Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title> <jats:p>We introduce a new Markov Chain Monte Carlo (MCMC) algorithm with parallel tempering for fitting theoretical models of horizon-scale images of black holes to the interferometric data from the Event Horizon Telescope (EHT). The algorithm implements forms of the noise distribution in the data that are accurate for all signal-to-noise ratios. In addition to being trivially parallelizable, the algorithm is optimized for high performance, achieving 1 million MCMC chain steps in under 20 s on a single processor. We use synthetic data for the 2017 EHT coverage of M87 that are generated based on analytic as well as General Relativistic Magnetohydrodynamic (GRMHD) model images to explore several potential sources of biases in fitting models to sparse interferometric data. We demonstrate that a very small number of data points that lie near salient features of the interferometric data exert disproportionate influence on the inferred model parameters. We also show that the preferred orientations of the EHT baselines introduce significant biases in the inference of the orientation of the model images. Finally, we discuss strategies that help identify the presence and severity of such biases in realistic applications.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The first fast radio burst (FRB) to be precisely localized was associated with a luminous persistent radio source (PRS). Recently, a second FRB/PRS association was discovered for another repeating source of FRBs. However, it is not clear what makes FRBs or PRS or how they are related. We compile FRB and PRS properties to consider the population of FRB/PRS sources. We suggest a practical definition for PRS as FRB associations with luminosity greater than 10<jats:sup>29</jats:sup> erg s<jats:sup>−1</jats:sup> Hz<jats:sup>−1</jats:sup> that are not attributed to star formation activity in the host galaxy. We model the probability distribution of the fraction of FRBs with PRS for repeaters and nonrepeaters, showing there is not yet evidence for repeaters to be preferentially associated with PRS. We discuss how FRB/PRS sources may be distinguished by the combination of active repetition and an excess dispersion measure local to the FRB environment. We use CHIME/FRB event statistics to bound the mean per-source repetition rate of FRBs to be between 25 and 440 yr<jats:sup>−1</jats:sup>. We use this to provide a bound on the density of FRB-emitting sources in the local universe of between 2.2 × 10<jats:sup>2</jats:sup> and 5.2 × 10<jats:sup>4</jats:sup> Gpc<jats:sup>−3</jats:sup> assuming a pulsar-like beamwidth for FRB emission. This density implies that PRS may comprise as much as 1% of compact, luminous radio sources detected in the local universe. The cosmic density and phenomenology of PRS are similar to that of the newly discovered, off-nuclear “wandering” active galactic nuclei (AGN). We argue that it is likely that some PRS have already been detected and misidentified as AGN.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>In this paper, we evaluate the heliospheric current sheet (HCS) north–south asymmetry using the ecliptical sector structure of the interplanetary magnetic field (IMF) reconstructed since the second half of the 19th century. During the last five solar cycles, the inferred IMF polarities fairly reproduce the observed dominance of the sectors with the polarity of the northern solar hemisphere, i.e., the prolonged southward shift of the HCS. For the presatellite era, we found that the northward shift of the HCS was more common in cycles 10, 15, and 17–19, and the southward HCS shift was more common in cycles 9, 11–14, and 16. We also analyzed the north–south asymmetry in sunspot group numbers since 1749 and found that the northern hemisphere dominated in cycles 2–3, 7–9, and 15–20, and the southern hemisphere activity was stronger in cycles 4, 9–14, and 21–24. Moreover, other solar phenomena bear similar long-term asymmetry variations. The regularity of these variations is not clear. According to the available proxies of the solar data, the dominance of the northern hemisphere is found in the ascending phase of the secular solar cycle, and the dominance of the southern hemisphere coincides with the descending phase.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The LIGO–Virgo–KAGRA Collaboration recently detected gravitational waves (GWs) from the merger of black hole–neutron star (BHNS) binary systems GW200105 and GW200115. No coincident electromagnetic (EM) counterparts were detected. While the mass ratio and BH spin in both systems were not sufficient to tidally disrupt the NS outside the BH event horizon, other, magnetospheric mechanisms for EM emission exist in this regime and depend sensitively on the NS magnetic field strength. Combining GW measurements with EM flux upper limits, we place upper limits on the NS surface magnetic field strength above which magnetospheric emission models would have generated an observable EM counterpart. We consider fireball models powered by the black hole battery mechanism, where energy is output in gamma rays over ≲1 s. Consistency with no detection by Fermi-GBM or INTEGRAL SPI-ACS constrains the NS surface magnetic field to ≲10<jats:sup>15</jats:sup> G. Hence, joint GW detection and EM upper limits rule out the theoretical possibility that the NSs in GW200105 and GW200115, and the putative NS in GW190814, retain dipolar magnetic fields ≳10<jats:sup>15</jats:sup> G until merger. They also rule out formation scenarios where strongly magnetized magnetars quickly merge with BHs. We alternatively rule out operation of the BH-battery-powered fireball mechanism in these systems. This is the first multimessenger constraint on NS magnetic fields in BHNS systems and a novel approach to probe fields at this point in NS evolution. This demonstrates the constraining power that multimessenger analyses of BHNS mergers have on BHNS formation scenarios, NS magnetic field evolution, and the physics of BHNS magnetospheric interactions.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The properties of young massive clusters (YMCs) are key to understanding the star formation mechanism in starburst systems, especially mergers. We present Atacama Large Millimeter/submillimeter Array high-resolution (∼10 pc) continuum (100 and 345 GHz) data of YMCs in the overlap region of the Antennae galaxy. We identify six sources in the overlap region, including two sources that lie in the same giant molecular cloud (GMC). These YMCs correspond well with radio sources in lower-resolution continuum (100 and 220 GHz) images at GMC scales (∼60 pc). We find most of these YMCs are bound clusters through virial analysis. We estimate their ages to be ∼1 Myr and that they are either embedded or just beginning to emerge from their parent cloud. We also compare each radio source with a Pa<jats:italic>β</jats:italic> source, and find they have consistent total ionizing photon numbers, which indicates they are tracing the same physical source. By comparing the free–free emission at ∼10 pc scale and ∼60 pc scale, we find that ∼50% of the free–free emission in GMCs actually comes from these YMCs. This indicates that roughly half of the stars in massive GMCs are formed in bound clusters. We further explore the mass correlation between YMCs and GMCs in the Antennae and find it generally agrees with the predictions of the star cluster simulations. The most massive YMC has a stellar mass that is 1%–5% of its host GMC mass.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Green Pea and Blueberry galaxies are well known for their compact size, low mass, strong emission lines, and analogs to high-<jats:italic>z</jats:italic> Ly<jats:italic>α</jats:italic>-emitting galaxies. In this study, 1547 strong [O <jats:sc>iii</jats:sc>]<jats:italic> λ</jats:italic>5007 emission-line compact galaxies with 1694 spectra are selected from LAMOST DR9 at the redshift range from 0.0 to 0.59. According to the redshift distribution, these samples can be separated into three groups: Blueberries, Green Peas, and Purple Grapes. Optical [Mg <jats:sc>ii</jats:sc>]<jats:italic> λ</jats:italic>2800 line feature, BPT diagram, multiwavelength spectral energy distribution (SED) fitting, mid-IR (MIR) color, and MIR variability are deployed to identify 23 active galactic nucleus candidates from these samples, which are excluded for the following star formation rate (SFR) discussions. We perform the multiwavelength SED fitting with GALEX UV and WISE MIR data. Color excess from the Balmer decrement shows that these strong [O <jats:sc>iii</jats:sc>]<jats:italic> λ</jats:italic>5007 emission-line compact galaxies are not highly reddened. The stellar mass of the galaxies is obtained by fitting LAMOST calibrated spectra with the emission lines masked. We find that the SFR is increasing with the increase of redshift, while for the sources within the same redshift bin the SFR increases with mass with a similar slope to the star-forming main sequence. These samples have a median metallicity of 12 + log(O/H) of 8.10. The metallicity increases with mass, and all the sources are below the mass–metallicity relation. The direct-derived <jats:italic>T</jats:italic> <jats:sub> <jats:italic>e</jats:italic> </jats:sub>-based metallicity from the [O <jats:sc>iii</jats:sc>]<jats:italic> λ</jats:italic>4363 line agrees with the empirical N2-based empirical gas-phase metallicity. Moreover, these compact strong [O <jats:sc>iii</jats:sc>]<jats:italic> λ</jats:italic>5007 lines are mostly in a less dense environment.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The Sloan Digital Sky Survey MaNGA program has now obtained integral field spectroscopy for over 10,000 galaxies in the nearby universe. We use the final MaNGA data release DR17 to study the correlation between ionized gas velocity dispersion and galactic star formation rate, finding a tight correlation in which <jats:italic>σ</jats:italic> <jats:sub>H<jats:italic>α</jats:italic> </jats:sub> from galactic H <jats:sc>ii</jats:sc> regions increases significantly from ∼18–30 km s<jats:sup>−1</jats:sup>, broadly in keeping with previous studies. In contrast, <jats:italic>σ</jats:italic> <jats:sub>H<jats:italic>α</jats:italic> </jats:sub> from diffuse ionized gas increases more rapidly from 20–60 km s<jats:sup>−1</jats:sup>. Using the statistical power of MaNGA, we investigate these correlations in greater detail using multiple emission lines and determine that the observed correlation of <jats:italic>σ</jats:italic> <jats:sub>H<jats:italic>α</jats:italic> </jats:sub> with local star formation rate surface density is driven primarily by the global relation of increasing velocity dispersion at higher total star formation rate, as are apparent correlations with stellar mass. Assuming H <jats:sc>ii</jats:sc> region models consistent with our finding that <jats:italic>σ</jats:italic> <jats:sub>[O <jats:sc>III</jats:sc>]</jats:sub> &lt; <jats:italic>σ</jats:italic> <jats:sub>H<jats:italic>α</jats:italic> </jats:sub> &lt; <jats:italic>σ</jats:italic> <jats:sub>[O I]</jats:sub>, we estimate the velocity dispersion of the molecular gas in which the individual H <jats:sc>ii</jats:sc> regions are embedded, finding values <jats:italic>σ</jats:italic> <jats:sub>Mol</jats:sub> = 5–30 km s<jats:sup>−1</jats:sup> consistent with ALMA observations in a similar mass range. Finally, we use variations in the relation with inclination and disk azimuthal angle to constrain the velocity dispersion ellipsoid of the ionized gas <jats:italic>σ</jats:italic> <jats:sub> <jats:italic>z</jats:italic> </jats:sub>/<jats:italic>σ</jats:italic> <jats:sub> <jats:italic>r</jats:italic> </jats:sub> = 0.84 ± 0.03 and <jats:italic>σ</jats:italic> <jats:sub> <jats:italic>ϕ</jats:italic> </jats:sub>/<jats:italic>σ</jats:italic> <jats:sub> <jats:italic>r</jats:italic> </jats:sub> = 0.91 ± 0.03, similar to that of young stars in the Galactic disk. Our results are most consistent with the theoretical models in which turbulence in modern galactic disks is driven primarily by star formation feedback.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The quasar 3C 273 has been observed with infrared spectroastrometry (SA) of the broad Pa<jats:italic>α</jats:italic> line and optical reverberation mapping (RM) of the broad H<jats:italic>β</jats:italic> line. SA delivers information about the angular size and structure of the Pa<jats:italic>α</jats:italic> broad-line region (BLR), while RM delivers information about the physical size and structure of the H<jats:italic>β</jats:italic> BLR. Based on the fact that the two BLRs share the mass of the supermassive black hole (SMBH) and viewing inclination, a combination of SA and velocity-resolved RM (SARM) thereby allows us to simultaneously determine the SMBH mass and geometric distance through dynamically modeling the two BLRs. We construct a suite of dynamical models with different geometric configurations and apply a Bayesian approach to obtain the parameter inferences. Overall the obtained masses and distances are insensitive to specific BLR configurations but more or less depend on parameterizations of the vertical distributions. The most probable model, chosen in light of the Bayes factor, yields an angular-size distance <jats:inline-formula> <jats:tex-math> <?CDATA $\mathrm{log}({D}_{{\rm{A}}}/\mathrm{Mpc})={2.83}_{-0.28}^{+0.32}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>log</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:msub> <mml:mrow> <mml:mi>D</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">A</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy="true">/</mml:mo> </mml:mrow> <mml:mi>Mpc</mml:mi> <mml:mo stretchy="false">)</mml:mo> <mml:mo>=</mml:mo> <mml:msubsup> <mml:mrow> <mml:mn>2.83</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.28</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.32</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac4bcbieqn1.gif" xlink:type="simple" /> </jats:inline-formula> and an SMBH mass <jats:inline-formula> <jats:tex-math> <?CDATA $\mathrm{log}({M}_{\bullet }/{M}_{\odot })={9.06}_{-0.27}^{+0.21}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>log</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>•</mml:mo> </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 stretchy="false">)</mml:mo> <mml:mo>=</mml:mo> <mml:msubsup> <mml:mrow> <mml:mn>9.06</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.27</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.21</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac4bcbieqn2.gif" xlink:type="simple" /> </jats:inline-formula>, which agree with the relationships between SMBH masses and bulge properties. The BLRs have an inclination of <jats:inline-formula> <jats:tex-math> <?CDATA ${5}_{-1}^{+1}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>5</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac4bcbieqn3.gif" xlink:type="simple" /> </jats:inline-formula> degrees, consistent with that of the large-scale jet in 3C 273. Our approach reinforces the capability of SARM analysis to measure SMBH masses and distances of active galactic nuclei and quasars even though SA and RM observations are undertaken with different emission lines and/or in different periods.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Deep Chandra and Very Large Array imaging reveals a clear correlation between X-ray and radio emission on scales ∼100 kpc in the Spiderweb radio galaxy at <jats:italic>z</jats:italic> = 2.16. The X-ray emission associated with the extended radio source is likely dominated by inverse Compton upscattering of cosmic microwave background photons by the radio-emitting relativistic electrons. For regions dominated by high surface brightness emission, such as hot spots and jet knots, the implied magnetic fields are ∼50–70 <jats:italic>μ</jats:italic>G. The nonthermal pressure in these brighter regions is then ∼9 × 10<jats:sup>−10</jats:sup> dynes cm<jats:sup>−2</jats:sup>, or three times larger than the nonthermal pressure derived assuming minimum energy conditions, and an order of magnitude larger than the thermal pressure in the ambient cluster medium. Assuming ram pressure confinement implies an average advance speed for the radio source of ∼2400 km s<jats:sup>−1</jats:sup> and a source age of ∼3 × 10<jats:sup>7</jats:sup> yr. Considering the lower surface brightness, diffuse radio-emitting regions, we identify an evacuated cavity in the Ly<jats:italic>α</jats:italic> emission coincident with the tail of the eastern radio lobe. Making reasonable assumptions for the radio spectrum, we find that the relativistic electrons and fields in the lobe are plausibly in pressure equilibrium with the thermal gas and close to a minimum energy configuration. The radio morphology suggests that the Spiderweb is a high-<jats:italic>z</jats:italic> example of the rare class of hybrid morphology radio sources (or HyMoRS), which we attribute to interaction with the asymmetric gaseous environment indicated by the Ly<jats:italic>α</jats:italic> emission.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The repeating FRB 20201124A was first discovered by CHIME/FRB in November of 2020, after which it was seen to repeat a few times over several months. It entered a period of high activity in April of 2021, at which time several observatories recorded tens to hundreds more bursts from the source. These follow-up observations enabled precise localization and host-galaxy identification. In this paper, we report on the CHIME/FRB-detected bursts from FRB 20201124A, including their best-fit morphologies, fluences, and arrival times. The large exposure time of the CHIME/FRB telescope toward the location of this source allows us to constrain its rates of activity. We analyze the repetition rates over different spans of time, constraining the rate prior to discovery to &lt;3.4 day<jats:sup>−1</jats:sup> (at 3<jats:italic>σ</jats:italic>), and demonstrate a significant change in the event rate following initial detection. Lastly, we perform a maximum-likelihood estimation of a power-law luminosity function, finding a best-fit index <jats:italic>α</jats:italic> = −4.6 ± 1.3 ± 0.6, with a break at a fluence threshold of <jats:inline-formula> <jats:tex-math> <?CDATA ${F}_{\min }\sim 16.6$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>F</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>min</mml:mi> </mml:mrow> </mml:msub> <mml:mo>∼</mml:mo> <mml:mn>16.6</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac4bc7ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> Jy ms, consistent with the fluence completeness limit of the observations. This index is consistent within uncertainties with those of other repeating FRBs for which it has been determined.</jats:p>