Mission Overview
Pan-STARRS1 Source Types and Redshifts with Machine Learning (PS1-STRM)
Primary Investigator: István Szapudi
HLSP Authors: Róbert Beck
Released: 2020-10-08
Updated: 2020-10-08
Primary Reference(s): Beck et al. (2020)
Citations: See ADS Statistics
Overview
PS1-STRM is a neural network source classification and photometric redshift catalog created from the PanSTARRS1 (PS1) 3π DR1. Neural networks have been trained on a compilation of spectroscopic measurements, cross-matched with PS1. Based on PS1 forced mean photometry, a source is classified as galaxy, star, quasar, or unsure. For galaxies, photometric redshift estimation is performed, also yielding an estimate of redshift error via Monte-Carlo sampling. Sources lying outside the parameter coverage of the training set (i.e. extrapolated sources) are identified using self-organizing maps. Classification and photo-z results are provided for every source in the PS1 3π DR1 ForcedMeanObject table, a total of 2,902,054,648 objects. See the README file and the primary reference paper for a detailed description of the catalog metadata.
Data Products
Data file naming convention:
hlsp_ps1-strm_ps1_gpc1_<decmin>-<decmax>_multi_v1_cat.csv.gz
where:
- <decmin> = Minimum declination this file covers (in degrees). "m" and "p" represent negative and postive signs.
- <decmax> = Maximum declination this file covers (in degrees). "m" and "p" represent negative and postive signs.
An example file name that covers a declination range from -2 < dec < +1 degrees is:
hlsp_ps1-strm_ps1_gpc1_m02-p01_multi_v1_cat.csv.gz
Data file types:
_cat.csv.gz | Portion of the catalog covering a given declination range. |
_md5sum.txt | Checksum file for all _cat.csv.gz files. |
_readme.txt | README containing a description of the catalog and columns. |
Catalog Column Descriptions
Note: B20 = Beck et al. (2020), F16 = Flewelling et al. (2016).
Column Name | Data Type | Description |
---|---|---|
objID | bigint | The main PS1 source identifier, should be used to match with other PS1 tables (see F16). Not unique. |
uniquePspsOBid | bigint | A unique PS1 source identifier, can be used to match with MeanObject and ObjectThin (see F16). |
raMean | float | The PS1 J2000 equatorial right ascension coordinate of the source, in degrees (see F16). |
decMean | float | The PS1 J2000 equatorial declination coordinate of the source, in degrees (see F16). |
l | float | The PS1 J2000 Galactic longitude coordinate of the source, in degrees (see F16). |
b | float | The PS1 J2000 Galactic latitude coordinate of the source, in degrees (see F16). |
class | varchar[8] | The class assigned to the source, using the fiducial decision boundary b=0.7 (see Sect. 4.1 of B20). Can take the following values: "GALAXY", "STAR", "QSO" or "UNSURE". |
prob_Galaxy | float | The probability-like neural network output for the galaxy class. Corresponds to the P_{class} general notation in the text. Refer to Sect. 4.1 of B20 for more details. |
prob_Star | float | The probability-like neural network output for the star class. Corresponds to the P_{class} general notation in the text. Refer to Sect. 4.1 of B20 for more details. |
prob_QSO | float | The probability-like neural network output for the quasar class. Corresponds to the P_{class} general notation in the text. Refer to Sect. 4.1 of B20 for more details. |
extrapolation_Class | int | The extrapolation flag for the classification, 0 if non-extrapolated, 1 if extrapolated. Definition: d_{SOM} > 1.562 (see Sect. 3.3 of B20). |
cellDistance_Class | int | The distance to the nearest SOM cell centre in the classification SOM. Denoted d_{SOM} in the text (see Sect. 3.3 of B20). |
cellID_Class | int | The identifier of the nearest SOM cell in the classification SOM (see Sect. 3.3 of B20). |
z_phot | float | The Monte-Carlo photometric redshift estimate z_{phot}. Slightly less accurate than z_{phot,0}. Refer to Sect. 3.4 and 4.2 of B20 for more details. |
z_photErr | float | The calibrated redshift error estimate \tilde{\Delta z}_{phot} = 1.986 \Delta z_{phot}. Refer to Sect. 3.4 and 4.2 of B20 for more details. |
z_phot0 | float | The base photometric redshift estimate z_{phot,0}. Refer to Sect. 3.4 and 4.2 of B20 for more details. |
extrapolation_Photoz | int | The extrapolation flag for the photo-z estimation, 0 if non-extrapolated, 1 if extrapolated. Definition: d_{SOM} > 1.246 (see Sect. 3.3 of B20). |
cellDistance_Photoz | float | The distance to the nearest SOM cell centre in the photo-z SOM. Denoted d_{SOM} in the text (see Sect. 3.3 of B20). |
cellID_Photoz | int | The identifier of the nearest SOM cell in the photo-z SOM (see Sect. 3.3 of B20). |
Data Access
PS1-STRM is available in MAST CasJobs for SQL queries, or can be downloaded as .csv.gz files based on strips of declination. There are two tables available in CasJobs: "catalogRecordRowStore" which is optimized for row extraction queries (queries where you want to retrieve a subset of the data) and "catalogRecordColumnStore" which is optimized for count() queries and should not be used for extracting subsets of the data. These tables can be found in the HLSP_PS1_STRM Context.
-
A web-based SQL interface to query and cross-match between catalogs. Export tables, saved queries, long query submissions.
NOTE: Each file in the table below is a few GB in size (~2-12 GB, depending on declination strip).
File | Min. Declination | Max. Declination |
---|---|---|
-33 | -28 | |
-28 | -25 | |
-25 | -22 | |
-22 | -18 | |
-18 | -15 | |
-15 | -12 | |
-12 | -09 | |
-09 | -05 | |
-05 | -02 | |
-02 | +01 | |
+01 | +05 | |
+05 | +08 | |
+08 | +11 | |
+11 | +15 | |
+15 | +18 | |
+18 | +21 | |
+21 | +25 | |
+25 | +28 | |
+28 | +31 | |
+31 | +34 | |
+34 | +38 | |
+38 | +41 | |
+41 | +44 | |
+44 | +48 | |
+48 | +51 | |
+51 | +54 | |
+54 | +58 | |
+58 | +61 | |
+61 | +64 | |
+64 | +69 | |
+69 | +77 | |
+77 | +90 |