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Your search keyword '"Koch-Hansen, A. J"' showing total 13 results
Start Over Author "Koch-Hansen, A. J" Publisher edp sciences
13 results on '"Koch-Hansen, A. J"'

2. The Halos and Environments of Nearby Galaxies (HERON) survey: IV. Complexity in the boxy galaxies NGC 720 and NGC 2768.

Author

Koch-Hansen, Andreas J., Pasquali, Anna, Michael Rich, R., Gerhard, Ortwin, and Müller, Oliver

Subjects
*ELLIPTICAL galaxies, *DWARF galaxies, *GALAXIES, *TIDAL currents, *HERONS
Abstract

The shapes of galaxies, their outer regions in particular, are important guideposts to their formation and evolution. In this work, we report on the discovery of strongly box-shaped morphologies of the otherwise well-studied elliptical and lenticular galaxies NGC 720 and NGC 2768 from deep imaging. The boxiness is strongly manifested in the parameter shape A4/a of −0.04 in both objects, and significant center shifts of the isophotes of ∼2–4 kpc are also seen. One reason for such asymmetries commonly stated in the literature is a merger origin, although the number of such cases is still sparse, and the exact properties of the individual boxy objects are highly diverse. Indeed, for NGC 2768, we identify a progenitor candidate (dubbed "Pelops") in the residual images, which appears to be a dwarf satellite that is currently merging with NGC 2768. At its absolute magnitude of Mr of −12.2 mag, the corresponding Sersic radius of 2.4 kpc is more extended than those of typical dwarf galaxies from the literature. However, systematically larger radii are known to occur in systems that are in tidal disruption. This finding is bolstered by the presence of a tentative tidal stream feature on archival GALEX data. Finally, further structures in the fascinating host galaxy include rich dust lanes and a vestigial X-shaped bulge component. [ABSTRACT FROM AUTHOR]

Published
2024
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3. TOPoS

Author

Bonifacio, P., primary, Monaco, L., additional, Salvadori, S., additional, Caffau, E., additional, Spite, M., additional, Sbordone, L., additional, Spite, F., additional, Ludwig, H.-G., additional, Di Matteo, P., additional, Haywood, M., additional, François, P., additional, Koch-Hansen, A. J., additional, Christlieb, N., additional, and Zaggia, S., additional

Published
2022
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4. Chemical Evolution of R-process Elements in Stars (CERES)

Author

Lombardo, Linda, primary, Bonifacio, Piercarlo, additional, François, Patrick, additional, Hansen, Camilla J., additional, Caffau, Elisabetta, additional, Hanke, Michael, additional, Skúladóttir, Ása, additional, Arcones, Almudena, additional, Eichler, Marius, additional, Reichert, Moritz, additional, Psaltis, Athanasios, additional, Koch Hansen, Andreas J., additional, and Sbordone, Luca, additional

Published
2022
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5. Blanco DECam Bulge Survey (BDBS)

Author

Marchetti, Tommaso, primary, Johnson, Christian I., additional, Joyce, Meridith, additional, Rich, R.Michael, additional, Simion, Iulia T., additional, Young, Michael D., additional, Clarkson, William, additional, Pilachowski, Catherine A., additional, Michael, Scott, additional, Kunder, Andrea, additional, and Koch-Hansen, Andreas J., additional

Published
2022
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6. Milky Way archaeology using RR Lyrae and type II Cepheids

Author

Prudil, Z., primary, Koch-Hansen, A. J., additional, Lemasle, B., additional, Grebel, E. K., additional, Marchetti, T., additional, Hansen, C. J., additional, Crestani, J., additional, Braga, V. F., additional, Bono, G., additional, Chaboyer, B., additional, Fabrizio, M., additional, Dall’Ora, M., additional, and Martínez-Vázquez, C. E., additional

Published
2022
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9. TOPoS

Author

Bonifacio, P., primary, Monaco, L., additional, Salvadori, S., additional, Caffau, E., additional, Spite, M., additional, Sbordone, L., additional, Spite, F., additional, Ludwig, H.-G., additional, Di Matteo, P., additional, Haywood, M., additional, François, P., additional, Koch-Hansen, A. J., additional, Christlieb, N., additional, and Zaggia, S., additional

Published
2021
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10. Milky Way archaeology using RR Lyrae and type II Cepheids

Author

Prudil, Z., primary, Hanke, M., additional, Lemasle, B., additional, Crestani, J., additional, Braga, V. F., additional, Fabrizio, M., additional, Koch-Hansen, A. J., additional, Bono, G., additional, Grebel, E. K., additional, Matsunaga, N., additional, Marengo, M., additional, da Silva, R., additional, Dall’Ora, M., additional, Martínez-Vázquez, C. E., additional, Altavilla, G., additional, Lala, H., additional, Chaboyer, B., additional, Ferraro, I., additional, Fiorentino, G., additional, Gilligan, C., additional, Nonino, M., additional, and Thévenin, F., additional

Published
2021
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11. Blanco DECam Bulge Survey (BDBS)

Author

Lim, D., primary, Koch-Hansen, A. J., additional, Chung, C., additional, Johnson, C. I., additional, Kunder, A., additional, Simion, I. T., additional, Rich, R. M., additional, Clarkson, W. I., additional, Pilachowski, C. A., additional, Michael, S., additional, Vivas, A. K., additional, and Young, M. D., additional

Published
2021
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12. Purveyors of fine halos

Author

Koch-Hansen, Andreas J., primary, Hansen, Camilla Juul, additional, Lombardo, Linda, additional, Bonifacio, Piercarlo, additional, Hanke, Michael, additional, and Caffau, Elisabetta, additional

Published
2021
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13. TOPoS: VI. The metal-weak tail of the metallicity distribution functions of the Milky Way and the Gaia-Sausage-Enceladus structure (Corrigendum).

Author

Bonifacio, P., Monaco, L., Salvadori, S., Caffau, E., Spite, M., Sbordone, L., Spite, F., Ludwig, H.-G., Di Matteo, P., Haywood, M., François, P., Koch-Hansen, A. J., Christlieb, N., and Zaggia, S.

Subjects
DISTRIBUTION (Probability theory), STELLAR populations
Abstract

Keywords: stars: Population II; stars: abundances; Galaxy: abundances; Galaxy: halo; errata, addenda EN stars: Population II stars: abundances Galaxy: abundances Galaxy: halo errata, addenda 1 1 1 10/03/22 20220929 NES 220929 We realised that there was a mistake in the code that computed parameters for the photometric data sample. Furthermore, for 301 763 stars, the interpolation arrived at the edge in metallicity of the synthetic grid (+0.5) and the program was not extrapolating. Stars: Population II, stars: abundances, Galaxy: abundances, Galaxy: halo, errata, addenda. [Extracted from the article]

Published
2022
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