XQR-30: The ultimate XSHOOTER quasar sample at the reionization epoch

Valentina D'odorico, E. Bañados, G. D. Becker, M. Bischetti, S. E.I. Bosman, G. Cupani, R. Davies, E. P. Farina, A. Ferrara, C. Feruglio, C. Mazzucchelli, E. Ryan-Weber, J. T. Schindler, A. Sodini, B. P. Venemans, F. Walter, H. Chen, S. Lai, Y. Zhu, F. BianS. Campo, S. Carniani, S. Cristiani, F. Davies, R. Decarli, A. Drake, A. C. Eilers, X. Fan, P. Gaikwad, S. Gallerani, B. Greig, M. G. Haehnelt, J. Hennawi, L. Keating, G. Kulkarni, A. Mesinger, R. A. Meyer, M. Neeleman, M. Onoue, A. Pallottini, Y. Qin, S. Rojas-Ruiz, S. Satyavolu, A. Sebastian, R. Tripodi, F. Wang, M. Wolfson, J. Yang, M. V. Zanchettin

Research output: Contribution to journalArticlepeer-review

19 Scopus citations

Abstract

The final phase of the reionization process can be probed by rest-frame UV absorption spectra of quasars at z ≳ 6, shedding light on the properties of the diffuse intergalactic medium within the first Gyr of the Universe. The ESO Large Programme 'XQR-30: the ultimate XSHOOTER legacy survey of quasars at z ≃ 5.8-6.6' dedicated ∼250 h of observations at the VLT to create a homogeneous and high-quality sample of spectra of 30 luminous quasars at z ∼6, covering the rest wavelength range from the Lyman limit to beyond the Mg ii emission. Twelve quasar spectra of similar quality from the XSHOOTER archive were added to form the enlarged XQR-30 sample, corresponding to a total of ∼350 h of on-source exposure time. The median effective resolving power of the 42 spectra is R ≃ 11 400 and 9800 in the VIS and NIR arm, respectively. The signal-to-noise ratio per 10 km s-1 pixel ranges from ∼11 to 114 at λ ≃ 1285 Å rest frame, with a median value of ∼29. We describe the observations, data reduction, and analysis of the spectra, together with some first results based on the E-XQR-30 sample. New photometry in the H and K bands are provided for the XQR-30 quasars, together with composite spectra whose characteristics reflect the large absolute magnitudes of the sample. The composite and the reduced spectra are released to the community through a public repository, and will enable a range of studies addressing outstanding questions regarding the first Gyr of the Universe.

Original languageEnglish (US)
Pages (from-to)1399-1420
Number of pages22
JournalMonthly Notices of the Royal Astronomical Society
Volume523
Issue number1
DOIs
StatePublished - Jul 1 2023

Keywords

  • dark ages, reionization, first stars
  • galaxies: high-redshift
  • intergalactic medium
  • quasars: absorption lines
  • quasars: emission lines

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint

Dive into the research topics of 'XQR-30: The ultimate XSHOOTER quasar sample at the reionization epoch'. Together they form a unique fingerprint.

Cite this