Search Publications
Orbital Inclination of Astrometric Binaries and the Dearth of Face-on Orbits in Gaia DR3 Solutions
Makarov, Valeri V.
The orbital solutions for astrometric (unresolved) binary stars provided in the Gaia mission DR3 reveal an obvious deficit of face-on orbits with line-of-sight inclinations close to 0 or π. This is shown to be an intrinsic mathematical feature of the orbit estimation technique involving the intermediate Thiele-Innes parameters, which are transform…
Swift-XRT and NuSTAR Monitoring of Obscuration Variability in Mrk 477
Ajello, M.; Marchesi, S.; Torres-Albà, N. +6 more
We present the analysis of 15 X-ray observations of Mrk 477, a nearby Seyfert 2 active galactic nucleus, with the objective to monitor its obscuring column density variability. The full data set consists of five archival observations, split into two XMM-Newton, two NuSTAR and one Chandra observation, plus two dedicated monitoring campaigns. The mo…
Detection of a Magnetic Discontinuity in the Upper Solar Chromosphere Associated with a Coronal Loop Brightening Observed by CLASP2.1
Song, Donguk; Rachmeler, Laurel A.; Kobayashi, Ken +15 more
We report the first detection of a magnetic discontinuity in the upper solar chromosphere associated with a coronal loop brightening. Our findings are based on novel observations obtained by the Chromospheric LAyer SpectroPolarimeter (CLASP2.1) suborbital space experiment. During its short 6 minute flight, CLASP2.1 successfully obtained spectropol…
Implication of Galaxy-scale Negative Feedback by One of the Most Powerful Multiphase Outflows in a Hyperluminous Infrared Galaxy at Intermediate Redshift
Imanishi, Masatoshi; Iono, Daisuke; Saito, Toshiki +12 more
Powerful galactic outflows driven by active galactic nuclei (AGNs) are commonly considered as one of the main mechanisms to regulate star formation in massive galaxies. Ultra- and hyperluminous IR galaxies (U/HyLIRGs) are thought to represent a transition phase of galaxies from a rapidly growing period to a quiescent status as gas is swept out by …
Temporal Evolution of a Network Jet's Physical Properties Inferred from FISS/GST and IRIS Observations
Yurchyshyn, Vasyl; Chae, Jongchul; Cho, Kyuhyoun +6 more
Small-scale jets, such as chromospheric and transition region (TR) network jets, are of great interest regarding coronal heating and solar wind acceleration. Spectroscopic analysis based on multiple spectral lines with different formation temperatures is essential for understanding the physical properties and driving mechanisms of jets. Here, we c…
A Long-term Study of Mrk 50: Appearance and Disappearance of Soft Excess
Naik, Sachindra; Jana, Arghajit; Nandi, Prantik +1 more
We present an extensive temporal and spectral study of the Seyfert 1 AGN Mrk 50 using 15 yr (2007–2022) of multiwavelength observations from XMM-Newton, Swift, and NuSTAR for the first time. From the timing analysis, we found that the source exhibited variability of ∼20% during the 2007 observation, which reduced to below 10% in the subsequent obs…
The Multiwavelength Extinction Law and Its Variation in the Coalsack Molecular Cloud Based on the Gaia, APASS, SMSS, 2MASS, GLIMPSE, and WISE Surveys
Wang, Shu; Jiang, Biwei; Zhao, He +1 more
Accurate interpretation of observations relies on the interstellar dust extinction law, which also serves as a powerful diagnostic for probing dust properties. In this study, we investigate the multiwavelength extinction law of the quiescent, starless molecular cloud Coalsack and explore its potential variation across different interstellar enviro…
Superstrong Magnetic Fields in Sunspot Bipolar Light Bridges
Solanki, S. K.; Korpi-Lagg, A.; Castellanos Durán, J. S. +2 more
Recent solar observations of bipolar light bridges (BLBs) in sunspots have, in a few individual cases, revealed magnetic fields up to 8.2 kG, which is at least twice as strong as typical values measured in sunspot umbrae. However, the small number of such observations hinted that such strong fields in these bright photospheric features that separa…
Primordial Origin of Methane on Eris and Makemake Supported by D/H Ratios
Mousis, Olivier; Werlen, Aaron; Benest Couzinou, Tom +1 more
Deuterium, a heavy isotope of hydrogen, is a key tracer of the formation of the solar system. Recent James Webb Space Telescope observations have expanded the data set of deuterium-to-hydrogen (D/H) ratios in methane on the KBOs Eris and Makemake, providing new insights into their origins. This study examines the elevated D/H ratios in methane on …
Boulder Migration in the Khonsu Region of Comet 67P/Churyumov–Gerasimenko
Shi, Xian; El-Maarry, Mohamed Ramy; Tang, Xiang
The European Space Agency's Rosetta mission is the only space mission that has performed long-term monitoring of a comet at close distances. For over two years, Rosetta rendezvoused with comet 67P/Churyumov–Gerasimenko, which revealed diverse evolutionary processes of the cometary nucleus. One of the most striking events is the migration of a ∼30 …