A spectroscopic survey of the youngest field stars in the solar neighbourhood

Guillout, P.; Klutsch, A.; Frasca, A.; Ferrero, R. Freire; Marilli, E.; Mignemi, Giuseppe; Biazzo, K.; Bouvier, J.; Monier, Richard; Motch, C.; Sterzik, M.

doi:10.1051/0004-6361/200811313

Cited by 69 publications

(82 citation statements)

References 83 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Only the UMa stream is clearly separated from the others in the (U, V) plane. It is not unusual that one source may be reported as a candidate of several groups of comoving stars (see, Guillout et al 2009Guillout et al , 2010. In such cases, the stellar properties (and a coherent sky position for the candidate to MGs) help recognize the best SKG match.…”

Section: Testing the Robustness Of Our Methodsmentioning

confidence: 99%

“…Moreover, this SKG is undoubtedly a more complex structure because several nearby young associations have the same kinematics (Zuckerman & Song 2004;Torres et al 2008). As an example, Guillout et al (2009) found that BD+44 3670 is a highly probable candidate of the Pleiades group, while Zuckerman et al (2011) proposed it as a Columba association member. A thorough study of the membership for all the Pleiades MG candidates of these young associations is out of the scope of the present paper and will be addressed in a future work.…”

Section: Kinematic Distributionmentioning

confidence: 99%

“…Eggen (1973a) and Eggen & Iben (1988) denoted the locus of the UVW space that encompasses all these SKGs as the very young disk. From the analysis of the RasTyc sample (Guillout et al 2009;Frasca et al, in prep. ), four comoving T Tauri stars were recently discovered in a sky region of few degrees toward the CO Cepheus void (Guillout et al 2010).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Reliable probabilistic determination of membership in stellar kinematic groups in the young disk

Klutsch

Ferrero

Guillout

et al. 2014

A&A

Self Cite

View full text Add to dashboard Cite

Context. Over the last century, the overdensities in the velocity distributions of nearby stars were attributed to stellar kinematic groups or moving groups. Although their reality was initially questioned, their existence is now supported by a confluence of evidence. Aims. To pursue investigations, quantitative methods should be clearly defined to identify new stars belonging to these groups. Here, we present two probabilistic methods to determine the likelihood of kinematic membership for possible candidates in five of the known young stellar kinematic groups -namely, Pleiades, IC 2391, Castor, Ursa Major, and Hyades -in which all are younger than 650 Myr. Methods. We tried different methods to handle kinematic data of their known members. We succeeded in developing two independent procedures able to identify new candidates of these five stellar stream. We tested the robustness of our two approaches by means of extensive Monte Carlo simulations. Results. Our methods are consistent with one another in more than 90% of cases and for almost all the stellar kinematic groups under scrutiny. The IC 2391 supercluster is an exception. Applying our statistical methods to a large sample of young low-mass stars, we confirmed almost all the likely members and good candidates of these stellar streams. We also proposed 39 additional candidates based on the agreement and the high likelihood of age and kinematic membership. Conclusions. These probabilistic methods are very powerful to reliably identify new candidate members of young stellar kinematic groups. However, the kinematic criteria alone are not sufficient to distinguish between coeval stars that are evaporated from open clusters and other field stars trapped by dynamical processes generated by galactic perturbations. The identification of stars belonging to the remnant of a past star-forming event can be possible with the help of additional information, such as indicators of chromospheric activity, age proxies (lithium abundance), and chemical composition.

show abstract

Section: Testing the Robustness Of Our Methodsmentioning

confidence: 99%

Section: Kinematic Distributionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Reliable probabilistic determination of membership in stellar kinematic groups in the young disk

Klutsch

Ferrero

Guillout

et al. 2014

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…For instance, Strassmeier et al (2000) presented measurements of equivalent widths of Ca ii H & K, Hα, and Li i in addition to the kinematics of a substantial sample of active and inactive FGK stars. Also, Torres et al (2006) and Guillout et al (2009) determined kinematics and age indicators in comprehensive samples of late-type stars to select members of young moving groups and associations. White et al (2007) determined the same parameters for stars in the Spitzer Legacy Science Program "The Formation and Evolution of Planetary Systems", aimed at studying the formation and evolution of protoplanetary disks.…”

Section: Introductionmentioning

confidence: 99%

A high-resolution spectroscopic survey of late-type stars: chromospheric activity, rotation, kinematics, and age

López‐Santiago¹,

Montes²,

Galvez-Ortiz

et al. 2010

A&A

View full text Add to dashboard Cite

Aims. We present a compilation of spectroscopic data from a survey of 144 chromospherically active young stars in the solar neighborhood, which may be used to investigate different aspects of its formation and evolution in terms of kinematics and stellar formation history. The data have already been used by us in several studies. With this paper, we make all these data accessible to the scientific community for future studies on different topics. Methods. We performed spectroscopic observations with echelle spectrographs to cover the entirety of the optical spectral range simultaneously. Standard data reduction was performed with the IRAF echelle package. We applied the spectral subtraction technique to reveal chromospheric emission in the stars of the sample. The equivalent width of chromospheric emission lines was measured in the subtracted spectra and then converted to fluxes using equivalent width-flux relationships. Radial and rotational velocities were determined by the cross-correlation technique. Kinematics, equivalent widths of the lithium line λ6707.8 Å and spectral types were also determined. Results. A catalog of spectroscopic data is compiled: radial and rotational velocities, space motion, equivalent widths of optical chromospheric activity indicators from Ca ii H & K to the calcium infrared triplet and the lithium line in λ6708 Å. Fluxes in the chromospheric emission lines and R HK are also determined for each observation of a star in the sample. We used these data to investigate the emission levels of our stars. The study of the Hα emission line revealed two different populations of chromospheric emitters in the sample, clearly separated in the log F Hα /F bol − (V − J) diagram. The dichotomy may be associated with the age of the stars.

show abstract

“…Only very few spatially unresolved SDSS sources matching 2XMMi entries have combined u − g, g − r and r − i colours compatible with those expected from giant class III stars, not to mention supergiants. In a recent paper, Guillout et al (2009) estimate that their sample of |b| < ∼ 30 • RASS sources identified with bright Tycho stars has a mean contamination of 35% by evolved stars with a peak at 60% for K stars. However, a smaller fraction of X-ray emitting evolved stars of ∼10% was present in the sample of Covey et al (2008), which is more representative of what we should expect in our case because it was selected at higher galactic latitude and fainter flux.…”

Section: X-ray Active Starsmentioning

confidence: 99%

Cross-correlation of the 2XMMi catalogue with Data Release 7 of the Sloan Digital Sky Survey

Pineau

Motch

Carrera

et al. 2011

A&A

Self Cite

102

View full text Add to dashboard Cite

The Survey Science Centre of the XMM-Newton satellite released the first incremental version of the 2XMM catalogue in August 2008. Containing more than 220 000 X-ray sources, the 2XMMi was at that time the largest catalogue of X-ray sources ever published and thus constitutes an unprecedented resource for studying the high-energy properties of various classes of X-ray emitters such as AGN and stars. Thanks to the high throughput of the EPIC cameras on board XMM-Newton accurate positions, fluxes, and hardness ratios are available for a substantial fraction of the X-ray detections. The advent of the 7th release of the Sloan Digital Sky Survey offers the opportunity to cross-match two major surveys and extend the spectral energy distribution of many 2XMMi sources towards the optical bands. This implies building extensive homogeneous samples with a statistically controlled rate of spurious matches and completeness. We here present a cross-matching algorithm based on the classical likelihood ratio estimator. The method developed has the advantage of providing true probabilities of identifications without resorting to heavy Monte-Carlo simulations. Over 30,000 2XMMi sources have SDSS counterparts with individual probabilities of identification higher than 90%. At this threshold, the sample has only 2% spurious matches and contains 77% of all expected SDSS identifications. Using spectroscopic identifications from the SDSS DR7 catalogue supplemented by extraction from other catalogues, we build an identified sample from which the way the various classes of X-ray emitters gather in the multi dimensional parameter space can be analysed and later used to design a source classification scheme. We illustrate the interest of this clean source sample by investigating two scientific use cases. In the first example we show how these multi-wavelength data can be used to search for new QSO2s. Although no specific range of observed properties allows us to efficiently identify Compton Thick QSO2s, we show that the prospects are much better for Compton Thin AGN2 and discuss several possible multi-parameter selection strategies. In a second example, we confirm the hardening of the mean X-ray spectrum with increasing X-ray luminosity on a sample of over 500 X-ray active stars and reveal that on average X-ray active M stars display bluer g − r colour indexes than less active ones. Although this catalogue of 2XMM-SDSS sources cannot be used directly for statistical studies, it nevertheless represents an excellent starting point to select well defined samples of X-ray-emitting objects.

show abstract

A spectroscopic survey of the youngest field stars in the solar neighbourhood

Cited by 69 publications

References 83 publications

Reliable probabilistic determination of membership in stellar kinematic groups in the young disk

Reliable probabilistic determination of membership in stellar kinematic groups in the young disk

A high-resolution spectroscopic survey of late-type stars: chromospheric activity, rotation, kinematics, and age

Cross-correlation of the 2XMMi catalogue with Data Release 7 of the Sloan Digital Sky Survey

Contact Info

Product

Resources

About