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The Outer spiral arm of the Milky Way using red clump stars. Tracing the asymmetry across the disc
Ganesh, Shashikiran; Schultheis, Mathias; Uppal, Namita
Aims: Our aim is to provide an observational view of the old disc structure of the Milky Way galaxy using the distribution of red clump (RC) stars. The spiral arms, warp structure, and other asymmetries present in the disc are revisited using a systematic study of RC star counts over the disc of the Galaxy.
Methods: We developed a method…
Probing the Galactic halo with RR Lyrae stars - IV. On the Oosterhoff dichotomy of RR Lyrae stars
Tian, Haijun; Liu, Gaochao; Huang, Yang +8 more
We use 3653 (2661 RRab, 992 RRc) RR Lyrae stars (RRLs) with 7D (3D position, 3D velocity, and metallicity) information selected from Sloan Digital Sky Survey, Large Sky Area Multi-Object Fiber Spectroscopic Telescope, and Gaia EDR3, and divide the sample into two Oosterhoff groups (Oo I and Oo II) according to their amplitude-period behaviour in t…
Gaia view of primitive inner-belt asteroid families. Searching for the origins of asteroids Bennu and Ryugu
Delbo, M.; Avdellidou, C.; Walsh, K. J.
Aims: The near-Earth asteroids Ryugu and Bennu were visited, characterised, and sampled by the Hayabusa2 and OSIRIS-REx missions, where remote sensing data and sample return analysis showed that both asteroids have primitive, hydrated, and organic-rich compositions. The dark families of the inner main belt that belong to the spectroscopic C-c…
NuSTAR Observations of a Heavily X-Ray-obscured AGN in the Dwarf Galaxy J144013+024744
Trump, Jonathan R.; Brandt, W. N.; Swartz, Douglas A. +10 more
We present a multiwavelength analysis of the dwarf Seyfert 2 galaxy J144013+024744, a candidate obscured active galactic nucleus (AGN) thought to be powered by an intermediate-mass black hole (IMBH, M • ≈ 104-106 M ⊙) of mass M • ~ 105.2 M ⊙. To study its X-ray properties…
Modulation of Cosmic-Ray Antiprotons in the Heliosphere: Simulations for a Solar Cycle
Luo, Xi; Potgieter, M. S.; Aslam, O. P. M. +1 more
The precision measurements of galactic cosmic-ray protons from the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics and the Alpha Magnetic Spectrometer are reproduced using a well-established three-dimensional numerical model for the period 2006 July-2019 November. The resulting modulation parameters are applied to simulate …
Assessing the spectral characteristics of band splitting type II radio bursts observed by CALLISTO spectrometers
Kozarev, Kamen; Minta, Felix N.; Nozawa, Satoshi I. +2 more
Metric type II radio bursts are usually early indicators of CME-driven shocks and other space weather phenomena in the solar corona. This paper presents a detailed investigation of the spectral properties of band splitting type II radio bursts and their association with sunspot number. Using type II radio bursts in a frequency range [20 MHz-200 MH…
Understanding the Duration of Solar and Stellar Flares at Various Wavelengths
Reep, Jeffrey W.; Airapetian, Vladimir S.
Recent irradiance measurements from numerous heliophysics and astrophysics missions including Solar Dynamics Observatory (SDO), GOES, Kepler, TESS, Chandra, the X-ray Multi-Mirror Mission, and NICER have provided critical input into understanding the physics of the most powerful transient events on the Sun and magnetically active stars:solar and s…
The high energy X-ray probe (HEX-P): studying extreme accretion with ultraluminous X-ray sources
Maitra, Chandreyee; Mori, Kaya; Wolter, Anna +25 more
Introduction: Ultraluminous X-ray sources (ULXs) represent an extreme class of accreting compact objects: from the identification of some of the accretors as neutron stars to the detection of powerful winds travelling at 0.1–0.2 c, the increasing evidence points towards ULXs harbouring stellar-mass compact objects undergoing highly super-Eddington…
A Search for Technosignatures Around 11,680 Stars with the Green Bank Telescope at 1.15-1.73 GHz
Margot, Jean-Luc; Lynch, Ryan S.; Chen, James +77 more
We conducted a search for narrowband radio signals over four observing sessions in 2020-2023 with the L-band receiver (1.15-1.73 GHz) of the 100 m diameter Green Bank Telescope. We pointed the telescope in the directions of 62 TESS Objects of Interest, capturing radio emissions from a total of ~11,680 stars and planetary systems in the ~9' beam of…
A Young White Dwarf Orbiting PSR J1835-3259B in the Bulge Globular Cluster NGC 6652
Cadelano, Mario; Pallanca, Cristina; Ferraro, Francesco R. +8 more
We report on the discovery of the companion star to the millisecond pulsar PSR J1835-3259B in the Galactic globular cluster NGC 6652. Taking advantage of deep photometric archival observations acquired through the Hubble Space Telescope in near-UV and optical bands, we identified a bright and blue object at a position compatible with that of the r…