Search Publications
A comparative analysis of the active galactic nucleus and star formation characteristics of broad- and narrow-line Seyfert 1 galaxies
Stalin, C. S.; Mountrichas, G.; Sagar, R. +4 more
We report here our comparative analysis of the active galactic nucleus (AGN) and star formation (SF) characteristics of a sample of narrow-line Seyfert 1 (NLS1) and broad-line Seyfert 1 (BLS1) galaxies. Our sample consisted of 373 BLS1 and 240 NLS1 galaxies and spanned the redshift 0.02 < z < 0.8. The broad-band spectral energy distribution,…
Composition Variation of the 2023 May 16 Solar Energetic Particle Event Observed by SolO and PSP
Mitchell, D. G.; McComas, D. J.; Wimmer-Schweingruber, R. F. +13 more
In this study, we employ the combined charged particle measurements from Integrated Science Investigation of the Sun on board the Parker Solar Probe (PSP) and Energetic Particle Detector on board the Solar Orbiter (SolO) to study the composition variation of the solar energetic particle (SEP) event occurring on 2023 May 16. During the event, SolO …
First joint X-ray solar microflare observations with NuSTAR and Solar Orbiter/STIX
Krucker, Säm; Jeffrey, Natasha L. S.; Grefenstette, Brian W. +5 more
We present the first joint spectral and imaging analysis of hard X-ray (HXR) emission from three microflares observed by the Nuclear Spectroscopic Telescope ARray (NuSTAR) and Solar Orbiter/Spectrometer/Telescope for Imaging X-rays (STIX). We studied 5 joint spectra from GOES A7, B1, and B6 class microflares from active region AR12765 on 2020 June…
Impact crater recognition methods: A review
Wu, Yunzhao; Chen, Dong; Hu, Fan +3 more
Impact craters are formed due to the high-speed collisions between small to medium-sized celestial bodies. Impact is the most significant driving force in the evolution of celestial bodies, and the impact craters provide crucial insights into the formation, evolution, and impact history of celestial bodies. In this paper, we present a detailed rev…
Ultraviolet spectrum reveals the presence of ozone on Jupiter's moon Callisto
Janardhan, P.; Bhardwaj, Anil; Ramachandran, R. +11 more
Sulphur dioxide (SO2) is known to be present on Callisto. In this paper, we studied the chemical evolution of SO2 astrochemical ice induced by irradiation using 9 eV (137.7 nm) vacuum ultraviolet light produced from the high-flux beamline of the storage ring at the National Synchrotron Radiation Research Centre in Taiwan. Ult…
Predicting Photospheric Ultraviolet Emission from Stellar Evolutionary Models
Liu, Jifeng; Wang, Song; Li, Xue +1 more
Stellar ultraviolet (UV) emission serves as a crucial indicator for estimating magnetic activity and evaluating the habitability of exoplanets orbiting stars. In this paper, we present a straightforward method to derive stellar photospheric UV emission for F to M main-sequence stars. By using PARSEC models, we establish relations between near-UV (…
Oblique Electrostatic Solitary and Supersolitary Waves in Earth's Magnetosheath
Singh, Kuldeep; Varghese, Steffy Sara; Saini, Nareshpal Singh +1 more
Nonlinear electrostatic solitary waves (ESWs) are routinely detected at various regions of Earth's magnetosphere using the Wideband Data plasma wave receivers mounted on board the Cluster satellite(s). This mission has facilitated the observation and analysis of ESW characteristics, such as amplitude and temporal duration within the magnetosheath,…
The time-variable ultraviolet sky: Active galactic nuclei, stars, and white dwarfs
Bühler, R.; Schliwinski, J.
Here, we present the first catalog of Ultraviolet time-VAriable sources (1UVA). We describe a new analysis pipeline called VAriable Source Clustering Analysis (VASCA). We applied this pipeline to 10 yr of data from the Galaxy Evolution Explorer (GALEX) satellite. We analyzed a sky area 302 deg2, and detected 4,202 time-variable ultravio…
Connecting integrated red giant branch mass loss from asteroseismology and globular clusters
Miglio, A.; Brogaard, K.; Willett, E. +2 more
Context. Asteroseismic investigations of solar-like oscillations in giant stars enable the derivation of their masses and radii. For mono-age mono-metallicity populations of stars, this allows the integrated red giant branch (RGB) mass loss to be estimated by comparing the median mass of the low-luminosity RGB stars to that of the helium-core-burn…
Particle sizes in Saturn's rings from UVIS stellar occultations 2. Outlier Populations in the C ring and Cassini Division
Colwell, J. E.; Esposito, L. W.; Jerousek, R. G. +1 more
The Cassini Ultraviolet Imaging Spectrograph (UVIS) included a High-Speed Photometer (HSP), which observed hundreds of stellar occultations by Saturn's ring system across a range of viewing geometries (Colwell et al. 2010). The unocculted time series data from the HSP follow Poisson counting statistics, such that the second and third central momen…