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Probing ultralight isospin-violating mediators at GW170817
Liu, Zuowei; Tang, Zi-Wei
Gravitational wave (GW) signals arising from binary neutron star mergers offer new, sensitive probes to ultralight mediators. Here we analyze the GW signals in the GW170817 event detected by the LIGO/Virgo collaboration to impose constraints on the ultralight isospin-violating mediator that has different couplings to protons and neutrons. Neutron …
Bidirectional propagating brightenings in arch filament systems observed by Solar Orbiter/EUI
Chen, Yajie; Peter, Hardi; Chitta, Lakshmi Pradeep +1 more
Arch filament systems (AFSs) are chromospheric and coronal manifestations of emerging magnetic flux. Using high spatial resolution observations taken at a high cadence by the Extreme Ultraviolet Imager (EUI) on board Solar Orbiter, we identified small-scale elongated brightenings within the AFSs. These brightenings appear as bidirectional flows al…
Has the Palomar 14 Globular Cluster Been Captured by the Milky Way?
Kroupa, Pavel; Haghi, Hosein; Zonoozi, Akram Hasani +1 more
We examine a new scenario to model the outer halo globular cluster (GC) Palomar 14 (Pal 14) over its lifetime by performing a comprehensive set of direct N-body calculations. We assume Pal 14 was born in a now detached/disrupted dwarf galaxy with a strong tidal field. Pal 14 evolved there until the slope of the stellar mass function (MF) became cl…
X-Ray and Spectral Ultraviolet Observations of Periodic Pulsations in a Solar Flare Fan/Looptop
Reeves, Katharine K.; Kazachenko, Maria D.; Lörinčík, Juraj +3 more
We present simultaneous X-ray and spectral ultraviolet observations of strikingly coherent oscillations in emission from a coronal looptop and fan structure, during the impulsive phase of a long-duration M-class solar flare. The ≈50 s oscillations are observed near in-phase by Solar Orbiter/STIX, GOES, and IRIS Fe XXI intensity, Doppler, and nonth…
IRIS Observational Approach to the Oscillatory and Damping Nature of Network and Internetwork Chromosphere Small-Scale Brightening (SSBs) and Their Unusual Dynamical and Morphological Differences in Different Regions on the Solar Disk
Tavabi, Ehsan; Sadeghi, Rayhaneh
One of the most exciting benefits of solar small-scale brightening is their oscillations. This study investigated the properties of small-scale brightening (SSBs) in different regions of the Sun and found that there are differences and similarities in the properties of oscillated and non-oscillated SSBs in different regions of the Sun, including q…
KPF Confirms a Polar Orbit for KELT-18 b
Howard, Andrew W.; Petigura, Erik A.; Behmard, Aida +24 more
We present the first spectroscopic transit results from the newly commissioned Keck Planet Finder on the Keck-I telescope at W. M. Keck Observatory. We observed a transit of KELT-18 b, an inflated ultrahot Jupiter orbiting a hot star (T eff = 6670 K) with a binary stellar companion. By modeling the perturbation to the measured cross-cor…
Solar Soft X-ray Irradiance Variability III: Magnetic Field Variations of Coronal X-ray Features
Matsumoto, Takuma; Masuda, Satoshi; DeLuca, Edward +7 more
The magnetic field changes the radiative output of the Sun and is the main source for all the solar surface features. To study the role of the underlying photospheric magnetic field in relation to emission features observed in the solar corona, we have used the full-disk soft X-ray images from Hinode/X-Ray Telescope (Hinode/XRT) and the magnetogra…
Magnetic Helicity Signs and Flaring Propensity: Comparing the Force-free Parameter with the Helicity Signs of Hα Filaments and X-Ray Sigmoids
Martens, Petrus C.; Georgoulis, Manolis K.; Aparna, V.
Sigmoids produce strong eruptive events. Earlier studies have shown that the ICME axial magnetic field Bz can be predicted with some credibility by observing the corresponding filament or the polarity inversion line in the region of eruption and deriving the magnetic field direction from that. Sigmoids are coronal structures often associated with …
Correcting Fabry-Pérot etalon effects in solar observations
Blanco Rodríguez, J.; Orozco Suárez, D.; Bailén, F. J. +1 more
Context. Data processing pipelines of Fabry-Pérot interferometers (FPI) must take into account the side effects these devices introduce in the observations. Interpretation of these observations without proper correction can lead to inaccurate or false results, with consequent impact on their physical interpretation. Corrections typically require p…
Skewness and kurtosis of solar wind proton distribution functions: The normal inverse-Gaussian model and its implications
André, N.; Fedorov, A.; Livi, S. +27 more
Context. In the solar wind (SW), the particle distribution functions are generally not Gaussian. They present nonthermal features that are related to underlying acceleration and heating processes. These processes are critical in the overall dynamics of this expanding astrophysical fluid.
Aims: The Proton Alpha Sensor (PAS) on board Solar Orbi…