Search Publications
Confirmation of a Sub-Saturn-size Transiting Exoplanet Orbiting a G Dwarf: TOI-1194 b and a Very Low Mass Companion Star: TOI-1251 B from TESS
Zheng, Jie; Bieryla, Allyson; Howell, Steve B. +18 more
We report the confirmation of a sub-Saturn-size exoplanet, TOI-1194 b, with a mass of about
One-dimensional Microphysics Model of Venusian Clouds from 40 to 100 km: Impact of the Middle-atmosphere Eddy Transport and SOIR Temperature Profile on the Cloud Structure
Vandaele, Ann Carine; Terada, Naoki; Imamura, Takeshi +4 more
We conducted a simulation of H2SO4 vapor, H2O vapor, and H2SO4–H2O liquid aerosols from 40 to 100 km, using a 1D Venus cloud microphysics model based on the one detailed in Imamura & Hashimoto. The cloud distribution obtained is in good agreement with in situ observations by Pio…
Machine learning applications in studies of the physical properties of active galactic nuclei based on photometric observations
Ackermann, Markus; Kowalski, Marek; Mechbal, Sarah
Context. We investigate the physical nature of active galactic nuclei (AGNs) using machine learning (ML) tools.
Aims: We show that the redshift, z, bolometric luminosity, LBol, central mass of the supermassive black hole (SMBH), MBH, Eddington ratio, λEdd, and AGN class (obscured or unobscured) can be reconstr…
Ejection and dynamics of aggregates in the coma of comet 67P/Churyumov-Gerasimenko
Agarwal, J.; Lemos, P.; Marschall, R. +1 more
Context. The process of gas-driven ejection of refractory materials from cometary surfaces continues to pose a challenging question in cometary science. The activity modeling of comet 67P/Churyumov-Gerasimenko, based on data from the Rosetta mission, has significantly enhanced our comprehension of cometary activity. But thermophysical models have …
Characterization of aqueous alteration and formation of salty exposures at Ius Chasma, Mars
Flahaut, Jessica; Weitz, Catherine M.; Bishop, Janice L. +6 more
Intriguing outcrops in Ius Chasma provide a window into past aqueous processes in Valles Marineris, Mars. Hydrous sulfate minerals are abundant throughout this region, but one area in Ius Chasma includes phyllosilicates, opal, and additional materials with unusual spectral features. This study at Geryon Montes, an east-west horst that divides Ius …
Variation in the Pedersen Conductance Near Jupiter's Main Emission Aurora: Comparison of Hubble Space Telescope and Galileo Measurements
Nichols, J. D.; Vogt, M. F.; Rutala, M. J. +1 more
We present the first large-scale statistical survey of the Jovian main emission (ME) to map auroral properties from their ionospheric locations out into the equatorial plane of the magnetosphere, where they are compared directly to in-situ spacecraft measurements. We use magnetosphere-ionosphere (MI) coupling theory to calculate currents from the …
Does High-Latitude Ionospheric Electrodynamics Exhibit Hemispheric Mirror Symmetry?
Hatch, Spencer Mark; Vanhamäki, Heikki; Magnus Laundal, Karl +6 more
Ionospheric electrodynamics is a problem of mechanical stress balance mediated by electromagnetic forces. Joule heating (the total rate of frictional heating of thermospheric gases and ionospheric plasma) and ionospheric Hall and Pedersen conductances comprise three of the most basic descriptors of this problem. More than half a century after iden…
HD 12098: a highly distorted dipole mode in an obliquely pulsating roAp star
Saio, H.; Kurtz, D. W.; Joshi, Santosh +2 more
HD 12098 is a rapidly oscillating Ap star pulsating in the most distorted dipole mode yet observed in this class of star. Using Transiting Exoplanet Survey Satellite (TESS) Sector 58 observations, we show that there are photometric spots at both the magnetic poles of this star. It pulsates obliquely primarily in a strongly distorted dipole mode wi…
Very metal-poor stars I: a catalogue derived from LAMOST DR9
Zhao, Gang; Li, Haining; Hou, Xiaokun
In this paper, a semisupervised machining learning technique had been utilized to analyse low-resolution stellar spectra from Large sky Area Multi-Object fiber Spectroscopic Telescope (LAMOST) Data Release 9 (DR9). We identified approximately 111 000 potential very metal-poor stars. Estimation of their stellar parameters ($T_{\rm eff}$, ${\rm log}…
The outflowing ionised gas of I Zw 1 observed by HST COS
Brandt, W. N.; Kriss, G. A.; Costantini, E. +8 more
Aims: We present an analysis of the Hubble Space Telescope Cosmic Origins Spectrograph spectrum of I Zw 1 aiming to probe the absorbing medium associated with the active galactic nucleus (AGN).
Methods: We fitted the emission spectrum and performed spectral analysis of the identified absorption features to derive the corresponding ionic …