Search Publications
Searching for Evidence of Subchromospheric Magnetic Reconnection on the Sun
Long, D. M.; van Driel-Gesztelyi, L.; Démoulin, P. +13 more
Within the coronae of stars, abundances of those elements with low first ionization potential (FIP) often differ from their photospheric values. The coronae of the Sun and solar-type stars mostly show enhancements of low-FIP elements (the FIP effect) while more active stars such as M dwarfs have coronae generally characterized by the inverse-FIP (…
Ionized Carbon in Galaxies: The [C II] 158 µm Line as a Total Molecular Gas Mass Tracer Revisited
Zhang, Zhi-Yu; Zhao, Yinghe; Liu, Jiamin +1 more
In this paper, we present a statistical study of the [C II] 158 µm line and the CO(1‑0) emission for a sample of ∼200 local and high-z (32 sources with z > 1) galaxies with very different physical conditions. We explore the correlation between the luminosities of [C II] and CO(1‑0) lines and obtain a strong linear relationship, confirming…
Forecasting Constraints from Surface Brightness Fluctuations in Galaxy Clusters
Romero, Charles E.
Studies of surface brightness (SB) fluctuations in the intracluster medium present an indirect estimate of turbulent pressure support and associated Mach numbers. While high-resolution X-ray spectroscopy can directly constrain line-of-sight gas motions, including those due to turbulence, such observations are relatively expensive and will be limit…
Formation and Eruption of a Hot Channel Magnetic Flux Rope in a Nested Double Null Magnetic System
Yao, Surui; Shen, Yuandeng; Zhou, Chengrui +2 more
The coronal magnetic topology significantly affects the outcome of magnetic flux rope (MFR) eruptions. The recently reported nested double null magnetic system remains unclear as to how it affects MFR eruptions. Using observations from the New Vacuum Solar Telescope and the Solar Dynamics Observatory, we studied the formation and successful erupti…
Dust-obscured Galaxies in the XMM-SERVS Fields: Selection, Multiwavelength Characterization, and Physical Nature
Brandt, W. N.; Yu, Zhibo; Zou, Fan +7 more
Dust-obscured galaxies (DOGs) are enshrouded by dust and many are believed to host accreting supermassive black holes (SMBHs), which makes them unique objects for probing the coevolution of galaxies and SMBHs. We select and characterize DOGs in the 13 deg2 XMM-Spitzer Extragalactic Representative Volume Survey (XMM-SERVS), leveraging th…
Solar Flare Ribbon Fronts. II. Evolution of Heating Rates in Individual Flare Footpoints
Polito, Vanessa; Xu, Yan; Kerr, Graham S. +1 more
Solar flare ribbon fronts appear ahead of the bright structures that normally characterize solar flares, and can persist for an extended period of time in spatially localized patches before transitioning to "regular" bright ribbons. They likely represent the initial onset of flare energy deposition into the chromosphere. Chromospheric spectra (e.g…
Multiwavelength Pulsations and Surface Temperature Distribution in the Middle-aged Pulsar B1055–52
Santangelo, A.; Johnston, S.; Pavlov, G. G. +3 more
We present a detailed study of the X-ray emission from PSR B1055–52 using XMM-Newton observations from 2019 and 2000. The phase-integrated X-ray emission from this pulsar is poorly described by existing models of neutron star atmospheres. Instead, we confirm that, similar to other middle-aged pulsars, the best-fitting spectral model consists of tw…
AGN STORM 2. IX. Studying the Dynamics of the Ionized Obscurer in Mrk 817 with High-resolution X-Ray Spectroscopy
Kaspi, Shai; Hall, Patrick B.; Barth, Aaron J. +45 more
We present the results of the XMM-Newton and NuSTAR observations taken as part of the ongoing, intensive multiwavelength monitoring program of the Seyfert 1 galaxy Mrk 817 by the AGN Space Telescope and Optical Reverberation Mapping 2 (AGN STORM 2) Project. The campaign revealed an unexpected and transient obscuring outflow, never before seen in t…
Transverse MHD Waves as Signatures of Braiding-induced Magnetic Reconnection in Coronal Loops
Antolin, Patrick; Sukarmadji, A. Ramada C.
A major coronal heating theory based on magnetic reconnection relies on the existence of braided magnetic field structures in the corona. In this small-angle reconnection scenario, numerical simulations indicate that the reconnected magnetic field lines are driven sideways by magnetic tension and can overshoot from their new rest position, thereby…
Fundamental Tests of White Dwarf Cooling Physics with Wide Binaries
Blouin, Simon; Bergeron, Pierre; Kilic, Mukremin +3 more
We present follow-up spectroscopy and a detailed model atmosphere analysis of 29 wide double white dwarfs, including eight systems with a crystallized C/O core member. We use the state-of-the-art evolutionary models to constrain the physical parameters of each star, including the total age. Assuming that the members of wide binaries are coeval, an…