Journal: The Astrophysical Journal

  • Publication
    On the Use of the Index N2 to Derive the Metallicity in Metal-poor Galaxies
    The N2 index ([N II] λ6584/Hα) is used to determine emission line galaxy metallicities at all redshifts, including high redshift, where galaxies tend to be...
  • Publication
    On the Variation of the Peak Asymmetry of Low-l Solar p Modes
    The resonant peaks of solar p modes show small amounts of asymmetry in frequency. Here, we use five independent sets of contemporaneous data, collected over a ~...
  • Publication
    On the White Dwarf Cooling Sequence of the Globular Cluster ω Centauri
    We present deep and precise photometry (F435W, F625W, F658N) of ω Cen collected with the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope...
  • Publication
    On the α-Element Abundance Gradients in the Disk of the Sculptor Spiral Galaxy NGC 300
    We have carried out a detailed spectral analysis of six early B-type supergiants in the Sculptor Group spiral galaxy NGC 300. To this end, we used state-of-the...
  • Publication
    On the ΔV bump HB Parameter in Globular Clusters
    We present new empirical estimates of the ΔV bump HB parameter for 15 Galactic globular clusters (GGCs) using accurate and homogeneous ground-based optical data...
  • Publication
    Open Cluster Chemical Homogeneity throughout the Milky Way
    The chemical homogeneity of surviving stellar clusters contains important clues about interstellar medium (ISM) mixing efficiency, star formation, and the...
  • Publication
    Optical and Infrared Observations of the Bipolar Proto-Planetary Nebula Henize 401
    Based on optical and near-infrared ground-based spectroscopy and optical and near-infrared Hubble Space Telescope (HST) images, we confirm the classification of...
  • Publication
    Optical and Near-infrared Spectra of σ Orionis Isolated Planetary-mass Objects
    We have obtained low-resolution optical (0.7–0.98 μm) and near-infrared (1.11–1.34 μm and 0.8–2.5 μm) spectra of 12 isolated planetary-mass candidates (J = 18.2...
  • Publication
    Optical Counterparts of Ultraluminous X-Ray Sources
    We present the optical identification and characterization of counterparts of four objects previously cataloged as ultraluminous X-ray (ULX) sources. The...