Search Publications
A Modeling Investigation for Solar Flare X-Ray Stereoscopy with Solar Orbiter/STIX and Earth-orbiting Missions
Krucker, Säm; Veronig, Astrid; Su, Yang +9 more
The Spectrometer/Telescope for Imaging X-rays (STIX) on board Solar Orbiter (SolO) provides a unique opportunity to systematically perform stereoscopic X-ray observations of solar flares with current and upcoming X-ray missions at Earth. These observations will produce the first reliable measurements of hard X-ray (HXR) directivity in decades, pro…
The Complex Star Formation History of the Halo of NGC 5128 (Cen A)
Javadi, Atefeh; Saremi, Elham; van Loon, Jacco Th. +6 more
NGC 5128 (Cen A) is the nearest giant elliptical galaxy and one of the brightest extragalactic radio sources in the sky, boasting a prominent dust lane and jets emanating from its nuclear supermassive black hole. In this paper, we construct the star formation history (SFH) of two small fields in the halo of NGC 5128: a northeastern field (Field 1)…
Gaia23bab: A New EXor
Ábrahám, P.; Nagy, Z.; Schisano, E. +11 more
On 2023 March 6, the Gaia telescope alerted a 2 mag burst from Gaia23bab, a young stellar object in the Galactic plane. We observed Gaia23bab with the Large Binocular Telescope obtaining optical and near-infrared spectra close in time to the peak of the burst, and collected all public multiband photometry to reconstruct the historical light curve.…
Internal 1000 au Scale Structures of the R CrA Cluster-forming Cloud. I. Filamentary Structures
Inoue, Tsuyoshi; Shoshi, Ayumu; Harada, Naoto +17 more
We report Atacama Large Millimeter/submillimeter Array/Atacama Compact Array observations of a high-density region of the Corona Australis cloud forming a young star cluster, and the results of resolving internal structures. In addition to embedded Class 0/I protostars in the continuum, a number of complex dense filamentary structures are detected…
A Multiwavelength, Multiepoch Monitoring Campaign of Accretion Variability in T Tauri Stars from the ODYSSEUS Survey. III. Optical Spectra
Ábrahám, Péter; Kóspál, Ágnes; Fiorellino, Eleonora +20 more
Classical T Tauri Stars (CTTSs) are highly variable stars that possess gas- and dust-rich disks from which planets form. Much of their variability is driven by mass accretion from the surrounding disk, a process that is still not entirely understood. A multiepoch optical spectral monitoring campaign of four CTTSs (TW Hya, RU Lup, BP Tau, and GM Au…
JWST/MIRI Detection of [Ne V], [Ne VI], and [O IV] Wind Emission in the O9 V Star 10 Lacertae
Kumari, Nimisha; Gordon, Karl D.; Law, David R. +5 more
We report the detection of broad, flat-topped emission in the fine-structure lines of [Ne V], [Ne VI], and [O IV] in mid-infrared spectra of the O9 V star 10 Lacertae obtained with James Webb Space Telescope/Mid-Infrared Instrument. Optically thin emission in these high ions traces a hot, low-density component of the wind. The observed line fluxes…
TYC 3340-2437-1: A Quadruple System with a Massive Star
Fang, Min; Jin, Chichuan; Liu, Chao +11 more
Hierarchical massive quadruple systems are ideal laboratories for examining the theories of star formation, dynamical evolution, and stellar evolution. The successive mergers of hierarchical quadruple systems might explain the mass gap between neutron stars and black holes. Looking for light curves of O-type binaries identified by LAMOST, we find …
The Low-mass Stellar Initial Mass Function in Nearby Ultrafaint Dwarf Galaxies
van der Marel, Roeland P.; Wyse, Rosemary F. G.; Sacchi, Elena +3 more
The stellar initial mass function (IMF) describes the distribution of stellar masses that form in a given star formation event. The long main-sequence lifetimes of low-mass stars mean that the IMF in this regime (below ∼ 1 M ⊙) can be investigated through star counts. Ultrafaint dwarf galaxies are low-luminosity systems with ancient, me…
DESI Emission-line Galaxies: Unveiling the Diversity of [O II] Profiles and Its Links to Star Formation and Morphology
Brooks, D.; Doel, P.; Gutierrez, G. +34 more
We study the [O II] profiles of emission-line galaxies (ELGs) from the Early Data Release of the Dark Energy Spectroscopic Instrument (DESI). To this end, we decompose and classify the shape of [O II] profiles with the first two eigenspectra derived from principal component analysis. Our results show that DESI ELGs have diverse line profiles, whic…
The Regulation of the Solar Wind Electron Heat Flux by Wave–Particle Interactions
Verscharen, Daniel; Chen, Christopher H. K.; Maksimovic, Milan +11 more
The solar wind electrons carry a significant heat flux into the heliosphere. The weakly collisional state of the solar wind implicates collisionless processes as the primary factor that constrains nonthermal features of the velocity distribution function (VDF), including the heat flux. Previous observational work suggests that the electron VDF som…