Search Publications
SynthIA: A Synthetic Inversion Approximation for the Stokes Vector Fusing SDO and Hinode into a Virtual Observatory
Liu, Yang; Antiochos, Spiro K.; Leka, K. D. +7 more
Both NASA's Solar Dynamics Observatory (SDO) and the JAXA/NASA Hinode mission include spectropolarimetric instruments designed to measure the photospheric magnetic field. SDO's Helioseismic and Magnetic Imager (HMI) emphasizes full-disk, high-cadence, and good-spatial-resolution data acquisition while Hinode's Solar Optical Telescope Spectro-Polar…
Multiple Stellar Populations of Globular Clusters from Homogeneous Ca-CN-CH-NH Photometry. VII. Metal-poor Populations in 47 Tucanae (NGC 104)
Lee, Jae-Woo
We present new large field-of-view (~1°×1°) Ca-CN photometry of the prototypical metal-rich globular cluster 47 Tucanae (NGC 104). Our results are the following. (1) The populational number ratios of the red giant branch (RGB) and red horizontal branch (RHB) are in excellent agreement: n(CN-w):n(CN-s) = 30:70 (±1-2), where the CN-w and CN-s stand …
Interstellar Neutral He Parameters from Crossing Parameter Tubes with the Interstellar Mapping and Acceleration Probe Informed by 10 yr of Interstellar Boundary Explorer Observations
McComas, D. J.; Fuselier, S. A.; Möbius, E. +11 more
The Sun's motion through the interstellar medium leads to an interstellar neutral (ISN) wind through the heliosphere. Several ISN species, including He, moderately depleted by ionization are observed with pickup ions and directly imaged. Since 2009, analyzed Interstellar Boundary Explorer (IBEX) observations returned a precise 4D parameter tube as…
Can We Detect Coronal Mass Ejections through Asymmetries of Sun-as-a-star Extreme-ultraviolet Spectral Line Profiles?
Chen, Yajie; Gao, Yuhang; Tian, Hui +8 more
Coronal mass ejections (CMEs) are the largest-scale eruptive phenomena in the solar system. Associated with enormous plasma ejections and energy releases, CMEs have an important impact on the solar-terrestrial environment. Accurate predictions of the arrival times of CMEs at the Earth depend on precise measurements of their 3D velocities, which ca…
Stellar Chromospheric Activity Database of Solar-like Stars Based on the LAMOST Low-Resolution Spectroscopic Survey
Zhang, Jun; Zhang, Haotong; Luo, Ali +3 more
A stellar chromospheric activity database of solar-like stars is constructed based on the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Low-Resolution Spectroscopic Survey. The database contains spectral bandpass fluxes and indexes of Ca II H and K lines derived from 1,330,654 high-quality LRS spectra of solar-like stars. We m…
The Intermediate-ionization Lines as Virial Broadening Estimators for Population A Quasars
Piconcelli, Enrico; D'Onofrio, Mauro; Martínez-Aldama, Mary Loli +10 more
The identification of a virial broadening estimator in the quasar UV rest frame suitable for black hole mass computation at high redshift has become an important issue. We compare the H I Balmer H β line width to the ones of two intermediate-ionization lines: the Al III λ1860 doublet and the C III] λ1909 line, over a wide interval of redshift and …
Magnetic Activity and Physical Parameters of Exoplanet Host Stars Based on LAMOST DR7, TESS, Kepler, and K2 Surveys
Han, Xianming L.; Misra, Prabhakar; Zhang, Li-yun +6 more
Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) low- and medium-resolution spectroscopic surveys are important for determination of the orbital parameters and chromospheric activity of extrasolar planet systems. We crossmatched the exoplanet catalog confirmed before 2021 March 11 with the LAMOST DR7 survey to study their propert…
Dust Extinction Law in Nearby Star-resolved Galaxies. I. M31 Traced by Supergiants
Gao, Jian; Ren, Yi; Wang, Yuxi
The dust extinction laws and dust properties in M31 are explored with a sample of reddened O-type and B-type supergiants obtained from the Local Group Galaxies Survey (LGGS). The observed spectral energy distributions (SEDs) for each tracer are constructed with multiband photometry from the LGGS, PS1 Survey, UKIRT, PHAT Survey, Swift/UVOT, and XMM…
A Census of 163 Large-scale (≥10 pc), Velocity-coherent Filaments in the Inner Galactic Plane: Physical Properties, Dense-gas Fraction, and Association with Spiral Arms
Wang, Ke; Ge, Yifei
The interstellar medium has a highly filamentary and hierarchical structure that may play a significant role in star formation. A systematical study of the large-scale filaments toward their physical parameters, distribution, structures, and kinematics will inform us about which types of filaments have the potential to form stars, how the material…
A Population of Dipper Stars from the Transiting Exoplanet Survey Satellite Mission
Kostov, Veselin B.; Powell, Brian P.; Rappaport, Saul A. +12 more
Dipper stars are a classification of young stellar objects that exhibit dimming variability in their light curves, dropping in brightness by 10%-50%, likely induced by occultations due to circumstellar disk material. This variability can be periodic, quasiperiodic, or aperiodic. Dipper stars have been discovered in young stellar associations via g…