Search Publications
The alignment between brightest cluster galaxies and host clusters
Yuan, Z. S.; Wen, Z. L.
The alignment between the brightest cluster galaxies (BCGs) and host clusters can reveal the mystery of the formation and evolution of galaxy clusters. We measure cluster orientations in optical based on the projected distribution of member galaxies and in X-ray by fitting the morphology of intracluster medium (ICM). Cluster orientations determine…
A holistic approach to understand helium enrichment in interplanetary coronal mass ejections: new insights
Yogesh; Chakrabarty, D.; Srivastava, N.
Despite helium abundance [AHe = (nH/nHe) × 100] being ~8 per cent at the solar photospheric/chromospheric heights, AHe can be found to exceed 8 per cent in interplanetary coronal mass ejections (ICMEs) on many occasions. Although various factors like interplanetary shocks, chromospheric evaporation, and …
Statistical study of lightning-generated whistler-mode waves observed by Venus Express
Zhang, Tielong; Russell, Christopher T.; Hart, Richard A.
From 2006 through 2014, Venus Express regularly observed lightning-generated whistler-mode waves in the ionosphere of Venus. Since the ionopause of Venus is relatively low on the dayside, we restrict our statistical results to below 400 km altitude. Although the detections were of comparable rates for solar minimum and solar maximum (5.4% and 5.0%…
Sensitivity estimation for dark matter subhalos in synthetic Gaia DR2 using deep learning
Benito, M.; Bazarov, A.; Hütsi, G. +3 more
The abundance of dark matter subhalos orbiting a host galaxy is a generic prediction of the cosmological framework, and is a promising way to constrain the nature of dark matter. In this paper, we investigate the use of machine learning-based tools to quantify the magnitude of phase-space perturbations caused by the passage of dark matter subhalos…
Modeling the Luminosity-dependent Pulse Profile and Emission Geometry of SMC X-2 during a Giant Outburst
Laycock, Silas G. T.; Vasilopoulos, Georgios; Christodoulou, Dimitris M. +3 more
One of the brightest X-ray pulsars in the Small Magellanic Cloud is SMC X-2. During its most recent major outburst in 2015, this transient pulsar displayed significant changes in both its accretion state and magnetosphere, particularly when it entered the low-luminosity regime of subcritical accretion. Polestar is a pulse-profile modeling code tha…
Short-timescale X-ray spectral variability in the Seyfert 1 galaxy NGC 3783
Kaastra, J. S.; Kriss, G. A.; Bianchi, S. +9 more
Aims: We report on the X-ray time-resolved spectral analysis of XMM-Newton observations of NGC 3783. Our main goal is to detect transient features in the Fe K line complex in order to study the dynamics of the innermost accretion flow.
Methods: We reanalyse archival observations of NGC 3783, a bright local active galactic nucleus, for wh…
Chronological and compositional mapping of the Mare Orientale basin using Chandrayaan-1 - M3 and LRO datasets
Karthi, A.; Arivazhagan, S.
The lunar multiring mare basins have different ages, compositions and are associated with the diverse unit of mare deposits, providing evidence for the origin and evolution of the lunar crust. The multiring basins offer the opportunity to assess many unknown questions that may reveal the lunar geologic standpoint. The Mare Orientale basin is one o…
Solar Orbiter SWA Observations of Electron Strahl Properties Inside 1 AU
Verscharen, Daniel; Louarn, Philippe; Owen, Christopher J. +3 more
The Solar Wind Analyser (SWA) suite on Solar Orbiter includes an Electron Analyser System (SWA-EAS) which is capable of high temporal and angular resolution measurements of solar wind electrons in the energy range ∼1 eV to ∼5 keV. In this article we report early nominal phase observations of the suprathermal electron population at energies ≥70 eV …
Gaia-DR2 asteroid observations and INPOP planetary ephemerides
Laskar, J.; Fienga, A.; Gastineau, M. +2 more
We used the INPOP19a planetary ephemerides to perform the orbital adjustment of 14099 asteroids based on Gaia-DR2 observations and compare for 23 of them the resulting orbits to radar data. As Gaia-DR2 has been processed using the planetary ephemeris INPOP10e, the primary goal of this paper is to confirm the portability of the data when using an u…
Determining Emplacement Conditions and Vent Locations for Channelized Lava Flows Southwest of Arsia Mons
Flynn, I. T. W.; Crown, D. A.; Ramsey, M. S.
The lava flow field southwest of Arsia Mons, Mars has complex volcanic geomorphology. Overlapping flows make observations of their total lengths and identification of their source vents impossible. Application of flow emplacement models, which rely upon physical parameters such as flow length, using only the exposed flow may produce inaccurate est…