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Water Ice and Possible Habitability in the Landing Area of Tianwen-1 Mission
Ding, Chunyu; Su, Yan; Li, Jiawei +3 more
The Tianwen-1 mission, marking China's inaugural venture into Mars exploration, successfully deployed the Zhurong rover on Utopia Planitia. This review primarily focuses on the insights provided by the Mars Rover Penetrating Radar (RoPeR), a pivotal component of the mission's scientific payload. The article synthesizes the RoPeR findings with an e…
Orbital and Atmospheric Characterization of the 1RXS J034231.8+121622 System using High-resolution Spectroscopy Confirms that the Companion is a Low-mass Star
Do Ó, Clarissa R.; Fitzgerald, Michael P.; López, Ronald A. +33 more
The 1RXS J034231.8+121622 system consists of an M dwarf primary and a directly imaged low-mass stellar companion. We use high-resolution spectroscopic data from Keck/KPIC to estimate the objects' atmospheric parameters and radial velocities (RVs). Using PHOENIX stellar models, we find that the primary has a temperature of 3460 ± 50 K and a metalli…
Non-radial oscillations mimicking a brown dwarf orbiting the cluster giant NGC 4349 No. 127
Reffert, Sabine; Quirrenbach, Andreas; Hunt, Emily L. +2 more
Context. Several evolved stars have been found to exhibit long-period radial velocity variations that cannot be explained by planetary or brown dwarf companions. Non-radial oscillations caused by oscillatory convective modes have been put forth as an alternative explanation, but no modeling attempt has yet been undertaken. Aims. We provide a model…
Generating Stellar Spectra Using Neural Networks
Gebran, Marwan
A new generative technique is presented in this paper that uses Deep Learning to reconstruct stellar spectra based on a set of stellar parameters. Two different Neural Networks were trained allowing the generation of new spectra. First, an autoencoder is trained on a set of BAFGK synthetic data calculated using ATLAS9 model atmospheres and SYNSPEC…
Activity of main-belt comet 324P/La Sagra
Agarwal, J.; Kim, Y.; Mastropietro, M. +1 more
Aims. We study the activity evolution of the main-belt comet 324P/La Sagra over time and the properties of its emitted dust. Methods. We performed aperture photometry on images taken by a wide range of telescopes at optical and thermal infrared wavelengths between 2010 and 2021. We derived the combined scattering cross section of the nucleus and d…
Kinematic properties and ages of extended fast, neutral gas around η Carinae: tracing the pre-eruption bipolar wind
Smith, Nathan; Morse, Jon A.
We present proper-motion measurements and long-slit spectroscopy of the Mg II nebula around η Carinae obtained with the Wide Field Camera 3 and Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope. Detailed kinematics of the Mg II-emitting material constrain the geometry and history of mass-loss from η Car, and provide est…
Systematic Study of the Inner Structure of Molecular Tori in Nearby U/LIRGs Using Velocity Decomposition of CO Rovibrational Absorption Lines
Onishi, Shusuke; Nakagawa, Takao; Baba, Shunsuke +6 more
Determining the inner structure of the molecular torus around an active galactic nucleus is essential for understanding its formation mechanism. However, spatially resolving the torus is difficult because of its small size. To probe the clump conditions in the torus, we therefore perform the systematic velocity-decomposition analyses of the gaseou…
Criteria for Forecasting Proton Events by Real-Time Solar Observations
Struminsky, A. B.; Grigorieva, I. Yu.; Sadovskii, A. M.
The sequence for overcoming the threshold values of a number of physical characteristics for proton event forecasting in real time is discussed. Each characteristic adds a new physical meaning that refines the forecast. To take into account all the characteristics, the following continuous patrol observations are necessary: (1) the magnetic field …
The COS CGM Compendium. V. The Dichotomy of O VI Associated with Low- and High-metallicity Cool Gas at z < 1
Sameer; Fox, Andrew J.; Lehner, Nicolas +3 more
We analyze the O VI content and kinematics for 126 H I-selected absorbers at 0.14 ≲ z ≲ 0.73 for which the metallicities of their cool photoionized phase have been determined. We separate the absorbers into 100 strong Lyα forest systems (SLFSs with 15 ≲ log N(H I) < 16.2) and 26 partial Lyman Limit systems (pLLSs with 16.2 ≤ log N(H I) ≤ 17.2).…
Siril: An Advanced Tool for Astronomical Image Processing
Richard, Cyril; Hourdin, Vincent; Melis, Cécile +1 more
Siril is a powerful open-source software package designed for the preprocessing and post-processing of astronomical images. It is particularly well-suited for astrophotography enthusiasts and professional astronomers alike. Siril provides advanced tools for tasks such as image stacking, calibration, registration, and enhancement, enabling users to…