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Rotation velocities of hot horizontal branch stars in the globular clusters NGC 1904, NGC 2808, NGC 6093, and NGC 7078: the database

Alejandra Recio-Blanco·Giampaolo Piotto·Antonio Aparicio·Alvio Renzini
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Abstract

We present radial and rotation (v sini) velocity measurements, from UVES+VLT high resolution spectra of 61 stars in the blue horizontal branches (HB) of the Galactic globular clusters NGC 1904 (M79), NGC 2808, NGC 6093 (M80), and NGC 7078 (M15). The data reduction and the velocity determination, based on cross-correlation techniques, are discussed in detail. Most of this database has been used by Recio-Blanco et al. (2002) in their analysis of the rotation velocity properties of blue HB stars. Here we present additional data for NGC 2808. We confirm the results of the previous paper, in particular, a possible link between the HB jump and the abrupt change in the rotational velocity distribution around Teff ~ 11,500 K.

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Alejandra Recio-Blanco, Giampaolo Piotto, Antonio Aparicio, Alvio Renzini. 2004-01-05. Rotation velocities of hot horizontal branch stars in the globular clusters NGC 1904, NGC 2808, NGC 6093, and NGC 7078: the database. https://doi.org/10.1051/0004-6361%3A20040003

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