The Sloan Digital Sky Survey (SDSS) is a comprehensive survey of the northern sky. This dataset contains a subset of this survey, of 60247 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):

• objid: unique SDSS object identifier
• mjd: MJD of observation
• plate: plate identifier
• tile: tile identifier
• fiberid: fiber identifier
• run: run number
• rerun: rerun number
• camcol: camera column
• field: field number
• ra: right ascension
• dec: declination
• class: spectroscopic class (only objetcs with GALAXY are included)
• subclass: spectroscopic subclass
• modelMag_u: better of DeV/Exp magnitude fit for band u
• modelMag_g: better of DeV/Exp magnitude fit for band g
• modelMag_r: better of DeV/Exp magnitude fit for band r
• modelMag_i: better of DeV/Exp magnitude fit for band i
• modelMag_z: better of DeV/Exp magnitude fit for band z
• redshift: final redshift from SDSS data z
• stellarmass: stellar mass extracted from the eBOSS Firefly catalog
• w1mag: WISE W1 "standard" aperture magnitude
• w2mag: WISE W2 "standard" aperture magnitude
• w3mag: WISE W3 "standard" aperture magnitude
• w4mag: WISE W4 "standard" aperture magnitude
• gz2c_f: Galaxy Zoo 2 classification from Willett et al 2013
• gz2c_s: 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 objid column from the CSV file, with the corresponding data, the following directories tree is available:

sdss-gs/
├── data.csv
├── fits
├── img
├── spectra
└── ssel

Where, each directory contains:

• img: RGB images from the object in JPEG format, 150x150 pixels, generated using the SkyServer DR16 API
• fits: FITS data subsets around the object across the u, g, r, i, z bands; cut is done using the ImageCutter library
• spectra: full best fit spectra data from SDSS between 4000 and 9000 wavelengths
• ssel: best fit spectra data from SDSS for specific selected intervals of wavelengths discussed by Sánchez Almeida 2010

Changelog

• v0.0.3 - Increase number of objects to ~80k.
• v0.0.2 - Increase number of objects to ~60k.
• v0.0.1 - Initial import.

RMSE and R2 for different data groupings. The first column contains the species composition (inter, intra, or species specific) and the second column the data composition for each statistic reported in the remaining columns. Columns 3-5 contain the RMSE (kg), columns 6-8 the R2, and columns 9-11 the % error relative to the mean biomass in the dataset for BSD, D30, and DBH, respectively (see Methods). The subset of the data for trees that had all three measurements is denoted by the terms “Combined 3” and “Site 3” in the Data column. The lowest RMSE value in a row for each metric is in bold. Similarly, the highest R2 for each row is in bold. Values that represent means are underlined. The mean for each column and each grouping is given in the final two rows. The final row contains means for those trees with all three measures. The row above it contains means for all trees.