Estimation of galactic model parameters and metalicity distribution in intermediate latitudes with SDSS

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dc.contributor.authorYaz, E.
dc.contributor.authorKaraali, S.
dc.date.accessioned2024-03-13T10:35:07Z
dc.date.available2024-03-13T10:35:07Z
dc.date.issued2010
dc.departmentİstanbul Beykent Üniversitesien_US
dc.description.abstractWe estimated the galactic model parameters for a set of 20 intermediate-latitude fields with galactic longitudes 0 degrees <= 1 <= 100 degrees and 160 degrees <= 1 <= 240 degrees, included in the currently available Data Release 6 (DR6) of the Sloan Digital Sky Survey (SDSS), to explore their possible variation with galactic longitude. The local space densities of the thick disc and halo are almost the same for all fields, <(n(2)/n(1))> = 6.52% and <(n(3)/n(1))> = 0.35%, respectively, a result different than the one cited for high latitude fields. The thin disc's scaleheight is 325 pc in the galactic centre and it changes to 369 pc in the third quadrant, which confirms the existence of disc flare, whereas the thick disc scaleheight is as large as 952 pc at galactic longitude I = 20 degrees and 10% lower at I = 160 degrees, which confirms the existence of the disc long bar in the direction I similar or equal to 27 degrees. Finally, the variation of the axis ratio of the halo with galactic longitude is almost flat, <(c/a)> = 0.56, except a slight minimum and a small maximum in the second and third quadrants, respectively, indicating an effect of the long bar which seems plausible for a shallow halo. We estimated the metallicities of unevolved G-type stars and discussed the metallicity gradient for different vertical distances. The metallicity gradient is d[M/H]/dz similar to -0.30 dex kpc(-1) for short distances, confirming the formation of this region of the Galaxy by dissipational collapse. However, its change is steeper in the transition regions of different galactic components. The metallicity gradient: is almost zero for inner halo (5 < z < 10 kpc), indicating a formation of merger or accretion of numerous fragments such as dwarf galaxies. (C) 2009 Elsevier B.V. All rights reserved.en_US
dc.description.sponsorshipBeykent University; Alfred P. Sloan Foundation; Participating Institutions; National Aeronautics and Space Administration; National Science Foundation; US Department of Energy; Japanese Monbukagakusho; Max Planck Societyen_US
dc.description.sponsorshipWe thank the anonymous referee for a thorough report and useful comments that helped improving an early version of the paper. We would like to thank Dr. Selcuk Bilir, Dr. Serap Ak, Dr. Antonio Cabrera-Lavers and K. Basar Coskunoglu for their contributions. Also, we thank to Hikmet Cakmak and Tugkent Akkurum for preparing some computer codes for this study. Salih Kaarali thanks to Beykent University for financial support.r The SDSS is managed by the Astrophysical Research Consortium (ARC) for the Participating Institutions. The Participating Institutions are The University of Chicago, Fermilab, the Institute for Advanced Study, the Japan Participation Group, The Johns Hopkins University, the Korean Scientist Group, Los Alamos National Laboratory, the Max-Planck-Institute for Astronomy (MPIA), the Max-Planck-Institute for Astrophysics (MPA), New Mexico State University, University of Pittsburgh, University of Portsmouth, Princeton University, the United States Naval Observatory, and the University of Washington. Funding for the creation and distribution of the SDSS Archive has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Aeronautics and Space Administration, the National Science Foundation, the US Department of Energy, the Japanese Monbukagakusho, and the Max Planck Society. The SDSS Web site is http://www.sdss.org/.en_US
dc.identifier.doi10.1016/j.newast.2009.07.010
dc.identifier.endpage246en_US
dc.identifier.issn1384-1076
dc.identifier.issn1384-1092
dc.identifier.issue2en_US
dc.identifier.scopus2-s2.0-70350046231en_US
dc.identifier.scopusqualityQ3en_US
dc.identifier.startpage234en_US
dc.identifier.urihttps://doi.org/10.1016/j.newast.2009.07.010
dc.identifier.urihttps://hdl.handle.net/20.500.12662/4245
dc.identifier.volume15en_US
dc.identifier.wosWOS:000271732000006en_US
dc.identifier.wosqualityQ3en_US
dc.indekslendigikaynakWeb of Scienceen_US
dc.indekslendigikaynakScopusen_US
dc.language.isoenen_US
dc.publisherElsevier Science Bven_US
dc.relation.ispartofNew Astronomyen_US
dc.relation.publicationcategoryMakale - Uluslararası Hakemli Dergi - Kurum Öğretim Elemanıen_US
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.subjectGalaxy: discen_US
dc.subjectGalaxy: structureen_US
dc.subjectGalaxy: fundamental parametersen_US
dc.titleEstimation of galactic model parameters and metalicity distribution in intermediate latitudes with SDSSen_US
dc.typeArticleen_US

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