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| Main Authors: | , , , |
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| Format: | Preprint |
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2025
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/2506.13108 |
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| _version_ | 1866915348142358528 |
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| author | Yi, Jinwon Rey, Soo-Chang Kim, Suk Lee, Youngdae |
| author_facet | Yi, Jinwon Rey, Soo-Chang Kim, Suk Lee, Youngdae |
| contents | We present a structural analysis of 138 compact elliptical galaxies (cEs) in the redshift range of $z < 0.05$ using the Sloan Digital Sky Survey (SDSS) DR12 data. We perform single- and double-component Sérsic model fitting to their SDSS $r$-band surface brightness profiles. By dividing cEs into those with [cE(w)] and without [cE(w/o)] a bright host galaxy, we find a significant structural dichotomy: the majority ($\sim$85\%) of cE(w)s exhibit single-component profiles, while a similar proportion ($\sim$85\%) of isolated cE(w/o)s display double-component profiles, characterized by a compact, inner component and a diffuse, disk-like outer component. These results suggest that host-associated cE(w)s primarily form through the tidal stripping of larger progenitors, resulting in a compact bulge-like core. In contrast, isolated cE(w/o)s appear to form intrinsically at early epochs, likely through gas-rich mergers, and retain disk-like outer structures. The Sérsic index distribution of cE(w)s with single-component structure indicates progenitor types ranging from pseudo-bulge to classical bulge, supported by differences in stellar populations. A small fraction of cEs, including double-component cE(w)s and single-component cE(w/o)s, suggests complex evolutionary channels involving environmental capture or ejection. Our results emphasize that the structural characteristics of cEs, specifically the presence or absence of an extended outer envelope, serve as a crucial diagnostic tool to distinguish tidally stripped remnants from intrinsically formed low-mass cEs in isolation. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2506_13108 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Formation Pathways of Compact Elliptical Galaxies: Perspective of Internal Structures Yi, Jinwon Rey, Soo-Chang Kim, Suk Lee, Youngdae Astrophysics of Galaxies We present a structural analysis of 138 compact elliptical galaxies (cEs) in the redshift range of $z < 0.05$ using the Sloan Digital Sky Survey (SDSS) DR12 data. We perform single- and double-component Sérsic model fitting to their SDSS $r$-band surface brightness profiles. By dividing cEs into those with [cE(w)] and without [cE(w/o)] a bright host galaxy, we find a significant structural dichotomy: the majority ($\sim$85\%) of cE(w)s exhibit single-component profiles, while a similar proportion ($\sim$85\%) of isolated cE(w/o)s display double-component profiles, characterized by a compact, inner component and a diffuse, disk-like outer component. These results suggest that host-associated cE(w)s primarily form through the tidal stripping of larger progenitors, resulting in a compact bulge-like core. In contrast, isolated cE(w/o)s appear to form intrinsically at early epochs, likely through gas-rich mergers, and retain disk-like outer structures. The Sérsic index distribution of cE(w)s with single-component structure indicates progenitor types ranging from pseudo-bulge to classical bulge, supported by differences in stellar populations. A small fraction of cEs, including double-component cE(w)s and single-component cE(w/o)s, suggests complex evolutionary channels involving environmental capture or ejection. Our results emphasize that the structural characteristics of cEs, specifically the presence or absence of an extended outer envelope, serve as a crucial diagnostic tool to distinguish tidally stripped remnants from intrinsically formed low-mass cEs in isolation. |
| title | Formation Pathways of Compact Elliptical Galaxies: Perspective of Internal Structures |
| topic | Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2506.13108 |