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Title: The Morphology and Structure of Stellar Populations in the Fornax Dwarf Spheroidal Galaxy from Dark Energy Survey Data

Abstract

Using deep wide-field photometry 3 yr data (Y3) from the Dark Energy Survey (DES), we introduce a panoramic study of the Fornax dwarf spheroidal galaxy. The data discussed here—a small subset of the full survey—uniformly cover a region of 25 deg 2 centered on the galaxy to a depth of g ~ 23.5. We use these data to study the structural properties of Fornax, overall stellar population, and its member stars in different evolutionary phases. We also search for possible signs of tidal disturbance. Fornax is found to be significantly more spatially extended than what early studies suggested. No statistically significant distortions or signs of tidal disturbances were found down to a surface brightness limit of ~32.1 mag arcsec -2. Yet, there are hints of shell-like features located ~20'–40' from the center of Fornax that may be stellar debris from past merger events. We also find that intermediate-age and young main-sequence populations show different orientation at the galaxy center and have many substructures. The deep DES Y3 data allow us to characterize the age of those young stellar substructures with great accuracy, both those previously known and those newly identified as possible overdensities in this work, on the basis ofmore » their color–magnitude diagram morphology. We find that the youngest overdensities are all found on the eastern side of Fornax, where the Fornax field population itself is slightly younger than in the west. In summary, the high-quality DES Y3 data reveal that Fornax has many rich structures and provide insights into its complex formation history.« less

Authors:
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Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Org.:
DES Collaboration
OSTI Identifier:
1562457
Grant/Contract Number:  
AC02-76SF00515
Resource Type:
Accepted Manuscript
Journal Name:
The Astrophysical Journal (Online)
Additional Journal Information:
Journal Name: The Astrophysical Journal (Online); Journal Volume: 881; Journal Issue: 2; Journal ID: ISSN 1538-4357
Publisher:
Institute of Physics (IOP)
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; galaxies: dwarf; galaxies: individual (Fornax); Local Group

Citation Formats

Wang, M. Y., de Boer, T., Pieres, A., Li, T. S., Drlica-Wagner, A., Koposov, S. E., Vivas, A. K., Pace, A. B., Santiago, B., Walker, A. R., Tucker, D. L., Strigari, L., Marshall, J. L., Yanny, B., DePoy, D. L., Bechtol, K., Roodman, A., Abbott, T. M. C., Abdalla, F. B., Allam, S., Annis, J., Avila, S., Bertin, E., Brooks, D., Burke, D. L., Rosell, A. Carnero, Carrasco Kind, M., Cunha, C. E., D’Andrea, C. B., da Costa, L. N., De Vicente, J., Desai, S., Eifler, T. F., Estrada, J., Flaugher, B., Frieman, J., García-Bellido, J., Gerdes, D. W., Gruen, D., Gruendl, R. A., Gutierrez, G., Hollowood, D. L., Honscheid, K., James, D. J., Kuehn, K., Kuropatkin, N., Lahav, O., Maia, M. A. G., Miquel, R., Sanchez, E., Scarpine, V., Sevilla-Noarbe, I., Smith, M., Smith, R. C., Sobreira, F., Suchyta, E., Swanson, M. E. C., and Tarle, G. The Morphology and Structure of Stellar Populations in the Fornax Dwarf Spheroidal Galaxy from Dark Energy Survey Data. United States: N. p., 2019. Web. doi:10.3847/1538-4357/ab31a9.
Wang, M. Y., de Boer, T., Pieres, A., Li, T. S., Drlica-Wagner, A., Koposov, S. E., Vivas, A. K., Pace, A. B., Santiago, B., Walker, A. R., Tucker, D. L., Strigari, L., Marshall, J. L., Yanny, B., DePoy, D. L., Bechtol, K., Roodman, A., Abbott, T. M. C., Abdalla, F. B., Allam, S., Annis, J., Avila, S., Bertin, E., Brooks, D., Burke, D. L., Rosell, A. Carnero, Carrasco Kind, M., Cunha, C. E., D’Andrea, C. B., da Costa, L. N., De Vicente, J., Desai, S., Eifler, T. F., Estrada, J., Flaugher, B., Frieman, J., García-Bellido, J., Gerdes, D. W., Gruen, D., Gruendl, R. A., Gutierrez, G., Hollowood, D. L., Honscheid, K., James, D. J., Kuehn, K., Kuropatkin, N., Lahav, O., Maia, M. A. G., Miquel, R., Sanchez, E., Scarpine, V., Sevilla-Noarbe, I., Smith, M., Smith, R. C., Sobreira, F., Suchyta, E., Swanson, M. E. C., & Tarle, G. The Morphology and Structure of Stellar Populations in the Fornax Dwarf Spheroidal Galaxy from Dark Energy Survey Data. United States. doi:10.3847/1538-4357/ab31a9.
Wang, M. Y., de Boer, T., Pieres, A., Li, T. S., Drlica-Wagner, A., Koposov, S. E., Vivas, A. K., Pace, A. B., Santiago, B., Walker, A. R., Tucker, D. L., Strigari, L., Marshall, J. L., Yanny, B., DePoy, D. L., Bechtol, K., Roodman, A., Abbott, T. M. C., Abdalla, F. B., Allam, S., Annis, J., Avila, S., Bertin, E., Brooks, D., Burke, D. L., Rosell, A. Carnero, Carrasco Kind, M., Cunha, C. E., D’Andrea, C. B., da Costa, L. N., De Vicente, J., Desai, S., Eifler, T. F., Estrada, J., Flaugher, B., Frieman, J., García-Bellido, J., Gerdes, D. W., Gruen, D., Gruendl, R. A., Gutierrez, G., Hollowood, D. L., Honscheid, K., James, D. J., Kuehn, K., Kuropatkin, N., Lahav, O., Maia, M. A. G., Miquel, R., Sanchez, E., Scarpine, V., Sevilla-Noarbe, I., Smith, M., Smith, R. C., Sobreira, F., Suchyta, E., Swanson, M. E. C., and Tarle, G. Wed . "The Morphology and Structure of Stellar Populations in the Fornax Dwarf Spheroidal Galaxy from Dark Energy Survey Data". United States. doi:10.3847/1538-4357/ab31a9.
@article{osti_1562457,
title = {The Morphology and Structure of Stellar Populations in the Fornax Dwarf Spheroidal Galaxy from Dark Energy Survey Data},
author = {Wang, M. Y. and de Boer, T. and Pieres, A. and Li, T. S. and Drlica-Wagner, A. and Koposov, S. E. and Vivas, A. K. and Pace, A. B. and Santiago, B. and Walker, A. R. and Tucker, D. L. and Strigari, L. and Marshall, J. L. and Yanny, B. and DePoy, D. L. and Bechtol, K. and Roodman, A. and Abbott, T. M. C. and Abdalla, F. B. and Allam, S. and Annis, J. and Avila, S. and Bertin, E. and Brooks, D. and Burke, D. L. and Rosell, A. Carnero and Carrasco Kind, M. and Cunha, C. E. and D’Andrea, C. B. and da Costa, L. N. and De Vicente, J. and Desai, S. and Eifler, T. F. and Estrada, J. and Flaugher, B. and Frieman, J. and García-Bellido, J. and Gerdes, D. W. and Gruen, D. and Gruendl, R. A. and Gutierrez, G. and Hollowood, D. L. and Honscheid, K. and James, D. J. and Kuehn, K. and Kuropatkin, N. and Lahav, O. and Maia, M. A. G. and Miquel, R. and Sanchez, E. and Scarpine, V. and Sevilla-Noarbe, I. and Smith, M. and Smith, R. C. and Sobreira, F. and Suchyta, E. and Swanson, M. E. C. and Tarle, G.},
abstractNote = {Using deep wide-field photometry 3 yr data (Y3) from the Dark Energy Survey (DES), we introduce a panoramic study of the Fornax dwarf spheroidal galaxy. The data discussed here—a small subset of the full survey—uniformly cover a region of 25 deg2 centered on the galaxy to a depth of g ~ 23.5. We use these data to study the structural properties of Fornax, overall stellar population, and its member stars in different evolutionary phases. We also search for possible signs of tidal disturbance. Fornax is found to be significantly more spatially extended than what early studies suggested. No statistically significant distortions or signs of tidal disturbances were found down to a surface brightness limit of ~32.1 mag arcsec-2. Yet, there are hints of shell-like features located ~20'–40' from the center of Fornax that may be stellar debris from past merger events. We also find that intermediate-age and young main-sequence populations show different orientation at the galaxy center and have many substructures. The deep DES Y3 data allow us to characterize the age of those young stellar substructures with great accuracy, both those previously known and those newly identified as possible overdensities in this work, on the basis of their color–magnitude diagram morphology. We find that the youngest overdensities are all found on the eastern side of Fornax, where the Fornax field population itself is slightly younger than in the west. In summary, the high-quality DES Y3 data reveal that Fornax has many rich structures and provide insights into its complex formation history.},
doi = {10.3847/1538-4357/ab31a9},
journal = {The Astrophysical Journal (Online)},
number = 2,
volume = 881,
place = {United States},
year = {2019},
month = {8}
}

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