Search Publications
Composition and Chemistry of the Martian Atmosphere as Observed by Mars Express and ExoMars Trace Gas Orbiter
Montmessin, Franck; Korablev, Oleg; Fedorova, Anna +13 more
The atmosphere of Mars has been studied for many years now by a long series of missions. The paper focuses on the results obtained by two of these that are led by European researchers overseen by the European Space Agency, i.e., Mars Express which was launched in 2003 and ExoMars Trace Gas Orbiter launched in 2016. Both missions are still providin…
Observations of Five Major Uranian Satellites during 2013–2020 Based on Gaia DR3
Cheng, X.; Zhang, H. Y.; Yan, D. +4 more
A total of 10,339 positions of the five major Uranian satellites (Ariel, Umbriel, Titania, Oberon and Miranda) were collected at the Yunnan Observatories from 2013 to 2020 with the 1.0 m astrometric reflector. A median filtering method was applied to reduce the influence of the bright Uranus halo. All CCD observational data was analyzed by the new…
An acceleration-radiation model for nonthermal flares from Sgr A*
Ponti, Gabriele; Petropoulou, Maria; Stel, Giovanni +1 more
Context. Sgr A⋆ is the electromagnetic counterpart of the accreting supermassive black hole in the Galactic center. Its emission is variable in the near-infrared (NIR) and X-ray wavelengths on short timescales (several minutes to a few hours). The NIR light curve displays red-noise variability, while the X-ray light curve exhibits brigh…
SuperSynthIA: Physics-ready Full-disk Vector Magnetograms from HMI, Hinode, and Machine Learning
Liu, Yang; Antiochos, Spiro K.; Leka, K. D. +7 more
Vector magnetograms of the Sun's photosphere are cornerstones for much of solar physics research. These data are often produced by data-analysis pipelines combining per-pixel Stokes polarization vector inversion with a disambiguation that resolves an intrinsic 180° ambiguity. We introduce a learning-based method, SuperSynthIA, that produces full-d…
Carbon- and Oxygen-rich stars in MaStar: identification and classification
Hill, Lewis; Thomas, Daniel; Maraston, Claudia +5 more
Carbon- and Oxygen-rich stars populating the Thermally Pulsing Asymptotic Giant Branch (TP-AGB) phase of stellar evolution are relevant contributors to the spectra of ~1 Gyr old populations. Atmosphere models for these types are uncertain, due to complex molecules and mass-loss effects. Empirical spectra are then crucial, but samples are small due…
GMRT observations of the radio trail from CXOU J163802.6-471358
Roy, S.; Green, D. A.
The X-ray source CXOU J163802.6-471358 is thought to be a pulsar wind nebula (PWN), as it shows an extended, ≈40 arcsec trail from a compact source. Here, we present Giant Metrewave Radio Telescope observations of this source at 330 and 1390 MHz, which reveal a remarkable linear radio trail ≈90 arcsec in extent. Although the radio trail points bac…
Changes in the Plasma Sheet Conditions at Europa's Orbit Retrieved From Lead Angle of the Satellite Auroral Footprints
Tsuchiya, Fuminori; Kasaba, Yasumasa; Nichols, Jonathan D. +5 more
The electromagnetic interaction between Europa and the plasma sheet in the Jovian magnetosphere generates Alfvén waves, ultimately generating auroral footprints in Jupiter's atmosphere. The position of Europa's auroral footprint is a proxy for travel time of the Alfvén waves. We measured Europa's footprint position using the far-ultraviolet images…
Feasibility of Gallium Nitride for Astronomical Charge-Coupled Devices
Seabroke, George M.; Aggarwal, Anmol; Puri, Nitin K.
All astronomical missions use charge-coupled devices (CCDs) as vital organs. Usually, silicon (Si) is preferred to build them, which does not perform well without enhancements such as anti-reflection (AR) coatings. Such devices exhibit poor performance in the large (> 800 nm) and small (< 500 nm) wavelength ranges, even with AR coatings. We …
Molecular gas budget of strongly magnified low-mass star-forming galaxies at cosmic noon
Sharon, K.; Bayliss, M.; Mahler, G. +9 more
Aims. The aim of this study is to investigate the molecular gas content of strongly magnified low-mass star-forming galaxies (SFGs) around the cosmic noon period (z ∼ 2) through observations of carbon monoxide (CO) emission lines and dust continuum emission, both of which serve as tracers of molecular gas (H2). Methods. We observed 12 s…
The stellar population of a z ∼ 3.25 Lyα-emitting group associated with a damped Lyα absorber
Rafelski, Marc; Fumagalli, Michele; Fossati, Matteo +4 more
We present near-infrared observations, acquired with the Wide Field Camera 3 (WFC3) on board the Hubble Space Telescope (HST), of a Lyα-emitting double-clumped nebula at z ≈ 3.25 associated with a damped Lyα absorber (DLA). With the WFC3/F160W data we observe the stellar continuum around 3600 Å in the rest frame of a galaxy embedded in the west cl…