Zobrazeno 1 - 10
of 1 150
pro vyhledávání: '"P. NORRIS, J."'
GRB 230307A is an extremely bright long duration GRB with an observed gamma-ray fluence of $\gtrsim$3$\times$10$^{-3}$ erg cm$^{-2}$ (10-1000 keV), second only to GRB 221009A. Despite its long duration, it is possibly associated with a kilonova, thus
Externí odkaz:
http://arxiv.org/abs/2307.02996
We investigate the distribution of the lithium abundances, A(Li), of metal-poor dwarf and subgiant stars within the limits 5500 K < Teff < 6700 K, -6.0 < [Fe/H] < -1.5, and logg > ~3.5 (a superset of parameters first adopted by Spite and Spite), usin
Externí odkaz:
http://arxiv.org/abs/2303.11497
Autor:
Troja, E., Fryer, C. L., O'Connor, B., Ryan, G., Dichiara, S., Kumar, A., Ito, N., Gupta, R., Wollaeger, R., Norris, J. P., Kawai, N., Butler, N., Aryan, A., Misra, K., Hosokawa, R., Murata, K. L., Niwano, M., Pandey, S. B., Kutyrev, A., van Eerten, H. J., Chase, E. A., Hu, Y. -D., Caballero-Garcia, M. D., Castro-Tirado, A. J.
Publikováno v:
Nature, volume 612, pages 228-231 (2022)
Gamma-ray bursts (GRBs) are flashes of high-energy radiation arising from energetic cosmic explosions. Bursts of long (>2 s) duration are produced by the core-collapse of massive stars, those of short (< 2 s) duration by the merger of two neutron sta
Externí odkaz:
http://arxiv.org/abs/2209.03363
Autor:
Salgado, C., Da Costa, G. S., Yong, D., Salinas, R., Norris, J. E., Mackey, A. D., Marino, A. F., Milone, A. P.
Using spectra obtained with the VLT/FORS2 and Gemini-S/GMOS instruments we have investigated carbon, nitrogen and sodium abundances in a sample of red giants in the Small Magellanic Cloud cluster Kron 3. The metallicity and luminosity of this cluster
Externí odkaz:
http://arxiv.org/abs/2202.00849
Autor:
Yong, D., Da Costa, G. S., Bessell, M. S., Chiti, A., Frebel, A., Gao, X., Lind, K., Mackey, A. D., Marino, A. F., Murphy, S. J., Nordlander, T., Asplund, M., Casey, A. R., Kobayashi, C., Norris, J. E., Schmidt, B. P.
We present chemical abundances for 21 elements (from Li to Eu) in 150 metal-poor Galactic stars spanning $-$4.1 $<$ [Fe/H] $<$ $-$2.1. The targets were selected from the SkyMapper survey and include 90 objects with [Fe/H] $\le$ $-$3 of which some 15
Externí odkaz:
http://arxiv.org/abs/2107.06430
Autor:
Sameer, Charlton, J. C., Norris, J. M., Gebhardt, M., Churchill, C. W., Kacprzak, G. G., Muzahid, S., Narayanan, Anand, Nielsen, N. M., Richter, Philipp, Wakker, Bart P.
We present a new method aimed at improving the efficiency of component by component ionization modeling of intervening quasar absorption line systems. We carry out cloud-by-cloud, multiphase modeling making use of CLOUDY and Bayesian methods to extra
Externí odkaz:
http://arxiv.org/abs/2012.00021
Autor:
Cordoni, G., Da Costa, G. S., Yong, D., Mackey, A. D., Marino, A. F., Monty, S., Nordlander, T., Norris, J. E., Asplund, M., Bessell, M. S., Casey, A. R., Frebel, A., Lind, K., Murphy, S. J., Schmidt, B. P., Gao, X. D., Xylakis-Dornbusch, T., Amarsi, A. M., Milone, A. P.
In this work we combine spectroscopic information from the \textit{SkyMapper survey for Extremely Metal-Poor stars} and astrometry from Gaia DR2 to investigate the kinematics of a sample of 475 stars with a metallicity range of $ -6.5 \leq \rm [Fe/H]
Externí odkaz:
http://arxiv.org/abs/2011.01189
Autor:
Cordoni, G., Milone, A. P., Marino, A. F., Da Costa, G. S., Dondoglio, E., Jerjen, H., Lagioia, E. P., Mastrobuono-Battisti, A., Norris, J. E., Tailo, M., Yong, D.
The origin of multiple stellar populations in Globular Clusters (GCs) is one of the greatest mysteries of modern stellar astrophysics. N-body simulations suggest that the present-day dynamics of GC stars can constrain the events that occurred at high
Externí odkaz:
http://arxiv.org/abs/2006.16355
Autor:
Da Costa, G. S., Bessell, M. S., Mackey, A. D., Nordlander, T., Asplund, M., Casey, A. R., Frebel, A., Lind, K., Marino, A. F., Murphy, S. J., Norris, J. E., Schmidt, B. P., Yong, D.
Publikováno v:
MNRAS, 489, 5900-5918 (2019)
We present and discuss the results of a search for extremely metal-poor stars based on photometry from data release DR1.1 of the SkyMapper imaging survey of the southern sky. In particular, we outline our photometric selection procedures and describe
Externí odkaz:
http://arxiv.org/abs/1909.06227
Autor:
Nordlander, T., Bessell, M. S., Da Costa, G. S., Mackey, A. D., Asplund, M., Casey, A. R., Chiti, A., Ezzeddine, R., Frebel, A., Lind, K., Marino, A. F., Murphy, S. J., Norris, J. E., Schmidt, B. P., Yong, D.
We report the discovery of SMSS J160540.18-144323.1, a new ultra-metal poor halo star discovered with the SkyMapper telescope. We measure [Fe/H] = -6.2 +- 0.2 (1D LTE), the lowest ever detected abundance of iron in a star. The star is strongly carbon
Externí odkaz:
http://arxiv.org/abs/1904.07471