@article{14852,
  abstract     = {The physical conditions giving rise to high escape fractions of ionizing radiation (LyC fesc) in star-forming galaxies – most likely protagonists of cosmic reionization – are not yet fully understood. Using the VLT/MUSE observations of ∼1400 Ly α emitters at 2.9 < z < 6.7, we compare stacked rest-frame UV spectra of candidates for LyC leakers and non-leakers selected based on their Ly α profiles. We find that the stacks of potential LyC leakers, i.e. galaxies with narrow, symmetric Ly α profiles with small peak separation, generally show (i) strong nebular O iii]λ1666, [Si iii]λ1883, and [C iii]λ1907 +C iii]λ1909 emission, indicating a high-ionization state of the interstellar medium (ISM); (ii) high equivalent widths of He iiλ1640 (∼1 − 3 Å), suggesting the presence of hard ionizing radiation fields; (iii) Si ii*λ1533 emission, revealing substantial amounts of neutral hydrogen off the line of sight; (iv) high C ivλλ1548,1550 to [C iii]λ1907 +C iii]λ1909 ratios (C iv/C iii] ≳0.75) , signalling the presence of low column density channels in the ISM. In contrast, the stacks with broad, asymmetric Ly α profiles with large peak separation show weak nebular emission lines, low He iiλ1640 equivalent widths (≲1 Å), and low C iv/C iii] (≲0.25), implying low-ionization states and high-neutral hydrogen column densities. Our results suggest that C iv/C iii] might be sensitive to the physical conditions that govern LyC photon escape, providing a promising tool for identification of ionizing sources among star-forming galaxies in the epoch of reionization.},
  author       = {Kramarenko, Ivan and Kerutt, J and Verhamme, A and Oesch, P A and Barrufet, L and Matthee, Jorryt J and Kusakabe, H and Goovaerts, I and Thai, T T},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics},
  number       = {4},
  pages        = {9853--9871},
  publisher    = {Oxford University Press},
  title        = {{Linking UV spectral properties of MUSE Ly α emitters at <i>z</i> ≳ 3 to Lyman continuum escape}},
  doi          = {10.1093/mnras/stad3853},
  volume       = {527},
  year         = {2024},
}

@article{14104,
  abstract     = {Thorne–Żytkow objects (TŻO) are potential end products of the merger of a neutron star with a non-degenerate star. In this work, we have computed the first grid of evolutionary models of TŻOs with the MESA stellar evolution code. With these models, we predict several observational properties of TŻOs, including their surface temperatures and luminosities, pulsation periods, and nucleosynthetic products. We expand the range of possible TŻO solutions to cover 3.45≲log(Teff/K)≲3.65 and 4.85≲log(L/L⊙)≲5.5⁠. Due to the much higher densities our TŻOs reach compared to previous models, if TŻOs form we expect them to be stable over a larger mass range than previously predicted, without exhibiting a gap in their mass distribution. Using the GYRE stellar pulsation code we show that TŻOs should have fundamental pulsation periods of 1000–2000 d, and period ratios of ≈0.2–0.3. Models computed with a large 399 isotope fully coupled nuclear network show a nucleosynthetic signal that is different to previously predicted. We propose a new nucleosynthetic signal to determine a star’s status as a TŻO: the isotopologues 44TiO2 and 44TiO⁠, which will have a shift in their spectral features as compared to stable titanium-containing molecules. We find that in the local Universe (∼SMC metallicities and above) TŻOs show little heavy metal enrichment, potentially explaining the difficulty in finding TŻOs to-date.},
  author       = {Farmer, R and Renzo, M and Götberg, Ylva Louise Linsdotter and Bellinger, E and Justham, S and de Mink, S E},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics},
  number       = {2},
  pages        = {1692--1709},
  publisher    = {Oxford University Press},
  title        = {{Observational predictions for Thorne–Żytkow objects}},
  doi          = {10.1093/mnras/stad1977},
  volume       = {524},
  year         = {2023},
}

@article{11521,
  abstract     = {The cosmic ionizing emissivity from star-forming galaxies has long been anchored to UV luminosity functions. Here, we introduce an emissivity framework based on Lyα emitters (LAEs), which naturally hones in on the subset of galaxies responsible for the ionizing background due to the intimate connection between production and escape of Lyα and LyC photons. Using constraints on the escape fractions of bright LAEs (LLyα > 0.2L*) at z ≈ 2 obtained from resolved Lyα profiles, and arguing for their redshift-invariance, we show that: (i) quasars and LAEs together reproduce the relatively flat emissivity at z ≈ 2–6, which is non-trivial given the strong evolution in both the star formation density and quasar number density at these epochs and (ii) LAEs produce late and rapid reionization between z ≈ 6−9 under plausible assumptions. Within this framework, the >10 × rise in the UV population-averaged fesc between z ≈ 3–7 naturally arises due to the same phenomena that drive the growing LAE fraction with redshift. Generally, a LAE dominated emissivity yields a peak in the distribution of the ionizing budget with UV luminosity as reported in latest simulations. Using our adopted parameters (⁠fesc=50 per cent⁠, ξion = 1025.9 Hz erg−1 for half the bright LAEs), a highly ionizing minority of galaxies with MUV < −17 accounts for the entire ionizing budget from star-forming galaxies. Rapid flashes of LyC from such rare galaxies produce a ‘disco’ ionizing background. We conclude proposing tests to further develop our suggested Lyα-anchored formalism.},
  author       = {Matthee, Jorryt J and Naidu, Rohan P. and Pezzulli, Gabriele and Gronke, Max and Sobral, David and Oesch, Pascal A. and Hayes, Matthew and Erb, Dawn and Schaerer, Daniel and Amorín, Ricardo and Tacchella, Sandro and Ana Paulino-Afonso, Ana Paulino-Afonso and Llerena, Mario and Calhau, João and Röttgering, Huub},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {galaxies: high-redshift, intergalactic medium, cosmology: observations, dark ages, reionization, first stars, ultraviolet: galaxies},
  number       = {4},
  pages        = {5960--5977},
  publisher    = {Oxford University Press},
  title        = {{(Re)Solving reionization with Lyα: How bright Lyα emitters account for the z ≈ 2 − 8 cosmic ionizing background}},
  doi          = {10.1093/mnras/stac801},
  volume       = {512},
  year         = {2022},
}

@article{13452,
  abstract     = {Magnetic fields can drastically change predictions of evolutionary models of massive stars via mass-loss quenching, magnetic braking, and efficient angular momentum transport, which we aim to quantify in this work. We use the MESA software instrument to compute an extensive main-sequence grid of stellar structure and evolution models, as well as isochrones, accounting for the effects attributed to a surface fossil magnetic field. The grid is densely populated in initial mass (3–60 M⊙), surface equatorial magnetic field strength (0–50 kG), and metallicity (representative of the Solar neighbourhood and the Magellanic Clouds). We use two magnetic braking and two chemical mixing schemes and compare the model predictions for slowly rotating, nitrogen-enriched (‘Group 2’) stars with observations in the Large Magellanic Cloud. We quantify a range of initial field strengths that allow for producing Group 2 stars and find that typical values (up to a few kG) lead to solutions. Between the subgrids, we find notable departures in surface abundances and evolutionary paths. In our magnetic models, chemical mixing is always less efficient compared to non-magnetic models due to the rapid spin-down. We identify that quasi-chemically homogeneous main sequence evolution by efficient mixing could be prevented by fossil magnetic fields. We recommend comparing this grid of evolutionary models with spectropolarimetric and spectroscopic observations with the goals of (i) revisiting the derived stellar parameters of known magnetic stars, and (ii) observationally constraining the uncertain magnetic braking and chemical mixing schemes.},
  author       = {Keszthelyi, Z and de Koter, A and Götberg, Ylva Louise Linsdotter and Meynet, G and Brands, S A and Petit, V and Carrington, M and David-Uraz, A and Geen, S T and Georgy, C and Hirschi, R and Puls, J and Ramalatswa, K J and Shultz, M E and ud-Doula, A},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics},
  number       = {2},
  pages        = {2028--2055},
  publisher    = {Oxford University Press},
  title        = {{The effects of surface fossil magnetic fields on massive star evolution: IV. Grids of models at Solar, LMC, and SMC metallicities}},
  doi          = {10.1093/mnras/stac2598},
  volume       = {517},
  year         = {2022},
}

@article{14098,
  abstract     = {Magnetic fields can drastically change predictions of evolutionary models of massive stars via mass-loss quenching, magnetic braking, and efficient angular momentum transport, which we aim to quantify in this work. We use the MESA software instrument to compute an extensive main-sequence grid of stellar structure and evolution models, as well as isochrones, accounting for the effects attributed to a surface fossil magnetic field. The grid is densely populated in initial mass (3–60 M⊙), surface equatorial magnetic field strength (0–50 kG), and metallicity (representative of the Solar neighbourhood and the Magellanic Clouds). We use two magnetic braking and two chemical mixing schemes and compare the model predictions for slowly rotating, nitrogen-enriched (‘Group 2’) stars with observations in the Large Magellanic Cloud. We quantify a range of initial field strengths that allow for producing Group 2 stars and find that typical values (up to a few kG) lead to solutions. Between the subgrids, we find notable departures in surface abundances and evolutionary paths. In our magnetic models, chemical mixing is always less efficient compared to non-magnetic models due to the rapid spin-down. We identify that quasi-chemically homogeneous main sequence evolution by efficient mixing could be prevented by fossil magnetic fields. We recommend comparing this grid of evolutionary models with spectropolarimetric and spectroscopic observations with the goals of (i) revisiting the derived stellar parameters of known magnetic stars, and (ii) observationally constraining the uncertain magnetic braking and chemical mixing schemes.},
  author       = {Keszthelyi, Z. and Koter, A. de and Götberg, Ylva Louise Linsdotter and Meynet, G. and Brands, S. A. and Petit, V. and Carrington, M. and A. David-Uraz, A. David-Uraz and Geen, S. T. and Georgy, C. and Hirschi, R. and Puls, J. and Ramalatswa, K. J. and Shultz, M. E. and A. ud-Doula, A. ud-Doula},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  number       = {2},
  pages        = {2028--2055},
  publisher    = {Oxford Academic},
  title        = {{The effects of surface fossil magnetic fields on massive star evolution: IV. Grids of models at solar, LMC, and SMC metallicities}},
  doi          = {10.1093/mnras/stac2598},
  volume       = {517},
  year         = {2022},
}

@article{11522,
  abstract     = {The decline in abundance of Lyman-α (Lyα) emitting galaxies at z ≳ 6 is a powerful and commonly used probe to constrain the progress of cosmic reionization. We use the CODAII simulation, which is a radiation hydrodynamic simulation featuring a box of ∼94 comoving Mpc side length, to compute the Lyα transmission properties of the intergalactic medium (IGM) at z ∼ 5.8 to 7. Our results mainly confirm previous studies, i.e. we find a declining Lyα transmission with redshift and a large sightline-to-sightline variation. However, motivated by the recent discovery of blue Lyα peaks at high redshift, we also analyse the IGM transmission on the blue side, which shows a rapid decline at z ≳ 6 of the blue transmission. This low transmission can be attributed not only to the presence of neutral regions but also to the residual neutral hydrogen within ionized regions, for which a density even as low as nHI∼10−9cm−3 (sometimes combined with kinematic effects) leads to a significantly reduced visibility. Still, we find that ∼1 per cent of sightlines towards M1600AB ∼ −21 galaxies at z ∼ 7 are transparent enough to allow a transmission of a blue Lyα peak. We discuss our results in the context of the interpretation of observations.},
  author       = {Gronke, Max and Ocvirk, Pierre and Mason, Charlotte and Matthee, Jorryt J and Bosman, Sarah E I and Sorce, Jenny G and Lewis, Joseph and Ahn, Kyungjin and Aubert, Dominique and Dawoodbhoy, Taha and Iliev, Ilian T and Shapiro, Paul R and Yepes, Gustavo},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {dark ages, reionization, first stars, intergalactic medium, galaxies: formation},
  number       = {3},
  pages        = {3697--3709},
  publisher    = {Oxford University Press},
  title        = {{Lyman-α transmission properties of the intergalactic medium in the CoDaII simulation}},
  doi          = {10.1093/mnras/stab2762},
  volume       = {508},
  year         = {2021},
}

@article{11523,
  abstract     = {We present the first results from the X-SHOOTER Lyman α survey at z = 2 (XLS-z2). XLS-z2 is a deep spectroscopic survey of 35 Lyman α emitters (LAEs) utilizing ≈90 h of exposure time with Very Large Telescope/X-SHOOTER and covers rest-frame Ly α to H α emission with R ≈ 4000. We present the sample selection, the observations, and the data reduction. Systemic redshifts are measured from rest-frame optical lines for 33/35 sources. In the stacked spectrum, our LAEs are characterized by an interstellar medium with little dust, a low metallicity, and a high ionization state. The ionizing sources are young hot stars that power strong emission lines in the optical and high-ionization lines in the ultraviolet (UV). The LAEs exhibit clumpy UV morphologies and have outflowing kinematics with blueshifted Si II absorption, a broad [O III] component, and a red-skewed Ly α line. Typically, 30 per cent of the Ly α photons escape, of which one quarter on the blue side of the systemic velocity. A fraction of Ly α photons escape directly at the systemic suggesting clear channels enabling an ≈10 per cent escape of ionizing photons, consistent with an inference based on Mg II. A combination of a low effective H I column density, a low dust content, and young starburst determines whether a star-forming galaxy is observed as an LAE. The first is possibly related to outflows and/or a fortunate viewing angle, while we find that the latter two in LAEs are typical for their stellar mass of 109 M⊙.},
  author       = {Matthee, Jorryt J and Sobral, David and Hayes, Matthew and Pezzulli, Gabriele and Gronke, Max and Schaerer, Daniel and Naidu, Rohan P and Röttgering, Huub and Calhau, João and Paulino-Afonso, Ana and Santos, Sérgio and Amorín, Ricardo},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics, galaxies: formation, galaxies: ISM, galaxies: starburst, dark ages, reionization, first stars},
  number       = {1},
  pages        = {1382--1412},
  publisher    = {Oxford University Press},
  title        = {{The X-SHOOTER Lyman α survey at z = 2 (XLS-z2) I: What makes a galaxy a Lyman α emitter?}},
  doi          = {10.1093/mnras/stab1304},
  volume       = {505},
  year         = {2021},
}

@article{11524,
  abstract     = {We measure the evolution of the rest-frame UV luminosity function (LF) and the stellar mass function (SMF) of Lyman-α (Ly α) emitters (LAEs) from z ∼ 2 to z ∼ 6 by exploring ∼4000 LAEs from the SC4K sample. We find a correlation between Ly α luminosity (LLy α) and rest-frame UV (MUV), with best fit MUV=−1.6+0.2−0.3log10(LLyα/ergs−1)+47+12−11 and a shallower relation between LLy α and stellar mass (M⋆), with best fit log10(M⋆/M⊙)=0.9+0.1−0.1log10(LLyα/ergs−1)−28+4.0−3.8⁠. An increasing LLy α cut predominantly lowers the number density of faint MUV and low M⋆ LAEs. We estimate a proxy for the full UV LFs and SMFs of LAEs with simple assumptions of the faint end slope. For the UV LF, we find a brightening of the characteristic UV luminosity (M∗UV⁠) with increasing redshift and a decrease of the characteristic number density (Φ*). For the SMF, we measure a characteristic stellar mass (⁠M∗⋆/M⊙⁠) increase with increasing redshift, and a Φ* decline. However, if we apply a uniform luminosity cut of log10(LLyα/ergs−1)≥43.0⁠, we find much milder to no evolution in the UV and SMF of LAEs. The UV luminosity density (ρUV) of the full sample of LAEs shows moderate evolution and the stellar mass density (ρM) decreases, with both being always lower than the total ρUV and ρM of more typical galaxies but slowly approaching them with increasing redshift. Overall, our results indicate that both ρUV and ρM of LAEs slowly approach the measurements of continuum-selected galaxies at z > 6, which suggests a key role of LAEs in the epoch of reionization.},
  author       = {Santos, S and Sobral, D and Butterworth, J and Paulino-Afonso, A and Ribeiro, B and da Cunha, E and Calhau, J and Khostovan, A A and Matthee, Jorryt J and Arrabal Haro, P},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics, galaxies: evolution, galaxies: high-redshift, galaxies: luminosity function, mass function},
  number       = {1},
  pages        = {1117--1134},
  publisher    = {Oxford University Press},
  title        = {{The evolution of the UV luminosity and stellar mass functions of Lyman-α emitters from z ∼ 2 to z ∼ 6}},
  doi          = {10.1093/mnras/stab1218},
  volume       = {505},
  year         = {2021},
}

@article{11525,
  abstract     = {The intensity of the Cosmic UV background (UVB), coming from all sources of ionizing photons such as star-forming galaxies and quasars, determines the thermal evolution and ionization state of the intergalactic medium (IGM) and is, therefore, a critical ingredient for models of cosmic structure formation. Most of the previous estimates are based on the comparison between observed and simulated Lyman-α forest. We present the results of an independent method to constrain the product of the UVB photoionization rate and the covering fraction of Lyman limit systems (LLSs) by searching for the fluorescent Lyman-α emission produced by self-shielded clouds. Because the expected surface brightness is well below current sensitivity limits for direct imaging, we developed a new method based on 3D stacking of the IGM around Lyman-α emitting galaxies (LAEs) between 2.9 < z < 6.6 using deep MUSE observations. Combining our results with covering fractions of LLSs obtained from mock cubes extracted from the EAGLE simulation, we obtain new and independent constraints on the UVB at z > 3 that are consistent with previous measurements, with a preference for relatively low UVB intensities at z = 3, and which suggest a non-monotonic decrease of ΓH I with increasing redshift between 3 < z < 5. This could suggest a possible tension between some UVB models and current observations which however require deeper and wider observations in Lyman-α emission and absorption to be confirmed. Assuming instead a value of UVB from current models, our results constrain the covering fraction of LLSs at 3 < z < 4.5 to be less than 25 per cent within 150 kpc from LAEs.},
  author       = {Gallego, Sofia G and Cantalupo, Sebastiano and Sarpas, Saeed and Duboeuf, Bastien and Lilly, Simon and Pezzulli, Gabriele and Marino, Raffaella Anna and Matthee, Jorryt J and Wisotzki, Lutz and Schaye, Joop and Richard, Johan and Kusakabe, Haruka and Mauerhofer, Valentin},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics},
  number       = {1},
  pages        = {16--32},
  publisher    = {Oxford University Press},
  title        = {{Constraining the cosmic UV background at z > 3 with MUSE Lyman-α emission observations}},
  doi          = {10.1093/mnras/stab796},
  volume       = {504},
  year         = {2021},
}

@article{11526,
  abstract     = {We present the results from a MUSE survey of twelve z ≃ 3.15 quasars, which were selected to be much fainter (20 < iSDSS < 23) than in previous studies of giant Ly α nebulae around the brightest quasars (16.6 < iAB < 18.7). We detect H I Ly α nebulae around 100 per cent of our target quasars, with emission extending to scales of at least 60 physical kpc, and up to 190 pkpc. We explore correlations between properties of the nebulae and their host quasars, with the goal of connecting variations in the properties of the illuminating QSO to the response in nebular emission. We show that the surface brightness profiles of the nebulae are similar to those of nebulae around bright quasars, but with a lower normalization. Our targeted quasars are on average 3.7 mag (≃30 times) fainter in UV continuum than our bright reference sample, and yet the nebulae around them are only 4.3 times fainter in mean Ly α surface brightness, measured between 20 and 50 pkpc. We find significant correlations between the surface brightness of the nebula and the luminosity of the quasar in both UV continuum and Ly α. The latter can be interpreted as evidence for a substantial contribution from unresolved inner parts of the nebulae to the narrow components seen in the Ly α lines of some of our faint quasars, possibly from the inner circumgalactic medium or from the host galaxy’s interstellar medium.},
  author       = {Mackenzie, Ruari and Pezzulli, Gabriele and Cantalupo, Sebastiano and Marino, Raffaella A and Lilly, Simon and Muzahid, Sowgat and Matthee, Jorryt J and Schaye, Joop and Wisotzki, Lutz},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics, techniques: imaging spectroscopy, intergalactic medium, quasars: emission lines, quasars: general},
  number       = {1},
  pages        = {494--509},
  publisher    = {Oxford University Press},
  title        = {{Revealing the impact of quasar luminosity on giant Lyα nebulae}},
  doi          = {10.1093/mnras/staa3277},
  volume       = {502},
  year         = {2021},
}

@article{11528,
  abstract     = {Ly α emission lines are typically found to be redshifted with respect to the systemic redshifts of galaxies, likely due to resonant scattering of Ly α photons. Here, we measure the average velocity offset for a sample of 96 z ≈ 3.3 Ly α emitters (LAEs) with a median Ly α flux (luminosity) of ≈10−17 erg cm−2 s−1 (⁠≈1042 erg s−1⁠) and a median star formation rate (SFR) of ≈1.3 M⊙ yr−1 (not corrected for possible dust extinction), detected by the Multi-Unit Spectroscopic Explorer as part of our MUSEQuBES circumgalactic medium (CGM) survey. By postulating that the stacked CGM absorption profiles of these LAEs, probed by eight background quasars, must be centred on the systemic redshift, we measure an average velocity offset, Voffset = 171\pm 8 km s−1, between the Ly α emission peak and the systemic redshift. The observed Voffset is lower by factors of ≈1.4 and ≈2.6 compared to the velocity offsets measured for narrow-band-selected LAEs and Lyman break galaxies, respectively, which probe galaxies with higher masses and SFRs. Consistent with earlier studies based on direct measurements for individual objects, we find that the Voffset is correlated with the full width at half-maximum of the red peak of the Ly α line, and anticorrelated with the rest-frame equivalent width. Moreover, we find that Voffset is correlated with SFR with a sub-linear scaling relation, Voffset∝SFR0.16±0.03⁠. Adopting the mass scaling for main-sequence galaxies, such a relation suggests that Voffset scales with the circular velocity of the dark matter haloes hosting the LAEs.},
  author       = {Muzahid, Sowgat and Schaye, Joop and Marino, Raffaella Anna and Cantalupo, Sebastiano and Brinchmann, Jarle and Contini, Thierry and Wendt, Martin and Wisotzki, Lutz and Zabl, Johannes and Bouché, Nicolas and Akhlaghi, Mohammad and Chen, Hsiao-Wen and Claeyssens, Adélaîde and Johnson, Sean and Leclercq, Floriane and Maseda, Michael and Matthee, Jorryt J and Richard, Johan and Urrutia, Tanya and Verhamme, Anne},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics, galaxies: haloes, galaxies: high-redshift, quasars: absorption lines},
  number       = {2},
  pages        = {1013--1022},
  publisher    = {Oxford University Press},
  title        = {{MUSEQuBES: Calibrating the redshifts of Lyα emitters using stacked circumgalactic medium absorption profiles}},
  doi          = {10.1093/mnras/staa1347},
  volume       = {496},
  year         = {2020},
}

@article{11529,
  abstract     = {CR7 is among the most luminous Ly α emitters (LAEs) known at z = 6.6 and consists of at least three UV components that are surrounded by Ly α emission. Previous studies have suggested that it may host an extreme ionizing source. Here, we present deep integral field spectroscopy of CR7 with VLT/Multi Unit Spectroscopic Explorer (MUSE). We measure extended emission with a similar halo scale length as typical LAEs at z ≈ 5. CR7’s Ly α halo is clearly elongated along the direction connecting the multiple components, likely tracing the underlying gas distribution. The Ly α emission originates almost exclusively from the brightest UV component, but we also identify a faint kinematically distinct Ly α emitting region nearby a fainter component. Combined with new near-infrared data, the MUSE data show that the rest-frame Ly α equivalent width (EW) is ≈100 Å. This is a factor 4 higher than the EW measured in low-redshift analogues with carefully matched Ly α profiles (and thus arguably H I column density), but this EW can plausibly be explained by star formation. Alternative scenarios requiring active galactic nucleus (AGN) powering are also disfavoured by the narrower and steeper Ly α spectrum and much smaller IR to UV ratio compared to obscured AGN in other Ly α blobs. CR7’s Ly α emission, while extremely luminous, resembles the emission in more common LAEs at lower redshifts very well and is likely powered by a young metal-poor starburst.},
  author       = {Matthee, Jorryt J and Pezzulli, Gabriele and Mackenzie, Ruari and Cantalupo, Sebastiano and Kusakabe, Haruka and Leclercq, Floriane and Sobral, David and Richard, Johan and Wisotzki, Lutz and Lilly, Simon and Boogaard, Leindert and Marino, Raffaella and Maseda, Michael and Nanayakkara, Themiya},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics, galaxies: evolution, galaxies: high-redshift, dark ages, reionization, first stars, cosmology: observations},
  number       = {2},
  pages        = {3043--3059},
  publisher    = {Oxford University Press},
  title        = {{The nature of CR7 revealed with MUSE: A young starburst powering extended Ly α emission at z = 6.6}},
  doi          = {10.1093/mnras/staa2550},
  volume       = {498},
  year         = {2020},
}

@article{11530,
  abstract     = {A prediction of the classic active galactic nucleus (AGN) unification model is the presence of ionization cones with different orientations depending on the AGN type. Confirmations of this model exist for present times, but it is less clear in the early Universe. Here, we use the morphology of giant Ly α nebulae around AGNs at redshift z ∼ 3 to probe AGN emission and therefore the validity of the AGN unification model at this redshift. We compare the spatial morphology of 19 nebulae previously found around type I AGNs with a new sample of four Ly α nebulae detected around type II AGNs. Using two independent techniques, we find that nebulae around type II AGNs are more asymmetric than around type I, at least at radial distances r > 30 physical kpc (pkpc) from the ionizing source. We conclude that the type I and type II AGNs in our sample show evidence of different surrounding ionizing geometries. This suggests that the classical AGN unification model is also valid for high-redshift sources. Finally, we discuss how the lack of asymmetry in the inner parts (r ≲ 30 pkpc) and the associated high values of the He II to Ly α ratios in these regions could indicate additional sources of (hard) ionizing radiation originating within or in proximity of the AGN host galaxies. This work demonstrates that the morphologies of giant Ly α nebulae can be used to understand and study the geometry of high-redshift AGNs on circumnuclear scales and it lays the foundation for future studies using much larger statistical samples.},
  author       = {den Brok, J S and Cantalupo, S and Mackenzie, R and Marino, R A and Pezzulli, G and Matthee, Jorryt J and Johnson, S D and Krumpe, M and Urrutia, T and Kollatschny, W},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics, galaxies: active, galaxies: high-redshift, intergalactic medium, quasars: emission lines, quasars: general},
  number       = {2},
  pages        = {1874--1887},
  publisher    = {Oxford University Press},
  title        = {{Probing the AGN unification model at redshift z ∼ 3 with MUSE observations of giant Lyα nebulae}},
  doi          = {10.1093/mnras/staa1269},
  volume       = {495},
  year         = {2020},
}

@article{11531,
  abstract     = {While low-luminosity galaxies dominate number counts at all redshifts, their contribution to cosmic reionization is poorly understood due to a lack of knowledge of their physical properties. We isolate a sample of 35 z ≈ 4–5 continuum-faint Lyman-α emitters from deep VLT/MUSE spectroscopy and directly measure their H α emission using stacked Spitzer/IRAC Ch. 1 photometry. Based on Hubble Space Telescope imaging, we determine that the average UV continuum magnitude is fainter than −16 (≈ 0.01 L⋆), implying a median Lyman-α equivalent width of 259 Å. By combining the H α measurement with the UV magnitude, we determine the ionizing photon production efficiency, ξion, a first for such faint galaxies. The measurement of log10 (ξion [Hz erg−1]) = 26.28 (⁠+0.28−0.40⁠) is in excess of literature measurements of both continuum- and emission line-selected samples, implying a more efficient production of ionizing photons in these lower luminosity, Lyman-α-selected systems. We conclude that this elevated efficiency can be explained by stellar populations with metallicities between 4 × 10−4 and 0.008, with light-weighted ages less than 3 Myr.},
  author       = {Maseda, Michael V and Bacon, Roland and Lam, Daniel and Matthee, Jorryt J and Brinchmann, Jarle and Schaye, Joop and Labbe, Ivo and Schmidt, Kasper B and Boogaard, Leindert and Bouwens, Rychard and Cantalupo, Sebastiano and Franx, Marijn and Hashimoto, Takuya and Inami, Hanae and Kusakabe, Haruka and Mahler, Guillaume and Nanayakkara, Themiya and Richard, Johan and Wisotzki, Lutz},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics, Galaxies: evolution, Galaxies: high-redshift, Galaxies: ISM},
  number       = {4},
  pages        = {5120--5130},
  publisher    = {Oxford University Press},
  title        = {{Elevated ionizing photon production efficiency in faint high-equivalent-width Lyman-α emitters}},
  doi          = {10.1093/mnras/staa622},
  volume       = {493},
  year         = {2020},
}

@article{11533,
  abstract     = {We explore deep rest-frame UV to FIR data in the COSMOS field to measure the individual spectral energy distributions (SED) of the ∼4000 SC4K (Sobral et al.) Lyman α (Ly α) emitters (LAEs) at z ∼ 2–6. We find typical stellar masses of 109.3 ± 0.6 M⊙ and star formation rates (SFR) of SFRSED=4.4+10.5−2.4 M⊙ yr−1 and SFRLyα=5.9+6.3−2.6 M⊙ yr−1, combined with very blue UV slopes of β=−2.1+0.5−0.4⁠, but with significant variations within the population. MUV and β are correlated in a similar way to UV-selected sources, but LAEs are consistently bluer. This suggests that LAEs are the youngest and/or most dust-poor subset of the UV-selected population. We also study the Ly α rest-frame equivalent width (EW0) and find 45 ‘extreme’ LAEs with EW0 > 240 Å (3σ), implying a low number density of (7 ± 1) × 10−7 Mpc−3. Overall, we measure little to no evolution of the Ly α EW0 and scale length parameter (w0), which are consistently high (EW0=140+280−70 Å, w0=129+11−11 Å) from z ∼ 6 to z ∼ 2 and below. However, w0 is anticorrelated with MUV and stellar mass. Our results imply that sources selected as LAEs have a high Ly α escape fraction (fesc,Ly α) irrespective of cosmic time, but fesc,Ly α is still higher for UV-fainter and lower mass LAEs. The least massive LAEs (<109.5 M⊙) are typically located above the star formation ‘main sequence’ (MS), but the offset from the MS decreases towards z ∼ 6 and towards 1010 M⊙. Our results imply a lack of evolution in the properties of LAEs across time and reveals the increasing overlap in properties of LAEs and UV-continuum selected galaxies as typical star-forming galaxies at high redshift effectively become LAEs.},
  author       = {Santos, S and Sobral, D and Matthee, Jorryt J and Calhau, J and da Cunha, E and Ribeiro, B and Paulino-Afonso, A and Arrabal Haro, P and Butterworth, J},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics, galaxies: evolution, galaxies: formation, galaxies: high-redshift, galaxies: star formation},
  number       = {1},
  pages        = {141--160},
  publisher    = {Oxford University Press},
  title        = {{The evolution of rest-frame UV properties, Ly α EWs, and the SFR–stellar mass relation at z ∼ 2–6 for SC4K LAEs}},
  doi          = {10.1093/mnras/staa093},
  volume       = {493},
  year         = {2020},
}

@article{11534,
  abstract     = {The observed properties of the Lyman-α (Ly α) emission line are a powerful probe of neutral gas in and around galaxies. We present spatially resolved Ly α spectroscopy with VLT/MUSE targeting VR7, a UV-luminous galaxy at z = 6.532 with moderate Ly α equivalent width (EW0 ≈ 38 Å). These data are combined with deep resolved [CII]158μm spectroscopy obtained with ALMA and UV imaging from HST and we also detect UV continuum with MUSE. Ly α emission is clearly detected with S/N ≈ 40 and FWHM of 374 km s−1. Ly α and [C II] are similarly extended beyond the UV, with effective radius reff = 2.1 ± 0.2 kpc for a single exponential model or reff,Lyα,halo=3.45+1.08−0.87 kpc when measured jointly with the UV continuum. The Ly α profile is broader and redshifted with respect to the [C II] line (by 213 km s−1), but there are spatial variations that are qualitatively similar in both lines and coincide with resolved UV components. This suggests that the emission originates from two components with plausibly different H I column densities. We place VR7 in the context of other galaxies at similar and lower redshift. The Ly α halo scale length is similar at different redshifts and velocity shifts with respect to the systemic are typically smaller. Overall, we find little indications of a more neutral vicinity at higher redshift. This means that the local (∼10 kpc) neutral gas conditions that determine the observed Ly α properties in VR7 resemble the conditions in post-reionization galaxies.},
  author       = {Matthee, Jorryt J and Sobral, David and Gronke, Max and Pezzulli, Gabriele and Cantalupo, Sebastiano and Röttgering, Huub and Darvish, Behnam and Santos, Sérgio},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics, galaxies: evolution, galaxies: high-redshift, dark ages, reionization, first stars, cosmology: observations},
  number       = {2},
  pages        = {1778--1790},
  publisher    = {Oxford University Press},
  title        = {{Resolved Lyman-α properties of a luminous Lyman-break galaxy in a large ionized bubble at z = 6.53 }},
  doi          = {10.1093/mnras/stz3554},
  volume       = {492},
  year         = {2020},
}

@article{11539,
  abstract     = {Despite recent progress in understanding Ly α emitters (LAEs), relatively little is known regarding their typical black hole activity across cosmic time. Here, we study the X-ray and radio properties of ∼4000 LAEs at 2.2 < z < 6 from the SC4K survey in the COSMOS field. We detect 254 (⁠6.8per cent±0.4per cent⁠) LAEs individually in the X-rays (S/N > 3) with an average luminosity of 1044.31±0.01ergs−1 and average black hole accretion rate (BHAR) of 0.72±0.01 M⊙ yr−1, consistent with moderate to high accreting active galactic neuclei (AGNs). We detect 120 sources in deep radio data (radio AGN fraction of 3.2per cent±0.3per cent⁠). The global AGN fraction (⁠8.6per cent±0.4per cent⁠) rises with Ly α luminosity and declines with increasing redshift. For X-ray-detected LAEs, Ly α luminosities correlate with the BHARs, suggesting that Ly α luminosity becomes a BHAR indicator. Most LAEs (⁠93.1per cent±0.6per cent⁠) at 2 < z < 6 have no detectable X-ray emission (BHARs < 0.017 M⊙ yr−1). The median star formation rate (SFR) of star-forming LAEs from Ly α and radio luminosities is 7.6+6.6−2.8 M⊙ yr−1. The black hole to galaxy growth ratio (BHAR/SFR) for LAEs is <0.0022, consistent with typical star-forming galaxies and the local BHAR/SFR relation. We conclude that LAEs at 2 < z < 6 include two different populations: an AGN population, where Ly α luminosity traces BHAR, and another with low SFRs which remain undetected in even the deepest X-ray stacks but is detected in the radio stacks.},
  author       = {Calhau, João and Sobral, David and Santos, Sérgio and Matthee, Jorryt J and Paulino-Afonso, Ana and Stroe, Andra and Simmons, Brooke and Barlow-Hall, Cassandra and Adams, Benjamin},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics, galaxies: active, galaxies: evolution, galaxies: high-redshift, quasars: supermassive black holes, galaxies: star formation, cosmology: observations, X-rays: galaxies},
  number       = {3},
  pages        = {3341--3362},
  publisher    = {Oxford University Press},
  title        = {{The X-ray and radio activity of typical and luminous Ly α emitters from z ∼ 2 to z ∼ 6: Evidence for a diverse, evolving population}},
  doi          = {10.1093/mnras/staa476},
  volume       = {493},
  year         = {2020},
}

@article{13465,
  abstract     = {Gravitational-wave detections are now probing the black hole (BH) mass distribution, including the predicted pair-instability mass gap. These data require robust quantitative predictions, which are challenging to obtain. The most massive BH progenitors experience episodic mass ejections on time-scales shorter than the convective turnover time-scale. This invalidates the steady-state assumption on which the classic mixing length theory relies. We compare the final BH masses computed with two different versions of the stellar evolutionary code MESA
⁠: (i) using the default implementation of Paxton et al. (2018) and (ii) solving an additional equation accounting for the time-scale for convective deceleration. In the second grid, where stronger convection develops during the pulses and carries part of the energy, we find weaker pulses. This leads to lower amounts of mass being ejected and thus higher final BH masses of up to ∼5M⊙
⁠. The differences are much smaller for the progenitors that determine the maximum mass of BHs below the gap. This prediction is robust at MBH,max≃48M⊙
⁠, at least within the idealized context of this study. This is an encouraging indication that current models are robust enough for comparison with the present-day gravitational-wave detections. However, the large differences between individual models emphasize the importance of improving the treatment of convection in stellar models, especially in the light of the data anticipated from the third generation of gravitational-wave detectors.},
  author       = {Renzo, M and Farmer, R J and Justham, S and de Mink, S E and Götberg, Ylva Louise Linsdotter and Marchant, P},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics},
  number       = {3},
  pages        = {4333--4341},
  publisher    = {Oxford University Press},
  title        = {{Sensitivity of the lower edge of the pair-instability black hole mass gap to the treatment of time-dependent convection}},
  doi          = {10.1093/mnras/staa549},
  volume       = {493},
  year         = {2020},
}

@article{11535,
  abstract     = {We investigate the clustering and halo properties of ∼5000 Ly α-selected emission-line galaxies (LAEs) from the Slicing COSMOS 4K (SC4K) and from archival NB497 imaging of SA22 split in 15 discrete redshift slices between z ∼ 2.5 and 6. We measure clustering lengths of r0 ∼ 3–6 h−1 Mpc and typical halo masses of ∼1011 M⊙ for our narrowband-selected LAEs with typical LLy α ∼ 1042–43 erg s−1. The intermediate-band-selected LAEs are observed to have r0 ∼ 3.5–15 h−1 Mpc with typical halo masses of ∼1011–12 M⊙ and typical LLy α ∼ 1043–43.6 erg s−1. We find a strong, redshift-independent correlation between halo mass and Ly α luminosity normalized by the characteristic Ly α luminosity, L⋆(z). The faintest LAEs (L ∼ 0.1 L⋆(z)) typically identified by deep narrowband surveys are found in 1010 M⊙ haloes and the brightest LAEs (L ∼ 7 L⋆(z)) are found in ∼5 × 1012 M⊙ haloes. A dependency on the rest-frame 1500 Å UV luminosity, MUV, is also observed where the halo masses increase from 1011 to 1013 M⊙ for MUV ∼ −19 to −23.5 mag. Halo mass is also observed to increase from 109.8 to 1012 M⊙ for dust-corrected UV star formation rates from ∼0.6 to 10 M⊙ yr−1 and continues to increase up to 1013 M⊙ in halo mass, where the majority of those sources are active galactic nuclei. All the trends we observe are found to be redshift independent. Our results reveal that LAEs are the likely progenitors of a wide range of galaxies depending on their luminosity, from dwarf-like, to Milky Way-type, to bright cluster galaxies. LAEs therefore provide unique insight into the early formation and evolution of the galaxies we observe in the local Universe.},
  author       = {Khostovan, A A and Sobral, D and Mobasher, B and Matthee, Jorryt J and Cochrane, R K and Chartab, N and Jafariyazani, M and Paulino-Afonso, A and Santos, S and Calhau, J},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics, galaxies: evolution, galaxies: haloes, galaxies: high-redshift, galaxies: star formation, cosmology: observations, large-scale structure of Universe},
  number       = {1},
  pages        = {555--573},
  publisher    = {Oxford University Press},
  title        = {{The clustering of typical Ly α emitters from z ∼ 2.5–6: Host halo masses depend on Ly α and UV luminosities}},
  doi          = {10.1093/mnras/stz2149},
  volume       = {489},
  year         = {2019},
}

@article{11540,
  abstract     = {Observations have revealed that the star formation rate (SFR) and stellar mass (Mstar) of star-forming galaxies follow a tight relation known as the galaxy main sequence. However, what physical information is encoded in this relation is under debate. Here, we use the EAGLE cosmological hydrodynamical simulation to study the mass dependence, evolution, and origin of scatter in the SFR–Mstar relation. At z = 0, we find that the scatter decreases slightly with stellar mass from 0.35 dex at Mstar ≈ 109 M⊙ to 0.30 dex at Mstar ≳ 1010.5 M⊙. The scatter decreases from z = 0 to z = 5 by 0.05 dex at Mstar ≳ 1010 M⊙ and by 0.15 dex for lower masses. We show that the scatter at z = 0.1 originates from a combination of fluctuations on short time-scales (ranging from 0.2–2 Gyr) that are presumably associated with self-regulation from cooling, star formation, and outflows, but is dominated by long time-scale (∼10 Gyr) variations related to differences in halo formation times. Shorter time-scale fluctuations are relatively more important for lower mass galaxies. At high masses, differences in black hole formation efficiency cause additional scatter, but also diminish the scatter caused by different halo formation times. While individual galaxies cross the main sequence multiple times during their evolution, they fluctuate around tracks associated with their halo properties, i.e. galaxies above/below the main sequence at z = 0.1 tend to have been above/below the main sequence for ≫1 Gyr.},
  author       = {Matthee, Jorryt J and Schaye, Joop},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics : galaxies: evolution, galaxies: formation, galaxies: star formation, cosmology: theory},
  number       = {1},
  pages        = {915--932},
  publisher    = {Oxford University Press},
  title        = {{The origin of scatter in the star formation rate–stellar mass relation}},
  doi          = {10.1093/mnras/stz030},
  volume       = {484},
  year         = {2019},
}