Search Publications
The Evolution of Plasma Composition during a Solar Flare
Long, David M.; Brooks, David H.; Baker, Deborah +4 more
We analyze the coronal elemental abundances during a small flare using Hinode/EIS observations. Compared to the preflare elemental abundances, we observed a strong increase in coronal abundance of Ca XIV 193.84 Å, an emission line with low first ionization potential (FIP < 10 eV), as quantified by the ratio Ca/Ar during the flare. This is in co…
The substructure of the Perseus star-forming region: a survey with Gaia DR2
Scholz, Aleks; Teixeira, Paula S.; Pavlidou, Tatiana
We use photometric and kinematic data from Gaia DR2 to explore the structure of the star-forming region associated with the molecular cloud of Perseus. Apart from the two well-known clusters, IC 348 and NGC 1333, we present five new clustered groups of young stars, which contain between 30 and 300 members, named Autochthe, Alcaeus, Heleus, Electry…
First Detection of Orbital Motion for HD 106906 b: A Wide-separation Exoplanet on a Planet Nine-like Orbit
Kalas, Paul; De Rosa, Robert J.; Nguyen, Meiji M.
HD 106906 is a 15 Myr old short-period (49 days) spectroscopic binary that hosts a wide-separation (737 au) planetary-mass ( $\sim 11\,{M}_{\mathrm{Jup}}$ ) common proper motion companion, HD 106906 b. Additionally, a circumbinary debris disk is resolved at optical and near-infrared wavelengths that exhibits a significant asymmetry at wide separat…
The 6.2 µm PAH Feature and the Role of Nitrogen: Revisited
Boersma, C.; Peeters, E.; Ricca, A.
This study revisits the role that nitrogen inclusion in polycyclic aromatic hydrocarbons (PAHs; those with nitrogen inclusion, PANHs) plays in their infrared (IR) spectral properties. We present spectra of pure PAHs, PANHs, and protonated PANHs, computed using density functional theory and basis sets that treat polarization. We investigate trends …
TOI-1431b/MASCARA-5b: A Highly Irradiated Ultrahot Jupiter Orbiting One of the Hottest and Brightest Known Exoplanet Host Stars
Latham, David W.; Stassun, Keivan G.; Wittenmyer, Robert A. +70 more
We present the discovery of a highly irradiated and moderately inflated ultrahot Jupiter, TOI-1431b/MASCARA-5 b (HD 201033b), first detected by NASA's Transiting Exoplanet Survey Satellite mission (TESS) and the Multi-site All-Sky Camera (MASCARA). The signal was established to be of planetary origin through radial velocity measurements obtained u…
The PAU Survey: narrow-band photometric redshifts using Gaussian processes
Alarcon, Alex; Carretero, Jorge; Castander, Francisco J. +16 more
We study the performance of the hybrid template machine learning photometric redshift (photo-z) algorithm DELIGHT, which uses Gaussian processes, on a subset of the early data release of the Physics of the Accelerating Universe Survey (PAUS). We calibrate the fluxes of the 40 PAUS narrow bands with six broad-band fluxes (uBVriz) in the Cosmic Evol…
Broadband X-ray spectral variability of the pulsing ULX NGC 1313 X-2
Cusumano, G.; Fabian, A. C.; Pinto, C. +12 more
Context. It is thought that ultraluminous X-ray sources (ULXs) are mainly powered by super-Eddington accreting neutron stars or black holes as shown by the recent discovery of X-ray pulsations and relativistic winds.
Aims: This work presents a follow-up study of the spectral evolution over two decades of the pulsing ULX NGC 1313 X-2 in order …
A Catalog of Host Galaxies for WISE-selected AGN: Connecting Host Properties with Nuclear Activity and Identifying Contaminants
Stern, Daniel; Comerford, Julia M.; Barrows, R. Scott +1 more
We present a catalog of physical properties for galaxies hosting active galactic nuclei (AGN) detected by the Wide-field Infrared Survey Explorer (WISE). By fitting broadband spectral energy distributions of sources in the WISE AGN Catalog with empirical galaxy and AGN templates, we derive photometric redshifts, AGN bolometric luminosities, measur…
Exploring the radial evolution of interplanetary coronal mass ejections using EUHFORIA
Zhukov, A. N.; Rodriguez, L.; Poedts, S. +2 more
Context. Coronal mass ejections (CMEs) are large-scale eruptions coming from the Sun and transiting into interplanetary space. While it is widely known that they are major drivers of space weather, further knowledge of CME properties in the inner heliosphere is limited by the scarcity of observations at heliocentric distances other than 1 au. In a…
Measuring the Magnetic Origins of Solar Flares, Coronal Mass Ejections, and Space Weather
Rempel, Matthias; de Toma, Giuliana; Ezzeddine, Rana +12 more
We take a broad look at the problem of identifying the magnetic solar causes of space weather. With the lackluster performance of extrapolations based upon magnetic field measurements in the photosphere, we identify a region in the near-UV (NUV) part of the spectrum as optimal for studying the development of magnetic free energy over active region…