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The Panchromatic Hubble Andromeda Treasury. XXI. The Legacy Resolved Stellar Photometry Catalog
Bell, Eric F.; Dolphin, Andrew E.; Yanchulova Merica-Jones, Petia +14 more
We present the final legacy version of stellar photometry for the Panchromatic Hubble Andromeda Treasury (PHAT) survey. We have reprocessed all of the Hubble Space Telescope Wide Field Camera 3 and Advanced Camera for Surveys near-ultraviolet (F275W, F336W), optical (F475W, F814W), and near-infrared (F110W, F160W) imaging from the PHAT survey usin…
All Spectral Type LAMOST Spectra Library (ATLAS)
Tian, Hao; Li, Jiadong; Deng, Licai +4 more
We present an empirical stellar spectra library, ATLAS, with resolution R ~ 1800 and wavelength coverage from 3800-8700 Å. These spectra are homogeneously observed by the Large Sky Area Multi-Object Fiber Spectroscopic Telescope and have been released in its DR5. ATLAS is separated into two groups, ATLAS-A and -T. The former contains 5584 spectra …
Chemical Differentiation around Five Massive Protostars Revealed by ALMA: Carbon-chain Species and Oxygen/Nitrogen-bearing Complex Organic Molecules
Caselli, Paola; Nakamura, Fumitaka; Li, Zhi-Yun +9 more
We present Atacama Large Millimeter/submillimeter Array Band 3 data toward five massive young stellar objects (MYSOs), and investigate relationships between unsaturated carbon-chain species and saturated complex organic molecules (COMs). An HC5N (J = 35-34) line has been detected from three MYSOs, where nitrogen (N)-bearing COMs (CH
Classification of Chandra X-Ray Sources in Cygnus OB2
Naylor, Tim; Drake, Jeremy J.; Wright, Nicholas J. +11 more
We have devised a predominantly Naive Bayes-based method to classify X-ray sources detected by Chandra in the Cygnus OB2 association into members, foreground objects, and background objects. We employ a variety of X-ray, optical, and infrared characteristics to construct likelihoods using training sets defined by well-measured sources. Combination…
A Coronal Mass Ejection Source Region Catalog and Their Associated Properties
Pant, Vaibhav; Banerjee, Dipankar; Patel, Ritesh +4 more
The primary objective of this study is to connect coronal mass ejections (CMEs) to their source regions, primarily to create a CME source region catalog, and secondarily to probe the influence that the source regions have on the different statistical properties of CMEs. We create a source region catalog for 3327 CMEs from 1998 to 2017, thus captur…
Spectral Features of the Solar Transition Region and Chromospheric Lines at Flare Ribbons Observed with IRIS
Cheng, X.; Ding, M. D.; Li, Y. +2 more
We report on the spectral features of the Si IV λ1402.77, C II λ1334.53, and Mg II h or k lines, formed in the layers from the transition region to the chromosphere, in three two-ribbon flares (with X, M, and C class) observed with IRIS. All three lines show significant redshifts within the main flare ribbons, which mainly originate from the chrom…
Age of FGK Dwarfs Observed with LAMOST and GALAH: Considering the Oxygen Enhancement
Bird, Sarah A.; Wu, Yaqian; Bi, Shaolan +11 more
Varying oxygen abundance could impact modeling-inferred ages. This work aims to estimate the ages of dwarfs considering observed oxygen abundance. To characterize 67,503 LAMOST and 4006 GALAH FGK-type dwarf stars, we construct a grid of stellar models, which take into account oxygen abundance as an independent model input. Compared with ages deter…
Toward a Live Homogeneous Database of Solar Active Regions Based on SOHO/MDI and SDO/HMI Synoptic Magnetograms. I. Automatic Detection and Calibration
Wang, Ruihui; Jiang, Jie; Luo, Yukun
Recent studies indicate that a small number of rogue solar active regions (ARs) may have a significant impact on the end-of-cycle polar field and the long-term behavior of solar activity. The impact of individual ARs can be qualified based on their magnetic field distribution. This motivates us to build a live homogeneous AR database in a series o…
The Evryscope Fast Transient Engine: Real-time Detection for Rapidly Evolving Transients
Law, Nicholas M.; Corbett, Hank; Carney, Jonathan +8 more
Astrophysical transients with rapid developments on subhour timescales are intrinsically rare. Due to their short durations, events like stellar superflares, optical flashes from gamma-ray bursts, and shock breakouts from young supernovae are difficult to identify on timescales that enable spectroscopic follow-up. This paper presents the Evryscope…
Application of Deep Reinforcement Learning to Major Solar Flare Forecasting
Moon, Yong-Jae; Yi, Kangwoo; Jeong, Hyun-Jin
In this study, we present the application of deep reinforcement learning to the forecasting of major solar flares. For this, we consider full-disk magnetograms at 00:00 UT from the Solar and Heliospheric Observatory/Michelson Doppler Imager (1996-2010) and the Solar Dynamics Observatory/Helioseismic and Magnetic Imager (2011-2019), as well as Geos…