Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title> <jats:p>We investigate the [O <jats:sc>ii</jats:sc>] emission-line galaxy (ELG)-host halo connection via auto and cross correlations, and propose a concise and effective method to populate ELGs in dark matter halos without assuming a parameterized halo occupation distribution (HOD) model. Using the observational data from VIMOS Public Extragalactic Redshift Survey, we measure the auto and cross correlation functions between ELGs selected by [O <jats:sc>ii</jats:sc>] luminosity and normal galaxies selected by stellar mass. Combining the stellar–halo mass relation derived for the normal galaxies and the fraction of ELGs observed in the normal galaxy population, we demonstrate that we can establish an accurate ELG–halo connection. With the ELG–halo connection, we can accurately reproduce the auto and cross correlation functions of ELGs and normal galaxies both in real space and in redshift space, once the satellite fraction is properly reduced. Our method provides a novel strategy to generate ELG mock catalogs for ongoing and upcoming galaxy redshift surveys. We also provide a simple description for the HOD of ELGs.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We present observations of three core-collapse supernovae (CCSNe) in elliptical hosts, detected by the Zwicky Transient Facility Bright Transient Survey (BTS). SN 2019ape is a SN Ic that exploded in the main body of a typical elliptical galaxy. Its properties are consistent with an explosion of a regular SN Ic progenitor. A secondary <jats:italic>g</jats:italic>-band light-curve peak could indicate interaction of the ejecta with circumstellar material (CSM). An H<jats:italic>α</jats:italic>-emitting source at the explosion site suggests a residual local star formation origin. SN 2018fsh and SN 2020uik are SNe II which exploded in the outskirts of elliptical galaxies. SN 2020uik shows typical spectra for SNe II, while SN 2018fsh shows a boxy nebular H<jats:italic>α</jats:italic> profile, a signature of CSM interaction. We combine these 3 SNe with 7 events from the literature and analyze their hosts as a sample. We present multi-wavelength photometry of the hosts, and compare this to archival photometry of all BTS hosts. Using the spectroscopically complete BTS, we conclude that <jats:inline-formula> <jats:tex-math> <?CDATA $0.3{ \% }_{-0.1}^{+0.3}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>0.3</mml:mn> <mml:msubsup> <mml:mrow> <mml:mo>%</mml:mo> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.1</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.3</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac4709ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> of all CCSNe occur in elliptical galaxies. We derive star formation rates and stellar masses for the host galaxies and compare them to the properties of other SN hosts. We show that CCSNe in ellipticals have larger physical separations from their hosts compared to SNe Ia in elliptical galaxies, and discuss implications for star-forming activity in elliptical galaxies.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We study X-ray and soft gamma-ray spectra from the hard state of the accreting black hole binary MAXI J1820+070. We perform an analysis of joint spectra from HXMT, NuSTAR, and INTEGRAL. We find an overall agreement between the spectra from all three satellites. Satisfactory fits to the data require substantial spectral complexity, with our models including two Comptonization regions and their associated disk reflection, a disk blackbody, and a narrow Fe K<jats:italic>α</jats:italic> line. Our fits confirm the presence of the truncation of the reflecting optically thick disk at least at &gt;10 gravitational radii. However, we find that the HXMT data alone cannot significantly constrain the disk inner radii.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Through phase-space mapping 6 yr of H<jats:sup>+</jats:sup>, O<jats:sup>+</jats:sup>, and <jats:inline-formula> <jats:tex-math> <?CDATA ${{\rm{O}}}_{2}^{+}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mi mathvariant="normal">O</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> </mml:mrow> </mml:msubsup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac4606ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> distributions measured in situ by the Mars Atmosphere and Volatiles EvolutioN (MAVEN) orbiter, we derive semiempirical average energetic neutral atom (ENA) distributions near Mars. Differential fluxes of H-ENAs and O-ENAs are estimated by line-integrating ENA production and loss rates in the average phase-space ion distributions. By repeating the procedure for a systematic series of vantage points, we produce synthetic ENA observations for virtual circular orbits with radii twice that of Mars, revealing the angular dependence of the observer’s position. Accounting for known ENA production and loss terms, we find that H<jats:sup>+</jats:sup> in the upstream solar wind yields total antisunward H-ENA fluxes of ∼3 × 10<jats:sup>5</jats:sup> cm<jats:sup>−2</jats:sup> s<jats:sup>−1</jats:sup>. The dayside magnetosheath produces H-ENA angular-differential fluxes of up to 3 × 10<jats:sup>5</jats:sup> cm<jats:sup>−2</jats:sup> s<jats:sup>−1</jats:sup> sr<jats:sup>−1</jats:sup>, while the magnetosheath flanks populate the planet’s nightside with H-ENA fluxes in the range of 10<jats:sup>4</jats:sup>–10<jats:sup>5</jats:sup> cm<jats:sup>−2</jats:sup> s<jats:sup>−1</jats:sup> sr<jats:sup>−1</jats:sup>. The O-ENA environment is dominated by a near-isotropic ∼10<jats:sup>5</jats:sup> cm<jats:sup>−2</jats:sup> s<jats:sup>−1</jats:sup> sr<jats:sup>−1</jats:sup> relatively low-energy (tens of eV) population originating in the top-side ionosphere, particularly on the dayside. Lower fluxes (10<jats:sup>3</jats:sup>–10<jats:sup>4</jats:sup> cm<jats:sup>−2</jats:sup> s<jats:sup>−1</jats:sup> sr<jats:sup>−1</jats:sup>) of energetic O-ENAs (≳100 eV) are mainly found on the nightside and above the electric polar regions of the induced magnetosphere. Asymmetries in the ENA flow are largely limited to the energetic O-ENA populations, while the H-ENA distribution is mostly symmetric around the Sun‒Mars line. We discuss how synthetic ENA observations can provide insight into the near-Mars space environment, including the planet’s plasma environment and exosphere.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The habitability of planets around M dwarfs (≲0.5 <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>) can be affected by the X-rays + extreme UV (XUV) emission of these stars, with flares occasionally increasing the XUV flux by more than 2 orders of magnitude above quiescent levels. This wavelength range can warm and ionize terrestrial planets’ upper atmospheres, which expands the planetary radius and promotes atmospheric loss. In this work, we study the contribution of the XUV flux due to flares on the atmospheric escape of Earth-like planets orbiting M dwarfs through numerical simulations. We considered the first Gyr of planets with initial surface water abundances between 1 and 10 terrestrial oceans (TO), a small primordial hydrogen envelope (≤10<jats:sup>−3</jats:sup> <jats:italic>M</jats:italic> <jats:sub>⊕</jats:sub>), and with host-star masses between 0.2 and 0.6 <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>. In this parameter range, we find that flares can remove up to two TO more than nonflaring stars, which, in some cases, translates to a doubling of the total water loss. We also find that flaring can increase atmospheric oxygen partial pressures by hundreds of bars in some cases. These results were obtained by adding a new module for flares to the <jats:monospace>VPLanet</jats:monospace> software package and upgrading its atmospheric escape module to account for Roche lobe overflow and radiation/recombination-limited escape.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>A photometric and spectroscopic investigation is performed on five W Ursae Majoris eclipsing binaries J015818.6+260247 (hereinafter as J0158b), J073248.4+405538 (hereinafter as J0732), J101330.8+494846 (hereinafter as J1013), J132439.8+130747 (hereinafter as J1324), and J152450.7+245943 (hereinafter as J1524). The photometric data are collected with the help of the 1.3 m Devasthal Fast Optical Telescope, the 1.04 m Sampurnanand Telescope, and the Transiting Exoplanet Survey Satellite space mission. The low-resolution spectra of the 4 m Large Sky Area Multi-Object Fiber Spectroscopic Telescope are used for spectroscopic analysis. The orbital period change of these systems is determined using our photometric data and previously available photometric data from different surveys. The orbital period of J1013 and J1524 is changing at a rate of −2.552 (±0.249) × 10<jats:sup>−7</jats:sup> days yr<jats:sup>−1</jats:sup> and −6.792( ±0.952) × 10<jats:sup>−8</jats:sup> days yr<jats:sup>−1</jats:sup>, respectively, while others do not show any orbital period change. The orbital period change of J1013 and J1524 corresponds to a mass transfer rate of 2.199 × 10<jats:sup>−7</jats:sup> <jats:italic> </jats:italic>and 6.151 × 10<jats:sup>−8</jats:sup> <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub> yr<jats:sup>−1</jats:sup> from the primary to the secondary component in these systems. It is likely that angular momentum loss via magnetic braking may also be responsible for the observed orbital period change in the case of J1524. All systems have a mass ratio lower than 0.5, except J0158b with a mass ratio of 0.71. All the systems are shallow-type contact binaries. J0158b and J1524 are subtype A while others are subtype W. The H<jats:sub> <jats:italic>α</jats:italic> </jats:sub> emission line region is compared with template spectra prepared using two inactive stars with the help of the STARMOD program. The J0158, J1324, and J1524 systems show excess emission in the residual spectra after subtraction of the template.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The astrometric satellite Gaia is expected to observe noninteracting black hole (BH) binaries with luminous companions (LCs; hereafter BH-LC binaries), a different population from BH X-ray binaries previously discovered. The detectability of BH-LC binaries with Gaia might be dependent on binary evolution models. We investigated the Gaia's detectability of BH-LC binaries formed through isolated binary evolution by means of the binary population synthesis technique and examined its dependence on single and binary star models: supernova models, common envelope (CE) ejection efficiency <jats:italic>α</jats:italic>, and BH natal kick models. We estimated that 1.1–46 BH-LC binaries can be detected within the five-year observation, and found that <jats:italic>α</jats:italic> has the largest impact on the detectable number. In each model, observable and intrinsic BH-LC binaries have similar distributions. Therefore, we found three important implications: (1) if the lower BH mass gap is not intrinsic (i.e., 3–5 <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub> BHs exist), Gaia will observe ≤5 <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub> BHs; (2) we may observe short orbital period binaries with light LCs if CE efficiency is significantly high; and (3) we may be able to identify the existence of natal kick from eccentricity distribution.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We present results from high-resolution (<jats:italic>R</jats:italic> ∼ 40,000) spectroscopic observations of over 200 metal-poor stars, mostly selected from the RAVE survey, using the Southern African Large Telescope. We were able to derive stellar parameters for a total of 108 stars; an additional sample of 50 stars from this same effort was previously reported on by Rasmussen et al. Among our newly reported observations, we identify 84 very metal-poor (VMP; [Fe/H] &lt; −2.0, 53 newly identified) stars and three extremely metal-poor (EMP; [Fe/H] &lt; −3.0, one newly identified) stars. The elemental abundances were measured for carbon, as well as several other <jats:italic>α</jats:italic>-elements (Mg, Ca, Sc, and Ti), iron-peak elements (Mn, Co, Ni, and Zn), and neutron-capture elements (Sr, Ba, and Eu). Based on these measurements, the stars are classified by their carbon and neutron-capture abundances into carbon-enhanced metal-poor (CEMP; [C/Fe] &gt; +0.70), CEMP subclasses, and by the level of their <jats:italic>r</jats:italic>-process abundances. A total of 17 are classified as CEMP stars. There are 11 CEMP-<jats:italic>r</jats:italic> stars (eight newly identified), one CEMP-<jats:italic>s</jats:italic> star (newly identified), two possible CEMP-<jats:italic>i</jats:italic> stars (one newly identified), and three CEMP-no stars (all newly identified) in this work. We found 11 stars (eight newly identified) that are strongly enhanced in <jats:italic>r</jats:italic>-process elements (<jats:italic>r</jats:italic>-II; [Eu/Fe] &gt; +0.70), 38 stars (31 newly identified) that are moderately enhanced in <jats:italic>r</jats:italic>-process elements (<jats:italic>r</jats:italic>-I; +0.30 &lt; [Eu/Fe] ≤ + 0.70), and one newly identified limited-<jats:italic>r</jats:italic> star.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Most of the baryons in <jats:italic>L</jats:italic>* galaxies are unaccounted for and are predicted to lie in hot gaseous halos (<jats:italic>T</jats:italic> ∼ 10<jats:sup>6.5</jats:sup> K) that may extend beyond <jats:italic>R</jats:italic> <jats:sub>200</jats:sub>. A hot gaseous halo will produce a thermal Sunyaev–Zeldovich signal that is proportional to the product of the gas mass and the mass-weighted temperature. To best detect this signal, we used a Needlet Independent Linear Combination all-sky Planck map that we produced from the most recent Planck data release, also incorporating WMAP data. The sample is 12 <jats:italic>L</jats:italic>* spiral galaxies with distances of 3−10 Mpc, which are spatially resolved so that contamination from the optical galaxy can be excluded. One galaxy, NGC 891, has a particularly strong SZ signal, and when excluding it, the stack of 11 galaxies is detected at about 4<jats:italic>σ</jats:italic> (declining with radius) and is extended to at least 250 kpc (≈<jats:italic>R</jats:italic> <jats:sub>200</jats:sub>) at &gt;99% confidence. The gas mass within a spherical volume to a radius of 250 kpc is 9.8 ± 2.8 × 10<jats:sup>10</jats:sup> <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>, for <jats:italic>T</jats:italic> <jats:sub>avg</jats:sub> = 3 × 10<jats:sup>6</jats:sup> K. This is about 30% of the predicted baryon content of the average galaxy (3.1 × 10<jats:sup>11</jats:sup> <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>), and about equal to the mass of stars, disk gas, and warm halo gas. The remaining missing baryons (≈1.4 × 10<jats:sup>11</jats:sup> <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>, 40%–50% of the total baryon content) are likely to be hot and extend to the 400–500 kpc volume, if not beyond. The result is higher than predictions, but within the uncertainties.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We report on the interstellar scintillation from pulsar J2048−1616 for the first time at 732, 1369, and 3100 MHz observed with the Parkes 64 m radio telescope. Dynamic spectra are obtained and diffractive parameters are derived from two-dimensional autocorrelation analyses. The frequency dependencies of the observed diffractive scintillation timescale and decorrelation bandwidth indicate that the electron density fluctuations in the interstellar medium (ISM) do not follow the Kolmogorov spectrum. The secondary spectra are calculated by forming the Fourier power spectra of the corresponding dynamic spectra. Prominent parabolic arcs are revealed in the secondary spectra at three frequencies, which indicate that they originated from scattering by a thin screen. The scattering screen is approximately located centrally between the pulsar and Earth assuming that the ISM is stationary.</jats:p>