2.5k citations · 18.7k across the 179 of their papers we have counts for
31 papers · 1 filter
Carbon Abundances of Three Carbon-Enhanced Metal-Poor Stars from High-Resolution Gemini-S/bHROS Spectra of the 8727A [C I] Line
S. C. Schuler, S. J. Margheim, T. Sivarani +4
We present the results from an analysis of the 8727ang forbidden [C I] line in high-resolution Gemini-S/bHROS spectra of three CEMP stars. We find the [C/Fe] ratios based on the [C…
Chemical abundances in giants stars of the tidally disrupted globular cluster NGC 6712 from high-resolution infrared spectroscopy
David Yong, Jorge Melendez, Katia Cunha +3
We present abundances of C, N, O, F, Na, and Fe in six giant stars of the tidally disrupted globular cluster NGC 6712. The abundances were derived by comparing synthetic spectra wi…
Fluorine Abundances in the Milky Way Bulge
K. Cunha, V. V. Smith, B. K. Gibson
Fluorine (19F) abundances are derived in a sample of 6 bulge red giants in Baade's Window. These giants span a factor of 10 in metallicity and this is the first study to define the…
Abundance Patterns in Stars in the Bulge and Galactic Center
K. Cunha, V. Smith, K. Sellgren +3
We discuss oxygen and iron abundance patterns in K and M red-giant members of the Galactic bulge and in the young and massive M-type stars inhabiting the very center of the Milky W…
Argon Abundances in the Solar Neighborhood: Non-LTE Analysis of Orion Association B-type Stars
Thierry Lanz, Katia Cunha, Jon Holtzman +1
Argon abundances have been derived for a sample of B main-sequence stars in the Orion association. The abundance calculations are based on NLTE metal line-blanketed model atmospher…
The Projected Rotational Velocity Distribution of a Sample of OB stars from a Calibration based on Synthetic He I lines
S. Daflon, K. Cunha, F. X. de Araujo +2
We derive projected rotational velocities (vsini) for a sample of 156 Galactic OB star members of 35 clusters, HII regions, and associations. The HeI lines at 4026, 4388, and 4…
Fluorine in a Carbon-Enhanced Metal-Poor Star
S. C. Schuler, K. Cunha, V. V. Smith +3
The fluorine abundance of the Carbon-Enhanced Metal-Poor (CEMP) star HE 1305+0132 has been derived by analysis of the molecular HF (1-0) R9 line at 2.3357 microns in a high-resolut…
Planetary Nebula Abundances and Morphology: Probing the Chemical Evolution of the Milky Way
L. Stanghellini, A. M. Guerrero, K. Cunha +2
This paper presents a homogeneous study of abundances in a sample of 79 northern galactic planetary nebulae whose morphological classes have been uniformly determined. Ionic abunda…
Chemical Evolution of the Galactic Bulge as Derived from High-Resolution Infrared Spectroscopy of K and M Red Giants
Katia Cunha, Verne V. Smith
We present chemical abundances in K and M red-giant members of the Galactic bulge derived from high-resolution infrared spectra obtained with the Phoenix spectrograph on Gemini-Sou…
Neon Abundances in B-Stars of the Orion Association: Solving the Solar Model Problem?
Katia Cunha, Ivan Hubeny, Thierry Lanz
We report on non-LTE Ne abundances for a sample of B-type stellar members of the Orion Association. The abundances were derived by means of non-LTE fully metal-blanketed model atmo…
A 2MASS All-Sky View of the Sagittarius Dwarf Galaxy: Variation of the Metallicity Distribution Function Along the Sagittarius Stream
Mei-Yin Chou, Steven R. Majewski, Katia Cunha +9
We present reliable measurements of the metallicity distribution function (MDF) at different points along the tidal stream of the Sagittarius (Sgr) dwarf spheroidal (dSph) galaxy,…
The Space Interferometry Mission Astrometric Grid Giant-Star Survey. I. Stellar Parameters and Radial Velocity Variability
Dmitry Bizyaev, Verne V. Smith, Jose Arenas +7
We present results from a campaign of multiple epoch echelle spectroscopy of relatively faint (V = 9.5-13.5 mag) red giants observed as potential astrometric grid stars for the Spa…
Hi-Res Spectroscopy of a Volume-Limited Hipparcos Sample within 100 parsec: Austin Bash Symposium Conference Proceeding
P. L. Lim, J. A. Holtzman, V. V. Smith +1
Accurate parallaxes from the Hipparcos catalog have enabled detailed studies of stellar properties. Subgiants are of particular interest because they lie in an area where isochrone…
Cloud Structure and Physical Conditions in Star-Forming Regions from Optical Observations. II. Analysis
K. Pan, S. R. Federman, Y. Sheffer +1
To complement the optical absorption-line survey of diffuse molecular gas in Paper I, we obtained and analyzed far ultraviolet H and CO data on lines of sight toward stars in C…
Fluorine Abundance Variations in Red Giants of the Globular Cluster M4 and Early-Cluster Chemical Pollution
V. V. Smith, K. Cunha, I. I. Ivans +2
We present fluorine abundances in seven red-giant members of the globular cluster M4 (NGC 6121). These abundances were derived from the HF (1--0) R9 line at 2.3357 microns in high-…
Abundances of Mn, Co and Eu in a sample of 20 F-G disk stars: the influence of hyperfine structure splitting
E. F. del Peloso, K. Cunha, L. da Silva +1
We present Mn, Co and Eu abundances for a sample of 20 disk F and G dwarfs and subgiants with metallicities in the range -0.8 <= [Fe/H] <= +0.3. We investigate the influence of hyp…
Hi-Res Spectroscopy of a Volume-Limited Hipparcos Sample within 100 parsec
P. L. Lim, J. A. Holtzman, V. V. Smith +1
We obtain high-resolution echelle spectra of evolved Hipparcos stars within 100 parsec for detailed abundance analysis. We are particularly interested in subgiants because their ag…
Fluorine Abundances in the Orion Nebula Cluster
Katia Cunha, Verne V. Smith
This study uses cool dwarfs as sources with which to probe fluorine abundances via HF. This molecule is detected for the first time in young K-M dwarf members of an OB association.…
Galactic Metallicity Gradients Derived from a Sample of OB Stars
Simone Daflon, Katia Cunha
The distribution of stellar abundances along the Galactic disk is an important constraint for models of chemical evolution and Galaxy formation. In this study we derive radial grad…
Cloud Structure and Physical Conditions in Star-forming Regions from Optical Observations. I. Data and Component Structure
K. Pan, S. R. Federman, K. Cunha +2
We present high-resolution optical spectra (at ~0.6--1.8 km s-1) of interstellar CN, CH, CH^+, \ion{Ca}{1}, \ion{K}{1}, and \ion{Ca}{2} absorption toward 29 lines of sight in three…
High-Resolution Infrared Spectroscopy of the Brown Dwarf Epsilon Indi Ba
Verne V. Smith, Takashi Tsuji, Kenneth H. Hinkle +6
We report on the analysis of high-resolution infrared spectra of the newly discovered brown dwarf Epsilon Indi Ba. This is the closest known brown dwarf to the solar system, with a…
Fluorine Abundances in the Large Magellanic Cloud and Omega Centauri: Evidence for Neutrino Nucleosynthesis?
K. Cunha, V. V. Smith, D. L. Lambert +1
The behavior of fluorine with metallicity has not yet been probed in any stellar population. In this work, we present the first fluorine abundances measured outside of the Milky Wa…
Non-LTE Abundances of Magnesium, Aluminum and Sulfur in OB Stars Near the Solar Circle
S. Daflon, K. Cunha, V. V. Smith +1
Non-LTE abundances of magnesium, aluminum and sulfur are derived for a sample of 23 low-v \sin i stars belonging to six northern OB associations of the Galactic disk within 1 kpc o…
Chemical Abundances in Twelve Red Giants of the Large Magellanic Cloud from High-Resolution Infrared Spectroscopy
V. V. Smith, K. H. Hinkle, K. Cunha +10
High-resolution infrared spectra (R=50,000) have been obtained for twelve red-giant members of the LMC with the Gemini South 8.3-meter telescope plus Phoenix spectrometer. Quantita…