Search Publications
Merging Mesoscale Magnetotail Features and Ground B-Field Perturbation Network Connectivity During Substorm Activity
Adewuyi, M.; Keesee, A.; Ferdousi, B.
The connection between the magnetosphere and ionosphere is particularly dynamic during substorms. Mesoscale features in the magnetotail are consistent with substorm activity, including magnetic reconnection in the tail, flow channels, and particle injections. Observations of substorm related phenomena can be made using energetic neutral atom (ENA)…
A jet-induced shock in a young, powerful radio galaxy at z = 3.00
Noirot, Gaël; Gupta, Anshu; Emonts, Bjorn +9 more
The bright radio source, GLEAM J091734 - 001243 (hereafter GLEAM J0917 - 0012), was previously selected as a candidate ultra-high redshift ( z > 5 ) radio galaxy due to its compact radio size and faint magnitude ( K(AB)=22.7 ). Its redshift was not conclusively determined from follow-up millimetre and near-infrared spectroscopy. Here we present…
A low cosmic-ray ionisation rate in the pre-stellar core Ophiuchus/H-MM1. Mapping of the molecular ions ortho-H2D+, N2H+, and DCO+
Belloche, A.; Vastel, C.; Wyrowski, F. +5 more
Aims: We test the use of three common molecular ions, ortho-H2D+ (oH2D+), N2H+, and DCO+, as probes of the internal structure and kinematics of a dense, starless molecular cloud core.
Methods: The pre-stellar core H-MM1 in Ophiuchus was mapped in the oH2
Evolution of the Ratio of Mg II Intensities during Solar Flares
Tripathi, Durgesh; Roy, Soumya
The Mg II k and h line intensity ratios can be used to probe the characteristics of the plasma in the solar atmosphere. In this study, using the observations recorded by the Interface Region Imaging Spectrometer, we study the variation of the Mg II k and h intensity ratio for three flares belonging to X-class, M-class, and C-class, throughout thei…
The Chemical Puzzle of Weak G-Band Stars: A Comprehensive Study of HD 54627, HD 105783, HD 198718, and HD 201557
Pereira, C. B.; Quispe-Huaynasi, F.; Holanda, N. +2 more
Weak G-band stars (WGBs) are a unique class of objects characterized by weak CH molecular lines in the Fraunhofer G band, indicative of a deficiency in 12C. This peculiar spectral feature is often accompanied by significant enrichments in N and, occasionally, Li and Na abundances. Despite their rarity and recent discoveries of new WGB c…
13 Galactic Star Clusters in Gaia DR3 Identified by An Improved FoF and UPMASK Hybrid Method Using MvC
Mei, Ying; Wang, Feng; Li, Zhongmu +2 more
Open clusters (OCs) serve as invaluable tracers for investigating the properties and evolution of stars and galaxies. Despite recent advancements in machine learning clustering algorithms, accurately discerning such clusters remains challenging. We re-visited the 3013 samples generated with a hybrid clustering algorithm of FoF and pyUPMASK. A mult…
Large-scale CO Multi-line Observations of the S187 HII Region
Chen, X. P.; Sun, Y.; Xu, X. Y. +1 more
The strong feedback of massive stars profoundly affects the interstellar medium around them, and may trigger the formation of next-generation stars. S187 is a massive star formation region located in the second quadrant of the Milky Way, showing a ``Collect and Collapse" triggered star formation pattern. Based on the $^{12}\mathrm{CO}$/$^{13}\math…
AstroSat Investigation of X-ray Flares on Two Active K-M Systems: CC Eri and AB Dor
Karmakar, Subhajeet; Rawat, Nikita; Pandey, Jeewan Chandra +2 more
We present an X-ray and UV investigation of five X-ray flares detected on two active systems, CC Eri and AB Dor, using the AstroSat observatory. The peak X-ray luminosities of the flares in the 0.3–7.0 keV band are found to be within 1031‑33 erg s‑1. Preliminary spectral analysis indicates the presence of three and four-temperature corona for CC E…
Plasma diagnostics of supernova remnant 3C 400.2 by Suzaku observations
Nobukawa, Masayoshi; Uchiyama, Hideki; Nobukawa, Kumiko K. +2 more
We report on the results of plasma diagnostics of the supernova remnant (SNR) 3C 400.2, which has been reported to have a recombining plasma by previous studies. For careful background estimation, we simultaneously fitted spectra extracted from the SNR and background regions and evaluated the SNR emission contaminating the background-region spectr…
Formation of a Magnetic Cloud from the Merging of Two Successive Coronal Mass Ejections
Wang, Rui; Liu, Ying D.; Hu, Huidong +2 more
On 2022 March 28 two successive coronal mass ejections (CMEs) were observed by multiple spacecraft and resulted in a magnetic cloud (MC) at 1 au. We investigate the propagation and interaction properties of the two CMEs correlated with the MC using coordinated multipoint remote sensing and in situ observations from Solar Orbiter, STEREO-A, Solar a…