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Dec 13, 2024 | 
academic.oup.com | Denys Wilkinson Building |Keble Road |Space science |Abu Dhabi
Low-mass X-ray binaries (LMXBs) are binary systems made up of a compact object, either a black hole (BH) or neutron star (NS), and a low-mass stellar companion. Mass is transferred from the star to the compact object via Roche Lobe overflow through the inner Lagrange point.
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Nov 30, 2024 | 
academic.oup.com | Denys Wilkinson Building |Keble Road |Madingley Road
Lyα is the transition to the ground state from the first excited state of hydrogen (the most common element). Resonant scattering of this line by neutral hydrogen greatly impedes its emergence from galaxies, so the fraction of galaxies emitting Lyα is a tracer of the neutral fraction of the intergalactic medium (IGM), and thus the history of reionisation.
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Nov 26, 2024 | 
academic.oup.com | Gower Street |Denys Wilkinson Building |Keble Road
The utility of Type Ia supernovae (SNe Ia) in cosmology arises from the fact that they are empirically standardizable candles, and are bright enough to be observed out to redshift .
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Nov 9, 2024 | 
academic.oup.com | Madingley Road |European Space Agency |Denys Wilkinson Building
The Epoch of Reionization (EoR) is one of the major phase transitions of the Universe, when it went from being dark and neutral to highly ionized, allowing Lyman Continuum (Ly C; with energies above 13.6 eV) radiation to travel through the intergalactic medium (IGM). Observations place the end of this epoch at (Becker et al. 2001; Fan et al. 2006; Yang et al. 2020), with some favouring a later reionization at (Keating et al. 2020; Bosman et al. 2022; Zhu et al. 2024).
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Nov 6, 2024 | 
academic.oup.com | Denys Wilkinson Building |Keble Road |Kavli IPMU
Much of the progress made so far in cosmological large-scale structure studies has been using tools that are only optimal for the study of Gaussian random fields, such as correlation functions and power spectra. There are good reasons for these: CMB observations have confirmed that the primordial density fluctuations were very close to Gaussian (Komatsu et al. 2003; Planck Collaboration VII 2020).
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Oct 17, 2024 | 
academic.oup.com | Max-Planck-Institut für Radioastronomie |Denys Wilkinson Building |Keble Road
The double pulsar system PSR J0737−3039A/B is an extraordinary astrophysical laboratory that offers us a chance to directly probe the magnetic field of an active pulsar. Due to its almost edge-on orbit ( ; Hu et al. 2022; Askew et al. submitted) the 22.7 ms PSR J0737−3039A (‘pulsar A’; Burgay et al. 2003; Kramer et al. 2021a) is eclipsed for approximately 30–40 s every 2.4 h by the magnetosphere of the slower 2.77 s PSR J0737−3039B (‘pulsar B’; Lyne et al. 2004).
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Oct 17, 2024 | 
academic.oup.com | Denys Wilkinson Building |Keble Road |Magdalen College |SKA Observatory
Searches for transient radio sources, independent of any multiwavelength trigger, have traditionally been hindered by a combination of sensitivity and field-of-view. However this has changed with the advent of the Square Kilometre Array (SKA) Pathfinders – the Murchison Widefield Array (MWA; Tingay et al. 2013; Wayth et al. 2018), the Low Frequency Array (van Haarlem et al. 2013), MeerKAT (Jonas & MeerKAT Team 2016), and the Australian SKA Pathfinder (ASKAP; Hotan et al. 2021).
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Sep 27, 2024 | 
academic.oup.com | Denys Wilkinson Building |Keble Road |Université Cote d’Azur |Laboratoire Lagrange
The arrival of data from JWST presents a huge increase in the resolution and wavelength coverage of exoplanet atmosphere spectra we can obtain from space-based observatories. Spanning from all the way to across four different instruments with spectroscopic capabilities, the gain in potential information for exoplanet atmospheres is no doubt extensive. This new wavelength domain has facilitated the discovery of new molecules and confirmed previous detections (e.g. Bell et al.
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Sep 13, 2024 | 
academic.oup.com | Denys Wilkinson Building |Keble Road |Gower Street
We assess the usefulness of gradient-based samplers, such as the No-U-Turn Sampler ( ), by comparison with traditional Metropolis-Hastings algorithms, in tomographic 3 × 2 point analyses. Specifically, we use the DES Year 1 data and a simulated future LSST-like survey as representative examples of these studies, containing a significant number of nuisance parameters (20 and 32, respectively) that affect the performance of rejection-based samplers.
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Jul 11, 2024 | 
academic.oup.com | Denys Wilkinson Building |Keble Road
Cold gas evolution ties the formation of dark matter halos to the star formation history of the universe. A primary component of cold gas, neutral atomic hydrogen (HI), can be traced by its 21-cm emission line. However, the faintness of this emission typically limits individual detections to low redshifts (z ≲ 0.2). To address this limitation, we investigate the potential of targeting gravitationally lensed systems.
