| --- |
| license: cc-by-4.0 |
| task_categories: |
| - image-to-image |
| tags: |
| - astronomy |
| - supernovae |
| - panstarrs |
| - delight |
| size_categories: |
| - 100K<n<1M |
| --- |
| |
| ## Description |
|
|
| This is the spectroscopic galaxy sample of Pasquet et al. [1], originally built |
| for photometric redshift estimation from SDSS, re-imaged as multi-resolution |
| PanSTARRS cutouts through |
| [hips2fits](https://alasky.cds.unistra.fr/hips-image-services/hips2fits) |
| (PanSTARRS DR1 HiPS, served by CDS). |
|
|
| It contains **481,589 galaxies**, one row each. Every cutout is centered on the |
| **galaxy itself**, which makes this the direct counterpart of |
| [h2f_ps1_pasquet_autolabeling_0_01pct](https://huggingface.co/datasets/PRISM-Astro/h2f_ps1_pasquet_autolabeling_0_01pct): |
| same sample, same metadata and same folds, but there the cutouts are centered on |
| a simulated transient position and a galaxy may appear several times. Here there |
| is no augmentation and no `host_pos` label, because the galaxy sits at the |
| center of every image by construction. |
|
|
| ## Cross-validation |
|
|
| The `fold` column holds a 5-fold split **stratified by spectroscopic redshift**. |
| Redshift is discretized into 180 uniform bins over `[0, 0.4]`, the same binning |
| PRISM uses for its classification head, and the split balances those classes |
| across folds. The 24 galaxies falling in bins with fewer than 5 members carry |
| `fold = 0` and belong to **training only**, since they cannot be stratified. |
|
|
| Folds are the same assignments used by the autolabeling counterpart, so the two datasets |
| can be combined without leaking a galaxy between training and validation. |
|
|
|
|
| ## Image format |
|
|
| `image` has shape `(481589, 5, 5, 30, 30)`, which maps to |
| `(examples, resolution levels, photometric bands, height, width)`. Bands are |
| **grizy** in that order. Level `L` has a pixel scale of `0.25 * 2^L` arcsec/px, |
| so level 0 spans 7.5 arcsec and level 4 spans 120 arcsec around the galaxy. |
|
|
| ## Columns |
|
|
| <div style="font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;max-width:1000px;margin:0 auto;padding:16px 0"> |
| <table style="width:100%;border-collapse:collapse;font-size:13px"> |
| <thead><tr> |
| <th style="padding:10px 7px;text-align:left;font-weight:600;border-bottom:2px solid #4a6fb5;color:#4a6fb5;font-size:14px;width:18%">Column</th> |
| <th style="padding:10px 7px;text-align:left;font-weight:500;border-bottom:2px solid #4a6fb5;color:#4a6fb5;font-size:14px;width:20%">Type</th> |
| <th style="padding:10px 7px;text-align:left;font-weight:500;border-bottom:2px solid #4a6fb5;color:#4a6fb5;font-size:14px">Description</th> |
| </tr></thead> |
| <tbody> |
|
|
| <tr><td colspan="3" style="padding:8px 12px;font-weight:600;color:#4a6fb5;border-bottom:1px solid rgba(74,111,181,0.25);background:rgba(74,111,181,0.12)">Image</td></tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>image</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>(5,5,30,30)</code> float32</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">Multi-resolution PanSTARRS <em>grizy</em> cutout, centered on the galaxy.</td> |
| </tr> |
|
|
| <tr><td colspan="3" style="padding:8px 12px;font-weight:600;color:#4a6fb5;border-bottom:1px solid rgba(74,111,181,0.25);background:rgba(74,111,181,0.12)">Identification</td></tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>objID</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">int64</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">SDSS photometric object identifier. Unique in this dataset, and the key to join with the autolabeling counterpart.</td> |
| </tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>specObjID</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">int64</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">SDSS spectroscopic identifier of the spectrum the redshift comes from.</td> |
| </tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>bestObjID</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">int64</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">Photometric object SDSS considers the best match to that spectrum.</td> |
| </tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>ps1_objID</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">int64</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">PanSTARRS DR1 identifier of the crossmatched source.</td> |
| </tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>sep_arcsec</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">float32</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">Angular separation of the SDSS–PanSTARRS crossmatch, in arcsec. At most 1.345.</td> |
| </tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>dup_ambiguo</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">int64</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">1 when several SDSS objects matched the same PanSTARRS source at a comparable distance, 0 otherwise. Set for 47 galaxies.</td> |
| </tr> |
| |
| <tr><td colspan="3" style="padding:8px 12px;font-weight:600;color:#4a6fb5;border-bottom:1px solid rgba(74,111,181,0.25);background:rgba(74,111,181,0.12)">Sky position</td></tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>ra</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">float32</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">Right ascension of the galaxy, in degrees. This is the center of the cutout.</td> |
| </tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>dec</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">float32</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">Declination of the galaxy, in degrees. This is the center of the cutout.</td> |
| </tr> |
| |
| <tr><td colspan="3" style="padding:8px 12px;font-weight:600;color:#4a6fb5;border-bottom:1px solid rgba(74,111,181,0.25);background:rgba(74,111,181,0.12)">Redshift</td></tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>z_spec</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">float32</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">Spectroscopic redshift, the regression target. Ranges from 0 to 0.4, with a median of 0.102.</td> |
| </tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>z_spec_err</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">float32</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">Uncertainty reported by the SDSS spectroscopic pipeline.</td> |
| </tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>z_class</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">int64</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">Redshift bin, 0 to 179, over <code>[0, 0.4]</code>. Used to stratify the folds and as the classification target.</td> |
| </tr> |
| |
| <tr><td colspan="3" style="padding:8px 12px;font-weight:600;color:#4a6fb5;border-bottom:1px solid rgba(74,111,181,0.25);background:rgba(74,111,181,0.12)">Photometry and extinction</td></tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>petroR90_r</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">float32</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">Radius enclosing 90% of the Petrosian flux in the r band, in arcsec.</td> |
| </tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>dered_petro_r</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">float32</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">Dereddened r-band Petrosian magnitude.</td> |
| </tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>extinction_r</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">float32</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">Galactic extinction in the r band, in magnitudes.</td> |
| </tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>ebv_sfd</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">float32</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">Reddening E(B−V) from the SFD dust map.</td> |
| </tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>ebv_from_ext_r</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">float32</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">Reddening E(B−V) implied by <code>extinction_r</code>, kept as a consistency check on the previous column.</td> |
| </tr> |
|
|
| <tr><td colspan="3" style="padding:8px 12px;font-weight:600;color:#4a6fb5;border-bottom:1px solid rgba(74,111,181,0.25);background:rgba(74,111,181,0.12)">Sérsic fit — r band, from CasJobs</td></tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>rSerRadius</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">float32</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">Effective radius Re of the r-band Sérsic fit, in arcsec.</td> |
| </tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>rSerAb</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">float32</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">Axis ratio b/a of the fitted ellipse, between 0 and 1.</td> |
| </tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>rSerPhi</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">float32</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">Position angle of the fitted ellipse, in degrees.</td> |
| </tr> |
|
|
| <tr><td colspan="3" style="padding:8px 12px;font-weight:600;color:#4a6fb5;border-bottom:1px solid rgba(74,111,181,0.25);background:rgba(74,111,181,0.12)">Cross-validation</td></tr> |
| <tr> |
| <td style="padding:7px 7px;padding-left:20px;border-bottom:1px solid rgba(128,128,128,0.15)"><code>fold</code></td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">int64</td> |
| <td style="padding:7px 7px;border-bottom:1px solid rgba(128,128,128,0.15)">Validation fold, 1 to 5, stratified by <code>z_class</code>. A value of 0 means the galaxy is used for training in every fold.</td> |
| </tr> |
| </tbody> |
| </table> |
| </div> |
| |
| ## References |
| [1] Pasquet, J., Bertin, E., Treyer, M., Arnouts, S., & Fouchez, D. 2019, |
| *Photometric redshifts from SDSS images using a convolutional neural network*, |
| Astronomy & Astrophysics, 621, A26. |
| [doi:10.1051/0004-6361/201833617](https://doi.org/10.1051/0004-6361/201833617) |
| ```bibtex |
| @article{Pasquet_2019, |
| doi = {10.1051/0004-6361/201833617}, |
| url = {https://doi.org/10.1051/0004-6361/201833617}, |
| year = {2019}, |
| month = {jan}, |
| publisher = {EDP Sciences}, |
| volume = {621}, |
| pages = {A26}, |
| author = {Pasquet, J. and Bertin, E. and Treyer, M. and Arnouts, S. and Fouchez, D.}, |
| title = {Photometric redshifts from SDSS images using a convolutional neural network}, |
| journal = {Astronomy \& Astrophysics}, |
| } |
| ``` |
| |
