Article
Astronomy & Astrophysics
Richard Teague, Jaehan Bae, Sean M. Andrews, Myriam Benisty, Edwin A. Bergin, Stefano Facchini, Jane Huang, Cristiano Longarini, David Wilner
Summary: We present ALMA observations of the CO J = 2 - 1 and CS J = 5 - 4 emission from the disk around TW Hydrae, which shows a predominantly Keplerian velocity structure. The rotation velocity slows down at the outer edge of the disk due to enhanced pressure support from the gas density taper. Localized deviations in the gas kinematics traced by CO and CS are revealed, and both molecules exhibit a Doppler flip feature centered along the minor axis of the disk. The features are interpreted as interactions with a Saturn-mass planet within the observed gap, consistent with theoretical predictions.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Richard Teague, Jaehan Bae, Myriam Benisty, Sean M. Andrews, Stefano Facchini, Jane Huang, David Wilner
Summary: This study presents new observations of the protoplanetary disk around TW Hya, analyzing the CO J = 2 - 1 emission. The emission is detected up to 240 au (4 ''), showing azimuthal variations beyond 180 au (3 ''), with the west side of the disk being brighter. The observed asymmetry correlates with the previously seen shadow in scattered light, and the temporal evolution of the shadow is better explained by an oscillatory motion rather than orbital motion. The angular offset between the dust shadow and gas shadow is attributed to the finite rate at which dust grains and gas molecules exchange heat.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
A. Sicilia-Aguilar, J. Campbell-White, V Roccatagliata, J. Desira, S. G. Gregory, A. Scholz, M. Fang, F. Cruz-Saenz de Miera, A. Kospal, S. Matsumura, P. Abraham
Summary: This study examines the long-term spectroscopic and photometric variability of two young stars, EX Lupi and TW Hya, to explore the presence of stable accretion and its role in observed changes. The research reveals that the accretion columns of both stars are remarkably stable, while the continuum emission is highly variable. The analysis also uncovers further structures in the emission lines and suggests that stable accretion footprints could be used to identify young planets.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
K. L. Luhman
Summary: This study used high-precision photometry and astrometry to identify candidate members of the 32 Ori association and determined their membership using spectral types and UVW velocities. The spectral type distribution of the association is similar to other young clusters, and the association is expanding. The study also compared the age of the 32 Ori association with other star groups and found that it is younger than the beta Pic moving group. Additionally, disks were detected among the candidate members of the 32 Ori association.
ASTRONOMICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Mate Szilagyi, Maria Kun, Peter abraham, Gabor Marton
Summary: Using Gaia DR3 data, this study investigates the structure and kinematics of the Cepheus OB2 association and characterizes its star formation history, with particular focus on the Cepheus Bubble. Thirteen stellar groups belonging to Cep OB2 are identified using a clustering algorithm, with four older groups located inside the bubble and younger groups found on the periphery. The tangential velocities suggest different formation mechanisms, with some groups born in an expanding system of star-forming clouds and others formed due to collision with the expanding bubble.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
P. S. Teixeira, J. Alves, A. Sicilia-Aguilar, A. Hacar, A. Scholz
Summary: Analysis of Gaia DR2 data revealed a new young star association, Monoceros OB4, co-moving with the Monoceros OB1 cloud complex. This association contains an estimated 1400-2500 stars and is expanding, indicating a larger and more complex Monoceros star formation region with an elongated arrangement of at least 300 x 60 pc.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Clinical Neurology
Leanna M. Delhey, Xu Shi, Lewis B. Morgenstern, Devin L. Brown, Melinda A. Smith, Erin C. Case, Mellanie V. Springer, Lynda D. Lisabeth
Summary: This study found that higher neighborhood socioeconomic status and density of recreation centers are favorably associated with poststroke outcomes, indicating that these resources may play a beneficial role in stroke recovery and rehabilitation.
Article
Astronomy & Astrophysics
Yilun Ma, Robert J. De Rosa, Paul Kalas
Summary: High-contrast imaging studies of debris disks have shown a significant diversity in their morphologies, including large-scale asymmetries. This study provides empirical evidence for the theorized stellar flybys as a potential cause for these morphological variations. The findings suggest that there is no significant correlation between past flyby events and infrared excess detections.
ASTRONOMICAL JOURNAL
(2022)
Article
Psychiatry
Chan Shen, Lucy Rashiwala, R. Constance Wiener, Patricia A. Findley, Hao Wang, Usha Sambamoorthi
Summary: This study aimed to assess the association between COVID-19 vaccine approval and availability and the prevalence of depression and anxiety among adults in the United States. The findings showed that there were no significant differences in the rates of depression and anxiety between June 2020 and March 2021, indicating that the impact of the pandemic continues to persist despite widespread availability of vaccines.
FRONTIERS IN PSYCHIATRY
(2022)
Article
Astronomy & Astrophysics
Jeremy Heyl, Ilaria Caiazzo, Harvey B. Richer
Summary: This study searches through a vast volume surrounding the Pleiades star cluster and the Sun to identify current and past members of the cluster. The findings include 1300 current cluster members and 289 former cluster candidates. The study also reveals the loss of twenty percent of the cluster's mass over the past 100 million years, as well as the discovery of two massive white dwarf stars and a variable star.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Timothy D. Brandt
Summary: This study presents a cross-calibration of Hipparcos and Gaia EDR3, resulting in a new catalog that can be used to identify astrometrically accelerating stars and fit orbits to stars with faint, massive companions. The data shows that in the new edition of HGCA, precision is improved through measurements of long-term proper motion, and evidence of locally variable frame rotations is observed.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2021)
Article
Astronomy & Astrophysics
D. Annie Dickson-Vandervelde, Emily C. Wilson, Joel H. Kastner
Summary: The study utilized Gaia DR2 data to reassess the membership of epsilon Cha Association and confirmed its distance, age, and binary system statuses. Results indicated that epsilon CA is one of the youngest known stellar groups near Earth, with several new photometric binary candidates identified.
ASTRONOMICAL JOURNAL
(2021)
Article
Geography
Xinkai Yu, Teng Fei, Xiang Li
Summary: This study utilized social computing tools to extract emotional information from user-generated content and correlated it with the characteristics of census tracts, revealing the influence of social and economic factors on human emotions. The proposed approach can assist local policymakers in comparing the quality of human life in different regions and formulating policies to improve residents' well-being.
TRANSACTIONS IN GIS
(2021)
Article
Astronomy & Astrophysics
Panagiotis Gavras, Lorenzo Rimoldini, Krzysztof Nienartowicz, Gregory Jevardat de Fombelle, Berry Holl, Peter Abraham, Marc Audard, Maria I. Carnerero, Gisella Clementini, Joris De Ridder, Elisa Distefano, Pedro Garcia-Lario, Alessia Garofalo, Agnes Kospal, Katarzyna Kruszynska, Maria Kun, Isabelle Lecoeur-Taibi, Gabor Marton, Tsevi Mazeh, Nami Mowlavi, Claudia M. Raiteri, Vincenzo Ripepi, Laszlo Szabados, Shay Zucker, Laurent Eyer
Summary: The study aims to provide a comprehensive data set of known variable objects from literature that are cross-matched with Gaia DR3 sources. The data set covers various variability types and can be used for training, classification, and validation of machine-learning algorithms. Statistical methods were applied to identify the correct counterparts of known objects in the Gaia data, resulting in a catalog of 7,841,723 Gaia sources, including non-variable objects, galaxies, and variable sources.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Andrew Everall, Douglas Boubert, Sergey E. Koposov, Leigh Smith, Berry Holl
Summary: Gaia Data Release 2 (DR2) has revolutionized Galactic dynamics by providing positions, parallaxes, and proper motions for 1331 909 727 unprecedented sources. The astrometry spread function (ASF) offers a Gaussian function that can be used to characterize binary systems, exoplanet orbits, astrometric microlensing events, and extended sources. By estimating the unit weight error of Gaia DR2 sources through ASF, users can directly probe excess source noise and access the ASF module via the PYTHON package SCANNINGLAW.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)