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Cosmology and fundamental physics with the ELT-ANDES spectrograph (2024)
Journal Article
Martins, C., Cooke, R., Liske, J., Murphy, M., Noterdaeme, P., Schmidt, T., …Zanutta, A. (2024). Cosmology and fundamental physics with the ELT-ANDES spectrograph. Experimental Astronomy, 57(1), Article 5. https://doi.org/10.1007/s10686-024-09928-w

State-of-the-art 19th century spectroscopy led to the discovery of quantum mechanics, and 20th century spectroscopy led to the confirmation of quantum electrodynamics. State-of-the-art 21st century astrophysical spectrographs, especially ANDES at ESO... Read More about Cosmology and fundamental physics with the ELT-ANDES spectrograph.

MUSE Analysis of Gas around Galaxies (MAGG) – IV. The gaseous environment of z ∼ 3–4 Ly α emitting galaxies (2022)
Journal Article
Lofthouse, E. K., Fumagalli, M., Fossati, M., Dutta, R., Galbiati, M., Arrigoni Battaia, F., …Prochaska, J. X. (2023). MUSE Analysis of Gas around Galaxies (MAGG) – IV. The gaseous environment of z ∼ 3–4 Ly α emitting galaxies. Monthly Notices of the Royal Astronomical Society, 518(1), 305 - 331. https://doi.org/10.1093/mnras/stac3089

We study the link between galaxies and H I-selected absorption systems at z ∼ 3–4 in the MUSE Analysis of Gas around Galaxies (MAGG) survey, an ESO large programme consisting of integral field spectroscopic observations of 28 quasar fields hosting 61... Read More about MUSE Analysis of Gas around Galaxies (MAGG) – IV. The gaseous environment of z ∼ 3–4 Ly α emitting galaxies.

Harvesting the Lyα forest with convolutional neural networks (2022)
Journal Article
Cheng, T., Cooke, R. J., & Rudie, G. (2022). Harvesting the Lyα forest with convolutional neural networks. Monthly Notices of the Royal Astronomical Society, 517, 755-775. https://doi.org/10.1093/mnras/stac2631

We develop a machine learning based algorithm using a convolutional neural network (CNN) to identify low H I column density Lyα absorption systems (log NHI/cm−2 < 17) in the Lyα forest, and predict their physical properties, such as their H I column... Read More about Harvesting the Lyα forest with convolutional neural networks.

Vacuum Ultraviolet Fourier-transform Spectroscopy of 16O and 18O (2022)
Journal Article
Lai, K., Manalili, D., Ubachs, W., Cooke, R., Pettini, M., de Oliveira, N., & Salumbides, E. (2022). Vacuum Ultraviolet Fourier-transform Spectroscopy of 16O and 18O. Astrophysical Journal Supplement, 260(2), Article 37. https://doi.org/10.3847/1538-4365/ac6350

A spectroscopic study of atomic oxygen (O I) is performed using the Fourier-transform vacuum ultraviolet (VUV) spectrometer at the Dichroïsme Et Spectroscopie par Interaction avec le Rayonnement Synchrotron beamline of the SOLEIL synchrotron. Transit... Read More about Vacuum Ultraviolet Fourier-transform Spectroscopy of 16O and 18O.

Primordial Helium-3 Redux: The Helium Isotope Ratio of the Orion Nebula* (2022)
Journal Article
Cooke, R. J., Noterdaeme, P., Johnson, J. W., Pettini, M., Welsh, L., Peroux, C., …Weinberg, D. H. (2022). Primordial Helium-3 Redux: The Helium Isotope Ratio of the Orion Nebula*. Astrophysical Journal, 932(1), Article 60. https://doi.org/10.3847/1538-4357/ac6503

We report the first direct measurement of the helium isotope ratio, 3He/4He, outside of the Local Interstellar Cloud, as part of science-verification observations with the upgraded CRyogenic InfraRed Echelle Spectrograph. Our determination of 3He/4He... Read More about Primordial Helium-3 Redux: The Helium Isotope Ratio of the Orion Nebula*.

MUSE analysis of gas around galaxies (MAGG) – III. The gas and galaxy environment of z = 3–4.5 quasars (2021)
Journal Article
Fossati, M., Fumagalli, M., Lofthouse, E., Dutta, R., Cantalupo, S., Arrigoni Battaia, F., …Cooke, R. (2021). MUSE analysis of gas around galaxies (MAGG) – III. The gas and galaxy environment of z = 3–4.5 quasars. Monthly Notices of the Royal Astronomical Society, 503(2), 3044-3064. https://doi.org/10.1093/mnras/stab660

We present a study of the environment of 27 z = 3–4.5 bright quasars from the MUSE Analysis of Gas around Galaxies (MAGG) survey. With medium-depth Multi Unit Spectroscopic Explorer (MUSE) observations (4 h on target per field), we characterize the e... Read More about MUSE analysis of gas around galaxies (MAGG) – III. The gas and galaxy environment of z = 3–4.5 quasars.

The stochastic enrichment of Population II stars (2020)
Journal Article
Welsh, L., Cooke, R., & Fumagalli, M. (2021). The stochastic enrichment of Population II stars. Monthly Notices of the Royal Astronomical Society, 500(4), 5214-5228. https://doi.org/10.1093/mnras/staa3342

We investigate the intrinsic scatter in the chemical abundances of a sample of metal-poor ([Fe/H] < −2.5) Milky Way halo stars. We draw our sample from four historic surveys and focus our attention on the stellar Mg, Ca, Ni, and Fe abundances. Using... Read More about The stochastic enrichment of Population II stars.

MUSE Analysis of Gas around Galaxies (MAGG) - II: Metal-enriched halo gas around z ∼ 1 galaxies (2020)
Journal Article
Dutta, R., Fumagalli, M., Fossati, M., Lofthouse, E. K., Prochaska, J. X., Battaia, F. A., …O’Meara, J. M. (2020). MUSE Analysis of Gas around Galaxies (MAGG) - II: Metal-enriched halo gas around z ∼ 1 galaxies. Monthly Notices of the Royal Astronomical Society, 499(4), 5022-5046. https://doi.org/10.1093/mnras/staa3147

We present a study of the metal-enriched cool halo gas traced by Mg II absorption around 228 galaxies at z ∼ 0.8–1.5 within 28 quasar fields from the MUSE Analysis of Gas around Galaxies survey. We observe no significant evolution in the Mg II equiva... Read More about MUSE Analysis of Gas around Galaxies (MAGG) - II: Metal-enriched halo gas around z ∼ 1 galaxies.

The PHLEK Survey: A New Determination of the Primordial Helium Abundance (2020)
Journal Article
Hsyu, T., Cooke, R. J., Prochaska, J. X., & Bolte, M. (2020). The PHLEK Survey: A New Determination of the Primordial Helium Abundance. Astrophysical Journal, 896(1), Article 77. https://doi.org/10.3847/1538-4357/ab91af

We present Keck NIRSPEC and Keck NIRES spectroscopy of sixteen metal-poor galaxies that have pre-existing optical observations. The near-infrared (NIR) spectroscopy specifically targets the He I λ10830 Å emission line, due to its sensitivity to the p... Read More about The PHLEK Survey: A New Determination of the Primordial Helium Abundance.

A limit on Planck-scale froth with ESPRESSO (2020)
Journal Article
Pettini, M., Fumagalli, M., Welsh, L., & Cooke, R. (2020). A limit on Planck-scale froth with ESPRESSO. Monthly Notices of the Royal Astronomical Society, 494(4), 4884-4890. https://doi.org/10.1093/mnras/staa440

Some models of quantum gravity predict that the very structure of space–time is ‘frothy’ due to quantum fluctuations. Although the effect is expected to be tiny, if these space–time fluctuations grow over a large distance, the initial state of a phot... Read More about A limit on Planck-scale froth with ESPRESSO.

A bound on the 12C/13C ratio in near-pristine gas with ESPRESSO (2020)
Journal Article
Pettini, M., Fumagalli, M., Cooke, R., & Welsh, L. (2020). A bound on the 12C/13C ratio in near-pristine gas with ESPRESSO. Monthly Notices of the Royal Astronomical Society, 494(1), 1411-1423. https://doi.org/10.1093/mnras/staa807

Using science verification observations obtained with ESPRESSO at the Very Large Telescope (VLT) in 4UT mode, we report the first bound on the carbon isotope ratio 12C/13C of a quiescent, near-pristine damped Lyα (DLA) system at z = 2.34. We infer a... Read More about A bound on the 12C/13C ratio in near-pristine gas with ESPRESSO.

Determining the primordial helium abundance and UV background using fluorescent emission in star-free dark matter haloes (2019)
Journal Article
Sykes, C., Fumagalli, M., Cooke, R., & Theuns, T. (2020). Determining the primordial helium abundance and UV background using fluorescent emission in star-free dark matter haloes. Monthly Notices of the Royal Astronomical Society, 492(2), 2151-2160. https://doi.org/10.1093/mnras/stz3573

Observational measures of the primordial helium mass fraction, YP, are of interest for cosmology and fundamental particle physics. Current measures obtained from HII HII regions agree with the Standard Model prediction to approximately 1% precision,... Read More about Determining the primordial helium abundance and UV background using fluorescent emission in star-free dark matter haloes.

The ACCELERATION programme: I. Cosmology with the redshift drift★ (2019)
Journal Article
Cooke, R. (2020). The ACCELERATION programme: I. Cosmology with the redshift drift★. Monthly Notices of the Royal Astronomical Society, 492(2), 2044-2057. https://doi.org/10.1093/mnras/stz3465

Detecting the change of a cosmological object’s redshift due to the time evolution of the Universal expansion rate is an ambitious experiment that will be attempted with future telescope facilities. In this paper, we describe the ACCELERATION program... Read More about The ACCELERATION programme: I. Cosmology with the redshift drift★.

MUSE Analysis of Gas around Galaxies (MAGG) - I: Survey design and the environment of a near pristine gas cloud at z ≈ 3.5 (2019)
Journal Article
Lofthouse, E. K., Fumagalli, M., Fossati, M., O’Meara, J. M., Murphy, M. T., Christensen, L., …Morris, S. L. (2020). MUSE Analysis of Gas around Galaxies (MAGG) - I: Survey design and the environment of a near pristine gas cloud at z ≈ 3.5. Monthly Notices of the Royal Astronomical Society, 491(2), 2057-2074. https://doi.org/10.1093/mnras/stz3066

We present the design, methods, and first results of the MUSE Analysis of Gas around Galaxies (MAGG) survey, a large programme on the Multi Unit Spectroscopic Explorer (MUSE) instrument at the Very Large Telescope (VLT) which targets 28 z > 3.2 quasa... Read More about MUSE Analysis of Gas around Galaxies (MAGG) - I: Survey design and the environment of a near pristine gas cloud at z ≈ 3.5.

The MUSE Ultra Deep Field (MUDF). II. Survey design and the gaseous properties of galaxy groups at 0.5 < z < 1.5 (2019)
Journal Article
Fossati, M., Fumagalli, M., Lofthouse, E., D’Odorico, V., Lusso, E., Cantalupo, S., …Theuns, T. (2019). The MUSE Ultra Deep Field (MUDF). II. Survey design and the gaseous properties of galaxy groups at 0.5 < z < 1.5. Monthly Notices of the Royal Astronomical Society, 490(1), 1451-1469. https://doi.org/10.1093/mnras/stz2693

We present the goals, design, and first results of the MUSE Ultra Deep Field (MUDF) survey, a large programme using the Multi Unit Spectroscopic Explorer (MUSE) instrument at the ESO Very Large Telescope. The MUDF survey is collecting ≈150 h on-sourc... Read More about The MUSE Ultra Deep Field (MUDF). II. Survey design and the gaseous properties of galaxy groups at 0.5 < z < 1.5.

Modelling the chemical enrichment of Population III supernovae: The origin of the metals in near-pristine gas clouds (2019)
Journal Article
Welsh, L., Cooke, R., & Fumagalli, M. (2019). Modelling the chemical enrichment of Population III supernovae: The origin of the metals in near-pristine gas clouds. Monthly Notices of the Royal Astronomical Society, 487(3), 3363-3376. https://doi.org/10.1093/mnras/stz1526

The most metal-poor, high redshift damped Lyman-α systems (DLAs) provide a window to study some of the first few generations of stars. In this paper, we present a novel model to investigate the chemical enrichment of the near-pristine DLA population.... Read More about Modelling the chemical enrichment of Population III supernovae: The origin of the metals in near-pristine gas clouds.

Fluorescent rings in star-free dark matter haloes (2019)
Journal Article
Sykes, C., Fumagalli, M., Cooke, R., Theuns, T., & Benítez–Llambay, A. (2019). Fluorescent rings in star-free dark matter haloes. Monthly Notices of the Royal Astronomical Society, 487(1), 609-621. https://doi.org/10.1093/mnras/stz1234

Photoheating of the gas in low-mass dark matter (DM) haloes prevents baryons from cooling, leaving the haloes free of stars. Gas in these ‘dark’ haloes remains exposed to the ultraviolet background (UVB), and so is expected to emit via fluorescent re... Read More about Fluorescent rings in star-free dark matter haloes.

Measurement of the primordial helium abundance from the intergalactic medium (2018)
Journal Article
Cooke, R., & Fumagalli, M. (2018). Measurement of the primordial helium abundance from the intergalactic medium. Nature Astronomy, 2(12), 957-961. https://doi.org/10.1038/s41550-018-0584-z

Almost every helium atom in the Universe was created just a few minutes after the Big Bang through a process commonly referred to as Big Bang nucleosynthesis1,2. The amount of helium that was made during Big Bang nucleosynthesis is determined by comb... Read More about Measurement of the primordial helium abundance from the intergalactic medium.