<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "RR Lyrae stars: Substructures and the Oosterhoff dichotomy\r\nin the Halo of the Milky Way\r\n"^^ . "We present the detection of 6371 RR Lyrae (RRL) stars distributed across 14000 deg2 of the sky from the combined\r\ndata of the Sloan Digital Sky Survey (SDSS), the Panoramic Survey Telescope and Rapid Response System 1 3pi\r\nsurvey (PS1), and the repeated observations from the second photometric catalogue from the Catalina Survey (CSDR2).\r\nAround 2000 of these stars are new discoveries. The completeness level of our RRL stars (4800 RRab and 1571 RRc\r\nstars) is 50 % while the efficiency levels for RRab and RRc stars are 99 % and 87 %, respectively. We show\r\nthat our method for selecting RRL stars allows us to recover halo substructures. Moreover, we present a method for selecting RRL stars and other types of variable stars in the absence of a large number of multi-epoch data and light curve analyses. Our method uses a Gaussian Mixture Bayesian Generative technique (GMM) to apply SDSS color\r\nand PS1 variability cuts instead of the commonly used rectangular cuts. A comparison between our efficiency and\r\ncompleteness levels using the GMM method to the efficiency and completeness levels using rectangular cuts that are\r\ncommonly used yielded a significant increase in the efficiency level from 13% to 77% and an insignificant change in the completeness levels. Although we develop it over the SDSSxPS1 footprint, our technique would work well on any multi-band, multi-epoch survey for which the number of epochs is limited.\r\nAdditionally, we study the different Oosterhoff populations (OoI and OoII) in the Milky Way’s halo using the\r\nlargest catalog of RRab stars from the Catalina Sky Survey (CSS). We show that 73% of the halo RRab stars are\r\nof OoI type (RRabOoI ) and that the latter stars are more metal-rich compared to RRabOoII stars. By examining the\r\nchange of RRabOoI and RRabOoII stars with Galactocentric distances (Rgc), we detect two turning points at Rgc \r\n25 kpc and Rgc 45 kpc. We believe that these turning points are associated with breaks in the power-laws of the halo and that they divide the stellar halo into three main components: the inner halo, the outer halo, and the “extreme outer halo” components. We also study the Oosterhoff populations of the RRL stars in the direction of the trailing arm of the Sagittarius dwarf spheroidal (dSph) galaxy, the Virgo substructure, and the Hercules-Aquila Cloud and we conclude that these substructures are dominated by RRabOoI stars (80%) and that the mean periods of their RRab stars fall near the boundary of the Oosterhoff gap; results that suggest that they had dSph galaxy progenitors."^^ . "2014" . . . . . . . "Mohamad"^^ . "Abbas"^^ . "Mohamad Abbas"^^ . . . . . . "RR Lyrae stars: Substructures and the Oosterhoff dichotomy\r\nin the Halo of the Milky Way\r\n (PDF)"^^ . . . "MohamadAbbas_Thesis.pdf"^^ . . . "RR Lyrae stars: Substructures and the Oosterhoff dichotomy\r\nin the Halo of the Milky Way\r\n (Other)"^^ . . . . . . "indexcodes.txt"^^ . . . "RR Lyrae stars: Substructures and the Oosterhoff dichotomy\r\nin the Halo of the Milky Way\r\n (Other)"^^ . . . . . . "lightbox.jpg"^^ . . . "RR Lyrae stars: Substructures and the Oosterhoff dichotomy\r\nin the Halo of the Milky Way\r\n (Other)"^^ . . . . . . "preview.jpg"^^ . . . "RR Lyrae stars: Substructures and the Oosterhoff dichotomy\r\nin the Halo of the Milky Way\r\n (Other)"^^ . . . . . . "medium.jpg"^^ . . . "RR Lyrae stars: Substructures and the Oosterhoff dichotomy\r\nin the Halo of the Milky Way\r\n (Other)"^^ . . . . . . "small.jpg"^^ . . "HTML Summary of #17887 \n\nRR Lyrae stars: Substructures and the Oosterhoff dichotomy \nin the Halo of the Milky Way \n\n\n" . "text/html" . . . "520 Astronomie"@de . "520 Astronomy and allied sciences"@en . .