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SN 2019va: a Type IIP Supernova with Large Influence of Nickel-56 Decay on the Plateau-phase Light Curve
Wang, Xiaofeng; Zhang, Jujia; Mo, Jun +12 more
We present multiband photometric and spectroscopic observations of the type II supernova, (SN) 2019va, which shows an unusually flat plateau-phase evolution in its V-band light curve. Its pseudo-bolometric light curve even shows a weak brightening towards the end of the plateau phase. These uncommon features are related to the influence of 56…
Automated algorithms to build active galactic nucleus classifiers
Larsson, J.; Falocco, S.; Carrera, F. J.
We present a machine learning model to classify active galactic nuclei (AGNs) and galaxies (AGN-galaxy classifier) and a model to identify type 1 (optically unabsorbed) and type 2 (optically absorbed) AGN (type 1/2 classifier). We test tree-based algorithms, using training samples built from the X-ray Multi-Mirror Mission-Newton (XMM-Newton) catal…
SDSS-IV MaStar: [α/Fe] for the MaNGA Stellar Library from synthetic model spectra
Bizyaev, Dmitry; Law, David R.; Stassun, Keivan G. +11 more
We calculate the α-enhancement ratio [α/Fe] for the Mapping Nearby Galaxies at APO (MaNGA) Stellar Library (MaStar) while also fitting for the fundamental atmospheric parameters effective temperature, surface gravity, and metallicity - Teff, log g, [Fe/H]. This approach builds upon a previous catalogue of stellar parameters, whereby onl…
Constraining X-ray emission of a magnetically arrested disk by radio-loud AGNs with an extreme-ultraviolet deficit
Li, Shuang-Liang; Gu, Minfeng; Zhou, Minhua
Aims: Active galactic nuclei (AGNs) with an extreme-ultraviolet (EUV) deficit are suggested to be powered by a magnetically arrested disk (MAD) surrounding the black hole, where the slope of EUV spectra (αEUV) is found to possess a clearly positive relationship with the jet efficiency. In this work, we investigate the properties of…
Active longitudes and starspot evolution of the young rapidly rotating star USNO-B1.0 1388-0463685 discovered in the Yunnan-Hong Kong survey
Bai, Jinming; Wang, Xiaobin; Xiang, Yue +12 more
We have discovered a young, rapidly rotating active star USNO-B1.0 1388-0463685 with a rotational period of 0.508750 ± 0.000153 d in the Yunnan-Hong Kong wide-field photometric survey. Based on the chromospheric activity identified in the dedicated spectroscopic observations, the brightness variation of this star is attributed to cool spots on its…
The Wind Temperature and Mass-loss Rate of Arcturus (K1.5 III)
Ayres, Thomas R.; Harper, Graham M.; O'Gorman, Eamon
In this paper we aim to constrain the wind temperature, outflow and turbulent velocities, ionization state, and mass-loss rate of the single red giant Arcturus (α Boo K1.5 III) using high spectral resolution Hubble Space Telescope Space Telescope Imaging Spectrograph profiles of Si III 1206.5 Å , O I 1304 Å and 1306 Å, C II 1334 Å and 1335 Å, and …
CHANG-ES - XXVII. A radio/X-ray catalogue of compact sources in and around edge-on galaxies
Wang, Q. Daniel; Irwin, Judith; Wiegert, Theresa +5 more
We present catalogues of discrete, compact radio sources in and around the discs of 35 edge-on galaxies in the Continuum Halos in Nearby Galaxies - an EVLA Survey. The sources were extracted using the PYBDSF program at both 1.6 GHz (L band) and 6.0 GHz (C band) from matching resolution (≈3 arcsec) data. We also present catalogues of X-ray sources …
The Lyα Emission in a C1.4 Solar Flare Observed by the Extreme Ultraviolet Imager aboard Solar Orbiter
Krucker, Säm; Gan, Weiqun; Ding, M. D. +7 more
The hydrogen Lyα (H I Lyα) emission during solar flares has rarely been studied in spatially resolved images, and its physical origin has not been fully understood. In this paper, we present novel Lyα images for a C1.4 solar flare (SOL2021-08-20T22:00) from the Extreme Ultraviolet Imager aboard Solar Orbiter, together with multi-wave-band and mult…
Integrated Photogrammetric and Photoclinometric Processing of Multiple HRSC Images for Pixelwise 3-D Mapping on Mars
Liu, Wai Chung; Wu, Bo; Chen, Zeyu +1 more
Informed Systematic Method to Identify Variable Mid- and Late-T Dwarfs
Karalidi, Theodora; Manjavacas, Elena; Faherty, Jacqueline K. +5 more
The majority of brown dwarfs show some level of photometric or spectrophotometric variability in different wavelength ranges. This variability allow us to trace the 3D atmospheric structures of variable brown dwarfs and directly-imaged exoplanets with radiative-transfer models and mapping codes. Nevertheless, to date, we do not have an informed me…