Search Publications
The kinematics of Polycyclic Aromatic Hydrocarbons (PAHs) in Galaxies revealed by Principal Component Analysis (PCA) tomography with JWST/NIRSpec
Rigopoulou, Dimitra; García-Bernete, Ismael; Donnan, Fergus R
Polycyclic Aromatic Hydrocarbons (PAHs) are organic molecules which comprise the smallest particles of dust in the interstellar medium (ISM). Due to their broad/complex emission profiles, obtaining kinematics is a challenge with traditional methods, especially before the advent of the JWST. In this work, we employ Principal Component Analysis (PCA…
Circumstellar Disk Accretion Across the Lagoon Nebula: The Influence of Environment and Stellar Mass
Howell, Steve B.; Cody, Ann Marie; Beccari, Giacomo +9 more
Pre-main-sequence disk accretion is pivotal for determining the final stellar properties and the early conditions for close-in planets. We aim to establish the impact of internal (stellar mass) and external (radiation field) parameters on the disk evolution in the Lagoon Nebula massive star-forming region. We employ simultaneous u, g, r, i, Hα tim…
Quality flags for GSP-Phot Gaia DR3 astrophysical parameters with machine learning: effective temperatures case study
Zhao, Gang; Kovaleva, Dana A.; Avdeeva, Aleksandra S. +1 more
Gaia Data Release 3 (DR3) provides extensive information on the astrophysical properties of stars, such as effective temperature, surface gravity, metallicity, and luminosity, for over 470 million objects. However, as Gaia's stellar parameters in GSP-Phot module are derived through model-dependent methods and indirect measurements, it can lead to …
The Leakage of Lyman-continuum Photons from a Major Merger at z ∼ 1
Saha, Kanak; Herenz, Edmund Christian; Maulick, Soumil +1 more
We report the detection of Lyman-continuum (LyC) photons from a massive interacting system at z = 1.097 in the Hubble Ultra Deep Field. The LyC detection is made in the far-ultraviolet F154W band of the UVIT telescope on board AstroSat. Both JWST and Hubble Space Telescope (HST) imaging of the system reveal signs that it is a likely merger. In par…
Probing the physical properties of the intergalactic medium using SRG/eROSITA spectra from blazars
Wilms, J.; Gatuzz, E.; Hämmerich, S. +1 more
Most baryonic matter resides in the intergalactic medium (IGM). This diffuse gas is primarily composed of ionized hydrogen and helium and fills the space between galaxies. Observations of this environment are crucial for better understanding the physical processes in it. We present an analysis of the IGM absorption using blazar spectra from the fi…
Peering into the Wolf-Rayet phenomenon through [WO] and [WC] stars
Toalá, Jesús A.; Todt, Helge; Sander, Andreas A. C.
Spectroscopic observations have shown for decades that the Wolf-Rayet (WR) phenomenon is ubiquitous among stars with different initial masses. Although much effort to understand the winds from massive WR stars has been presented in the literature, not much has been done for such type of stars in the low-mass range. Here we present an attempt to un…
A dynamic view of V Hydrae. Monitoring of a spectroscopic-binary AGB star with an alkaline jet
Jorissen, A.; Planquart, L.; Escorza, A. +2 more
Context. The well studied carbon star V Hydrae is known to exhibit a complex asymmetric environment made of a dense equatorial wind and high-velocity outflows, hinting at its transition from the AGB phase to the asymmetric planetary nebula phase. In addition, V Hydrae also exhibits a long secondary period of 17 yr in its light curve, suggesting th…
An Eccentric Binary with a Misaligned Circumbinary Disk
Fang, Min; Huang, Yang; Dai, Fei +4 more
We present spectroscopic and photometric observations of Bernhard-2, which was previously identified as a candidate system that hosts a misaligned circumbinary disk. Our spectroscopic measurements confirm that Bernhard-2 indeed contains an eccentric (e = 0.69 ± 0.08) binary and thus that the periodic variability in the photometric light curve is b…
TOI-663: A newly discovered multi-planet system with three transiting mini-Neptunes orbiting an early M star
Tamura, M.; Bouchy, F.; de Medeiros, J. R. +53 more
We present the detection of three exoplanets orbiting the early M dwarf TOI-663 (TIC 54962195; V = 13.7 mag, J = 10.4 mag, R★ = 0.512 ± 0.015 R⊙, M★ = 0.514 ± 0.012 M⊙, d = 64 pc). TOI-663 b, c, and d, with respective radii of 2.27 ± 0.10 R⊕, 2.26 ± 0.10 R⊕, and 1.92 ± 0.13 R⊕<…
MEMPSEP-I. Forecasting the Probability of Solar Energetic Particle Event Occurrence Using a Multivariate Ensemble of Convolutional Neural Networks
Chatterjee, Subhamoy; Dayeh, Maher A.; Muñoz-Jaramillo, Andrés. +3 more
The Sun continuously affects the interplanetary environment through a host of interconnected and dynamic physical processes. Solar flares, Coronal Mass Ejections (CMEs), and Solar Energetic Particles (SEPs) are among the key drivers of space weather in the near-Earth environment and beyond. While some CMEs and flares are associated with intense SE…