Initial Mass Functions of Young Stellar Clusters from the Gemini Spectroscopic Survey of Nearby Galaxies. I. Young Massive Clusters in the Antennae Galaxies
The stellar initial mass function (IMF) is a key parameter to understand the star formation process and the integrated properties of stellar populations in remote galaxies. We present a spectroscopic study of young massive clusters (YMCs) in the starburst galaxies NGC 4038/9. The integrated spectra...
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2024-01-01
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| author | Jae-Rim Koo Hyun-Jeong Kim Beomdu Lim |
| author_facet | Jae-Rim Koo Hyun-Jeong Kim Beomdu Lim |
| author_sort | Jae-Rim Koo |
| collection | DOAJ |
| description | The stellar initial mass function (IMF) is a key parameter to understand the star formation process and the integrated properties of stellar populations in remote galaxies. We present a spectroscopic study of young massive clusters (YMCs) in the starburst galaxies NGC 4038/9. The integrated spectra of seven YMCs obtained with GMOS-S attached to the 8.1 m Gemini South telescope reveal the spectral features associated with stellar ages and the underlying IMFs. We constrain the ages of the YMCs using the absorption lines and strong emission bands from Wolf–Rayet stars. The internal reddening is also estimated from the strength of the Na i D absorption lines. Based on these constraints, the observed spectra are matched with the synthetic spectra generated from a simple stellar population model. Several parameters of the clusters including age, reddening, cluster mass, and the underlying IMF are derived from the spectral matching. The ages of the YMCs range from 2.5 to 6.5 Myr, and these clusters contain stellar masses ranging from 1.6 × 10 ^5 M _☉ to 7.9 × 10 ^7 M _☉ . The underlying IMFs appear to differ from the universal form of the Salpeter/Kroupa IMF. Interestingly, massive clusters tend to have the bottom-heavy IMFs, although the masses of some clusters are overestimated due to the crowding effect. Based on this, our results suggest that the universal form of the IMF is not always valid when analyzing integrated light from unresolved stellar systems. However, further study with a larger sample size is required to reach a definite conclusion. |
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| institution | Kabale University |
| issn | 1538-3881 |
| language | English |
| publishDate | 2024-01-01 |
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| spelling | doaj-art-924c5937a3194b1aadf5eba056c6c7e72024-12-05T09:36:10ZengIOP PublishingThe Astronomical Journal1538-38812024-01-011691710.3847/1538-3881/ad8e3bInitial Mass Functions of Young Stellar Clusters from the Gemini Spectroscopic Survey of Nearby Galaxies. I. Young Massive Clusters in the Antennae GalaxiesJae-Rim Koo0https://orcid.org/0000-0001-8969-0009Hyun-Jeong Kim1https://orcid.org/0000-0001-9263-3275Beomdu Lim2https://orcid.org/0000-0001-5797-9828Earth Environment Research Center, Kongju National University , 56 Gongjudaehak-ro, Gongju-si, Chungcheongnam-do 32588, Republic of Korea ; blim@kongju.ac.krEarth Environment Research Center, Kongju National University , 56 Gongjudaehak-ro, Gongju-si, Chungcheongnam-do 32588, Republic of Korea ; blim@kongju.ac.kr; Korea Astronomy and Space Science Institute , 776 Daedeok-daero, Yuseong-gu, Daejeon 34055, Republic of KoreaEarth Environment Research Center, Kongju National University , 56 Gongjudaehak-ro, Gongju-si, Chungcheongnam-do 32588, Republic of Korea ; blim@kongju.ac.kr; Korea Astronomy and Space Science Institute , 776 Daedeok-daero, Yuseong-gu, Daejeon 34055, Republic of Korea; Department of Earth Science Education, Kongju National University , 56 Gongjudaehak-ro, Gongju-si, Chungcheongnam-do 32588, Republic of KoreaThe stellar initial mass function (IMF) is a key parameter to understand the star formation process and the integrated properties of stellar populations in remote galaxies. We present a spectroscopic study of young massive clusters (YMCs) in the starburst galaxies NGC 4038/9. The integrated spectra of seven YMCs obtained with GMOS-S attached to the 8.1 m Gemini South telescope reveal the spectral features associated with stellar ages and the underlying IMFs. We constrain the ages of the YMCs using the absorption lines and strong emission bands from Wolf–Rayet stars. The internal reddening is also estimated from the strength of the Na i D absorption lines. Based on these constraints, the observed spectra are matched with the synthetic spectra generated from a simple stellar population model. Several parameters of the clusters including age, reddening, cluster mass, and the underlying IMF are derived from the spectral matching. The ages of the YMCs range from 2.5 to 6.5 Myr, and these clusters contain stellar masses ranging from 1.6 × 10 ^5 M _☉ to 7.9 × 10 ^7 M _☉ . The underlying IMFs appear to differ from the universal form of the Salpeter/Kroupa IMF. Interestingly, massive clusters tend to have the bottom-heavy IMFs, although the masses of some clusters are overestimated due to the crowding effect. Based on this, our results suggest that the universal form of the IMF is not always valid when analyzing integrated light from unresolved stellar systems. However, further study with a larger sample size is required to reach a definite conclusion.https://doi.org/10.3847/1538-3881/ad8e3bStar forming regionsStarburst galaxiesStellar mass functionsYoung massive clusters |
| spellingShingle | Jae-Rim Koo Hyun-Jeong Kim Beomdu Lim Initial Mass Functions of Young Stellar Clusters from the Gemini Spectroscopic Survey of Nearby Galaxies. I. Young Massive Clusters in the Antennae Galaxies The Astronomical Journal Star forming regions Starburst galaxies Stellar mass functions Young massive clusters |
| title | Initial Mass Functions of Young Stellar Clusters from the Gemini Spectroscopic Survey of Nearby Galaxies. I. Young Massive Clusters in the Antennae Galaxies |
| title_full | Initial Mass Functions of Young Stellar Clusters from the Gemini Spectroscopic Survey of Nearby Galaxies. I. Young Massive Clusters in the Antennae Galaxies |
| title_fullStr | Initial Mass Functions of Young Stellar Clusters from the Gemini Spectroscopic Survey of Nearby Galaxies. I. Young Massive Clusters in the Antennae Galaxies |
| title_full_unstemmed | Initial Mass Functions of Young Stellar Clusters from the Gemini Spectroscopic Survey of Nearby Galaxies. I. Young Massive Clusters in the Antennae Galaxies |
| title_short | Initial Mass Functions of Young Stellar Clusters from the Gemini Spectroscopic Survey of Nearby Galaxies. I. Young Massive Clusters in the Antennae Galaxies |
| title_sort | initial mass functions of young stellar clusters from the gemini spectroscopic survey of nearby galaxies i young massive clusters in the antennae galaxies |
| topic | Star forming regions Starburst galaxies Stellar mass functions Young massive clusters |
| url | https://doi.org/10.3847/1538-3881/ad8e3b |
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