Search Publications
Very Local Interstellar Medium Revealed by a Complete Solar Cycle of Interstellar Neutral Helium Observations with IBEX
McComas, D. J.; Fuselier, S. A.; Galli, A. +8 more
The IBEX-Lo instrument on board the Interstellar Boundary Explorer (IBEX) mission samples interstellar neutral (ISN) helium atoms penetrating the heliosphere from the very local interstellar medium (VLISM). In this study, we analyze the IBEX-Lo ISN helium observations covering a complete solar cycle, from 2009 through 2020 using a comprehensive un…
Ninety-seven Eclipsing Quadruple Star Candidates Discovered in TESS Full-frame Images
Kostov, Veselin B.; Powell, Brian P.; Rappaport, Saul A. +17 more
We present a catalog of 97 uniformly vetted candidates for quadruple star systems. The candidates were identified in TESS full-frame image data from sectors 1-42 through a combination of machine-learning techniques and visual examination, with major contributions from a dedicated group of citizen scientists. All targets exhibit two sets of eclipse…
Supermassive Black Hole and Broad-line Region in NGC 5548: Results from Five-season Reverberation Mapping
Zhang, Zhi-Xiang; Du, Pu; Hu, Chen +9 more
NGC 5548 is one of the active galactic nuclei (AGNs) selected for our long-term spectroscopic monitoring with the Lijiang 2.4 m telescope, aiming at investigating the origin and evolution of broad-line regions (BLRs), accurately measuring the mass of supermassive black holes (SMBHs), and understanding the structure and evolution of the AGN. We hav…
The Spectroscopic Binaries from the LAMOST Medium-resolution Survey. I. Searching for Double-lined Spectroscopic Binaries with a Convolutional Neural Network
Tian, Hao; Ji, Xin; Zong, Weikai +13 more
We developed a convolutional neural network model to distinguish the double-lined spectroscopic binaries (SB2s) from others based on single-exposure medium-resolution spectra (R ~ 7500). The training set consists of a large set of mock spectra of single stars and binaries synthesized based on the MIST stellar evolutionary model and ATLAS9 atmosphe…
LISC Catalog of Star Clusters. I. Galactic Disk Clusters in Gaia EDR3
Li, Zhongmu; Liu, Xuejie; Chen, Wen +6 more
This work searches for the candidates of Galactic disk star clusters in Gaia Early Data Release 3 (Gaia EDR3) and determines their basic parameters from color-magnitude diagrams (CMDs). A friends-of-friends method for membership determination and stellar population models including binary stars (ASPS) and rotating stars are adopted. As a result, 8…
Stellar Loci. V. Photometric Metallicities of 27 Million FGK Stars Based on Gaia Early Data Release 3
Huang, Yang; Niu, Zexi; Beers, Timothy C. +3 more
We combine LAMOST DR7 spectroscopic data and Gaia EDR3 photometric data to construct high-quality giant (0.7 < (BP - RP) < 1.4) and dwarf (0.5 < (BP - RP) < 1.5) samples in the high Galactic latitude region, with precise corrections for magnitude-dependent systematic errors in the Gaia photometry and careful reddening corrections using…
A New 3D Solar Wind Speed and Density Model Based on Interplanetary Scintillation
Bzowski, M.; Tokumaru, M.; Porowski, C.
The solar wind (SW) is an outflow of the solar coronal plasma, which expands supersonically throughout the heliosphere. SW particles interact by charge exchange with interstellar neutral atoms; on the one hand, they modify the distribution of this gas in interplanetary space, and, on the other hand, they are the seed populations for heliospheric p…
Simulating the Legacy Survey of Space and Time Stellar Content with TRILEGAL
Clarkson, William I.; Girardi, Léo; Nikutta, Robert +19 more
We describe a large simulation of the stars to be observed by the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST). The simulation is based on the TRILEGAL code, which resorts to large databases of stellar evolutionary tracks, synthetic spectra, and pulsation models, added to simple prescriptions for the stellar density and star fo…
Predicting the Redshift of Gamma-Ray Loud AGNs Using Supervised Machine Learning. II
Poliszczuk, Artem; Pollo, Agnieszka; Liodakis, Ioannis +5 more
Measuring the redshift of active galactic nuclei (AGNs) requires the use of time-consuming and expensive spectroscopic analysis. However, obtaining redshift measurements of AGNs is crucial as it can enable AGN population studies, provide insight into the star formation rate, the luminosity function, and the density rate evolution. Hence, there is …
A Fresh Look at AGB Stars in Galactic Open Clusters with Gaia: Impact on Stellar Models and the Initial-Final Mass Relation
Girardi, Léo; Cummings, Jeffrey D.; Marigo, Paola +7 more
Benefiting from the Gaia second and early third releases of photometric and astrometric data, we examine the population of asymptotic giant branch (AGB) stars that appear in the fields of intermediate-age and young open star clusters. We identify 49 AGB star candidates, brighter than the tip of the red giant branch, with a good to high cluster mem…