Zobrazeno 11 - 20
of 85
pro vyhledávání: '"Holmbeck, Erika M."'
Autor:
Roederer, Ian U., Lawler, James E., Hartog, Elizabeth A. Den, Placco, Vinicius M., Surman, Rebecca, Beers, Timothy C., Ezzeddine, Rana, Frebel, Anna, Hansen, Terese T., Hattori, Kohei, Holmbeck, Erika M., Sakari, Charli M.
We present a nearly complete rapid neutron-capture process (r-process) chemical inventory of the metal-poor ([Fe/H] = -1.46 +/- 0.10) r-process-enhanced ([Eu/Fe] = +1.32 +/- 0.08) halo star HD 222925. This abundance set is the most complete for any o
Externí odkaz:
http://arxiv.org/abs/2205.03426
Binary neutron star mergers (NSMs) have been confirmed as one source of the heaviest observable elements made by the rapid neutron-capture (r-) process. However, modeling NSM outflows -- from the total ejecta masses to their elemental yields -- depen
Externí odkaz:
http://arxiv.org/abs/2110.06432
Autor:
Gudin, Dmitrii, Shank, Derek, Beers, Timothy C., Yuan, Zhen, Limberg, Guilherme, Roederer, Ian U., Placco, Vinicius, Holmbeck, Erika M., Dietz, Sarah, Rasmussen, Kaitlin C., Hansen, Terese T., Sakari, Charli M., Ezzeddine, Rana, Frebel, Anna
We derive dynamical parameters for a large sample of 446 $r$-process-enhanced (RPE) metal-poor stars in the halo and disk systems of the Milky Way, based on data releases from the $R$-Process Alliance, supplemented by additional literature samples. T
Externí odkaz:
http://arxiv.org/abs/2012.13808
Autor:
Holmbeck, Erika M., Frebel, Anna, McLaughlin, G. C., Surman, Rebecca, Fernandez, Rodrigo, Metzger, Brian D., Mumpower, Matthew R., Sprouse, Trevor M.
Neutron star mergers (NSMs) are promising astrophysical sites for the rapid neutron-capture ("$r$-") process, but can their integrated yields explain the majority of heavy-element material in the Galaxy? One method to address this question has utiliz
Externí odkaz:
http://arxiv.org/abs/2010.01621
Autor:
Roederer, Ian U., Lawler, James E., Holmbeck, Erika M., Beers, Timothy C., Ezzeddine, Rana, Frebel, Anna, Hansen, Terese T., Ivans, Inese I., Karakas, Amanda I., Placco, Vinicius M., Sakari, Charli M.
We report the first detection of the Pb II line at 2203.534 Angstroms in three metal-poor stars, using ultraviolet spectra obtained with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. We perform a standard abundance ana
Externí odkaz:
http://arxiv.org/abs/2009.14251
Autor:
Holmbeck, Erika M., Hansen, Terese T., Beers, Timothy C., Placco, Vinicius M., Whitten, Devin D., Rasmussen, Kaitlin C., Roederer, Ian U., Ezzeddine, Rana, Sakari, Charli M., Frebel, Anna, Drout, Maria R., Simon, Joshua D., Thompson, Ian B., Bland-Hawthorn, Joss, Gibson, Brad K., Grebel, Eva K., Kordopatis, Georges, Kunder, Andrea, Melendez, Jorge, Navarro, Julio F., Reid, Warren A., Seabroke, George, Steinmetz, Matthias, Watson, Fred, Wyse, Rosemary F. G.
This compilation is the fourth data release from the $R$-Process Alliance (RPA) search for $r$-process-enhanced stars, and the second release based on "snapshot" high-resolution ($R \sim 30,000$) spectra collected with the du Pont 2.5m Telescope. In
Externí odkaz:
http://arxiv.org/abs/2007.00749
Autor:
Placco, Vinicius M., Santucci, Rafael M., Yuan, Zhen, Mardini, Mohammad K., Holmbeck, Erika M., Wang, Xilu, Surman, Rebecca, Hansen, Terese T., Roederer, Ian U., Beers, Timothy C., Choplin, Arthur, Ji, Alexander P., Ezzeddine, Rana, Frebel, Anna, Sakari, Charli M., Whitten, Devin D., Zepeda, Joseph
We report on the spectroscopic analysis of RAVE J183013.5-455510, an extremely metal-poor star, highly enhanced in CNO, and with discernible contributions from the rapid neutron-capture process. There is no evidence of binarity for this object. At [F
Externí odkaz:
http://arxiv.org/abs/2006.04538
Autor:
Holmbeck, Erika M., Surman, Rebecca, Frebel, Anna, McLaughlin, G. C., Mumpower, Matthew R., Sprouse, Trevor M., Kawano, Toshihiko, Vassh, Nicole, Beers, Timothy C.
Publikováno v:
Journal of Physics: Conference Series 1668, 012020 (2020)
Of the variations in the elemental abundance patterns of stars enhanced with $r$-process elements, the variation in the relative actinide-to-lanthanide ratio is among the most significant. We investigate the source of these actinide differences in or
Externí odkaz:
http://arxiv.org/abs/2001.08792
Autor:
Holmbeck, Erika M., Frebel, Anna, McLaughlin, G. C., Mumpower, Matthew R., Sprouse, Trevor M., Surman, Rebecca
The astrophysical production site of the heaviest elements in the universe remains a mystery. Incorporating heavy element signatures of metal-poor, $r$-process enhanced stars into theoretical studies of $r$-process production can offer crucial constr
Externí odkaz:
http://arxiv.org/abs/1904.02139
Autor:
Placco, Vinicius M., Santucci, Rafael M., Beers, Timothy C., Chaname, Julio, Sepulveda, Maria Paz, Coronado, Johanna, Rossi, Silvia, Lee, Young Sun, Starkenburg, Else, Youakim, Kris, Barrientos, Manuel, Ezzeddine, Rana, Frebel, Anna, Hansen, Terese T., Holmbeck, Erika M., Ji, Alexander P., Rasmussen, Kaitlin C., Roederer, Ian U., Sakari, Charli M., Whitten, Devin D.
We present results from an observing campaign to identify low-metallicity stars in the Best & Brightest Survey. From medium-resolution (R ~ 1, 200 - 2, 000) spectroscopy of 857 candidates, we estimate the stellar atmospheric parameters (Teff, log g,
Externí odkaz:
http://arxiv.org/abs/1811.10367