Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title> <jats:p>We present Gemini/NIFS near-IR integral field spectroscopy of the fields-of-view around two AGNs behind the Fermi Bubbles (<jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="object" xlink:href="PDS 456" xlink:type="simple">PDS 456</jats:named-content> and <jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="object" xlink:href="1H1613-097" xlink:type="simple">1H1613-097</jats:named-content> ) to search for molecular gas in the Milky Way’s nuclear wind. These two AGN sightlines were selected by the presence of high-velocity neutral and ionized gas seen in UV absorption. We do not detect any extended emission from the H<jats:sub>2</jats:sub> rovibrational S(0) and S(1) lines at 2.224 and 2.122 <jats:italic>μ</jats:italic>m in either direction. For the H<jats:sub>2</jats:sub> 1-0 S(1) line, the 3<jats:italic>σ</jats:italic> surface brightness limits derived from spectra extracted across the full 3″ × 3″ NIFS field-of-view are 2.4 × 10<jats:sup>−17</jats:sup> erg cm<jats:sup>−2</jats:sup> s<jats:sup>−1</jats:sup> Å<jats:sup>−1</jats:sup> arcsec<jats:sup>−2</jats:sup> for <jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="object" xlink:href="PDS 456" xlink:type="simple">PDS 456</jats:named-content> and 4.9 × 10<jats:sup>−18</jats:sup> erg cm<jats:sup>−2</jats:sup> s<jats:sup>−1</jats:sup> Å<jats:sup>−1</jats:sup> arcsec<jats:sup>−2</jats:sup> for <jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="object" xlink:href="1H1613-097" xlink:type="simple">1H1613-097</jats:named-content>. Given these non-detections, we conclude that CO emission studies and H<jats:sub>2</jats:sub> UV absorption studies are more promising approaches for characterizing molecular gas in the Fermi Bubbles.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The Gaia Data Release 2 provides precise astrometry for nearly 1.5 billion sources across the entire sky, including several thousand asteroids. In this work, we provide evidence that reasonably large asteroids (diameter &gt;20 km) have high correlations with Gaia relative flux uncertainties and systematic R.A. errors. We further capture these correlations using a logistic Bayesian additive regression tree model. We compile a small list of probable large asteroids that can be targeted for direct diameter measurements and shape reconstruction.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>unWISE is a wide-ranging data analysis effort aimed at repurposing the combined Wide-field Infrared Survey Explorer (WISE) plus NEOWISE imaging archive for Galactic and extragalactic astrophysics. We present updated static sky maps incorporating seven years of <jats:italic>W</jats:italic>1 (3.4 <jats:italic>μ</jats:italic>m) and <jats:italic>W</jats:italic>2 (4.6 <jats:italic>μ</jats:italic>m) single-exposure images, uniformly coadding nearly a quarter petabyte of input pixel data. These new unWISE atlases now constitute the deepest ever full-sky maps at wavelengths of 3–5 <jats:italic>μ</jats:italic>m, and will be used to select millions of Dark Energy Spectroscopic Instrument quasar and luminous red galaxy targets.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>There has always been interest in the perceived colors of stars. They were key to the development of the Hertzsprung–Russell diagram, and they are also used widely in educational and public-outreach imagery. Thus, it is useful to develop tools to compute these colors from spectral energy distributions. This paper presents a collection of objective (CIE coordinate) and subjective (RGB triple) colors for main-sequence stars and brown dwarfs, as well as links to related codes and tables. Using the proposed conversion from CIE to RGB colors, O and B stars are bluer than equivalent blackbodies because of Paschen continuum absorption, and M dwarfs tend to be less red and more beige. Although brown dwarfs over a wide range of effective temperatures (400–2000 K) emit most of their flux in the infrared, their visible spectra are dominated by short wavelengths. Thus, they may appear violet to human eyes.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Polytropes have long been used to model a wide variety of astrophysical objects. A bipolytrope (composite polytrope) may be used for bodies with a distinct core-envelope structure. In this short paper, I demonstrate that a rotating bipolytrope is a reasonable approximation for Jovian interior. Similar models may be used to probe rotating exoplanets to gain an intuitive understanding of their internal structure.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The coaddition of 21 mid ultraviolet spectra of 21 Com taken over the International Ultraviolet Explorer (IUE) mission reveals three strong lines of Mn <jats:sc>ii</jats:sc> at 2576.10, 2593.72 and 2605.68 Å. The synthesis of these lines consistently yields a sizable overabundance of manganese about 10 times the solar manganese abundance. Inspection of the 10 individual spectra taken over the 24 hr monitoring of 21 Com with IUE on 1991 April 17 does not reveal convincing variations of these lines between rotational phases 0.18 and 0.65 of the 2 days period.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Classical novae contribute to the cycle of chemical enrichment of the interstellar medium through through explosive nucleosynthesis and the violent ejection of material dredged from the white dwarf progenitor and mixed with the accreted surface layers. Analysis of archival NASA Spitzer spectroscopic observations of V2615 Ophiuchus shows that [O <jats:sc>iv</jats:sc>] 25.89 <jats:italic>μ</jats:italic>m is a strong coolant and that no evidence for deceleration of the ejecta was present ∼1000 days after outburst, based on observed Spitzer InfraRed Spectrograph emission line average FWHM velocities of ≃600 km s<jats:sup>−1</jats:sup>.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>General relativity effects coupled with those derived from the von Zeipel–Lidov–Kozai mechanism may play a significant role on the evolution of members of the Atira dynamical class, particularly in the case of those with the shortest sidereal orbital periods. Here, we provide a preliminary assessment of the short-term orbital evolution of 2021 PH<jats:sub>27</jats:sub>, a recently discovered Atira that has the shortest period among known asteroids. Our calculations, based on a publicly available orbit determination and including post-Newtonian terms in the numerical integrations, show that 2021 PH<jats:sub>27</jats:sub> is a robust member of the Atira class and it may indeed be used to explore the combined effects of general relativity and the von Zeipel–Lidov–Kozai mechanism once its orbit determination is sufficiently improved.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Stars form in clusters within giant molecular clouds. Spectroscopic observations can reveal radial velocities from which virial masses can be estimated. The question we are investigating is how accurate these estimates are with respect to the number of stars observed. We simulated virialized clusters with King model distributions and from these clusters we simulated mock observations. From these observations cluster sizes and virial masses are estimated, and empirical distribution functions are constructed. A confidence interval table is produced considering the number of objects observed and the ratio of velocity dispersion to observational uncertainty.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We report seven new eclipse timings for the novalike variable 1RXS J064434.5+334451. An analysis of our data, along with all previously available timings (36 published and 16 unpublished), yields a best-fitting linear ephemeris of BJD<jats:sub>ecl</jats:sub> = 2,453,403.7611(2) + 0.269,374,43(2)<jats:italic>E</jats:italic>. We find a somewhat improved fit with a quadratic ephemeris given by: BJD<jats:sub>ecl</jats:sub> = 2,453,403.7598 + 0.269,374,87 <jats:italic>E</jats:italic> − 2.0 × 10<jats:sup>−11</jats:sup>  <jats:italic>E</jats:italic> <jats:sup>2</jats:sup>, which suggests that the orbital period may be decreasing at a rate given by <jats:inline-formula> <jats:tex-math> <?CDATA $\dot{P}\simeq -1.5\times {10}^{-10}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mrow> <mml:mi>P</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>˙</mml:mo> </mml:mrow> </mml:mover> <mml:mo>≃</mml:mo> <mml:mo>−</mml:mo> <mml:mn>1.5</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>10</mml:mn> </mml:mrow> </mml:msup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="rnaasac2516ieqn1.gif" xlink:type="simple" /> </jats:inline-formula>.</jats:p>