Halo streams in the SDSS-DR7

DOI

We have detected stellar halo streams in the solar neighborhood using data from the seventh public data release of the Sloan Digital Sky Survey (SDSS), which includes the directed stellar program Sloan Extension For Galactic Understanding and Exploration (SEGUE). In order to derive distances to each star, we used the metallicity-dependent photometric parallax relation from Ivezic et al. (2008ApJ...684..287I). Our final sample consists of 22321 nearby (d<=2kpc), metal-poor ([Fe/H]<=-0.5) main-sequence stars with six-dimensional estimates of position and space velocity (r{vec},{nu}{vec}). We characterize the orbits of these stars through suitable kinematic proxies for their "effective" integrals of motion, angular momentum, eccentricity, and orbital polar angle and compare the observed distribution to expectations from a smooth distribution in four [Fe/H] bins. The metallicities provide an additional dimension in parameter space that is well suited to distinguish tidal streams from those of dynamical origin. On this basis, we identify at least five significant "phase-space overdensities" of stars on very similar orbits in the solar neighborhood to which we can assign unambiguously peaked [Fe/H] distributions. Three of them have been identified previously, including the halo stream discovered by Helmi et al. (1999MNRAS.307..495H) at a significance level of {sigma}=12.0. In addition, we find at least two new genuine halo streams, judged by their kinematics and [Fe/H], at {sigma}=2.9 and 4.8, respectively.

Cone search capability for table J/ApJ/698/865/table3 (Putative members of the identified streams: astrophysical parameters)

Identifier
DOI http://doi.org/10.26093/cds/vizier.16980865
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/ApJ/698/865
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/698/865
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/698/865
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/ApJ/698/865
Provenance
Creator Klement R.; Rix H.-W.; Flynn C.; Fuchs B.; Beers T.C.; Allende Prieto C.,Bizyaev D.; Brewington H.; Lee Y.S.; Malanushenko E.; Malanushenko V.,Oravetz D.; Pan K.; Re Fiorentin P.; Simmons A.; Snedden S.
Publisher CDS
Publication Year 2011
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Exoplanet Astronomy; Galactic and extragalactic Astronomy; Interdisciplinary Astronomy; Natural Sciences; Observational Astronomy; Physics