@article{SelsingMalesaniGoldonietal.2019,
  author    = {Selsing, Jonatan and Malesani, D. and Goldoni, P. and Fynbo, Johan and Kr{\"u}hler, T. and Antonelli, L. A. and Arabsalmani, M. and Bolmer, J. and Cano, Z. and Christensen, L. and Covino, S. and De Cia, A. and de Ugarte Postigo, A. and Flores, H. and Fliis, M. and Gomboc, A. and Greiner, J. and Groot, P. and Hammer, F. and Hartoog, O. E. and Heintz, K. E. and Hjorth, J. and Jakobsson, P. and Japelj, J. and Kann, D. A. and Kaper, L. and Ledoux, C. and Leloudas, G. and Levan, A. J. and Maiorano, E. and Melandri, A. and Milvang-Jensen, B. and Palazzi, E. and Palmerio, J. T. and Perley, D. A. and Pian, E. and Piranomonte, S. and Pugliese, G. and Sanchez-Ramirez, R. and Savaglio, S. and Schady, P. and Schulze, S. and Sollerman, J. and Sparre, Martin and Tagliaferri, G. and Tanvir, N. R. and Thone, C. C. and Vergani, S. D. and Vreeswijk, P. and Watson, D. and Wiersema, K. and Wijers, R. and Xu, D. and Zafar, T.},
  title     = {The X-shooter GRB afterglow legacy sample (XS-GRB)},
  series = {Astronomy and astrophysics : an international weekly journal},
  volume    = {623},
  journal   = {Astronomy and astrophysics : an international weekly journal},
  publisher = {EDP Sciences},
  address   = {Les Ulis},
  issn      = {1432-0746},
  doi       = {10.1051/0004-6361/201832835},
  pages     = {42},
  year      = {2019},
  abstract  = {In this work we present spectra of all gamma-ray burst (GRB) afterglows that have been promptly observed with the X-shooter spectrograph until 31/03/2017. In total, we have obtained spectroscopic observations of 103 individual GRBs observed within 48 hours of the GRB trigger. Redshifts have been measured for 97 per cent of these, covering a redshift range from 0.059 to 7.84. Based on a set of observational selection criteria that minimise biases with regards to intrinsic properties of the GRBs, the follow-up effort has been focused on producing a homogeneously selected sample of 93 afterglow spectra for GRBs discovered by the Swift satellite. We here provide a public release of all the reduced spectra, including continuum estimates and telluric absorption corrections. For completeness, we also provide reductions for the 18 late-time observations of the underlying host galaxies. We provide an assessment of the degree of completeness with respect to the parent GRB population, in terms of the X-ray properties of the bursts in the sample and find that the sample presented here is representative of the full Swift sample. We have constrained the fraction of dark bursts to be <28 per cent and confirm previous results that higher optical darkness is correlated with increased X-ray absorption. For the 42 bursts for which it is possible, we have provided a measurement of the neutral hydrogen column density, increasing the total number of published HI column density measurements by similar to 33 per cent. This dataset provides a unique resource to study the ISM across cosmic time, from the local progenitor surroundings to the intervening Universe.},
  language  = {en}
}
@article{BergEllisonSanchezRamirezetal.2019,
  author    = {Berg, Trystyn A. M. and Ellison, Sara L. and Sanchez-Ramirez, Ruben and Lopez, Sebastian and Becker, George D. and Christensen, Lise and Cupani, Guido and Denney, Kelly D. and Worseck, Gabor},
  title     = {Sub-damped Lyman alpha systems in the XQ-100 survey - I. Identification and contribution to the cosmological H I budget},
  series = {Monthly notices of the Royal Astronomical Society},
  volume    = {488},
  journal   = {Monthly notices of the Royal Astronomical Society},
  number    = {3},
  publisher = {Oxford Univ. Press},
  address   = {Oxford},
  issn      = {0035-8711},
  doi       = {10.1093/mnras/stz2012},
  pages     = {4356 -- 4369},
  year      = {2019},
  language  = {en}
}
@article{PlatCharlotBruzualetal.2019,
  author    = {Plat, A. and Charlot, S. and Bruzual, G. and Feltre, A. and Vidal-Garcia, A. and Morisset, C. and Chevallard, Jacopo and Todt, Helge Tobias},
  title     = {Constraints on the production and escape of ionizing radiation from the emission-line spectra of metal-poor star-forming galaxies},
  series = {Monthly notices of the Royal Astronomical Society},
  volume    = {490},
  journal   = {Monthly notices of the Royal Astronomical Society},
  number    = {1},
  publisher = {Oxford Univ. Press},
  address   = {Oxford},
  issn      = {0035-8711},
  doi       = {10.1093/mnras/stz2616},
  pages     = {978 -- 1009},
  year      = {2019},
  abstract  = {We explore the production and escape of ionizing photons in young galaxies by investigating the ultraviolet and optical emission-line properties of models of ionization-bounded and density-bounded H II regions, active-galactic-nucleus (AGN) narrow-line regions, and radiative shocks computed all using the same physically consistent description of element abundances and depletion on to dust grains down to very low metallicities. We compare these models with a reference sample of metal-poor star-forming galaxies and Lyman-continuum (LyC) leakers at various redshifts, which allows the simultaneous exploration of more spectral diagnostics than typically available at once for individual subsamples. We confirm that current single- and binary-star population synthesis models do not produce hard-enough radiation to account for the high-ionization emission of the most metal-poor galaxies. Introducing either an AGN or radiative-shock component brings models into agreement with observations. A published model including X-ray binaries is an attractive alternative to reproduce the observed rise in He II lambda 4686/H beta ratio with decreasing oxygen abundance in metal-poor star-forming galaxies, but not the high observed He II lambda 4686/H beta ratios of galaxies with large EW(H beta). A source of harder ionizing radiation appears to be required in these extreme objects, such as an AGN or radiative-shock component, perhaps linked to an initial-mass-function bias towards massive stars at low metallicity. This would also account for the surprisingly high [O I]/[O III] ratios of confirmed LyC leakers relative to ionization-bounded models. We find no simple by-eye diagnostic of the nature of ionizing sources and the escape of LyC photon, which require proper simultaneous fits of several lines to be discriminated against.},
  language  = {en}
}