|   | 
Details
   web
Records
Author Ahrer, E.M.; Alderson, L.; Batalha, N.M.; Batalha, N.E.; Bean, J.L.; Beatty, T.G.; Bell, T.J.; Benneke, B.; Berta-Thompson, Z.K.; Carter, A.L.; Crossfield, I.J.M.; Espinoza, N.; Feinstein, A.D.; Fortney, J.J.; Gibson, N.P.; Goyal, J.M.; Kempton, E.M.R.; Kirk, J.; Kreidberg, L.; Lopez-Morales, M.; Line, M.R.; Lothringer, J.D.; Moran, S.E.; Mukherjee, S.; Ohno, K.; Parmentier, V.; Piaulet, C.; Rustamkulov, Z.; Schlawin, E.; Sing, D.K.; Stevenson, K.B.; Wakeford, H.R.; Allen, N.H.; Birkmann, S.M.; Brande, J.; Crouzet, N.; Cubillos, P.E.; Damiano, M.; Desert, J.M.; Gao, P.; Harrington, J.; Hu, R.Y.; Kendrew, S.; Knutson, H.A.; Lagage, P.O.; Leconte, J.; Lendl, M.; MacDonald, R.J.; May, E.M.; Miguel, Y.; Molaverdikhani, K.; Moses, J.I.; Murray, C.A.; Nehring, M.; Nikolov, N.K.; de la Roche, D.J.M.P.D.; Radica, M.; Roy, P.A.; Stassun, K.G.; Taylor, J.; Waalkes, W.C.; Wachiraphan, P.; Welbanks, L.; Wheatley, P.J.; Aggarwal, K.; Alam, M.K.; Banerjee, A.; Barstow, J.K.; Blecic, J.; Casewell, S.L.; Changeat, Q.; Chubb, K.L.; Colon, K.D.; Coulombe, L.P.; Daylan, T.; De Val-Borro, M.; Decin, L.; Dos Santos, L.A.; Flagg, L.; France, K.; Fu, G.W.; Munoz, A.G.; Gizis, J.E.; Glidden, A.; Grant, D.; Heng, K.; Henning, T.; Hong, Y.C.; Inglis, J.; Iro, N.; Kataria, T.; Komacek, T.D.; Krick, J.E.; Lee, E.K.H.; Lewis, N.K.; Lillo-Box, J.; Lustig-Yaeger, J.; Mancini, L.; Mandell, A.M.; Mansfield, M.; Marley, M.S.; Mikal-Evans, T.; Morello, G.; Nixon, M.C.; Ceballos, K.O.; Piette, A.A.A.; Powell, D.; Rackham, B.V.; Ramos-Rosado, L.; Rauscher, E.; Redfield, S.; Rogers, L.K.; Roman, M.T.; Roudier, G.M.; Scarsdale, N.; Shkolnik, E.L.; Southworth, J.; Spake, J.J.; Steinrueck, M.E.; Tan, X.Y.; Teske, J.K.; Tremblin, P.; Tsai, S.M.; Tucker, G.S.; Turner, J.D.; Valenti, J.A.; Venot, O.; Waldmann, I.P.; Wallack, N.L.; Zhang, X.; Zieba, S.
Title Identification of carbon dioxide in an exoplanet atmosphere Type
Year 2023 Publication Nature Abbreviated Journal Nature
Volume Early Access Issue Pages
Keywords GIANT PLANETS; BROWN DWARFS; LINE LISTS; H2O; SKY
Abstract Carbon dioxide (CO2) is a key chemical species that is found in a wide range of planetary atmospheres. In the context of exoplanets, CO2 is an indicator of the metal enrichment (that is, elements heavier than helium, also called 'metallicity')(1-3), and thus the formation processes of the primary atmospheres of hot gas giants(4-6). It is also one of the most promising species to detect in the secondary atmospheres of terrestrial exoplanets(7-9). Previous photometric measurements of transiting planets with the Spitzer Space Telescope have given hints of the presence of CO2, but have not yielded definitive detections owing to the lack of unambiguous spectroscopic identification(10-12). Here we present the detection of CO2 in the atmosphere of the gas giant exoplanet WASP-39b from transmission spectroscopy observations obtained with JWST as part of the Early Release Science programme(13,14). The data used in this study span 3.0-5.5micrometres in wavelength and show a prominent CO2 absorption feature at 4.3micrometres (26-sigma significance). The overall spectrum is well matched by one-dimensional, ten-times solar metallicity models that assume radiative-convective-thermochemical equilibrium and have moderate cloud opacity. These models predict that the atmosphere should have water, carbon monoxide and hydrogen sulfide in addition to CO2, but little methane. Furthermore, we also tentatively detect a small absorption feature near 4.0micrometres that is not reproduced by these models.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0028-0836 ISBN Medium
Area Expedition Conference
Notes WOS:000927885000001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1760
Permanent link to this record
 

 
Author Allen, N.H.; Espinoza, N.; Jordan, A.; Lopez-Morales, M.; Apai, D.; Rackham, B.V.; Kirk, J.; Osip, D.J.; Weaver, I.C.; McGruder, C.; Ceballos, K.O.; Reggiani, H.; Brahm, R.; Rodler, F.; Lewis, N.K.; Fraine, J.
Title ACCESS: Tentative Detection of H2O in the Ground-based Optical Transmission Spectrum of the Low-density Hot Saturn HATS-5b Type
Year 2022 Publication Astronomical Journal Abbreviated Journal Astron. J.
Volume 164 Issue 4 Pages 153
Keywords BAYESIAN-INFERENCE; EXOPLANET; SKY; ATMOSPHERES; EFFICIENT; TOOL; CHEMISTRY; ASTROPY
Abstract We present a precise ground-based optical transmission spectrum of the hot Saturn HATS-5b (T (eq) = 1025 K), obtained as part of the ACCESS survey with the IMACS multi-object spectrograph mounted on the Magellan Baade Telescope. Our spectra cover the 0.5-0.9 mu m region and are the product of five individual transits observed between 2014 and 2018. We introduce the usage of additional second-order light in our analyses, which allows us to extract an “extra” transit light curve, improving the overall precision of our combined transit spectrum. We find that the favored atmospheric model for this transmission spectrum is a solar-metallicity atmosphere with subsolar C/O, whose features are dominated by H2O and with a depleted abundance of Na and K. If confirmed, this would point to a “clear” atmosphere at the pressure levels probed by transmission spectroscopy for HATS-5b. Our best-fit atmospheric model predicts a rich near-IR spectrum, which makes this exoplanet an excellent target for future follow-up observations with the James Webb Space Telescope, both to confirm this H2O detection and to superbly constrain the atmosphere's parameters.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-6256 ISBN Medium
Area Expedition Conference
Notes WOS:000856537200001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1650
Permanent link to this record
 

 
Author Carrasco-Davis, R.; Reyes, E.; Valenzuela, C.; Forster, F.; Estevez, P.A.; Pignata, G.; Bauer, F.E.; Reyes, I.; Sanchez-Saez, P.; Cabrera-Vives, G.; Eyheramendy, S.; Catelan, M.; Arredondo, J.; Castillo-Navarrete, E.; Rodriguez-Mancini, D.; Ruz-Mieres, D.; Moya, A.; Sabatini-Gacitua, L:, Sepulveda-Cobo, C.; Mahabal, A.A.; Silva-Farfan, J.; Camacho-Iniguez, E.; Galbany, L.
Title Alert Classification for the ALeRCE Broker System: The Real-time Stamp Classifier Type
Year 2021 Publication Astronomical Journal Abbreviated Journal Astron. J.
Volume 162 Issue 6 Pages 231
Keywords ASAS-SN CATALOG; CIRCUM; STELLAR MATERIAL; VARIABLE-STARS; IA SUPERNOVA; SKY; IDENTIFICATION
Abstract We present a real-time stamp classifier of astronomical events for the Automatic Learning for the Rapid Classification of Events broker, ALeRCE. The classifier is based on a convolutional neural network, trained on alerts ingested from the Zwicky Transient Facility (ZTF). Using only the science, reference, and difference images of the first detection as inputs, along with the metadata of the alert as features, the classifier is able to correctly classify alerts from active galactic nuclei, supernovae (SNe), variable stars, asteroids, and bogus classes, with high accuracy (similar to 94%) in a balanced test set. In order to find and analyze SN candidates selected by our classifier from the ZTF alert stream, we designed and deployed a visualization tool called SN Hunter, where relevant information about each possible SN is displayed for the experts to choose among candidates to report to the Transient Name Server database. From 2019 June 26 to 2021 February 28, we have reported 6846 SN candidates to date (11.8 candidates per day on average), of which 971 have been confirmed spectroscopically. Our ability to report objects using only a single detection means that 70% of the reported SNe occurred within one day after the first detection. ALeRCE has only reported candidates not otherwise detected or selected by other groups, therefore adding new early transients to the bulk of objects available for early follow-up. Our work represents an important milestone toward rapid alert classifications with the next generation of large etendue telescopes, such as the Vera C. Rubin Observatory.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-6256 ISBN Medium
Area Expedition Conference
Notes WOS:000714746100001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1499
Permanent link to this record
 

 
Author Saji, C.; Troncoso, R.E.; Carvalho-Santos, V.L.; Altbir, D.; Nunez, A.S.
Title Hopfion-Driven Magnonic Hall Effect and Magnonic Focusing Type
Year 2023 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 131 Issue 16 Pages 166702
Keywords MAGNETIC; SKYRMIONS
Abstract Hopfions are localized and topologically nontrivial magnetic configurations that have received considerable attention in recent years. In this Letter, we use a micromagnetic approach to analyze the scattering of spin waves (SWs) by magnetic hopfions. Our results evidence that SWs experience an electromagnetic field generated by the hopfion and sharing its topological properties. In addition, SWs propagating along the hopfion symmetry axis are deflected by the magnetic texture, which acts as a convergent or divergent lens, depending on the SWs' propagation direction. Assuming that SWs propagate along the plane perpendicular to the symmetry axis, the scattering is closely related to the Aharonov-Bohm effect, allowing us to identify the magnetic hopfion as a scattering center.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:001102983000014 Approved
Call Number UAI @ alexi.delcanto @ Serial 1922
Permanent link to this record
 

 
Author Sanchez-Saez, P.; Lira, H.; Marti, L.; Sanchez-Pi, N.; Arredondo, J.; Bauer, F.E.; Bayo, A.; Cabrera-Vives, G.; Donoso-Oliva, C.; Estevez, P.A.; Eyheramendy, S.; Forster, F.; Hernandez-Garcia, L.; Arancibia, A.M.M.; Perez-Carrasco, M.; Sepulveda, M.; Vergara, J.R.
Title Searching for Changing-state AGNs in Massive Data Sets. I. Applying Deep Learning and Anomaly-detection Techniques to Find AGNs with Anomalous Variability Behaviors Type
Year 2021 Publication Astronomical Journal Abbreviated Journal Astron. J.
Volume 162 Issue 5 Pages 206
Keywords DIGITAL SKY SURVEY; STRIPE 82 QUASARS; INFRARED VARIABILITY; GALACTIC NUCLEI; CLASSIFICATION
Abstract The classic classification scheme for active galactic nuclei (AGNs) was recently challenged by the discovery of the so-called changing-state (changing-look) AGNs. The physical mechanism behind this phenomenon is still a matter of open debate and the samples are too small and of serendipitous nature to provide robust answers. In order to tackle this problem, we need to design methods that are able to detect AGNs right in the act of changing state. Here we present an anomaly-detection technique designed to identify AGN light curves with anomalous behaviors in massive data sets. The main aim of this technique is to identify CSAGN at different stages of the transition, but it can also be used for more general purposes, such as cleaning massive data sets for AGN variability analyses. We used light curves from the Zwicky Transient Facility data release 5 (ZTF DR5), containing a sample of 230,451 AGNs of different classes. The ZTF DR5 light curves were modeled with a Variational Recurrent Autoencoder (VRAE) architecture, that allowed us to obtain a set of attributes from the VRAE latent space that describes the general behavior of our sample. These attributes were then used as features for an Isolation Forest (IF) algorithm that is an anomaly detector for a “one class” kind of problem. We used the VRAE reconstruction errors and the IF anomaly score to select a sample of 8809 anomalies. These anomalies are dominated by bogus candidates, but we were able to identify 75 promising CSAGN candidates.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-6256 ISBN Medium
Area Expedition Conference
Notes WOS:000709102700001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1483
Permanent link to this record