Zobrazeno 1 - 10
of 60
pro vyhledávání: '"Peterson, Ruth C."'
Autor:
Peterson, Ruth C., Kurucz, Robert L.
The spectrum of neutral iron is critical to astrophysics, yet furnace laboratory experiments cannot reach many high-lying Fe I levels. Instead, Peterson & Kurucz (2015) and Peterson, Kurucz & Ayres (2017) turned to UV and optical spectra of warm star
Externí odkaz:
http://arxiv.org/abs/2112.14742
Autor:
Peterson, Ruth C.
Cowan et al. (2021) review how roughly half the elements heavier than iron found in the Sun are produced by rapid neutron capture and half by slow neutron capture, the r- and s-processes. In the Sun, their relative contribution to individual elementa
Externí odkaz:
http://arxiv.org/abs/2105.09456
Autor:
Peterson, Ruth C., Kurucz, Robert L.
The spectrum of the Fe I atom is critical to many areas of astrophysics and beyond. Measurements of the energies of its high-lying levels remain woefully incomplete, however, despite extensive analysis of ultraviolet laboratory iron absorption spectr
Externí odkaz:
http://arxiv.org/abs/1406.0933
Autor:
Peterson, Ruth C.
The ratios of elemental abundances observed in metal-poor stars of the Galactic halo provide a unique present-day record of the nucleosynthesis products of its earliest stars. While the heaviest elements were synthesized by the r- and s-processes, do
Externí odkaz:
http://arxiv.org/abs/1304.1050
Autor:
Peterson, Ruth C.
Publikováno v:
Astrophysical Journal (2011, 742, 21)
We report determinations of the molybdenum abundances in five mildly to extremely metal-poor turnoff stars using five Mo II lines near 2000A. In two of the stars, the abundance of molybdenum is found to be extremely enhanced, as high or higher than t
Externí odkaz:
http://arxiv.org/abs/1108.3542
Autor:
Sneden, Christopher, Kraft, Robert P., Guhathakurta, Puragra, Peterson, Ruth C., Fulbright, Jon P.
Publikováno v:
Astron.J.127:2162-2184,2004
We report new chemical abundances of 23 bright red giants of the globular cluster M3, based on high-resolution spectra obtained with the Keck I telescope. Combining these data with a previously-reported small sample of M3 giants obtained with the Lic
Externí odkaz:
http://arxiv.org/abs/astro-ph/0311510
Autor:
Terndrup, Donald M., An, Deokkeun, Hansen, Angela, Peterson, Ruth C., Walker, Alistair R., Sadler, Elaine M.
Publikováno v:
Astrophys.Space Sci.291:247-252,2004
We present a progress report on an extensive survey to find and characterize all types of blue horizontal-branch stars in the nuclear bulge of the Galaxy. We have obtained wide, shallow imaging in UBV of ~12 square degrees in the bulge, with follow-u
Externí odkaz:
http://arxiv.org/abs/astro-ph/0309700
Autor:
Peterson, Ruth C., Carney, Bruce W., Dorman, Ben, Green, Elizabeth M., Landsman, Wayne, Liebert, James, O'Connell, Robert W., Rood, Robert T.
Publikováno v:
Astrophys.J. 588 (2003) 299-310
Twenty years ago, Burstein et al. (1984)suggested that strong CN and Hbeta absorption meant younger ages among globular clusters in the Andromeda galaxy (M31), unless blue stars above the main-sequence turnoff or on the horizontal branch were uncommo
Externí odkaz:
http://arxiv.org/abs/astro-ph/0301412
Determining the properties of old stellar systems using evolutionary population synthesis requires a library of reliable model stellar fluxes. Empirical libraries are limited to spectra of stars in the solar neighborhood, with nearly solar abundances
Externí odkaz:
http://arxiv.org/abs/astro-ph/0009208
We have obtained echelle spectra with the Hubble Space Telescope (HST) of the MgII 2800A region of ten stars whose metallicities range from 1/300 to 1/3 that of the Sun, and whose space velocities suggest a halo or old thick-disk origin. Spectra of a
Externí odkaz:
http://arxiv.org/abs/astro-ph/0005367