## 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)

## 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 Description
_cat.csv.gz Portion of the catalog covering a given declination range.
_md5sum.txt Checksum file for all _cat.csv.gz files.

#### 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.

MAST CasJobs

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

hlsp_ps1-strm_ps1_gpc1_m33-m28_multi_v1_cat.csv.gz

-33 -28

hlsp_ps1-strm_ps1_gpc1_m28-m25_multi_v1_cat.csv.gz

-28 -25

hlsp_ps1-strm_ps1_gpc1_m25-m22_multi_v1_cat.csv.gz

-25 -22

hlsp_ps1-strm_ps1_gpc1_m22-m18_multi_v1_cat.csv.gz

-22 -18

hlsp_ps1-strm_ps1_gpc1_m18-m15_multi_v1_cat.csv.gz

-18 -15

hlsp_ps1-strm_ps1_gpc1_m15-m12_multi_v1_cat.csv.gz

-15 -12

hlsp_ps1-strm_ps1_gpc1_m12-m09_multi_v1_cat.csv.gz

-12 -09

hlsp_ps1-strm_ps1_gpc1_m09-m05_multi_v1_cat.csv.gz

-09 -05

hlsp_ps1-strm_ps1_gpc1_m05-m02_multi_v1_cat.csv.gz

-05 -02

hlsp_ps1-strm_ps1_gpc1_m02-p01_multi_v1_cat.csv.gz

-02 +01

hlsp_ps1-strm_ps1_gpc1_p01-p05_multi_v1_cat.csv.gz

+01 +05

hlsp_ps1-strm_ps1_gpc1_p05-p08_multi_v1_cat.csv.gz

+05 +08

hlsp_ps1-strm_ps1_gpc1_p08-p11_multi_v1_cat.csv.gz

+08 +11

hlsp_ps1-strm_ps1_gpc1_p11-p15_multi_v1_cat.csv.gz

+11 +15

hlsp_ps1-strm_ps1_gpc1_p15-p18_multi_v1_cat.csv.gz

+15 +18

hlsp_ps1-strm_ps1_gpc1_p18-p21_multi_v1_cat.csv.gz

+18 +21

hlsp_ps1-strm_ps1_gpc1_p21-p25_multi_v1_cat.csv.gz

+21 +25

hlsp_ps1-strm_ps1_gpc1_p25-p28_multi_v1_cat.csv.gz

+25 +28

hlsp_ps1-strm_ps1_gpc1_p28-p31_multi_v1_cat.csv.gz

+28 +31

hlsp_ps1-strm_ps1_gpc1_p31-p34_multi_v1_cat.csv.gz

+31 +34

hlsp_ps1-strm_ps1_gpc1_p34-p38_multi_v1_cat.csv.gz

+34 +38

hlsp_ps1-strm_ps1_gpc1_p38-p41_multi_v1_cat.csv.gz

+38 +41

hlsp_ps1-strm_ps1_gpc1_p41-p44_multi_v1_cat.csv.gz

+41 +44

hlsp_ps1-strm_ps1_gpc1_p44-p48_multi_v1_cat.csv.gz

+44 +48

hlsp_ps1-strm_ps1_gpc1_p48-p51_multi_v1_cat.csv.gz

+48 +51

hlsp_ps1-strm_ps1_gpc1_p51-p54_multi_v1_cat.csv.gz

+51 +54

hlsp_ps1-strm_ps1_gpc1_p54-p58_multi_v1_cat.csv.gz

+54 +58

hlsp_ps1-strm_ps1_gpc1_p58-p61_multi_v1_cat.csv.gz

+58 +61

hlsp_ps1-strm_ps1_gpc1_p61-p64_multi_v1_cat.csv.gz

+61 +64

hlsp_ps1-strm_ps1_gpc1_p64-p69_multi_v1_cat.csv.gz

+64 +69

hlsp_ps1-strm_ps1_gpc1_p69-p77_multi_v1_cat.csv.gz

+69 +77

hlsp_ps1-strm_ps1_gpc1_p77-p90_multi_v1_cat.csv.gz

+77 +90

## Citations

Please remember to cite the appropriate paper(s) below and the DOI if you use these data in a published work.

Note: These HLSP data products are licensed for use under CC BY 4.0.