Search Publications
Citizen ASAS-SN Data Release. I. Variable Star Classification Using Citizen Science
Kochanek, C. S.; Stanek, K. Z.; Shappee, B. J. +7 more
We present the first results from Citizen ASAS-SN, a citizen science project for the All-Sky Automated Survey for Supernovae (ASAS-SN) hosted on the Zooniverse platform. Citizen ASAS-SN utilizes the newer, deeper, higher cadence ASAS-SN g-band data and tasks volunteers to classify periodic variable star candidates based on their phased light curve…
Role of Longitudinal Waves in Alfvén-wave-driven Solar Wind
Shoda, Munehito; Shimizu, Kimihiko; Suzuki, Takeru K.
We revisit the role of longitudinal waves in driving the solar wind. We study how the p-mode-like vertical oscillation on the photosphere affects the properties of solar winds in the framework of Alfvén-wave-driven winds. We perform a series of one-dimensional magnetohydrodynamical numerical simulations from the photosphere to beyond several tens …
The Second AGILE MCAL Gamma-Ray Burst Catalog: 13 yr of Observations
Longo, F.; Morselli, A.; Chen, A. +20 more
We present the results of a systematic search and analysis of GRBs detected by the Astrorivelatore Gamma ad Immagini LEggero (AGILE) MiniCALorimeter (MCAL; 0.4-100 MeV) over a time frame of 13 yr, from 2007 to 2020 November. The MCAL GRB sample consists of 503 bursts triggered by MCAL, 394 of which were fully detected onboard with high time resolu…
Conditions for Proton Temperature Anisotropy to Drive Instabilities in the Solar Wind
Verscharen, Daniel; Chen, Christopher H. K.; Opie, Simon +2 more
Using high-resolution data from Solar Orbiter, we investigate the plasma conditions necessary for the proton temperature-anisotropy-driven mirror-mode and oblique firehose instabilities to occur in the solar wind. We find that the unstable plasma exhibits dependencies on the angle between the direction of the magnetic field and the bulk solar wind…
Gravity or turbulence V: star-forming regions undergoing violent relaxation
Aguilar, Luis; Ballesteros-Paredes, Javier; Bonilla-Barroso, Andrea +6 more
Using numerical simulations of the formation and evolution of stellar clusters within molecular clouds (MCs), we show that the stars in clusters formed within collapsing MC clumps exhibit a constant velocity dispersion regardless of their mass, as expected in violent relaxation processes. In contrast, clusters formed in turbulence-dominated enviro…
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…
Introducing the MeVCube concept: a CubeSat for MeV observations
Lucchetta, Giulio; Ackermann, Markus; Berge, David +1 more
Despite the impressive progress achieved both by X-ray and gamma-ray observatories in the last few decades, the energy range between ~ 200 keV and ~ 50 MeV remains poorly explored. COMPTEL, on-board the Compton Gamma-Ray Observatory (CGRO, 1991-2000), opened the MeV gamma-ray band as a new window to astronomy, performing the first all-sky survey i…
Dramatic Changes in the Observed Velocity of the Accretion Disk Wind in MCG-03-58-007 Are Revealed by XMM-Newton and NuSTAR
Ballo, L.; Reeves, J. N.; Braito, V. +6 more
Past X-ray observations of the nearby Seyfert 2 MCG-03-58-007 revealed the presence of a powerful and highly variable disk wind, where two possible phases outflowing with v out1/c ~ -0.07 and v out2/c ~ -0.2 were observed. Multi-epoch X-ray observations, covering the period from 2010 to 2018, showed that the lower-velocity co…
Kepler-93: A testbed for detailed seismic modelling and orbital evolution of super-Earths around solar-like stars
Bétrisey, J.; Buldgen, G.; Khan, S. +4 more
Context. The advent of space-based photometry missions such as CoRoT, Kepler and TESS has sparkled the rapid development of asteroseismology and its synergies with exoplanetology. In the near future, the advent of PLATO will further strengthen such multi-disciplinary studies. In that respect, testing asteroseismic modelling strategies and their im…
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…