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arXiv · 2402.16987

X-Shooting ULLYSES: Massive Stars at low metallicity II. DR1: Advanced optical data products for the Magellanic Clouds

H. Sana·F. Tramper·M. Abdul-Masih·R. Blomme·K. Dsilva·G. Maravelias·L. Martins·A. Mehner·A. Wofford·G. Banyard·C. L. Barbosa·J. Bestenlehner·C. Hawcroft·D. John Hillier·H. Todt·C. J. K. Larkin·L. Mahy·F. Najarro·V. Ramachandran·M. C. Ramirez-Tannus·M. M. Rubio-Diez·A. A. C. Sander·T. Shenar·J. S. Vink·F. Backs·S. A. Brands·P. Crowther·L. Decin·A. de Koter·W. -R. Hamann·C. Kehrig·R. Kuiper·L. Oskinova·D. Pauli·J. Sundqvist·O. Verhamme·the XSHOOT-U collaboration
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Abstract

Using the medium resolution spectrograph X-shooter, spectra of 235 OB and Wolf-Rayet (WR) stars in sub-solar metallicity environments have been secured. [...]This second paper focuses on the optical observations of 232 Magellanic Clouds targets. It describes the uniform reduction of the UVB (300 - 560 nm) and VIS (550 - 1020 nm) XShootU data as well as the preparation of advanced data products [...] . The data reduction of the raw data is based on the ESO CPL X-shooter pipeline. We paid particular attention to the determination of the response curves [...] We implemented slit-loss correction, absolute flux calibration, (semi-)automatic rectification to the continuum, and a correction for telluric lines. The spectra of individual epochs were corrected for the barycentric motion, re-sampled and co-added, and the spectra from the two arms were merged into a single flux calibrated spectrum covering the entire optical range with maximum signal-to-noise ratio. [...] We provide three types of data products: (i) two-dimensional spectra for each UVB and VIS exposure; (ii) one-dimensional UVB and VIS spectra before and after response-correction, as well as after applying various processing, including absolute flux calibration, telluric removal, normalisation and barycentric correction; and (iii) co-added flux-calibrated and rectified spectra over the full optical range, for which all available XShootU exposures were combined. For many of the targets, the final signal-to-noise ratio per resolution element is above 200 in both the UVB and the VIS co-added spectra. The reduced data and advanced scientific data products will be made available to the community upon publication of this paper. [...]

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H. Sana, F. Tramper, M. Abdul-Masih, R. Blomme, K. Dsilva, G. Maravelias, L. Martins, A. Mehner, A. Wofford, G. Banyard, C. L. Barbosa, J. Bestenlehner, C. Hawcroft, D. John Hillier, H. Todt, C. J. K. Larkin, L. Mahy, F. Najarro, V. Ramachandran, M. C. Ramirez-Tannus, M. M. Rubio-Diez, A. A. C. Sander, T. Shenar, J. S. Vink, F. Backs, S. A. Brands, P. Crowther, L. Decin, A. de Koter, W. -R. Hamann, C. Kehrig, R. Kuiper, L. Oskinova, D. Pauli, J. Sundqvist, O. Verhamme, the XSHOOT-U collaboration. 2024-02-26. X-Shooting ULLYSES: Massive Stars at low metallicity II. DR1: Advanced optical data products for the Magellanic Clouds. https://doi.org/10.1051/0004-6361/202347479

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