Search Publications

Determining the Nanoflare Heating Frequency of an X-Ray Bright Point Observed by MaGIXS
DOI: 10.3847/1538-4357/ad2766 Bibcode: 2024ApJ...967...23M

Reeves, Katharine K.; Del Zanna, Giulio; Golub, Leon +18 more

Nanoflares are thought to be one of the prime candidates that can heat the solar corona to its multimillion kelvin temperature. Individual nanoflares are difficult to detect with the present generation of instruments, but their presence can be inferred by comparing simulated nanoflare-heated plasma emissions with the observed emission. Using HYDRA…

2024 The Astrophysical Journal
Hinode 1
Photometric Metallicity and Distance for the Two RR Lyrae in Segue II and Ursa Major II Dwarf Galaxies Based on Multiband Light Curves
DOI: 10.3847/1538-3881/ad11f6 Bibcode: 2024AJ....167...42N

Ngeow, Chow-Choong; Bhardwaj, Anupam

Multiband light curves of two RR Lyrae variables in Segue II and Ursa Major II ultrafaint dwarf galaxies were collected from near simultaneous observations using the Lulin One-meter Telescope in Vgri bands. Together with Gaia G-band light curves, we determined photometric metallicities using empirical relations involving pulsation period and Fouri…

2024 The Astronomical Journal
Gaia 1
Impact Ionization Double Peaks Analyzed In High Temporal Resolution On Solar Orbiter
DOI: 10.5194/angeo-42-191-2024 Bibcode: 2024AnGeo..42..191K

Meyer-Vernet, Nicole; Mann, Ingrid; Vaverka, Jakub +6 more

Solar Orbiter is equipped with electrical antennas performing fast measurements of the surrounding electric field. The antennas register high-velocity dust impacts through the electrical signatures of impact ionization. Although the basic principle of the detection has been known for decades, the understanding of the underlying process is not comp…

2024 Annales Geophysicae
SolarOrbiter 1
Abundant sub-micron grains revealed in newly discovered extreme debris discs
DOI: 10.1093/mnras/stae155 Bibcode: 2024MNRAS.528.4528M

Henning, Thomas; Moór, Attila; Pawellek, Nicole +7 more

Extreme debris discs (EDDs) are bright and warm circumstellar dusty structures around main sequence stars. They may represent the outcome of giant collisions occuring in the terrestrial region between large planetesimals or planetary bodies, and thus provide a rare opportunity to peer into the aftermaths of these events. Here, we report on results…

2024 Monthly Notices of the Royal Astronomical Society
AKARI Gaia 1
Survey of Variables with the ILMT
DOI: 10.25518/0037-9565.11927 Bibcode: 2024BSRSL..93..924G

Kumar, Brajesh; Surdej, Jean; Negi, Vibhore +11 more

Nestled in the mountains of Northern India, is a 4-metre rotating dish of liquid mercury. Over a 10-year period, the International Liquid Mirror Telescope (ILMT) will survey 117 square degrees of sky, to study the astrometric and photometric variability of all detected objects. One of the scientific programs will be a survey of variable stars. The…

2024 Bulletin de la Societe Royale des Sciences de Liege
Gaia 1
A multi-wavelength study of Galactic H II regions with extended emission
DOI: 10.1051/0004-6361/202450043 Bibcode: 2024A&A...689A.254D

Wyrowski, Friedrich; Menten, Karl M.; Dzib, Sergio A. +9 more

Context. H II regions are the signposts of massive (M ≥ 8 M) star-forming sites in our Galaxy. It has been observed that the ionizing photon rate inferred from the radio continuum emission of H II regions is significantly lower (~90%) than that inferred from far-infrared fluxes measured by the Infrared Astronomical Satellite. Aims. Thi…

2024 Astronomy and Astrophysics
Herschel 1
Winds of change: The nuclear and galaxy-scale outflows and the X-ray variability of 2MASS 0918+2117
DOI: 10.1051/0004-6361/202349071 Bibcode: 2024A&A...686A.217B

Buchner, J.; Merloni, A.; Vignali, C. +21 more

Context. In this work, we test feedback propagation models on the test case of 2MASS 0918+2117 (2M0918), a z = 0.149 X-ray variable AGN that shows tentative evidence for nuclear ultra-fast outflows (UFOs) in a 2005 XMM-Newton observation. We also investigate whether UFOs can be related to the observed X-ray variability.
Aims: We observed 2M09…

2024 Astronomy and Astrophysics
XMM-Newton 1
Stellar Characterization and a Chromospheric Activity Analysis of a K2 Sample of Planet-hosting Stars
DOI: 10.3847/1538-4357/ad4b15 Bibcode: 2024ApJ...970...53L

Cunha, Katia; Smith, Verne V.; Quispe-Huaynasi, F. +4 more

Effective temperatures, surface gravities, and iron abundances were derived for 109 stars observed by the K2 mission using equivalent width measurements of Fe I and Fe II lines. Calculations were carried out in local thermodynamic equilibrium using Kurucz model atmospheres. Stellar masses and radii were derived by combining the stellar parameters …

2024 The Astrophysical Journal
Gaia 1
Evidence for magnetic boundary layer accretion in RU Lup: A spectrophotometric analysis
DOI: 10.1051/0004-6361/202451065 Bibcode: 2024A&A...690A.225A

Alcalá, J. M.; Manara, C. F.; Frasca, A. +9 more

Context. It is well established that classical T Tauri stars accrete material from a circumstellar disk through magnetic fields. However, the physics regulating the processes in the inner (0.1 AU) disk is still not well understood. Aims. Our aim is to characterize the accretion process of the classical T Tauri Star RU Lup. Methods. Optical high-re…

2024 Astronomy and Astrophysics
Gaia 1
UVIT Survey of the Host Galaxies of Active Galactic Nuclei. I. Star Formation Scenarios
DOI: 10.3847/1538-4357/ad5da9 Bibcode: 2024ApJ...973....7N

Stalin, C. S.; Nandi, Payel; Saikia, D. J. +1 more

Circumnuclear star formation (SF) is generally seen in galaxies hosting active galactic nuclei (AGN); however, the connection between the AGN activity and SF in them is less well understood. To explore this connection on scales of a few tens of parsecs to a few tens of kiloparsecs and larger, we carried out an investigation of SF in seven Seyfert-…

2024 The Astrophysical Journal
Gaia 1