April 28, 2022 Dataset Open Access

Carvalho, Nuno Ramos

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{
  "publisher": "Zenodo", 
  "DOI": "10.5281/zenodo.6501642", 
  "title": "SDSS Galaxy Subset", 
  "issued": {
    "date-parts": [
      [
        2022, 
        4, 
        28
      ]
    ]
  }, 
  "abstract": "<p>The&nbsp;<a href=\"https://www.sdss.org\">Sloan Digital Sky Survey</a>&nbsp; (SDSS) is a comprehensive survey of the northern sky. This dataset contains a subset of this survey, of 60247&nbsp;objects classified as galaxies, it includes a CSV file with a collection of information and a set of files for each object, namely JPG image files, FITS and spectra data. This dataset is used to train and explore the&nbsp;<a href=\"https://github.com/nunorc/astromlp-models\">astromlp-models</a>&nbsp;collection of deep learning models for galaxies characterisation.</p>\n\n<p>The dataset includes a CSV data file where each row is an object from the SDSS database, and with the following columns (note that some data may not be available for all objects):</p>\n\n<ul>\n\t<li><strong>objid</strong>: unique SDSS object identifier&nbsp;</li>\n\t<li><strong>mjd</strong>: MJD of observation</li>\n\t<li><strong>plate</strong>: plate identifier</li>\n\t<li><strong>tile</strong>: tile identifier</li>\n\t<li><strong>fiberid</strong>: fiber identifier</li>\n\t<li><strong>run</strong>: run number</li>\n\t<li><strong>rerun</strong>: rerun number</li>\n\t<li><strong>camcol</strong>: camera column</li>\n\t<li><strong>field</strong>: field number</li>\n\t<li><strong>ra</strong>: right ascension</li>\n\t<li><strong>dec</strong>: declination</li>\n\t<li><strong>class</strong>: spectroscopic class (only objetcs with GALAXY are included)</li>\n\t<li><strong>subclass</strong>: spectroscopic subclass</li>\n\t<li><strong>modelMag_u</strong>: better of DeV/Exp magnitude fit for band u</li>\n\t<li><strong>modelMag_g</strong>: better of DeV/Exp magnitude fit for band g</li>\n\t<li><strong>modelMag_r</strong>: better of DeV/Exp magnitude fit for band r</li>\n\t<li><strong>modelMag_i</strong>: better of DeV/Exp magnitude fit for band i</li>\n\t<li><strong>modelMag_z</strong>: better of DeV/Exp magnitude fit for band z</li>\n\t<li><strong>redshift</strong>: final redshift from SDSS data z</li>\n\t<li><strong>stellarmass</strong>: stellar mass extracted from the&nbsp;<a href=\"https://www.sdss.org/dr16/spectro/eboss-firefly-value-added-catalog\">eBOSS Firefly catalog</a></li>\n\t<li><strong>w1mag</strong>: WISE W1 &quot;standard&quot; aperture magnitude</li>\n\t<li><strong>w2mag</strong>: WISE W2 &quot;standard&quot; aperture magnitude</li>\n\t<li><strong>w3mag</strong>: WISE W3 &quot;standard&quot; aperture magnitude</li>\n\t<li><strong>w4mag</strong>: WISE W4 &quot;standard&quot; aperture magnitude</li>\n\t<li><strong>gz2c_f</strong>: Galaxy Zoo 2 classification from&nbsp;<a href=\"https://academic.oup.com/mnras/article/435/4/2835/1022913\">Willett et al 2013</a></li>\n\t<li><strong>gz2c_s</strong>: simplified version of Galaxy Zoo 2 classification (<a href=\"https://github.com/nunorc/astromlp-models#galaxy-zoo-2-simplified-classes-gz2c\">labels set</a>)</li>\n</ul>\n\n<p>Besides the CSV file a set of directories are included in the dataset, in each directory you&#39;ll find a list of files named after the <strong>objid&nbsp;</strong>column from the CSV file, with the corresponding data, the following directories tree is&nbsp;available:</p>\n\n<pre><code class=\"language-bash\">sdss-gs/\n\u251c\u2500\u2500 data.csv\n\u251c\u2500\u2500 fits\n\u251c\u2500\u2500 img\n\u251c\u2500\u2500 spectra\n\u2514\u2500\u2500 ssel</code></pre>\n\n<p>Where, each directory contains:</p>\n\n<ul>\n\t<li><strong>img</strong>: RGB images from the object in JPEG format, 150x150 pixels, generated using the&nbsp;<a href=\"https://skyserver.sdss.org/dr16/en/help/docs/api.aspx\">SkyServer DR16 API</a></li>\n\t<li><strong>fits</strong>: FITS data subsets around the object across the u, g, r, i, z bands; cut is done using the&nbsp;<a href=\"https://github.com/jhoar/ImageCutter\">ImageCutter</a>&nbsp;library</li>\n\t<li><strong>spectra</strong>: full best fit spectra data from SDSS between 4000 and 9000 wavelengths</li>\n\t<li><strong>ssel</strong>: best fit spectra data from SDSS for specific selected intervals of wavelengths discussed by&nbsp;<a href=\"https://arxiv.org/abs/1003.3186\">S&aacute;nchez Almeida 2010</a></li>\n</ul>\n\n<p><strong>Changelog</strong></p>\n\n<ul>\n\t<li>v0.0.2&nbsp;- Increase number ob objects to ~60k..</li>\n\t<li>v0.0.1 - Initial import.</li>\n</ul>", 
  "author": [
    {
      "family": "Carvalho, Nuno Ramos"
    }
  ], 
  "version": "0.0.2", 
  "type": "dataset", 
  "id": "6501642"
}