Improved GALEX UV Photometry for 700,000 SDSS Galaxies
The Galaxy Evolution Explorer (GALEX) satellite performed the first and only large-area UV survey, which in tandem with the Sloan Digital Sky Survey (SDSS) has facilitated modeling of the spectral energy distributions of low-redshift galaxies and the determination of various galaxy properties, in pa...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal Supplement Series |
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| Online Access: | https://doi.org/10.3847/1538-4365/ace9de |
| _version_ | 1797690736383098880 |
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| author | Chandler Osborne Samir Salim Médéric Boquien Mark Dickinson Stéphane Arnouts |
| author_facet | Chandler Osborne Samir Salim Médéric Boquien Mark Dickinson Stéphane Arnouts |
| author_sort | Chandler Osborne |
| collection | DOAJ |
| description | The Galaxy Evolution Explorer (GALEX) satellite performed the first and only large-area UV survey, which in tandem with the Sloan Digital Sky Survey (SDSS) has facilitated modeling of the spectral energy distributions of low-redshift galaxies and the determination of various galaxy properties, in particular the star formation rate. However, the relatively crude angular resolution of GALEX (5″) made its images susceptible to blending of sources, resulting in potentially biased far-UV and near-UV (NUV) pipeline photometry. To remedy this issue and take advantage of model-fit photometry, we use the EMphot software to obtain forced GALEX photometry for ∼700,000 SDSS galaxies at z < 0.3. Positional priors of target galaxies and potentially contaminating neighbors were taken from SDSS. New photometry is based on the best-fitting of three model profiles: optical-like, exponential, and flat. New photometry mitigates blending present in the original pipeline catalogs, which affected 16% of galaxies at a level of >0.2 mag and 2% at a level of >1 mag. Pipeline NUV magnitudes are severely affected (≳1 mag) when the neighbor is brighter than the target galaxy and within 10″, or when the neighbor is fainter and within ∼3″ of the target. New photometry fixes edge-of-detector bias, which affected pipeline photometry by up to 0.1 mag in NUV. We present catalogs with new photometry for GALEX observations of different depths, corresponding to the all-sky imaging survey (AIS), medium imaging survey, and deep imaging survey. Catalogs feature combined magnitudes for multiple detections of the same galaxy in a survey. |
| first_indexed | 2024-03-12T02:03:25Z |
| format | Article |
| id | doaj.art-9b8dabb407b54f448b61553cfad6ee2a |
| institution | Directory Open Access Journal |
| issn | 0067-0049 |
| language | English |
| last_indexed | 2024-03-12T02:03:25Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal Supplement Series |
| spelling | doaj.art-9b8dabb407b54f448b61553cfad6ee2a2023-09-07T08:58:55ZengIOP PublishingThe Astrophysical Journal Supplement Series0067-00492023-01-0126812610.3847/1538-4365/ace9deImproved GALEX UV Photometry for 700,000 SDSS GalaxiesChandler Osborne0Samir Salim1https://orcid.org/0000-0003-2342-7501Médéric Boquien2https://orcid.org/0000-0003-0946-6176Mark Dickinson3https://orcid.org/0000-0001-5414-5131Stéphane Arnouts4Department of Astronomy, Indiana University , Bloomington, IN, 47408, USADepartment of Astronomy, Indiana University , Bloomington, IN, 47408, USAInstituto de Alta Investigación, Universidad de Tarapacá, Casilla 7D, Arica, ChileNSF's National Optical-Infrared Astronomy Research Laboratory , 950 N. Cherry Ave., Tucson, AZ 85719, USAAix Marseille University , CNRS, CNES, LAM, Marseille, FranceThe Galaxy Evolution Explorer (GALEX) satellite performed the first and only large-area UV survey, which in tandem with the Sloan Digital Sky Survey (SDSS) has facilitated modeling of the spectral energy distributions of low-redshift galaxies and the determination of various galaxy properties, in particular the star formation rate. However, the relatively crude angular resolution of GALEX (5″) made its images susceptible to blending of sources, resulting in potentially biased far-UV and near-UV (NUV) pipeline photometry. To remedy this issue and take advantage of model-fit photometry, we use the EMphot software to obtain forced GALEX photometry for ∼700,000 SDSS galaxies at z < 0.3. Positional priors of target galaxies and potentially contaminating neighbors were taken from SDSS. New photometry is based on the best-fitting of three model profiles: optical-like, exponential, and flat. New photometry mitigates blending present in the original pipeline catalogs, which affected 16% of galaxies at a level of >0.2 mag and 2% at a level of >1 mag. Pipeline NUV magnitudes are severely affected (≳1 mag) when the neighbor is brighter than the target galaxy and within 10″, or when the neighbor is fainter and within ∼3″ of the target. New photometry fixes edge-of-detector bias, which affected pipeline photometry by up to 0.1 mag in NUV. We present catalogs with new photometry for GALEX observations of different depths, corresponding to the all-sky imaging survey (AIS), medium imaging survey, and deep imaging survey. Catalogs feature combined magnitudes for multiple detections of the same galaxy in a survey.https://doi.org/10.3847/1538-4365/ace9deGalaxiesGalactic and extragalactic astronomyGalaxy photometryCatalogsSky surveysPhotometry |
| spellingShingle | Chandler Osborne Samir Salim Médéric Boquien Mark Dickinson Stéphane Arnouts Improved GALEX UV Photometry for 700,000 SDSS Galaxies The Astrophysical Journal Supplement Series Galaxies Galactic and extragalactic astronomy Galaxy photometry Catalogs Sky surveys Photometry |
| title | Improved GALEX UV Photometry for 700,000 SDSS Galaxies |
| title_full | Improved GALEX UV Photometry for 700,000 SDSS Galaxies |
| title_fullStr | Improved GALEX UV Photometry for 700,000 SDSS Galaxies |
| title_full_unstemmed | Improved GALEX UV Photometry for 700,000 SDSS Galaxies |
| title_short | Improved GALEX UV Photometry for 700,000 SDSS Galaxies |
| title_sort | improved galex uv photometry for 700 000 sdss galaxies |
| topic | Galaxies Galactic and extragalactic astronomy Galaxy photometry Catalogs Sky surveys Photometry |
| url | https://doi.org/10.3847/1538-4365/ace9de |
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