Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title> <jats:p>The effects of solar activity on technology have increased the interest in solar forecasting both in the scientific community and in society. With two and a half years of data available, we are approximately halfway to the maximum of Solar Cycle 25. Several research groups around the world published their predictions for this cycle. In this work, we assess the forecast made by the Solar Cycle 25 Prediction Panel. Analyzing the sunspot number data available, we conclude that Solar Cycle 25 is one of the weakest cycles since mid-18th century and, however, it is stronger than the initial forecast of the highest range predicted by the Solar Cycle 25 Prediction Panel for the two first years and a half of its ascending phase.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The SNAD team reports the discovery of <jats:monospace>SNAD160</jats:monospace> (AT2018lzi) within the Zwicky Transient Facility third data release. The transient has been found using the active anomaly detection algorithm, an adaptive learning strategy aimed at incorporating expert knowledge into machine learning models. Our preliminary analysis shows that <jats:monospace>SNAD160</jats:monospace> could be a superluminous supernova powered by a pair-instability mechanism—its light curve behavior is consistent with the observed slow rise and slow decay expected from these events.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We investigate obscuration of Active Galactic Nuclei (AGNs), identified as Supermassive Black Holes (BH) in luminous galaxies. In this model, winds of plasma particles launched from the accretion disk are photoionized by hard X-ray continua from the AGN’s corona, resulting in obscuration in the X-ray band. Many X-ray spectroscopic observations suggest a majority of AGN are obscured by an intervening gas along our line of sight. Through photoionization calculations for selected wind solutions, we simulate the observed AGN obscuration distribution. We discuss the plausibility of the model by comparing our theoretical obscuration distribution to X-ray data by producing a library of synthetic absorption spectra of X-ray continua. Using our model’s obscuration findings, we show how the obscuration distribution is dependent on the model parameters.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>As an open cluster orbits the Milky Way, gravitational fields distort it, stripping stars from the core and forming tidal tails. Recent work has identified tidal tails of the Praesepe cluster; we explore rotation periods as a way to confirm these candidate members. In open clusters, the rotation period distribution evolves over time due to magnetic braking. Since tidally stripped stars originally formed within the cluster, they should follow the same period distribution as in the cluster core. We analyze 96 candidate members observed by NASA’s Transiting Exoplanet Survey Satellite mission. We measure reliable rotation periods for 32 stars, while 64 light curves are noise-dominated. The 32 newly identified rotators are consistent with the period distribution in the core, and with past membership in Praesepe. We therefore suggest that for nearby open clusters, stellar rotation offers a quick and inexpensive method for confirming past members dispersed into tidal tails.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>V1674 Her was not only the fastest nova on record, it was also a rare hybrid event, showing a transition between the Fe <jats:sc>ii</jats:sc> and He/N nova classes as early as 5.5 days after the outburst. Spectra now indicate the outburst is over; emission lines from the underlying binary system are now seen, although broad but weaker forbidden nebular emission lines are also present. Intriguing at this late evolutionary stage is a P Cygni-like line profile associated with H<jats:italic>α</jats:italic> suggesting the presence of a wind emanating from the binary system. The profile exhibits intensity and velocity variations perhaps correlated with its 0.153 day orbital period.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Modern galaxy simulations have reached the complexity required to create sophisticated mock catalogs. Ananke is a set of nine mock catalogs constructed from synthetic surveys of three Milky Way-like galaxies from the Latte suite of FIRE simulations. Ananke provides observed quantities for comparison with modern large-scale stellar surveys. In SDSS-IV DR17, mock catalogs for the Apache Point Galactic Evolution Experiment (APOGEE) were built from Ananke synthetic surveys as a Value-Added Catalog, but were only provided as large flat files (∼&gt;10's GB). Here we announce an &gt;40 Tb SQL database for nine APOGEE-specific mock catalogs and describe additions to the data model necessary for effective user queries. The catalogs can be accessed on the free, science platform, SciServer—supported by the Institute for Data Intensive Engineering and Science at the Johns Hopkins University (IDIES); SciServer supports server-side analysis with commonly used coding languages and tools.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The analysis of eighteen high resolution SWP spectra of the HgMn star HD 78316 (<jats:italic>κ</jats:italic> Cnc) recorded by the International Ultraviolet Explorer reveals that the far-ultraviolet flux of this star remained constant over the various observations with IUE. The TESS lightcurve of HD 78316 reveals a double-wave structure with a rotational period of about 6.25 days. The absence of far-ultraviolet variability and the reproducibility of the brightness in the <jats:italic>V</jats:italic> band during most IUE observations do not support the presence of large chemical gradients over the surface of <jats:italic>κ</jats:italic> Cnc at the time of the IUE observations.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We present WDJ220838.73+454434.04 (hereafter WD2208+454), a wide, co-moving white dwarf companion to the eclipsing binary system, AR Lacertae. The companion was discovered through the Backyard Worlds: Planet 9 citizen science collaboration. It has a separation of 21.″9 on the sky from the central eclipsing pair, translating to a projected separation of ∼930 au. We present a review of the physical properties and orbital parameters of this new addition to the system.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Galaxy morphological classification is a fundamental aspect of galaxy formation and evolution studies. Various machine learning tools have been developed for automated pipeline analysis of large-scale surveys, enabling a fast search for objects of interest. However, crowded regions in the image may pose a challenge as they can lead to bias in the learning algorithm. In this Research Note, we present <jats:monospace>galmask</jats:monospace>, an open-source package for unsupervised galaxy masking to isolate the central object of interest in the image. <jats:monospace>galmask</jats:monospace> is written in Python and can be installed from PyPI via the <jats:monospace>pip</jats:monospace> command.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We analyzed archival data of the warm Neptune HD 106315c, an exoplanet with an extended atmosphere orbiting an F-type star with a 21 days period. We used data from the HARPS instrument covering three transits and employed the high-resolution transmission spectroscopy technique. Our analysis yielded a non-detection of sodium with an upper limit of 0.24% on the depth of the planetary feature. This can hint at the presence of Rayleigh scattering in the atmosphere and/or clouds in the upper atmosphere. The HD 106315 system with its two Neptune-sized planets remains an intriguing target for comparative planetology in the starting era of JWST and the upcoming <jats:italic>Ariel</jats:italic> mission.</jats:p>