Search Publications
Flaring Activity for Low-mass Stars in the β Pictoris Moving Group
Schlieder, Joshua E.; Komacek, Thaddeus D.; Ealy, Jordan N. +1 more
Stellar flares from K and M dwarfs release panchromatic radiation characterized by a significantly higher brightness temperature (∼9–20 kK) than the star. The increased frequency of magnetic activity on young low-mass stars results in the energy released during flaring events becoming a notable contributor to the radiation environment. This study …
Galaxy formation catalyzed by gravastars and the JWST, revisited
Adler, Stephen L.
We have proposed that galaxy formation is catalyzed by the collision of infalling and outstreaming particles from leaky, horizonless astrophysical black holes, most likely gravastars, and based on this gave a model for the disk galaxy scale length. In this paper we modify our original scale length formula by including an activation probability
SRGe J194401.8+284452—an X-ray Cataclysmic Variable in the Field of the Gamma-Ray Source 4FGL J1943.9+2841
Irtuganov, E. N.; Kolbin, A. I.; Karpova, A. V. +19 more
We have carried out multiwavelength spectroscopic and photometric studies of the object SRGe J194401.8+284452 (2RXS J194401.4+284456, XMMSL2 J194402.0+284451, 2SXPS J194401.7+284450), the brightest X-ray source in the position uncertainty ellipse of the unidentified gamma-ray source 4FGL J1943.9+2841, with the goal of determining its nature and th…
Highly collisional regions determined by interplanetary magnetic field structures
Lai, H. R.; Russell, C. T.; Jia, Y. D. +3 more
Submicron debris released in interplanetary collisions gets charged in the solar wind and generates disturbances to the magnetic field environment. The unique magnetic field disturbances, named interplanetary field enhancements (IFEs) are recorded by many spacecraft. In this study, we have developed a novel model to trace the IFEs to their origins…
Population of giant planets around B stars from the first part of the BEAST survey
Helled, R.; Henning, Th.; Mayer, L. +23 more
Context. Exoplanets form from circumstellar protoplanetary disks whose fundamental properties (notably their extent, composition, mass, temperature, and lifetime) depend on the host star properties, such as their mass and luminosity. B stars are among the most massive stars and their protoplanetary disks test extreme conditions for exoplanet forma…
Tilt-to-length coupling in LISA Pathfinder: Long-term stability
Mendes, L.; Russano, G.; Sanjuan, J. +75 more
The tilt-to-length coupling during the LISA Pathfinder mission has been numerically and analytically modeled for particular time spans. In this work, we investigate the long-term stability of the coupling coefficients of this noise. We show that they drifted slowly (by
Chandra Survey in the AKARI deep field at the North Ecliptic Pole: Optical and near-infrared identifications of X-ray sources
Malkan, M. A.; Ohyama, Y.; Takagi, T. +17 more
Aims. We present a catalog of optical and infrared (NIR) identifications (ID) of X-ray sources in the AKARI North Ecliptic Pole (NEP) deep field detected with Chandra, covering ~0.34 deg2 and with 0.5–2 keV flux limits ranging between ~2–20 × 10‑16 erg s‑1 cm‑2. Methods. The optical/NIR counterparts of t…
Fast and accurate evaluation of deep-space galactic cosmic ray fluxes with HelMod-4/CUDA
Gervasi, M.; Rancoita, P. G.; Boschini, M. J. +4 more
The accurate knowledge of cosmic ion fluxes is essential for fundamental physics, deep space missions, and exploration activities in the solar system. In the HelMod-4 model the Parker transport equation is solved using a Monte Carlo approach to evaluate the solar modulation effect on local interstellar spectra of Galactic Cosmic Rays (GCRs). This …
Measuring Fiber Positioning Accuracy and Throughput with Fiber Dithering for the Dark Energy Spectroscopic Instrument
Moustakas, J.; Brooks, D.; Doel, P. +48 more
Highly multiplexed, fiber-fed spectroscopy is enabling surveys of millions of stars and galaxies. The performance of these surveys depends on accurately positioning fibers in the focal plane to capture target light. We describe a technique to measure the positioning accuracy of fibers by dithering fibers slightly around their ideal locations. This…
Hidden cooling flows in elliptical galaxies
Fabian, A. C.; Pinto, C.; Ferland, G. J. +4 more
The radiative cooling time of hot gas in the cool cores of many galaxy clusters and massive elliptical galaxies drops in the centre to below