Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title> <jats:p>We present LEGWORK (LISA Evolution and Gravitational Wave Orbit Kit), an open-source Python package for making predictions about stellar-origin gravitational-wave sources and their detectability in LISA or other space-based gravitational-wave detectors. LEGWORK can be used to evolve the orbits of sources due to gravitational-wave emission, calculate gravitational-wave strains (using post-Newtonian approximations), compute signal-to-noise ratios, and visualize the results. It can be applied to a variety of potential sources, including binaries consisting of white dwarfs, neutron stars, and black holes. Although we focus on double compact objects, in principle LEGWORK can be used for any system with a user-specified orbital evolution, such as those affected by a third object or gas drag. We optimized the package to make it efficient for use in population studies, which can contain tens of millions of sources. This paper describes the package and presents several potential use cases. We explain in detail the derivations of the expressions behind the package as well as identify and clarify some discrepancies currently present in the literature. We hope that LEGWORK will enable and accelerate future studies triggered by the rapidly growing interest in gravitational-wave sources.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We present an incremental version (4FGL-DR3, for Data Release 3) of the fourth Fermi Large Area Telescope (LAT) catalog of <jats:italic>γ</jats:italic>-ray sources. Based on the first 12 years of science data in the energy range from 50 MeV to 1 TeV, it contains 6658 sources. The analysis improves on that used for the 4FGL catalog over eight years of data: more sources are fit with curved spectra, we introduce a more robust spectral parameterization for pulsars, and we extend the spectral points to 1 TeV. The spectral parameters, spectral energy distributions, and associations are updated for all sources. Light curves are rebuilt for all sources with 1 yr intervals (not 2 month intervals). Among the 5064 original 4FGL sources, 16 were deleted, 112 are formally below the detection threshold over 12 yr (but are kept in the list), while 74 are newly associated, 10 have an improved association, and seven associations were withdrawn. Pulsars are split explicitly between young and millisecond pulsars. Pulsars and binaries newly detected in LAT sources, as well as more than 100 newly classified blazars, are reported. We add three extended sources and 1607 new point sources, mostly just above the detection threshold, among which eight are considered identified, and 699 have a plausible counterpart at other wavelengths. We discuss the degree-scale residuals to the global sky model and clusters of soft unassociated point sources close to the Galactic plane, which are possibly related to limitations of the interstellar emission model and missing extended sources.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The Subaru Hyper Suprime-Cam (HSC) Strategic Survey is the latest-generation multiband optical imaging survey for galaxy evolution and structure formation. The “Ultra-deep” component of the HSC survey provides <jats:italic>grizy</jats:italic> broadband images over ∼3.4 deg<jats:sup>2</jats:sup> to detection limits of ∼26–28 AB, along with narrowband images, in the COSMOS and SXDS fields. These images provide an unprecedented combination of depths and area coverage, for studies of galaxies up to <jats:italic>z</jats:italic> ∼ 7. However, the lack of coverage at &lt;4000 Å implies an incomplete sampling of the rest-frame UV at <jats:italic>z</jats:italic> ≲ 3, which is critically needed for understanding the buildup of stellar mass in later cosmic time. We conducted a multiyear CFHT <jats:italic>u</jats:italic>*-band imaging campaign in the two HSC Ultra-deep fields with CFHT MegaCam. By including shallower archival data, we reached 5<jats:italic>σ</jats:italic> depths of <jats:italic>u</jats:italic>* = 28.1 and 28.4 (AB) at the centers of the COSMOS and SXDS fields, respectively, and <jats:italic>u</jats:italic>* = 27.7 and 27.8 in the central 1 deg<jats:sup>2</jats:sup> fields. The image quality is ≳ 0.″90, fairly good for the <jats:italic>u</jats:italic>* band. Both the photometric and astrometric quality of our data are excellent. We show that the combination of our <jats:italic>u</jats:italic>*-band and HSC data can lead to high-quality photometric redshifts at <jats:italic>z</jats:italic> = 0–3, and robust measurements of rest-frame UV on galaxies at 0.4 &lt; <jats:italic>z</jats:italic> &lt; 0.6 for distinguishing green-valley galaxies from star-forming and quiescent galaxies. We publicly release our reduced <jats:italic>u</jats:italic>*-band images and reference catalogs, which can be used readily for scientific studies.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>This supplement provides supporting material for Lam et al. We briefly summarize past gravitational microlensing searches for black holes (BHs) and present details of the observations, analysis, and modeling of five BH candidates observed with both ground-based photometric microlensing surveys and Hubble Space Telescope astrometry and photometry. We present detailed results for four of the five candidates that show no or low probability for the lens to be a BH. In these cases, the lens masses are &lt;2 <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>, and two of the four are likely white dwarfs or neutron stars. We also present detailed methods for comparing the full sample of five candidates to theoretical expectations of the number of BHs in the Milky Way (∼10<jats:sup>8</jats:sup>).</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Using the time-resolved laser-induced fluorescence technique, the radiative lifetimes for 15 odd-parity levels from 47,003 to 61,475 cm<jats:sup>−1</jats:sup> in Ir <jats:sc>ii</jats:sc> were measured. To the best of our knowledge, 11 lifetime results among these levels are reported for the first time, and hence they should be a good complement to the measured lifetime data of 10 levels previously published in the literature. The pseudorelativistic Hartree–Fock including core-polarization corrections method was used to calculate the lifetimes and branching fractions (BFs) of the investigated energy levels. Combining the experimental lifetime with the theoretical BFs, the transition probabilities and oscillator strengths for 124 transitions were determined.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The BAT AGN Spectroscopic Survey (BASS) is designed to provide a highly complete census of the key physical parameters of the supermassive black holes (SMBHs) that power local active galactic nuclei (AGNs) (<jats:italic>z</jats:italic> ≲ 0.3), including their bolometric luminosity (<jats:italic>L</jats:italic> <jats:sub>bol</jats:sub>), black hole (BH) mass (<jats:italic>M</jats:italic> <jats:sub>BH</jats:sub>), accretion rates (<jats:italic>L</jats:italic> <jats:sub>bol</jats:sub>/<jats:italic>L</jats:italic> <jats:sub>Edd</jats:sub>), line-of-sight gas obscuration (<jats:italic>N</jats:italic> <jats:sub>H</jats:sub>), and the distinctive properties of their host galaxies (e.g., star formation rates, masses, and gas fractions). We present an overview of the second data release of BASS (DR2), an unprecedented spectroscopic AGN survey in spectral range, resolution, and sensitivity, including 1449 optical (∼3200 Å–1 <jats:italic>μ</jats:italic>m) and 233 near-IR (1–2.5 <jats:italic>μ</jats:italic>m) spectra for the brightest 858 ultrahard X-ray (14–195 keV) selected AGNs across the entire sky and essentially all levels of obscuration. This release provides a highly complete set of key measurements (emission-line measurements and central velocity dispersions), with 99.9% measured redshifts and 98% BH masses estimated (for unbeamed AGNs outside the Galactic plane). The BASS DR2 AGN sample represents a unique census of nearby powerful AGNs, spanning over 5 orders of magnitude in AGN bolometric luminosity (<jats:italic>L</jats:italic> <jats:sub>bol</jats:sub> ∼ 10<jats:sup>40</jats:sup>–10<jats:sup>47</jats:sup> erg s<jats:sup>−1</jats:sup>), BH mass (<jats:italic>M</jats:italic> <jats:sub>BH</jats:sub> ∼ 10<jats:sup>5</jats:sup>–10<jats:sup>10</jats:sup> <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>), Eddington ratio (<jats:italic>L</jats:italic> <jats:sub>bol</jats:sub>/<jats:italic>L</jats:italic> <jats:sub>Edd</jats:sub> ≳ 10<jats:sup>−5</jats:sup>), and obscuration (<jats:italic>N</jats:italic> <jats:sub>H</jats:sub> ∼ 10<jats:sup>20</jats:sup>–10<jats:sup>25</jats:sup> cm<jats:sup>−2</jats:sup>). The public BASS DR2 sample and measurements can thus be used to answer fundamental questions about SMBH growth and its links to host galaxy evolution and feedback in the local universe, as well as open questions concerning SMBH physics. Here we provide a brief overview of the survey strategy, the key BASS DR2 measurements, data sets and catalogs, and scientific highlights from a series of DR2-based works pursued by the BASS team.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We present the active galactic nucleus (AGN) catalog and optical spectroscopy for the second data release of the Swift BAT AGN Spectroscopic Survey (BASS DR2). With this DR2 release we provide 1449 optical spectra, of which 1182 are released for the first time, for the 858 hard-X-ray-selected AGNs in the Swift BAT 70-month sample. The majority of the spectra (801/1449, 55%) are newly obtained from Very Large Telescope (VLT)/X-shooter or Palomar/Doublespec. Many of the spectra have both higher resolution (<jats:italic>R</jats:italic> &gt; 2500, <jats:italic>N</jats:italic> ∼ 450) and/or very wide wavelength coverage (3200–10000 Å, <jats:italic>N</jats:italic> ∼ 600) that are important for a variety of AGN and host galaxy studies. We include newly revised AGN counterparts for the full sample and review important issues for population studies, with 47 AGN redshifts determined for the first time and 790 black hole mass and accretion rate estimates. This release is spectroscopically complete for all AGNs (100%, 858/858), with 99.8% having redshift measurements (857/858) and 96% completion in black hole mass estimates of unbeamed AGNs (722/752). This AGN sample represents a unique census of the brightest hard-X-ray-selected AGNs in the sky, spanning many orders of magnitude in Eddington ratio (<jats:italic>L</jats:italic>/<jats:italic>L</jats:italic> <jats:sub>Edd</jats:sub> = 10<jats:sup>−5</jats:sup>–100), black hole mass (<jats:italic>M</jats:italic> <jats:sub>BH</jats:sub> = 10<jats:sup>5</jats:sup>–10<jats:sup>10</jats:sup> <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>), and AGN bolometric luminosity (<jats:italic>L</jats:italic> <jats:sub>bol</jats:sub> = 10<jats:sup>40</jats:sup>–10<jats:sup>47</jats:sup> erg s<jats:sup>−1</jats:sup> ).</jats:p>

<jats:title>Abstract</jats:title> <jats:p>In this study, we use the Swift/BAT AGN sample, which has received extensive multiwavelength follow-up analysis as a result of the BAT AGN Spectroscopic Survey, to develop a diagnostic for nuclear obscuration by examining the relationship between the line-of-sight column densities (<jats:italic>N</jats:italic> <jats:sub>H</jats:sub>), the 2–10 keV to 12 <jats:italic>μ</jats:italic>m luminosity ratio, and WISE mid-infrared colors. We demonstrate that heavily obscured AGNs tend to exhibit both preferentially “redder” mid-infrared colors and lower values of <jats:italic>L</jats:italic> <jats:sub>X,Obs.</jats:sub>/<jats:italic>L</jats:italic> <jats:sub>12 <jats:italic>μ</jats:italic>m</jats:sub> than less obscured AGNs, and we derive expressions relating <jats:italic>N</jats:italic> <jats:sub>H</jats:sub> to the <jats:italic>L</jats:italic> <jats:sub>X,Obs.</jats:sub>/<jats:italic>L</jats:italic> <jats:sub>12 <jats:italic>μ</jats:italic>m</jats:sub> and <jats:italic>L</jats:italic> <jats:sub>22 <jats:italic>μ</jats:italic>m</jats:sub>/<jats:italic>L</jats:italic> <jats:sub>4.6 <jats:italic>μ</jats:italic>m</jats:sub> luminosity ratios, as well as develop diagnostic criteria using these ratios. Our diagnostic regions yield samples that are ≳80% complete and ≳60% pure for AGNs with log(<jats:italic>N</jats:italic> <jats:sub>H</jats:sub>/cm<jats:sup>−2</jats:sup>) ≥ 24, as well as ≳85% pure for AGNs with <jats:inline-formula> <jats:tex-math> <?CDATA $\mathrm{log}({N}_{{\rm{H}}}/{\mathrm{cm}}^{-2})\gtrsim 23.5$?> </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>N</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">H</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy="true">/</mml:mo> </mml:mrow> <mml:msup> <mml:mrow> <mml:mi>cm</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> <mml:mo stretchy="false">)</mml:mo> <mml:mo>≳</mml:mo> <mml:mn>23.5</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjsac5b65ieqn1.gif" xlink:type="simple" /> </jats:inline-formula>. We find that these diagnostics cannot be used to differentiate between optically star-forming galaxies and active galaxies. Further, mid-IR contributions from host galaxies that dominate the observed 12 <jats:italic>μ</jats:italic>m emission can lead to larger apparent X-ray deficits and redder mid-IR colors than the AGNs would intrinsically exhibit, though this effect helps to better separate less and more obscured AGNs. Finally, we test our diagnostics on two catalogs of AGNs and infrared galaxies, including the XMM-Newton XXL-N field, and we identify several known Compton-thick AGNs, as well as a handful of candidate heavily obscured AGNs based upon our proposed obscuration diagnostics.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We present the second catalog and data release of optical spectral line measurements and active galactic nucleus (AGN) demographics of the BAT AGN Spectroscopic Survey, which focuses on the Swift-BAT hard X-ray detected AGNs. We use spectra from dedicated campaigns and publicly available archives to investigate spectral properties of most of the AGNs listed in the 70 month Swift-BAT all-sky catalog; specifically, 743 of the 746 unbeamed and unlensed AGNs (99.6%). We find a good correspondence between the optical emission line widths and the hydrogen column density distributions using the X-ray spectra, with a clear dichotomy of AGN types for <jats:italic>N</jats:italic> <jats:sub>H</jats:sub> = 10<jats:sup>22</jats:sup> cm<jats:sup>−2</jats:sup>. Based on optical emission-line diagnostics, we show that 48%–75% of BAT AGNs are classified as Seyfert, depending on the choice of emission lines used in the diagnostics. The fraction of objects with upper limits on line emission varies from 6% to 20%. Roughly 4% of the BAT AGNs have lines too weak to be placed on the most commonly used diagnostic diagram, [O <jats:sc>iii</jats:sc>]<jats:italic>λ</jats:italic>5007/H<jats:italic>β</jats:italic> versus [N <jats:sc>ii</jats:sc>]<jats:italic>λ</jats:italic>6584/H<jats:italic>α</jats:italic>, despite the high signal-to-noise ratio of their spectra. This value increases to 35% in the [O <jats:sc>iii</jats:sc>]<jats:italic>λ</jats:italic>5007/[O <jats:sc>ii</jats:sc>]<jats:italic>λ</jats:italic>3727 diagram, owing to difficulties in line detection. Compared to optically selected narrow-line AGNs in the Sloan Digital Sky Survey, the BAT narrow-line AGNs have a higher rate of reddening/extinction, with H<jats:italic>α</jats:italic>/H<jats:italic>β</jats:italic> &gt; 5 (∼36%), indicating that hard X-ray selection more effectively detects obscured AGNs from the underlying AGN population. Finally, we present a subpopulation of AGNs that feature complex broad lines (34%, 250/743) or double-peaked narrow emission lines (2%, 17/743).</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We present measurements of broad emission lines and virial estimates of supermassive black hole masses (<jats:italic>M</jats:italic> <jats:sub>BH</jats:sub>) for a large sample of ultrahard X-ray-selected active galactic nuclei (AGNs) as part of the second data release of the BAT AGN Spectroscopic Survey (BASS/DR2). Our catalog includes <jats:italic>M</jats:italic> <jats:sub>BH</jats:sub> estimates for a total of 689 AGNs, determined from the H<jats:italic>α</jats:italic>, H<jats:italic>β</jats:italic>, Mg <jats:sc>ii</jats:sc> <jats:italic>λ</jats:italic>2798, and/or C <jats:sc>iv</jats:sc> <jats:italic>λ</jats:italic>1549 broad emission lines. The core sample includes a total of 512 AGNs drawn from the 70 month Swift/BAT all-sky catalog. We also provide measurements for 177 additional AGNs that are drawn from deeper Swift/BAT survey data. We study the links between <jats:italic>M</jats:italic> <jats:sub>BH</jats:sub> estimates and line-of-sight obscuration measured from X-ray spectral analysis. We find that broad H<jats:italic>α</jats:italic> emission lines in obscured AGNs (<jats:inline-formula> <jats:tex-math> <?CDATA $\mathrm{log}({N}_{{\rm{H}}}/{\mathrm{cm}}^{-2})\gt 22.0$?> </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>N</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">H</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy="true">/</mml:mo> </mml:mrow> <mml:msup> <mml:mrow> <mml:mi>cm</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> <mml:mo stretchy="false">)</mml:mo> <mml:mo>&gt;</mml:mo> <mml:mn>22.0</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjsac6602ieqn1.gif" xlink:type="simple" /> </jats:inline-formula>) are on average a factor of <jats:inline-formula> <jats:tex-math> <?CDATA ${8.0}_{-2.4}^{+4.1}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>8.0</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>2.4</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>4.1</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjsac6602ieqn2.gif" xlink:type="simple" /> </jats:inline-formula> weaker relative to ultrahard X-ray emission and about <jats:inline-formula> <jats:tex-math> <?CDATA ${35}_{-12}^{\,+7}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>35</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>12</mml:mn> </mml:mrow> <mml:mrow> <mml:mspace width="0.25em" /> <mml:mo>+</mml:mo> <mml:mn>7</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjsac6602ieqn3.gif" xlink:type="simple" /> </jats:inline-formula>% narrower than those in unobscured sources (i.e., <jats:inline-formula> <jats:tex-math> <?CDATA $\mathrm{log}({N}_{{\rm{H}}}/{\mathrm{cm}}^{-2})\lt 21.5$?> </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>N</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">H</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy="true">/</mml:mo> </mml:mrow> <mml:msup> <mml:mrow> <mml:mi>cm</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> <mml:mo stretchy="false">)</mml:mo> <mml:mo>&lt;</mml:mo> <mml:mn>21.5</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjsac6602ieqn4.gif" xlink:type="simple" /> </jats:inline-formula>). This indicates that the innermost part of the broad-line region is preferentially absorbed. Consequently, current single-epoch <jats:italic>M</jats:italic> <jats:sub>BH</jats:sub> prescriptions result in severely underestimated (&gt;1 dex) masses for Type 1.9 sources (AGNs with broad H<jats:italic>α</jats:italic> but no broad H<jats:italic>β</jats:italic>) and/or sources with <jats:inline-formula> <jats:tex-math> <?CDATA $\mathrm{log}({N}_{{\rm{H}}}/{\mathrm{cm}}^{-2})\gtrsim 22.0$?> </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>N</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">H</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy="true">/</mml:mo> </mml:mrow> <mml:msup> <mml:mrow> <mml:mi>cm</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> <mml:mo stretchy="false">)</mml:mo> <mml:mo>≳</mml:mo> <mml:mn>22.0</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjsac6602ieqn5.gif" xlink:type="simple" /> </jats:inline-formula>. We provide simple multiplicative corrections for the observed luminosity and width of the broad H<jats:italic>α</jats:italic> component (<jats:italic>L</jats:italic>[bH<jats:italic>α</jats:italic>] and FWHM[bH<jats:italic>α</jats:italic>]) in such sources to account for this effect and to (partially) remedy <jats:italic>M</jats:italic> <jats:sub>BH</jats:sub> estimates for Type 1.9 objects. As a key ingredient of BASS/DR2, our work provides the community with the data needed to further study powerful AGNs in the low-redshift universe.</jats:p>