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X-Ray and Near-Infrared Observations of the Middle-aged Pulsar B1055-52, Its Multiwavelength Spectrum, and Proper Motion
Pavlov, G. G.; Kargaltsev, O.; Hare, J. +1 more
Previous observations of the middle-aged γ-ray, X-ray, and radio pulsar B1055-52 indicated some peculiarities, such as a suspected changing of the X-ray flux and spectral parameters, a large excess of the alleged thermal component of the UV spectrum over the Rayleigh-Jeans extension of the X-ray thermal spectrum, and a possible double break in the…
Exploring the short-term variability of H α and H β emissions in a sample of M dwarfs
Queiroz, A. B. A.; Fernández-Trincado, José G.; Kumar, Vipin +2 more
The time-scales of variability in active M dwarfs can be related to their various physical parameters. Thus, it is important to understand such variability to decipher the physics of these objects. In this study, we have performed the low resolution (~5.7 Å) spectroscopic monitoring of 83 M dwarfs (M0-M6.5) to study the variability of H α/H β emis…
DeGaPe 35: Amateur discovery of a new southern symbiotic star
Charbonnel, Stéphane; Garde, Olivier; Merc, Jaroslav +6 more
In this work, we present the discovery and characterization of a new southern S-type symbiotic star, DeGaPe 35. We have obtained the low-resolution spectroscopic observations and supplemented them with the photometry from Gaia DR3 and other surveys. The optical spectra of this target show prominent emission lines, including highly ionized [Fe VII]…
Detection of Multiple Phase Space Overdensities of GSE Stars by Orbit Integration
Zhao, Gang; Chen, Yuqin; Li, Chengdong +5 more
In N-body simulations, nearly radial mergers can form shell-like overdensities in the sky position and phase space (r - v r ) due to the combination of dynamical friction and tidal stripping. The merger event of Gaia-Sausage-Enceladus (GSE) has provided a unique opportunity to study the shells in the phase space. To search for them, we…
The spectra of IceCube Neutrino (SIN) candidate sources - IV. Spectral energy distributions and multiwavelength variability
Giommi, Paolo; Padovani, Paolo; Karl, Martina
We present hybrid spectral energy distributions, combining photon, and neutrino fluxes, for a sample of blazars, which are candidate IceCube neutrino sources. We furthermore check for differences in our sources' variability in the near-infrared, optical, X-ray, and γ-ray bands compared to a sample of non-neutrino source candidate blazars, and inve…
Salt Constructs in Paleo-Lake Basins as High-Priority Astrobiology Targets
Cabrol, Nathalie A.; Phillips, Michael S.; McInenly, Michael +4 more
In extreme environments, microbial organisms reside in pockets with locally habitable conditions. Micro-climates conducive to the persistence of life in an otherwise inhospitable environment—"refugia"—are spatially restricted and can be micro- to centimeters in extent. If martian microbes are preserved in fossil refugia, this presents a double-edg…
The Isaac Newton Telescope Monitoring Survey of Local Group Dwarf Galaxies. V. The Star Formation History of Sagittarius Dwarf Irregular Galaxy Derived from Long-period Variable Stars
Javadi, Atefeh; Saremi, Elham; van Loon, Jacco Th. +7 more
We conducted an optical monitoring survey of the Sagittarius dwarf irregular galaxy (SagDIG) during the period of 2016 June-2017 October, using the 2.5 m Isaac Newton Telescopeat La Palama. Our goal was to identify long-period variable stars (LPVs), namely, asymptotic giant branch stars (AGBs) and red supergiant stars, to obtain the star formation…
Statistical Study of Release Time and Its Energy Dependence of In Situ Energetic Electrons in Impulsive Solar Flares
Li, Gang; Wang, Linghua; Zhao, Lulu +3 more
Using the fraction velocity dispersion analysis method, it has been shown recently that in two impulsive solar energetic electron (SEE) events, the release times of near-relativistic electrons at the Sun for outward-propagating electrons are energy dependent and are delayed compared to those of the downward-propagating electrons. In this work, we …
Steadiness of Coronal Heating
Judge, P. G.
The EUI instrument on the Solar Orbiter spacecraft has obtained the most stable, high-resolution images of the solar corona from its orbit with a perihelion near 0.4 au. A sequence of 360 images obtained at 17.1 nm, between 2022 October 25 19:00 and 19:30 UT, is scrutinized. One image pixel corresponds to 148 km at the solar surface. The widely he…
Universal Upper End of the Stellar Initial Mass Function in the Young and Compact LEGUS Clusters
Schaerer, Daniel; Smith, Linda J.; Calzetti, Daniela +21 more
We investigate the variation in the upper end of the stellar initial mass function (uIMF) in 375 young and compact star clusters in five nearby galaxies within ~5 Mpc. All the young stellar clusters (YSCs) in the sample have ages ≲ 4 Myr and masses above 500 M ⊙, according to standard stellar models. The YSC catalogs were produced from …