DOI: 10.5281/zenodo.7050898
title: SDSS Galaxy Subset

description: The Sloan Digital Sky Survey (SDSS) is a comprehensive survey of the northern sky. This dataset contains a subset of this survey, of 100077 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 astromlp-models collection of deep learning models for galaxies characterisation. 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): <strong>objid</strong>: unique SDSS object identifier <strong>mjd</strong>: MJD of observation <strong>plate</strong>: plate identifier <strong>tile</strong>: tile identifier <strong>fiberid</strong>: fiber identifier <strong>run</strong>: run number <strong>rerun</strong>: rerun number <strong>camcol</strong>: camera column <strong>field</strong>: field number <strong>ra</strong>: right ascension <strong>dec</strong>: declination <strong>class</strong>: spectroscopic class (only objetcs with GALAXY are included) <strong>subclass</strong>: spectroscopic subclass <strong>modelMag_u</strong>: better of DeV/Exp magnitude fit for band u <strong>modelMag_g</strong>: better of DeV/Exp magnitude fit for band g <strong>modelMag_r</strong>: better of DeV/Exp magnitude fit for band r <strong>modelMag_i</strong>: better of DeV/Exp magnitude fit for band i <strong>modelMag_z</strong>: better of DeV/Exp magnitude fit for band z <strong>redshift</strong>: final redshift from SDSS data z <strong>stellarmass</strong>: stellar mass extracted from the eBOSS Firefly catalog <strong>w1mag</strong>: WISE W1 "standard" aperture magnitude <strong>w2mag</strong>: WISE W2 "standard" aperture magnitude <strong>w3mag</strong>: WISE W3 "standard" aperture magnitude <strong>w4mag</strong>: WISE W4 "standard" aperture magnitude <strong>gz2c_f</strong>: Galaxy Zoo 2 classification from Willett et al 2013 <strong>gz2c_s</strong>: simplified version of Galaxy Zoo 2 classification (labels set) Besides the CSV file a set of directories are included in the dataset, in each directory you'll find a list of files named after the <strong>objid </strong>column from the CSV file, with the corresponding data, the following directories tree is available: <pre><code class="language-bash">sdss-gs/ ├── data.csv ├── fits ├── img ├── spectra └── ssel</code></pre> Where, each directory contains: <strong>img</strong>: RGB images from the object in JPEG format, 150x150 pixels, generated using the SkyServer DR16 API <strong>fits</strong>: FITS data subsets around the object across the u, g, r, i, z bands; cut is done using the ImageCutter library <strong>spectra</strong>: full best fit spectra data from SDSS between 4000 and 9000 wavelengths <strong>ssel</strong>: best fit spectra data from SDSS for specific selected intervals of wavelengths discussed by Sánchez Almeida 2010 <strong>Changelog</strong> v0.0.4 - Increase number of objects to ~100k. v0.0.3 - Increase number of objects to ~80k. v0.0.2 - Increase number of objects to ~60k. v0.0.1 - Initial import.