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A Peculiar Galaxy Near M104
Quiroga, E.
Messier 104, NGC 4594, also known as the Sombrero Galaxy, has been extensively studied, especially its structure and stellar halo. Its abundance of globular clusters has given rise to many theories and much speculation. However, other objects in the vicinity of such a spectacular galaxy are sometimes ignored. While studying HST images available on…
Fast Outflowing Warm Absorbers in Narrow-line Seyfert 1 Galaxy PG 1001+054 Revealed by HST/COS Spectra
Wang, Junfeng; Zhang, Zhi-Xiang; Fu, Xiao-Dan +1 more
Narrow-line Seyfert 1 (NLS1) galaxies are an important type of active galactic nucleus (AGN), generally expected to be accreting at a high Eddington rate. The properties of their outflows and importance of AGN feedback remain intriguing. We report on the discovery of fast outflowing warm absorbers (WAs) in the NLS1 PG 1001+054 with velocities in t…
Analysis of Two Selected Solar Events in 2011 and 2015 With Mars Express Radio Occultation Data
Witasse, Olivier; Sánchez-Cano, Beatriz; Karatekin, Ozgur +3 more
The temporal behavior of the Martian ionosphere is highly variable due to various dynamic processes including space weather events. Here, we study the effect of solar flares and coronal mass ejections (CMEs) on the Martian ionosphere for two selected solar events in 2011 and 2015, using the publicly available Mars EXpress (MEX) radio occultation (…
Large-Scale Disturbances of the Solar Wind According to Spacecraft Radio Transmission Data from the Mars Express and Local Measurements on the Wind Spacecraft
Efimov, A. I.; Smirnov, V. M.; Chashei, I. V. +1 more
The results of experiments on radio sounding of near the Sun plasma by the signals of the Mars Express Mars satellite are presented. In the region of heliocentric distances of the proximate point of the line of sight of 8–13 solar radii, frequency fluctuations of transmission radio signals were measured. During the experiments sharp increases in t…
Solar Orbiter fine pointing Mode improvement in flight: Challenges and achievements
Cantiello, Ilario; Chapman, Patrick; Monroig, Guillaume +2 more
ESA Solar Orbiter was launched from Cape Canaveral in collaboration with NASA on the February 10, 2020 to start its journey around the Sun, with the commissioning phase ending in April 2020. After commissioning, ESA set a tighter pointing requirement goal to further improve the performance in Fine Pointing Mode, in preparation of the upcoming star…
A simple linear model to aid in analyses of the β Pictoris moving group
Barbosa, Valmir C.; do Nascimento, Josina O.
We build a 4D linear model of object membership in the $\beta$ Pictoris moving group (BPMG), using two nested applications of Principal Component Analysis (PCA) for ~1.5 million objects with high-quality data. These data consist of 3D-Galactic space velocities and Gaia G magnitudes. Through PCA, they ultimately result in a 4D straight line, referr…
Estimation of the Flux at 1450 MHz of OB Stars for FAST and SKA
Jiang, Biwei; Deng, Dingshan; Zijlstra, Albert +2 more
Radio observation is crucial to understanding the wind mechanism of OB stars but very scarce. This work estimates the flux at 1450 MHz (S 1.4GHz) of about 5000 OB stars identified by the LAMOST spectroscopic survey and confirmed by the Gaia astrometric as well as astrophysical measurements. The calculation is performed under the free-fr…
OGLE-2019-BLG-1180Lb: Discovery of a Wide-orbit Jupiter-mass Planet around a Late-type Star
Han, Cheongho; Udalski, Andrzej; Lee, Chung-Uk +32 more
We report on the discovery and analysis of the planetary microlensing event OGLE-2019-BLG-1180 with a planet-to-star mass ratio q ~ 0.003. The event OGLE-2019-BLG-1180 has unambiguous cusp-passing and caustic-crossing anomalies, which were caused by a wide planetary caustic with s ≃ 2, where s is the star-planet separation in units of the angular …
Dendritic ridges in Antoniadi basin, Mars: Fluvial or volcanic landforms?
Mangold, N.; Thomas, N.; Hauber, E. +7 more
Antoniadi basin displays dark-toned dendritic ridges previously interpreted as inverted fluvial channels. Detailed observations of these dark-toned ridges as well as the geological units in the central region of Antoniadi basin are provided emphasizing images from the Colour and Stereo Surface Imaging System (CaSSIS), the High Resolution Stereo Ca…
New Insights into Aristarchus Crater with LRO LAMP Far-ultraviolet Observations
Hendrix, Amanda; Retherford, Kurt; Grava, Cesare +8 more
Aristarchus crater is a Copernican-age impact crater well known for its high-albedo ejecta blanket and nearby flow features rich in pyroclastic materials. The Lyman Alpha Mapping Project (LAMP) is a far-ultraviolet (FUV) spectrograph (57-197 nm) on board the Lunar Reconnaissance Orbiter (LRO). LAMP data identified Aristarchus crater as having a hi…