A Catalog of Rotational and Radial Velocities for Evolved Stars V

Astronomy & Astrophysics manuscript no. De˙Medeiros˙J˙R˙2013˙revised˙MS c ESO 2018 November 7, 2018 A catalog of rotational and radial velocities for evolved stars V. Southern stars ⋆,⋆⋆ J. R. De Medeiros1, S. Alves1, S. Udry2, J. Andersen3,4, B. Nordström3 and M. Mayor2 1 Departamento de F´ısica, Universidade Federal do Rio Grande do Norte, Campus Universitário, 59072-970 Natal, RN, Brasil e-mail: J. R. De Medeiros, [email protected] 2 Observatoire de Genève, Universitède Genève, Chemin des Maillettes 51, 1290 Sauverny, Switzerland 3 The Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen, Denmark 4 Nordic Optical Telescope, Apartado 474, 38700 Santa Cruz de La Palma, Spain Received Date:?? Accepted Date:?? ABSTRACT Rotational and radial velocities have been measured for 1589 evolved stars of spectral types F, G, and K and luminosity classes IV, III, II, and Ib, based on observations carried out with the CORAVEL spectrometers. The precision in radial velocity is better than 0.30 1 1 1 km s− per observation, whereas rotational velocity uncertainties are typically 1.0 km s− for subgiants and giants and 2.0 km s− for class II giants and Ib supergiants. Key words. Stars: Evolution – Stars: Late-Type – Stars: Fundamental Parameters – Stars: Binaries spectroscopic – Techniques: Radial Velocities – Catalogs 1. Introduction reliable investigations of stellar rotational characteristics in different regions of the H–R Diagram (Carlberg et al. 2011; Cortés Over the past two decades, observations have been carried out at et al. 2009; Melo et al. 2001), the relationship between rotation the Geneva Observatory, Switzerland, and the Federal University and different stellar properties (Monaco et al. 2011; Raghavan of Rio Grande do Norte, Brazil, to accurately measure projected et al. 2010; López-Santiago et al. 2010; Grunhut et al. 2010; rotational velocities (v sin i) of evolved stars, with the aim of Massarotti et al. 2008; De Medeiros et al. 2002; Cutispoto et studying the evolution of stellar rotation with stellar age. al. 2002), constraints on theoretical models (Eggenberger et al. The technique used is to combine a high-resolution spec- 2010; Brun & Palacios 2009) and in many studies on extra-solar trometer with the cross–correlation technique, which yields ac- planets (e.g. Watson et al. 2010; Döllinger et al. 2009). curate, high S/N cross–correlation line profiles from relatively The present work brings complementary results for our ob- low S/N spectra. From these profiles, accurate radial velocities servational efforts, with the measurements of projected rota- and, once calibrated, projected rotational velocities (v sin i) with tional velocity v sin i for southern subgiant, giant, bright giant, 1 an accuracy better than 1 kms− can be derived, allowing mea- and Ib supergiant stars of spectral types F, G, and K, listed in surements of v sin i for large samples of relatively faint stars with the Bright Star Catalog (Hoffleit & Jaschek 1982; Hoffleit et al. telescopes of moderate aperture. 1983). Although the primary aim of this investigation is to study Most of the observations presented here were made with the rotational behaviour of evolved stars, our observational pro- the CORAVEL cross–correlation spectrometers (Baranne et al. cedure also produceda large set of radial velocity measurements, 1979). In addition, De Medeiros et al. (2006) measured rota- representing an important tool for answering several questions tional velocities, v sin i , for 100 metal-poor stars with the in stellar astrophysics, including the search for planets around digital version of the cross–correlation procedure, using spec- evolved stars. tra obtained with the FEROS (Kaufer & Pasquini 1998) and This paper is arranged as follows. Section 2 presents the def- CORALIE (Baranne et al. 1996) spectrometers. inition of the sample, the observational procedure used through- arXiv:1312.3474v2 [astro-ph.SR] 19 Dec 2013 As part of this programme, De Medeiros & Mayor (1999) out this survey, and the calibration of rotational velocities, with measured v sin i for 1541 stars of luminosity classes IV, III, a discussion of their probable errors. The list of individual v sin i and II, De Medeiros et al. (2002) presented v sin i for 232 Ib measurements and mean radial velocities are presented in Sect. supergiant stars, and De Medeiros et al. (2004) also measured 3. v sin i for 78 double–lined binaries with an evolved component. These high–quality data have inspired several studies, enabling 2. The observational programme Send offprint requests to: J. R. De Medeiros ⋆ Based on observations collected at the Haute–Provence The present sample consists of a total of 1702 mainly southern Observatory, Saint–Michel, France, and at the European Southern F, G, and K stars of luminosity classes IV, III, II, and Ib listed Observatory, La Silla, Chile in the Bright Star Catalog. Most of these stars were observed ⋆⋆ Table 1 is only available in electronic form at the CDS via in different programmes carried out at the Geneva Observatory, anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via the majority devoted to studying stellar binarity (Duquennoy http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/???/??? et al. 1991; De Medeiros & Mayor 1999; De Medeiros et al. 1 J. R. De Medeiros et al.: A catalog of rotational and radial velocities for evolved stars 2002, 2004) or to precise measurements of radial velocity in pro- of CORAVEL observations. In this case, the uncertainty is given grammes on Galactic structure (Andersen et al. 1985; Prevot et by max (ǫ1/ √N, σ/ √N), where ǫ1 is the typical error for one al. 1985; Maurice et al. 1987; Nordström et al. 2004a). single radial velocity measurement; As in previous papers (De Medeiros & Mayor 1999; De 6. Radial velocity dispersion (rms) σ; Medeiros et al. 2002, 2004), the observations reported here were 7. E/T, the ratio of observed to expected rms dispersion for ob- made using the two CORAVEL spectrometers (Baranne et al. servations, when N 2; 1979) mounted on the 1.54-m Danish telescope at ESO, La 8. P(χ2), the probability≥ that the radial velocity of the star is con- Silla (Chile), and the 1-m Swiss telescope at Haute-Provence stant; Observatory, Saint Michel (France). Radial velocities were de- 9. N, number of observations for each star; rived by direct cross–correlation of the stellar spectra with a 10. Time span ∆ T of observations; binary (0, 1) physical template, constructed from the spec- 11-12. Rotational velocity V sin i and its uncertainty ǫrot; trum of the K2 III star Arcturus and mounted inside the spec- 13. Remarks. The remarks SBO, SB, and SB? indicate, respec- trometers. The radial-velocity system applied is that defined by tively, single-lined spectroscopic binaries for which orbital pa- Udry et al. (1999). Typical integration times were 5 min, and rameters are available in the literature, stars displaying single- data was reducted using standard procedures (Duquennoy 1987; lined spectroscopic binary behaviour, and stars for which the Duquennoy et al. 1991; De Medeiros & Mayor 1999). For a dispersion or any systematic trend in the CORAVEL velocities complete discussion of the observational procedure, calibration, suggest that they may be single–lined binaries, but for which no and error analysis, readers are referred to Duquennoy (1987), period could be determined. Nevertheless, for a few stars classi- Duquennoy et al. (1991), and De Medeiros & Mayor (1999). fied as SB and SB?, the RV variability may reflect another cause, Here, we just recall a few salient points. In all cases, the e.g. pulsation. radial velocity uncertainty is derived from an instrumental er- A number of the programmestars, identified in Table 1, were ror added in quadrature to photon and scintillation noise, which already included in the papers by Andersen et al. (1985), Prevot are estimated using the computed parameters of the cross– et al. (1985), and Maurice et al. (1987), with radial velocities correlation profiles (Baranne et al. 1979). Different studies of referred to in the 1985 standard system of Udry et al. (1999), large data samples (Duquennoyet al. 1991; Udry et al. 1997; De while the velocities listed here are referred to in the revised zero- Medeiros & Mayor 1999) show that the typical uncertainty for point of Udry et al. (1999). The colour-dependent differences 1 CORAVEL radial velocity is about 0.3 kms− for slowly rotat- from the earlier velocities are small, about 0.11, 0.31, and 0.45 1 1 ing stars, generally with v sin i < 20 kms− . For faster rotators, km s− for F–, G–, and K–type stars, respectively, but can be the uncertainty is somewhat greater. noticed in precise work. Rotational velocities (v sin i) were obtained through an ap- Table 2 lists 79 SB2 and SB3 binary systems also observed propriate calibration of the widths of cross–correlation profiles, by CORAVEL, many of which were detected here for the first as described by De Medeiros & Mayor (1999). The original time, while Table 3 presents the evolved F–type stars for which v sin i calibration by Benz & Mayor (1984) is also valid for sub- no correlation dip was obtained with CORAVEL. These are un- giant and giant stars of luminosityclasses IV andIII, but for class doubtedly fast rotators. II and Ib bright giants and supergiants, the increase in macro- The individual radial velocity measurements for single and turbulence with spectral type required a new calibration of the SBO stars, as well as for SB not included in follow–up width of the cross–correlation profile into v sin i as measured programmes, are available at the CDS “Centre de Données from a Fourier transform of line profiles from Gray & Toner Astronomiques de Strasbourg”.

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