Zobrazeno 1 - 10
of 382
pro vyhledávání: '"Freeman, Kenneth"'
Autor:
Carr, Anthony, Davis, Tamara M., Camilleri, Ryan, Lidman, Chris, Freeman, Kenneth C., Scolnic, Dan
We present high-resolution observations of nearby ($z\lesssim 0.1$) galaxies that have hosted Type Ia supernovae to measure systemic spectroscopic redshifts using the Wide Field Spectrograph (WiFeS) instrument on the Australian National University 2.
Externí odkaz:
http://arxiv.org/abs/2402.13484
Autor:
Bhattacharya, Souradeep, Arnaboldi, Magda, Gerhard, Ortwin, Caldwell, Nelson, Kobayashi, Chiaki, Hammer, Francois, Yang, Yanbin, Freeman, Kenneth C., Hartke, Johanna, McConnachie, Alan
Publikováno v:
Proceedings of the International Astronomical Union , Volume 18 , Symposium S377: Early Disk-Galaxy Formation from JWST to the Milky Way , December 2022 , pp. 123 - 126
The Andromeda galaxy (M 31) has experienced a tumultuous merger history as evidenced by the many substructures present in its inner halo. We use planetary nebulae (PNe) as chemodynamic tracers to shed light on the recent merger history of M 31. We id
Externí odkaz:
http://arxiv.org/abs/2305.02761
Autor:
Bhattacharya, Souradeep, Arnaboldi, Magda, Hammer, Francois, Yang, Yanbin, Gerhard, Ortwin, Caldwell, Nelson, Freeman, Kenneth C.
M31 has experienced a recent tumultuous merger history as evidenced from the many substructures that are still present in its inner halo, particularly the G1-Clump, NE- and W- shelves, and the Giant Stream (GS). We present planetary nebulae (PNe) lin
Externí odkaz:
http://arxiv.org/abs/2304.14151
Autor:
Arnaboldi, Magda, Bhattacharya, Souradeep, Gerhard, Ortwin, Kobayashi, Chiaki, Freeman, Kenneth C., Caldwell, Nelson, Hartke, Johanna, McConnachie, Alan, Guhathakurta, Puragra
Publikováno v:
A&A 666, A109 (2022)
We use oxygen and argon abundances for planetary nebulae (PNe) with low internal extinction (progenitor ages of (>4.5 Gyr) and high extinction (progenitor ages <2.5 Gyr), as well as those of the H II regions, to constrain the chemical enrichment and
Externí odkaz:
http://arxiv.org/abs/2208.02328
Autor:
Bhattacharya, Souradeep, Arnaboldi, Magda, Caldwell, Nelson, Gerhard, Ortwin, Kobayashi, Chiaki, Hartke, Johanna, Freeman, Kenneth C., McConnachie, Alan W., Guhathakurta, Puragra
We obtain a magnitude-limited sample of Andromeda (M 31) disc PNe with chemical abundance estimated through the direct detection of the [OIII] 4363 $\mathring{\mathrm A}$ line. This leads to $205$ and $200$ PNe with oxygen and argon abundances respec
Externí odkaz:
http://arxiv.org/abs/2203.06428
Autor:
Lucey, Madeline, Hawkins, Keith, Ness, Melissa, Nelson, Tyler, Debattista, Victor P., Luna, Alice, Bensby, Thomas, Freeman, Kenneth C., Kobayashi, Chiaki
The characteristics of the stellar populations in the Galactic Bulge inform and constrain the Milky Way's formation and evolution. The metal-poor population is particularly important in light of cosmological simulations, which predict that some of th
Externí odkaz:
http://arxiv.org/abs/2107.02793
Autor:
Bhattacharya, Souradeep, Arnaboldi, Magda, Gerhard, Ortwin, McConnachie, Alan, Caldwell, Nelson, Hartke, Johanna, Freeman, Kenneth C.
Publikováno v:
A&A 647, A130 (2021)
The Andromeda (M31) galaxy displays several substructures in its inner halo whose origin as remnants of accreted satellites or perturbations of the pre-existing disc are encoded in the properties of their stellar populations (SPs), leaving traces on
Externí odkaz:
http://arxiv.org/abs/2101.11860
Autor:
Zwitter, Tomaž, Kos, Janez, Buder, Sven, Čotar, Klemen, Asplund, Martin, Bland-Hawthorn, Joss, Casey, Andrew R., De Silva, Gayandhi M., D'Orazi, Valentina, Freeman, Kenneth C., Hayden, Michael R., Lewis, Geraint F., Lin, Jane, Lind, Karin, Martell, Sarah L., Schlesinger, Katharine J., Sharma, Sanjib, Simpson, Jeffrey D., Stello, Dennis, Zucker, Daniel B., Beeson, Kevin L., de Grijs, Richard, Nordlander, Thomas, Ting, Yuan-Sen, Traven, Gregor, Vogrinčič, Rok, Watson, Fred, Wittenmyer, Rob
Publikováno v:
2021, MNRAS, 508, 4202-4215
GALAH+ is a magnitude-limited survey of high resolution stellar spectra obtained by the HERMES spectrograph at the Australian Astronomical Observatory. Its third data release provides reduced spectra with new derivations of stellar parameters and abu
Externí odkaz:
http://arxiv.org/abs/2012.12201
Autor:
Simion, Iulia T., Shen, Juntai, Koposov, Sergey E., Ness, Melissa, Freeman, Kenneth, Bland-Hawthorn, Jonathan, Lewis, Geraint F.
Until the recent advent of $Gaia$ Data Release 2 (DR2) and deep multi-object spectroscopy, it has been difficult to obtain 6-D phase space information for large numbers of stars beyond 4 kpc, in particular towards the Galactic centre, where dust and
Externí odkaz:
http://arxiv.org/abs/2011.13905
Autor:
Lucey, Madeline, Hawkins, Keith, Ness, Melissa, Debattista, Victor P., Luna, Alice, Asplund, Martin, Bensby, Thomas, Casagrande, Luca, Feltzing, Sofia, Freeman, Kenneth C., Kobayashi, Chiaki, Marino, Anna F.
The metal-poor stars in the bulge are important relics of the Milky Way's formation history, as simulations predict that they are some of the oldest stars in the Galaxy. In order to determine if they are truly ancient stars, we must understand the or
Externí odkaz:
http://arxiv.org/abs/2009.03886