Assessment of SDSS-derived Galaxy Morphologies Using HST Imaging
The Sloan Digital Sky Survey (SDSS) was foundational to the study of galaxy evolution, having revealed the bimodality of galaxies and the relationship between their structure and star-forming activity. However, ground-based optical surveys like SDSS are limited in resolution and depth, which may lea...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/ad320f |
| _version_ | 1797202812114829312 |
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| author | Chandler Osborne Samir Salim |
| author_facet | Chandler Osborne Samir Salim |
| author_sort | Chandler Osborne |
| collection | DOAJ |
| description | The Sloan Digital Sky Survey (SDSS) was foundational to the study of galaxy evolution, having revealed the bimodality of galaxies and the relationship between their structure and star-forming activity. However, ground-based optical surveys like SDSS are limited in resolution and depth, which may lead to biases or poor quality in the derived morphological properties, potentially impacting our understanding of how and why galaxies cease their star formation (quench). We use archival Hubble Space Telescope (HST) imaging of ∼2000 SDSS objects to assess the reliability of SDSS-derived morphologies, taking advantage of both SDSS statistical samples and HST’s superior resolution and sensitivity. Single Sérsic fitting and bulge-disk decomposition is performed on HST images for direct comparison with SDSS results. Of the three catalogs of SDSS-derived morphologies considered, none is significantly more accurate or precise than the others. For disk-dominated galaxies ( n < 2.5), global Sérsic indices ( n ) from Meert et al. (hereafter, M15) are preferred. For bulge-dominated galaxies ( n > 2.5), Simard et al. (hereafter, S11) and M15 overestimate n by ∼20%, and derived global n from Blanton et al. are preferred. We provide an empirical relation to correct S11 global Sérsic indices. Global R _eff from S11 overestimates R _eff for the largest galaxies by 0.1 dex. Despite these moderate biases, SDSS-derived single-component parameters are generally significantly more robust than SDSS-derived two-component parameters. The bulge Sérsic index ( n _bulge ) cannot be reliably constrained from SDSS imaging at all, whereas the bulge-to-total ( B / T ) ratio can be inferred from SDSS (provided that n _bulge = 4 is enforced) but has a large random error of ∼0.2. |
| first_indexed | 2024-04-24T08:09:23Z |
| format | Article |
| id | doaj.art-62273f495101414ca31c97a45359d658 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-04-24T08:09:23Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-62273f495101414ca31c97a45359d6582024-04-17T08:21:20ZengIOP PublishingThe Astrophysical Journal1538-43572024-01-01965216110.3847/1538-4357/ad320fAssessment of SDSS-derived Galaxy Morphologies Using HST ImagingChandler Osborne0Samir Salim1https://orcid.org/0000-0003-2342-7501Department of Astronomy, Indiana University , Bloomington, IN 47408, USADepartment of Astronomy, Indiana University , Bloomington, IN 47408, USAThe Sloan Digital Sky Survey (SDSS) was foundational to the study of galaxy evolution, having revealed the bimodality of galaxies and the relationship between their structure and star-forming activity. However, ground-based optical surveys like SDSS are limited in resolution and depth, which may lead to biases or poor quality in the derived morphological properties, potentially impacting our understanding of how and why galaxies cease their star formation (quench). We use archival Hubble Space Telescope (HST) imaging of ∼2000 SDSS objects to assess the reliability of SDSS-derived morphologies, taking advantage of both SDSS statistical samples and HST’s superior resolution and sensitivity. Single Sérsic fitting and bulge-disk decomposition is performed on HST images for direct comparison with SDSS results. Of the three catalogs of SDSS-derived morphologies considered, none is significantly more accurate or precise than the others. For disk-dominated galaxies ( n < 2.5), global Sérsic indices ( n ) from Meert et al. (hereafter, M15) are preferred. For bulge-dominated galaxies ( n > 2.5), Simard et al. (hereafter, S11) and M15 overestimate n by ∼20%, and derived global n from Blanton et al. are preferred. We provide an empirical relation to correct S11 global Sérsic indices. Global R _eff from S11 overestimates R _eff for the largest galaxies by 0.1 dex. Despite these moderate biases, SDSS-derived single-component parameters are generally significantly more robust than SDSS-derived two-component parameters. The bulge Sérsic index ( n _bulge ) cannot be reliably constrained from SDSS imaging at all, whereas the bulge-to-total ( B / T ) ratio can be inferred from SDSS (provided that n _bulge = 4 is enforced) but has a large random error of ∼0.2.https://doi.org/10.3847/1538-4357/ad320fGalaxiesGalaxy bulgesGalaxy structureGalaxy quenchingGalaxy evolutionDisk galaxies |
| spellingShingle | Chandler Osborne Samir Salim Assessment of SDSS-derived Galaxy Morphologies Using HST Imaging The Astrophysical Journal Galaxies Galaxy bulges Galaxy structure Galaxy quenching Galaxy evolution Disk galaxies |
| title | Assessment of SDSS-derived Galaxy Morphologies Using HST Imaging |
| title_full | Assessment of SDSS-derived Galaxy Morphologies Using HST Imaging |
| title_fullStr | Assessment of SDSS-derived Galaxy Morphologies Using HST Imaging |
| title_full_unstemmed | Assessment of SDSS-derived Galaxy Morphologies Using HST Imaging |
| title_short | Assessment of SDSS-derived Galaxy Morphologies Using HST Imaging |
| title_sort | assessment of sdss derived galaxy morphologies using hst imaging |
| topic | Galaxies Galaxy bulges Galaxy structure Galaxy quenching Galaxy evolution Disk galaxies |
| url | https://doi.org/10.3847/1538-4357/ad320f |
| work_keys_str_mv | AT chandlerosborne assessmentofsdssderivedgalaxymorphologiesusinghstimaging AT samirsalim assessmentofsdssderivedgalaxymorphologiesusinghstimaging |