Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title> <jats:p>We present preliminary results of a submillimeter spectral line survey of a strongly lensed dusty star-forming galaxy (DSFG) at <jats:italic>z</jats:italic> ∼ 2, near the peak epoch of cosmic star formation. We use data from the Submillimeter Array, which recently completed a systems upgrade that substantially increased the instantaneous bandwidth. Focusing on the brightest spectral lines of CO and atomic carbon, we characterize the interstellar medium properties of this galaxy. We find highly excited CO and [C <jats:sc>i</jats:sc>] emission, and a large [C <jats:sc>i</jats:sc>] line ratio implies a higher excitation temperature than other extreme high-redshift sources. Based on this evidence, we infer that the source likely hosts a dust-obscured active galactic nucleus similar to other well-studied DSFGs.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We use a stacking method to study the radial light profiles of luminous red galaxies (LRGs) at redshift ∼0.62 and ∼0.25, out to a radial range of 200 kpc. We do not find noticeable evolution of the profiles at the two redshifts. The LRG profiles appear to be well approximated by a single Sérsic profile, although some excess light can be seen outside 60 kpc. We quantify the excess light by measuring the integrated flux and find that the excess is about 10%—a non-dominant but still nonnegligible component.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The DESI survey will measure large-scale structure using quasars as direct tracers of dark matter in the redshift range 0.9 &lt; <jats:italic>z</jats:italic> &lt; 2.1 and using quasar Ly<jats:italic>α</jats:italic> forests at <jats:italic>z</jats:italic> &gt; 2.1. We present two methods to select candidate quasars for DESI based on imaging in three optical (<jats:italic>g</jats:italic>, <jats:italic>r</jats:italic>, <jats:italic>z</jats:italic>) and two infrared (<jats:italic>W</jats:italic>1, <jats:italic>W</jats:italic>2) bands. The first method uses traditional color cuts and the second utilizes a machine-learning algorithm.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>DESI will precisely constrain cosmic expansion and the growth of structure by collecting ∼35 million redshifts across ∼80% of cosmic history and one third of the sky to study Baryon Acoustic Oscillations (BAO) and Redshift Space Distortions (RSD). We present a preliminary target selection for an Emission Line Galaxy (ELG) sample, which will comprise about half of all DESI tracers. The selection consists of a <jats:italic>g</jats:italic>-band magnitude cut and a (<jats:italic>g</jats:italic> − <jats:italic>r</jats:italic>) versus (<jats:italic>r</jats:italic> − <jats:italic>z</jats:italic>) color box, which we validate using HSC/PDR2 photometric redshifts and DEEP2 spectroscopy. The ELG target density should be ∼2400 deg<jats:sup>−2</jats:sup>, with ∼65% of ELG redshifts reliably within a redshift range of 0.6 &lt; <jats:italic>z</jats:italic> &lt; 1.6. ELG targeting for DESI will be finalized during a “Survey Validation” phase.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The DESI survey will observe more than 8 million candidate luminous red galaxies (LRGs) in the redshift range 0.3 &lt; <jats:italic>z</jats:italic> &lt; 1.0. Here we present a preliminary version of the DESI LRG target section developed using Legacy Surveys Data Release 8 <jats:italic>g</jats:italic>, <jats:italic>r</jats:italic>, <jats:italic>z</jats:italic> and <jats:italic>W</jats:italic>1 photometry. This selection yields a sample with a uniform surface density of ∼600 deg<jats:sup>−2</jats:sup> and very low predicted stellar contamination and redshift failure rates. During DESI Survey Validation, updated versions of this selection will be tested and optimized.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>A model of the brightness of the “visorsat” Starlink spacecraft is presented based on published information on the engineering design and 80 observations of individual visorsats. Comments are offered on the implications of this model on the visibility of visorsat spacecraft across the sky.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>X-ray missions with microcalorimeter technology will resolve spectral features with unprecedented detail. In this work, we improve the H-like K<jats:italic>α</jats:italic> energies for elements between 6 ≤ <jats:italic>Z</jats:italic> ≤ 30 for the release version of the spectral simulation code Cloudy to match laboratory energies. We update the ionization potential (<jats:italic>I</jats:italic> <jats:sub>ion</jats:sub>) for these elements and add a fourth-order polynomial to the level energy difference. This brings the release version of Cloudy into a near-perfect agreement with NIST. The updated energies are ∼15–4000 times more precise than that of the current release version of Cloudy (C17.02). These new changes will be a part of the next update to the release version, C17.03.</jats:p>