Browsing by Author "Mateo, Mario"

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    A giant protocluster of galaxies at redshift 5.7
    (2018) Jiang, , Linhua; Wu, Jin; Bian, Fuyan; Chiang, Yi-Kuan; Ho, Luis C.; Shen, Yue; Zheng, Zhen Ya; Bailey, John I.; Blanc, Guillermo; Crane, Jeffrey D.; Fan, Xiaohui; Mateo, Mario; Olszewski, Edward W.; Oyarzún, Grecco A.; Wang, Ran; Wu, Xue Bing
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    MAPPING DIFFERENTIAL REDDENING IN THE INNER GALACTIC GLOBULAR CLUSTER SYSTEM
    (2011) Alonso-Garcia, Javier; Mateo, Mario; Sen, Bodhisattva; Banerjee, Moulinath; von Braun, Kaspar
    A serious limitation in the study of many globular clusters-especially those located near the Galactic center-has been the existence of large and differential extinction by foreground dust. In a series of papers, we intend to map the differential extinction and remove its effects, using a new dereddening technique, in a sample of clusters in the direction of the inner Galaxy, observed using the Magellan 6.5 m telescope and the Hubble Space Telescope. These observations and their analysis will let us produce high-quality color-magnitude diagrams of these poorly studied clusters that will allow us to determine these clusters' relative ages, distances, and chemistry and to address important questions about the formation and the evolution of the inner Galaxy. We also intend to use the maps of the differential extinction to sample and characterize the interstellar medium along the numerous low-latitude lines of sight where the clusters in our sample lie. In this first paper, we describe in detail our dereddening method along with the powerful statistics tools that allow us to apply it, and we show the kind of results that we can expect, applying the method to M62, one of the clusters in our sample. The width of the main sequence and lower red giant branch narrows by a factor of two after applying our dereddening technique, which will significantly help to constrain the age, distance, and metallicity of the cluster.
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    Proper motions of dwarf spheroidal galaxies from Hubble Space Telescope imaging.: V.: Final measurement for Fornax
    (2007) Piatek, Slawomir; Pryor, Carlton; Bristow, Paul; Olszewski, Edward W.; Harris, Hugh C.; Mateo, Mario; Minniti, Dante; Tinney, Christopher G.
    The measured proper motion of Fornax, expressed in the equatorial coordinate system, is (mu(alpha), mu(delta)) = (47.6 +/- 4.6, -36.0 +/- 4.1) mas century(-1). This proper motion is a weighted mean of four independent measurements for three distinct fields. Each measurement uses a quasi-stellar object as a reference point. Removing the contribution of the motion of the Sun and of the local standard of rest to the measured proper motion produces a Galactic rest-frame proper motion of (mu(Grf)(alpha), mu(Grf)(delta)) = (24.4 +/- 4.6, -14.3 +/- 4.1) mas century(-1). The implied space velocity with respect to the Galactic center has a radial component of V-r = -31.8 +/- 1.7 km s(-1) and a tangential component of V-t = 196 +/- 29 km s(-1). Integrating the motion of Fornax in a realistic potential for the Milky Way produces orbital elements. The perigalacticon and apogalacticon are 118 ( 66, 137) and 152 ( 144, 242) kpc, respectively, where the values in the parentheses represent the 95% confidence intervals derived from Monte Carlo experiments. The eccentricity of the orbit is 0.13 (0.11, 0.38), and the orbital period is 3.2 (2.5, 4.6) Gyr. The orbit is retrograde and inclined by 101 degrees ( 94 degrees, 107 degrees) to the Galactic plane. Fornax could be a member of a proposed "stream'' of galaxies and globular clusters; however, the membership of another proposed galaxy in the stream, Sculptor, has been previously ruled out. Fornax is in the Kroupa-Theis-Boily plane, which contains 11 of the Galactic satellite galaxies, but its orbit will take it out of that plane.