Search Publications
Investigating and comparing the IRIS spectral lines Mg II, Si IV, and C II for flare precursor diagnostics
Kleint, Lucia; Panos, Brandon; Zbinden, Jonas
Context. Reliably predicting solar flares can mitigate the risks of technological damage and enhance scientific output by providing reliable pointings for observational campaigns. Flare precursors in the spectral line Mg II have been identified. Aims. We extend previous studies by examining the presence of flare precursors in additional spectral l…
Testing MOND using the dynamics of nearby stellar streams
Helmi, Amina; Koop, Orlin
Context. The stellar halo of the Milky Way is built up at least in part from debris from past mergers. The stars from these merger events define substructures in phase space, for example in the form of streams, which are groups of stars that move on similar trajectories. The nearby Helmi streams discovered more than two decades ago are a well-know…
Radio and gamma-ray timing of TRAPUM L-band Fermi pulsar survey discoveries
Ransom, S. M.; Possenti, A.; Kramer, M. +18 more
This paper presents the results of a joint radio and gamma-ray timing campaign on the nine millisecond pulsars (MSPs) discovered as part of the L-band targeted survey of Fermi-LAT sources performed in the context of the Transients and Pulsars with MeerKAT (TRAPUM) Large Survey Project. Out of these pulsars, eight are members of binary systems; of …
AGN feeding along a one-armed spiral in NGC 4593: A study using ALMA CO(2–1) observations
Andreani, P.; Hatziminaoglou, E.; Spinoglio, L. +9 more
Context. We investigate active galactic nuclei (AGN) feeding through the molecular gas (CO(2‑1) emission) properties of the local Seyfert 1 galaxy NGC 4593, using Atacama Large Millimeter Array (ALMA) observations and other multi-wavelength data. Aims. Our study aims to understand the interplay between the AGN and the interstellar medium (ISM) in …
Searching for pairs of actively accreting supermassive black holes in the Gaia FPR GravLens catalog
Galluccio, L.; Slezak, E.; Mahé, C.
Observational data on dual supermassive black holes (SMBHs) are scarce, even though they should be common according to the current hierarchical formation model for galaxies. We present hereby a method to detect such dual systems, involving an already known quasar, as two luminosity peaks with angular separations smaller than one arcsecond (1″). It…
The origin of the X-ray luminosity of the green pea galaxies: X-ray binaries or active galactic nuclei?
Luo, A. -Li; Zheng, Zhenya; Zhang, Wei +3 more
Context. Green pea galaxies (GPs) are renowned for their compact sizes, low masses, strong emission lines, high star formation rates (SFRs), and being analogs to high-z Lyα-emitting galaxies. Aims. This investigation focuses on a curated sample of six GPs with X-ray detections, sourced from XMM-Newton, Swift, Chandra and eROSITA, with the aim to e…
Five new eclipsing binaries with low-mass companions
Gandolfi, D.; Persson, C. M.; Deeg, H. J. +18 more
Precise space-based photometry from the Transiting Exoplanet Survey Satellite results in a huge number of exoplanetary candidates. However, the masses of these objects are unknown and must be determined by ground-based spectroscopic follow-up observations, frequently revealing the companions to be low-mass stars rather than exoplanets. We present …
SDSS J102915.14+172927.9: Revisiting the chemical pattern
Steffen, M.; Ludwig, H. -G.; Bonifacio, P. +7 more
Context. The small- to intermediate-mass (M < 0.8 M⊙), most metal-poor stars that formed in the infancy of the Universe are still shining today in the sky. They are very rare, but their discovery and investigation brings new knowledge on the formation of the first stellar generations. Aims. SDSS J102915.14+172927.9 is one of the most…
The observational evidence that all microflares that accelerate electrons to high energies are rooted in sunspots
Krucker, Säm; Veronig, Astrid M.; Ryan, Daniel F. +6 more
Context. In general, large solar flares are more efficient at accelerating high-energy electrons than microflares. Nonetheless, sometimes microflares that accelerate electrons to high energies are observed. Their origin is unclear. Aims. We statistically characterized microflares with strikingly hard spectra in the hard X-ray (HXR) range, which me…
A multi-instrument study of UV bursts and associated surges in AR 12957
Solanki, S. K.; Berghmans, D.; Calchetti, D. +6 more
Context. The relationship between UV bursts and solar surges is complex, with these events sometimes being observed together and sometimes being observed independently. Why this sporadic association exists is unknown; however, it likely relates to the physical conditions at the site of the energy release that drives these events. Aims. Here, we ai…