> <jats:tex-math> <?CDATA $\mathrm{log}\xi $?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>log</mml:mi> <mml:mi>ξ</mml:mi> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac7c6bieqn2.gif" xlink:type="simple" /> </jats:inline-formula> is found to be between 0.00 and 0.72. We find an anticorrelation between the log of total column density of the outflow and the log of AGN luminosity, and none with the black hole mass and accretion efficiency. A major improvement in the diagnostics of AGN outflows will potentially occur with the launch of the XRISM/Resolve spectrometer. We study the ability of Resolve to reveal the outflow ionization structure by constructing the absorption measure distribution from simulated Resolve spectra, utilizing its superior resolution and effective area. Resolve constrains the column density as well as HETG, but with much shorter observations.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We have developed a new numerical algorithm to study the joint evolution of galaxies and the intergalactic medium (IGM) in a cosmological context, with the specific goal of studying the deposition and dispersion of metals in the IGM. This algorithm combines a standard gasdynamical algorithm to simulate the evolution of the IGM, a semi-analytical model to describe the evolution of galaxies, and prescriptions for galaxy formation, accretion, mergers, and tidal disruption. The main goal in designing this algorithm was performance. In its current version, the algorithm can simulate the evolution of cosmological volumes containing thousands of galaxies in a few days, using between 12 and 32 processors. This algorithm is particularly suited for parameter surveys (both numerical parameters and physical parameters) since a large number of simulations can be completed in a fairly short amount of time. Furthermore, the algorithm provides a platform for the development and testing of new treatments of subgrid physics, which could then be implemented into other algorithms. In this paper, we describe the algorithm and present, for illustration, two simulations of the evolution of a (20 Mpc)<jats:sup>3</jats:sup> cosmological volume containing ∼1200 galaxies at <jats:italic>z</jats:italic> = 0.</jats:p>