Search Publications
Atmospheric carbon depletion as a tracer of water oceans and biomass on temperate terrestrial exoplanets
Triaud, Amaury H. M. J.; Seager, Sara; Rackham, Benjamin V. +9 more
The conventional observables to identify a habitable or inhabited environment in exoplanets, such as an ocean glint or abundant atmospheric O2, will be challenging to detect with present or upcoming observatories. Here we suggest a new signature. A low carbon abundance in the atmosphere of a temperate rocky planet, relative to other pla…
The extreme coronal line emitter AT 2022fpx: varying optical polarization properties and late-time X-ray flare
Reynolds, Thomas M.; Liodakis, Ioannis; Carbajo-Hijarrubia, Juan +8 more
Supermassive black holes disrupt passing stars, producing outbursts called tidal disruption events (TDEs). TDEs have recently gained attention due to their unique dynamics and emission processes, which are still not fully understood. Especially, the so-called optical TDEs are of interest as they often exhibit delayed or obscured X-ray emission fro…
Modelling two energetic storm particle events observed by Solar Orbiter using the combined EUHFORIA and iPATH models
Li, Gang; Poedts, Stefaan; Kouloumvakos, Athanasios +6 more
Context. By coupling the EUropean Heliospheric FORcasting Information Asset (EUHFORIA) and the improved Particle Acceleration and Transport in the Heliosphere (iPATH) models, we model two energetic storm particle (ESP) events originating from the same active region (AR 13088) and observed by Solar Orbiter (SolO) on August 31, 2022, and September 5…
JWST/MIRI unveils the stellar component of the GN20 dusty galaxy overdensity at z = 4.05
Östlin, G.; Colina, L.; Greve, T. R. +24 more
Dusty star-forming galaxies (DSFGs) at z > 2 have been commonly observed in overdense regions, where the merging processes and large halo masses induce rapid gas accretion, triggering star formation rates (SFRs) up to ∼1000 M⊙ yr‑1. Despite the importance of these DSFGs for understanding star formation in the early Univers…
Global-Scale Processes and Effects of Magnetic Reconnection on the Geospace Environment
Eastwood, J. P.; Lavraud, B.; Nakamura, R. +14 more
Recent multi-point measurements, in particular from the Magnetospheric Multiscale (MMS) spacecraft, have advanced the understanding of micro-scale aspects of magnetic reconnection. In addition, the MMS mission, as part of the Heliospheric System Observatory, combined with recent advances in global magnetospheric modeling, have furthered the unders…
Behind the mask: can HARMONI@ELT detect biosignatures in the reflected light of Proxima b?
Vigan, Arthur; Carlotti, Alexis; Pereira-Santaella, Miguel +7 more
Proxima b is a rocky exoplanet in the habitable zone of the nearest star system and a key test case in the search for extraterrestrial life. Here, we investigate the characterization of a potential Earth-like atmosphere around Proxima b in reflected light via molecule mapping, combining high-resolution spectroscopy (HRS) and high contrast imaging,…
CLASSY. IX. The Chemical Evolution of the Ne, S, Cl, and Ar Elements
Ravindranath, Swara; Martin, Crystal L.; Kumari, Nimisha +20 more
To study the chemical evolution across cosmic epochs, we investigate Ne, S, Cl, and Ar abundance patterns in the Cosmic Origins Spectrograph Legacy Archive Spectroscopic SurveY (CLASSY). CLASSY comprises local star-forming galaxies (SFGs; 0.02 < z < 0.18) with enhanced star formation rates, making them strong analogues to high-z SFGs. With d…
AGN STORM 2. VI. Mapping Temperature Fluctuations in the Accretion Disk of Mrk 817
Gorjian, Varoujan; Kaspi, Shai; Hall, Patrick B. +49 more
We fit the UV/optical lightcurves of the Seyfert 1 galaxy Mrk 817 to produce maps of the accretion disk temperature fluctuations δ T resolved in time and radius. The δ T maps are dominated by coherent radial structures that move slowly (v ≪ c) inward and outward, which conflicts with the idea that disk variability is driven only by reverberation. …
Revealing the chemical structure of the Magellanic Clouds with APOGEE. I. Calculating individual stellar ages of RGB stars in the Large Magellanic Cloud
Choi, Yumi; Cunha, Katia; Smith, Verne V. +12 more
Stellar ages are critical for understanding the temporal evolution of a galaxy. We calculate the ages of over 6000 red giant branch stars in the Large Magellanic Cloud (LMC) observed with SDSS-IV / APOGEE-S. Ages are derived using multiband photometry, spectroscopic parameters (
The Pristine Inner Galaxy Survey (PIGS): IX. The largest detailed chemical analysis of very metal-poor stars in the Sagittarius dwarf galaxy
Sestito, Federico; Martin, Nicolas F.; Kordopatis, Georges +16 more
The most metal-poor stars provide valuable insights into the early chemical enrichment history of a system, carrying the chemical imprints of the first generations of supernovae. The most metal-poor region of the Sagittarius dwarf galaxy remains inadequately observed and characterised. To date, only ∼4 stars with [Fe/H] < ‑2.0 have been chemica…