Zobrazeno 1 - 10
of 150
pro vyhledávání: '"Jacobson, Heather"'
Autor:
Mardini, Mohammad K., Frebel, Anna, Betre, Leyatt, Jacobson, Heather, Norris, John E., Christlieb, Norbert
Based on high-resolution spectra obtained with Magellan/MIKE, we present a chemo-dynamical analysis for 27 near main-sequence turnoff metal-poor stars, including 20 stars analyzed for the first time. The sample spans a range in [Fe/H] from -2.5 to -3
Externí odkaz:
http://arxiv.org/abs/2305.05363
Autor:
Jacobson, Heather
Publikováno v:
In Reproductive Biomedicine & Society Online March 2022 14:144-155
Akademický článek
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Neutron-capture elements, those with Z > 35, are the least well-understood in terms of nucleosynthesis and formation environments. The rapid neutron-capture, or r-process, elements are formed in the environments and/or remnants of massive stars, whil
Externí odkaz:
http://arxiv.org/abs/1604.05735
Autor:
Placco, Vinicius M., Frebel, Anna, Lee, Young Sun, Jacobson, Heather R., Beers, Timothy C., Pena, Jose M., Chan, Conrad, Heger, Alexander
We report the discovery of one extremely metal-poor (EMP; [Fe/H]<-3) and one ultra metal-poor (UMP; [Fe/H]<-4) star selected from the SDSS/SEGUE survey. These stars were identified as EMP candidates based on their medium-resolution (R~2,000) spectra,
Externí odkaz:
http://arxiv.org/abs/1507.03656
Autor:
Jacobson, Heather R., Frebel, Anna
With [Fe/H] ~ -3.3, CD -24_17504 is a canonical metal-poor main sequence turn-off star. Though it has appeared in numerous literature studies, the most comprehensive abundance analysis for the star based on high resolution, high signal-to-noise spect
Externí odkaz:
http://arxiv.org/abs/1507.02304
We present a Magellan/MIKE high-resolution (R ~ 35,000) spectrum of the ancient star SD 1313-0019 which has an iron abundance of [Fe/H] = -5.0, paired with a carbon enhancement of [C/Fe] ~ 3.0. The star was initially identified by Allende Prieto et a
Externí odkaz:
http://arxiv.org/abs/1507.01973
Nucleosynthesis in a Primordial Supernova: Carbon and Oxygen Abundances in SMSS J031300.36-670839.31
Autor:
Bessell, Michael, Collett, Remo, Keller, Stefan, Frebel, Anna, Heger, Alexander, Casey, Andrew, Masseron, Thomas, Asplund, Martin, Jacobson, Heather, Lind, Karin, Marino, Anna, Norris, John, Yong, David, Da Costa, Gary, Chan, Conrad, Magic, Zazralt, Schmidt, Brian, Tisserand, Patrick
SMSS J031300.36-670839.3 (hereafter SM0313-6708) is a sub-giant halo star, with no detectable Fe lines and large overabundances of C and Mg relative to Ca. We obtained VLT-UVES spectra extending to 3060 Angstroms showing strong OH A-X band lines enab
Externí odkaz:
http://arxiv.org/abs/1505.03756
Autor:
Jacobson, Heather. R., Keller, Stefan, Frebel, Anna, Casey, Andrew R., Asplund, Martin, Bessell, Michael S., Da Costa, Gary S., Lind, Karin, Marino, Anna F., Norris, John E., Pena, Jose M., Schmidt, Brian P., Tisserand, Patrick, Walsh, Jennifer M., Yong, David, Yu, Qinsi
Publikováno v:
2015 ApJ, 807, 171
The SkyMapper Southern Sky Survey is carrying out a search for the most metal-poor stars in the Galaxy. It identifies candidates by way of its unique filter set that allows for estimation of stellar atmospheric parameters. The set includes a narrow f
Externí odkaz:
http://arxiv.org/abs/1504.03344
Autor:
Overbeek, Jamie C., Friel, Eileen D., Jacobson, Heather R., Johnson, Christian I., Pilachowski, Catherine A., Meszaros, Szabolcs
Publikováno v:
2015, AJ, 149, 15
We have obtained high-resolution spectra of 32 giants in the open cluster NGC 7789 using the Wisconsin-Indiana-Yale-NOAO Hydra spectrograph. We explore differences in atmospheric parameters and elemental abundances caused by the use of the linelist d
Externí odkaz:
http://arxiv.org/abs/1502.02596