Browsing Research publications by Author "Ryan, Sean"

Now showing items 1-5 of 5

    • A Critique of the Spite Plateau, and the Astration of Primordial Lithium 

      Norris, J.E.; Yong, David; Frebel, Anna; Ryan, Sean (2023-03-30)
      We investigate the distribution of the lithium abundances, A(Li), of metal-poor dwarf and subgiant stars within the limits 5500 K< eff < 6700 K, –6.0 < [Fe/H] < –1.5, and log >∼3.5 (a superset of parameters first adopted ...

    • Dynamically Tagged Groups of Very Metal-poor Halo Stars from the HK and Hamburg/ESO Surveys 

      Limberg, Guilherme; Rossi, Silvia; Beers, Timothy; Perottoni, Helio; Perez-Villegas, Angeles; Santucci, Rafael; Abuchaim, Yuri; Placco, Vinicius; Lee, Young Sun; Christlieb, Norbert; Norris, John; Bessell, Michael; Ryan, Sean; Wilhelm, Ronald; Rhee, Jaehyon; Frebel, Anna (2021-01-20)
      We analyze the dynamical properties of ∼1500 very metal-poor (VMP; [Fe/H] ≲−2.0) halo stars, based primarily on medium-resolution spectroscopic data from the HK and Hamburg/ESO surveys. These data, collected over the past ...

    • Multi-fluorescence high-resolution episcopic microscopy (MF-HREM) for three dimensional imaging of adult murine organs 

      Walsh, Claire; Holroyd, Natalie; Finnerty, Eoin; Ryan, Sean; Sweeney, Paul; Shipley, Rebecca; Walker-Samuel, Simon (2021-05-26)
      Three-dimensional microscopy of large biological samples (greater than 0.5 cm^3) is transforming biological research. Many existing techniques require trade-offs between image resolution, sample size and method complexity. ...

    • The Rotation of the halo of NGC 6822 from the radial velocities of carbon stars 

      Thompson, Graham; Ryan, Sean; Sibbons, Lisette (2016-11-01)
      Using spectra taken with the AAOmega spectrograph, we measure the radial velocities of over 100 stars, many of which are intermediate age carbon stars, in the direction of the dwarf irregular galaxy NGC 6822. Kinematic ...

    • Theranostic NIR-active Conjugated Polymer Nanoparticles 

      Zhao, Miao; Leggett, Edward; Bourke, Struan; Poursanidou, Souzana; Carter-Searjeant, Sadie; Po, Steve; Palma do Carmo, Marciano; Dailey, Lea Ann; Manning, Philip; Ryan, Sean; Urbano, Laura; Green, Mark; Rakovich, Aliaksandra (2021-05-12)
      Conjugated polymer nanoparticles (CPNs) based on a common solar cell material (PTB7) have been prepared, and their potential in theranostic applications based on bioimaging and photosensitizing capabilities has been ...