Search Publications
Birth of the ELMs: a ZTF survey for evolved cataclysmic variables turning into extremely low-mass white dwarfs
Rix, Hans-Walter; El-Badry, Kareem; Kupfer, Thomas +2 more
We present a systematic survey for mass-transferring and recently detached cataclysmic variables (CVs) with evolved secondaries, which are progenitors of extremely low mass white dwarfs (ELM WDs), AM CVn systems, and detached ultracompact binaries. We select targets below the main sequence in the Gaia colour-magnitude diagram with ZTF light curves…
Comparing the pre-SNe feedback and environmental pressures for 6000 H II regions across 19 nearby spiral galaxies
Chevance, M.; Murphy, E. J.; Dale, D. A. +28 more
The feedback from young stars (i.e. pre-supernova) is thought to play a crucial role in molecular cloud destruction. In this paper, we assess the feedback mechanisms acting within a sample of 5810 H II regions identified from the PHANGS-MUSE survey of 19 nearby (<20 Mpc) star-forming, main-sequence spiral galaxies [log(M⋆/M⊙
Uncertain times: the redshift-time relation from cosmology and stars
Weisz, Daniel R.; Boylan-Kolchin, Michael
Planck data provide precise constraints on cosmological parameters when assuming the base ΛCDM model, including a 0.17 per cent measurement of the age of the Universe, $t_0=13.797 \pm 0.023\, {\rm Gyr}$. However, the persistence of the 'Hubble tension' calls the base ΛCDM model's completeness into question and has spurred interest in models such a…
The properties of polycyclic aromatic hydrocarbons in galaxies: constraints on PAH sizes, charge and radiation fields
Rigopoulou, D.; Pereira-Santaella, M.; Alonso-Herrero, A. +7 more
Based on theoretical spectra computed using Density Functional Theory we study the properties of polycyclic aromatic hydrocarbons (PAH). In particular using bin-average spectra of PAH molecules with varying number of carbons we investigate how the intensity of the mid-infrared emission bands, 3.3, 6.2, 7.7, and 11.3 $\mu$m, respond to changes in t…
Planet Hunters TESS II: findings from the first two years of TESS
Aigrain, S.; Vaughan, S.; Barragán, O. +23 more
We present the results from the first two years of the Planet Hunters TESS (PHT) citizen science project, which identifies planet candidates in the TESS (Transiting Exoplanet Survey Satellite) data by engaging members of the general public. Over 22 000 citizen scientists from around the world visually inspected the first 26 sectors of TESS data in…
Prestellar grain-surface origins of deuterated methanol in comet 67P/Churyumov-Gerasimenko
De Keyser, Johan; van Dishoeck, Ewine F.; Drozdovskaya, Maria N. +6 more
Deuterated methanol is one of the most robust windows astrochemists have on the individual chemical reactions forming deuterium-bearing molecules and the physicochemical history of the regions where they reside. The first-time detection of mono- and di-deuterated methanol in a cometary coma is presented for comet 67P/Churyumov-Gerasimenko using Ro…
A spectral survey of WASP-19b with ESPRESSO
MacDonald, Ryan J.; Brahm, Rafael; Sánchez-López, Alejandro +10 more
High-resolution precision spectroscopy provides a multitude of robust techniques for probing exoplanetary atmospheres. We present multiple VLT/ESPRESSO transit observations of the hot-Jupiter exoplanet WASP-19b with previously published but disputed atmospheric features from low resolution studies. Through spectral synthesis and modelling of the R…
Galactic potential constraints from clustering in action space of combined stellar stream data
Sharma, Sanjib; Helmi, Amina; Koppelman, Helmer H. +4 more
Stream stars removed by tides from their progenitor satellite galaxy or globular cluster act as a group of test particles on neighbouring orbits, probing the gravitational field of the Milky Way. While constraints from individual streams have been shown to be susceptible to biases, combining several streams from orbits with various distances reduc…
Assessing the sources of reionization: a spectroscopic case study of a 30× lensed galaxy at z 5 with Lyα, C IV, Mg II, and [Ne III]
Richard, Johan; Maiolino, Roberto; Massey, Richard +5 more
We present a detailed spectroscopic analysis of a galaxy at z ≃ 4.88 that is, by chance, magnified ~30× by gravitational lensing. Only three sources at z ≳ 5 are known with such high magnification. This particular source has been shown to exhibit widespread, high equivalent width ${{\rm C\, \small {IV}}}\ \lambda 1549\, \mathring{\rm A}$ emission,…
Constraining the solar neighbourhood age-metallicity relation from white dwarf-main sequence binaries
Gänsicke, B. T.; Tremblay, P. -E.; Koester, D. +11 more
The age-metallicity relation (AMR) is a fundamental tool for constraining the chemical evolution of the Galactic disc. In this work, we analyse the observational properties of this relation using binary stars that have not interacted consisting of a white dwarf (WD) - from which we can derive the total age of the system - and a main sequence (MS) …