A5090033636- Nuclear Physics and Applications
- Astro and Planetary Science
- Atmospheric Ozone and Climate
- Geomagnetism and Paleomagnetism Studies
- Stellar, planetary, and galactic studies
- Spectroscopy and Laser Applications
- Nuclear physics research studies
- Atomic and Subatomic Physics Research
- Advanced NMR Techniques and Applications
- Astronomy and Astrophysical Research
- Molecular Spectroscopy and Structure
- Calibration and Measurement Techniques
- Astronomical Observations and Instrumentation
- Methane Hydrates and Related Phenomena
- Medical Imaging Techniques and Applications
- Geochemistry and Geologic Mapping
- Gamma-ray bursts and supernovae
- Particle Detector Development and Performance
- Advanced Chemical Physics Studies
- Inorganic Fluorides and Related Compounds
- Spectroscopy Techniques in Biomedical and Chemical Research
- Solid-state spectroscopy and crystallography
- Quantum, superfluid, helium dynamics
- Geophysics and Gravity Measurements
- Spacecraft and Cryogenic Technologies
University College London
2016-2025
Center for Free-Electron Laser Science
2019-2024
Deutsches Elektronen-Synchrotron DESY
2019-2024
Universität Hamburg
2019-2024
University College Lahore
2021
E XO C ROSS is a Fortran code for generating spectra (emission, absorption) and thermodynamic properties (partition function, specific heat, etc.) from molecular line lists. Input taken in several formats, including ExoMol HITRAN formats. efficiently parallelized showing also high degree of vectorization. It can work with profiles such as Doppler, Lorentzian Voigt support broadening schemes. are handled by methods allowing fast accurate simulations. Two these new. capable working the...
Abstract We present a comprehensive analysis of the Hubble Space Telescope observations atmosphere WASP-121 b, an ultra-hot Jupiter. After reducing transit, eclipse, and phase-curve with uniform methodology addressing biases from instrument systematics, sophisticated atmospheric retrievals are used to extract robust constraints on thermal structure, chemistry, cloud properties atmosphere. Our shows that consistent strong inversion beginning at ∼10 4 Pa dayside, solar subsolar metallicity Z...
Abstract We present a population study of 20 exoplanets, ranging from Neptune-like to inflated hot-Jupiter planets, observed during transit with the Space Telescope Imaging Spectrograph (STIS) and Wide Field Camera 3 (WFC3) instruments on board Hubble (HST). To obtain spectral information near-ultraviolet near-infrared, we reanalyzed 16 WFC3 over 50 STIS archival data sets our dedicated HST pipeline. also include 24 previously reduced same software. Across target sample, observe significant...
A comprehensive hot line list is calculated for $^{31}$PH$_3$ in its ground electronic state. This list, called SAlTY, contains almost 16.8 billion transitions between 7.5 million energy levels and it suitable simulating spectra up to temperatures of 1500~K. It covers wavelengths longer than 1~$\mu$m includes all upper states with energies below $hc \cdot 18\,000$~cm$^{-1}$ rotational excitation $J=46$. The computed by variational solution the Schr\"odinger equation rotation-vibration motion...
Here we present a publicly available database of opacities for molecules astrophysical interest named ExoMolOP that has been compiled over 80 species, and is based on the latest line list data from ExoMol, HITEMP, MoLLIST databases. These are generally suitable characterising high-temperature exoplanet or cool stellar substellar atmospheres, have computed at variety pressures temperatures, with few included room temperature only HITRAN database. The formatted in different ways four...
We analyse the transmission and emission spectra of ultra-hot Jupiter WASP-76b, observed with G141 grism Hubble Space Telescope's Wide Field Camera 3 (WFC3). reduce fit raw data for each observation using open-source software Iraclis before performing a fully Bayesian retrieval publicly available analysis suite TauRex 3. Previous studies WFC3 WASP-76 b found hints titanium oxide (TiO) vanadium (VO) or non-grey clouds. Accounting fainter stellar companion to WASP-76, we reanalyse this show...
Abstract This paper presents the atmospheric characterization of three large, gaseous planets: WASP-127 b, WASP-79 and WASP-62 b. We analyzed spectroscopic data obtained with G141 grism (1.088–1.68 μ m) Wide Field Camera 3 on board Hubble Space Telescope using Iraclis pipeline TauREx3 retrieval code, both which are publicly available. For is least dense planet discovered so far located in short-period Neptune desert, our results found strong water absorption corresponding to an abundance...
Abstract Population studies of exoplanets are key to unlocking their statistical properties. So far, the inferred properties have been mostly limited planetary, orbital, and stellar parameters extracted from, e.g., Kepler, radial velocity, Gaia data. More recently an increasing number exoplanet atmospheres observed in detail from space ground. Generally, however, these atmospheric focused on individual planets, with exception a couple works that detected presence water vapor clouds...
Abstract We present analysis of the atmospheres 70 gaseous extrasolar planets via transit spectroscopy with Hubble’s Wide Field Camera 3 (WFC3). For over half these, we statistically detect spectral modulation that our retrievals attribute to molecular species. Among use Bayesian hierarchical modeling search for chemical trends bulk parameters. extracted water abundance infer atmospheric metallicity and compare it planet’s mass. also run equilibrium retrievals, fitting directly. However,...
ABSTRACT Retrieval methods are a powerful analysis technique for modelling exoplanetary atmospheres by estimating the bulk physical and chemical properties that combine in forward model to best fit an observed spectrum, they increasingly being applied observations of directly imaged exoplanets. We have adapted taurex3, Bayesian retrieval suite, near-infrared spectrophotometry from gas giant exoplanets brown dwarfs. demonstrate taurex3’s applicability sub-stellar presenting results dwarf...
Abstract Current endeavours in exoplanet characterization rely on atmospheric retrieval to quantify crucial physical properties of remote exoplanets from observations. However, the scalability and efficiency said technique are under strain with increasing spectroscopic resolution forward model complexity. The situation has become more acute recent launch James Webb Space Telescope other upcoming missions. Recent advances machine learning provide optimization-based variational inference as an...
A computed line list for formaldehyde, H212C16O, applicable to temperatures up T = 1500 K is presented. An empirical potential energy and ab initio dipole moment surfaces are used as the input nuclear motion program trove. The resulting list, referred AYTY, contains 10.3 million rotational-vibrational states around 10 billion transition frequencies. Each includes associated Einstein-A coefficients absolute intensities, wavenumbers below 000 cm−1 rotational excitations J 70. Room-temperature...
Abstract Atmospheric characterization of temperate, rocky planets is the holy grail exoplanet studies. These worlds are at limits our capabilities with current instrumentation in transmission spectroscopy and challenge state-of-the-art statistical techniques. Here we present spectrum temperate super-Earth LHS 1140b using Hubble Space Telescope (HST). The Wide Field Camera 3 (WFC3) G141 grism data this habitable-zone ( T eq = 235 K) R 1.7 ⊕ ) shows tentative evidence water. However,...
Abstract Thermochemical equilibrium is one of the most commonly used assumptions in current exoplanet retrievals. As science operations with James Webb Space Telescope (JWST) draw near and planned launch Ariel, it crucial to assess underlying biases made when applying self-consistent chemistry spectral Here we use flexibility TauREx 3.1 cross-compare three state-of-the-art chemical codes: ACE, FastChem, GGchem. We simulate JWST spectra for GGchem, GGchem+condensation containing only elements...
Collisions of low energy electrons with molecules are important for understanding many aspects the environment and technologies. Understanding processes that occur in these types collisions can give insights into plasma etching processes, edge effects fusion plasmas, radiation damage to biological tissues more. A radical update previous expert system computing observables relevant Quantemol-N, is presented. The new Quantemol Electron Collision (QEC) simplifyies user experience, improving...
Abstract TauREx 3 is the next generation of exoplanet atmospheric retrieval framework for Windows, Mac, and Linux. It a complete rewrite with full Python stack that makes it easy-to-use, high-performance, dynamic, flexible. The new main program built modularity in mind, allowing user to augment its functionalities custom code efficiently perform retrievals on parameters. We achieve this result by dynamic determination fitting parameters, whereby can detect parameters from through simple...
Abstract In the rapidly evolving field of exoplanetary science with missions like JWST and Ariel, there is a pressing need for fast accurate simulations disequilibrium chemistry in exoplanet atmospheres. Methods which assume chemical equilibrium simplify calculations but fail to capture more complex dynamics observed actual exoplanets. Accurate estimations require kinetic codes that are time-intensive due solve ordinary differential equations. Given an extensive parameter space needs be...
In this work, we present Alfnoor, a dedicated tool optimised for population studies of exoplanet atmospheres. Alfnoor combines the latest version retrieval algorithm TauREx 3, with instrument noise simulator ArielRad and enables simultaneous analysis large sample exo-atmospheres. We applied to Ariel list planetary candidates focus on hydrogen dominated, cloudy atmospheres observed in transit Tier-2 mode (medium resolution). As first experiment, randomised abundances - ranging from 10$^{-7}$...
Abstract The analysis of exoplanetary atmospheres often relies upon the observation transit or eclipse events. While very powerful, these snapshots provide mainly one-dimensional information on planet structure and do not easily allow precise latitude–longitude characterizations. phase curve technique, which consists measuring emission throughout its entire orbit, can break this limitation useful two-dimensional thermal chemical constraints atmosphere. As today, however, computing...
Sulphur trioxide (SO3) is a trace species in the atmospheres of Earth and Venus, as well being an industrial product environmental pollutant. A variational line list for 32S16O3, named UYT2, presented containing 21 billion vibration–rotation transitions. UYT2 can be used to model infrared spectra SO3 at wavelengths longwards 2 μm (ν < 5000 cm−1) temperatures up 800 K. Infrared absorption cross-sections recorded 300 500 C are validate list. The intensities scaled match measured...
The ARIADNE project is developing innovative optical readout technologies for two-phase liquid Argon time projection chambers (LArTPCs). Optical presents an exciting alternative to the current paradigm of charge readout. simple, scalable and cost effective. This paper first demonstration 3D TPC, using CF4 gas as a proof principle. Both cosmic rays Americium-241 alpha source have been imaged in 100 mbar CF4. A single-photon sensitive camera was developed by combining Timepix3 (TPX3) based...
We present an atmospheric characterization study of two medium sized planets bracketing the radius Neptune: HD 106315 c (R$_{\rm{P}}$=4.98 $\pm$ 0.23 R$_{\oplus}$) and 3167 (R$_{\rm{P}}$=2.740$_{-0.100}^{+0.106}$ R$_{\oplus}$). analyse spatially scanned spectroscopic observations obtained with G141 grism (1.125 - 1.650 $\mu$m) Wide Field Camera 3 (WFC3) onboard Hubble Space Telescope. use publicly available Iraclis pipeline TauREx3 retrieval code we detect water vapor in atmosphere both...