{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Exploratory analysis of unkown star cluster" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "We are going to explore the star population of the region of interest by analysing *Gaia* data. *Gaia* Data Release 2 provides high-precision astrometry and three-band photometry for about 1.3 billion sources over the full sky. Theprecision, accuracy, and homogeneity of both astrometry and photometry are unprecedented. To obtain the data we will use the astroquery TAP+ protocol. More information can be found here: https://astroquery.readthedocs.io/en/latest/" ] }, { "cell_type": "code", "execution_count": 1, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Created TAP+ (v1.2.1) - Connection:\n", "\tHost: gea.esac.esa.int\n", "\tUse HTTPS: True\n", "\tPort: 443\n", "\tSSL Port: 443\n", "Created TAP+ (v1.2.1) - Connection:\n", "\tHost: geadata.esac.esa.int\n", "\tUse HTTPS: True\n", "\tPort: 443\n", "\tSSL Port: 443\n" ] } ], "source": [ "%matplotlib inline\n", "import numpy as np\n", "import matplotlib.pyplot as plt\n", "import matplotlib\n", "\n", "matplotlib.rcParams['figure.figsize'] = (18.0, 10.0)\n", "from astroquery.gaia import Gaia\n", "Gaia.ROW_LIMIT = -1\n", "\n", "import astropy.units as u\n", "from astropy.coordinates import SkyCoord" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "To do a basic query on the *Gaia* DR2 catalogue we just need a pointing centre and the (width, height), or the radius, of the region of interest. This is a clear case where you could build a python function to retrieve data based only on those four parameters.\n", "\n", "Here we also include the Jupyter Magic `%time` that will report the execution time of a particular line of code to run. The Magic `%%time` could also be used to report the execution time of the whole cell." ] }, { "cell_type": "code", "execution_count": 2, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "INFO: Query finished. [astroquery.utils.tap.core]\n", "CPU times: user 13.7 s, sys: 245 ms, total: 14 s\n", "Wall time: 31 s\n" ] } ], "source": [ "ra0 = 130.025\n", "de0 = 19.98333\n", "w = 3\n", "h = 2\n", "\n", "# Define the region to query\n", "coord = SkyCoord(ra=ra0, dec=de0, unit=(u.degree, u.degree), frame='icrs')\n", "width = u.Quantity(w, u.deg)\n", "height = u.Quantity(h, u.deg)\n", "\n", "# Run the actual query to the catalogue\n", "%time r = Gaia.query_object_async(coordinate=coord, width=width, height=height)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Convert to pandas DataFrame and initial exploration of the dataset" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "We will work with a pandas DataFrame, for being an easy tabular format. We will start by adding a column with the distance in kpc, computed from the parallax in milliarcseconds." ] }, { "cell_type": "code", "execution_count": 3, "metadata": {}, "outputs": [ { "name": "stderr", "output_type": "stream", "text": [ "/home/jmoldon/miniconda3/envs/test/lib/python3.7/site-packages/IPython/core/interactiveshell.py:2878: TableReplaceWarning: converted column 'priam_flags' from integer to float\n", " exec(code_obj, self.user_global_ns, self.user_ns)\n", "/home/jmoldon/miniconda3/envs/test/lib/python3.7/site-packages/IPython/core/interactiveshell.py:2878: TableReplaceWarning: converted column 'flame_flags' from integer to float\n", " exec(code_obj, self.user_global_ns, self.user_ns)\n" ] }, { "data": { "text/html": [ "
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0 | \n", "0.009802 | \n", "1635721458409799680 | \n", "b'Gaia DR2 661322846442390784' | \n", "661322846442390784 | \n", "390503307 | \n", "2015.5 | \n", "130.015005 | \n", "0.248881 | \n", "19.980541 | \n", "0.193851 | \n", "... | \n", "NaN | \n", "NaN | \n", "NaN | \n", "NaN | \n", "NaN | \n", "NaN | \n", "NaN | \n", "b'https://gea.esac.esa.int/data-server/datalin... | \n", "b'' | \n", "1.206670 | \n", "
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2 | \n", "0.016757 | \n", "1635721458409799680 | \n", "b'Gaia DR2 661322919458270080' | \n", "661322919458270080 | \n", "1520423091 | \n", "2015.5 | \n", "130.008090 | \n", "18.646404 | \n", "19.988621 | \n", "11.796212 | \n", "... | \n", "NaN | \n", "NaN | \n", "NaN | \n", "NaN | \n", "NaN | \n", "NaN | \n", "NaN | \n", "b'https://gea.esac.esa.int/data-server/datalin... | \n", "b'' | \n", "NaN | \n", "
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30325 | \n", "1.714573 | \n", "1635721458409799680 | \n", "b'Gaia DR2 661860473268060032' | \n", "661860473268060032 | \n", "703312001 | \n", "2015.5 | \n", "131.523122 | \n", "0.696914 | \n", "20.968275 | \n", "0.478415 | \n", "... | \n", "NaN | \n", "NaN | \n", "NaN | \n", "NaN | \n", "NaN | \n", "NaN | \n", "NaN | \n", "b'https://gea.esac.esa.int/data-server/datalin... | \n", "b'' | \n", "-7.051204 | \n", "
30326 | \n", "1.716012 | \n", "1635721458409799680 | \n", "b'Gaia DR2 661047594874045696' | \n", "661047594874045696 | \n", "1141285327 | \n", "2015.5 | \n", "131.516276 | \n", "0.272562 | \n", "18.999212 | \n", "0.154463 | \n", "... | \n", "NaN | \n", "NaN | \n", "NaN | \n", "NaN | \n", "NaN | \n", "NaN | \n", "NaN | \n", "b'https://gea.esac.esa.int/data-server/datalin... | \n", "b'' | \n", "-5.330887 | \n", "
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30330 rows × 98 columns
\n", "\n", " | dist | \n", "solution_id | \n", "source_id | \n", "random_index | \n", "ref_epoch | \n", "ra | \n", "ra_error | \n", "dec | \n", "dec_error | \n", "parallax | \n", "... | \n", "e_bp_min_rp_percentile_lower | \n", "e_bp_min_rp_percentile_upper | \n", "flame_flags | \n", "radius_val | \n", "radius_percentile_lower | \n", "radius_percentile_upper | \n", "lum_val | \n", "lum_percentile_lower | \n", "lum_percentile_upper | \n", "distance | \n", "
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
count | \n", "30330.000000 | \n", "3.033000e+04 | \n", "3.033000e+04 | \n", "3.033000e+04 | \n", "30330.0 | \n", "30330.000000 | \n", "30330.000000 | \n", "30330.000000 | \n", "30330.000000 | \n", "25337.000000 | \n", "... | \n", "5053.000000 | \n", "5053.000000 | \n", "4318.0 | \n", "4318.000000 | \n", "4318.000000 | \n", "4318.000000 | \n", "4318.000000 | \n", "4318.000000 | \n", "4318.000000 | \n", "25337.000000 | \n", "
mean | \n", "0.926044 | \n", "1.635721e+18 | \n", "6.625714e+17 | \n", "8.481437e+08 | \n", "2015.5 | \n", "130.015400 | \n", "1.854095 | \n", "19.976328 | \n", "1.070778 | \n", "1.022348 | \n", "... | \n", "0.097709 | \n", "0.263006 | \n", "200111.0 | \n", "1.397740 | \n", "1.281509 | \n", "1.488634 | \n", "4.140486 | \n", "3.617357 | \n", "4.663615 | \n", "0.166190 | \n", "
std | \n", "0.364550 | \n", "0.000000e+00 | \n", "1.566766e+15 | \n", "4.907570e+08 | \n", "0.0 | \n", "0.864883 | \n", "5.116695 | \n", "0.574201 | \n", "2.918166 | \n", "1.569493 | \n", "... | \n", "0.141129 | \n", "0.213469 | \n", "0.0 | \n", "3.233030 | \n", "2.986711 | \n", "3.329456 | \n", "44.876537 | \n", "40.223827 | \n", "49.658024 | \n", "126.621830 | \n", "
min | \n", "0.009802 | \n", "1.635721e+18 | \n", "6.596981e+17 | \n", "1.996900e+04 | \n", "2015.5 | \n", "128.525007 | \n", "0.018194 | \n", "18.983352 | \n", "0.011679 | \n", "-12.538883 | \n", "... | \n", "0.000000 | \n", "0.007100 | \n", "200111.0 | \n", "0.500969 | \n", "0.313949 | \n", "0.513331 | \n", "0.030905 | \n", "0.030151 | \n", "0.031660 | \n", "-13671.029870 | \n", "
25% | \n", "0.659723 | \n", "1.635721e+18 | \n", "6.612667e+17 | \n", "4.222359e+08 | \n", "2015.5 | \n", "129.266310 | \n", "0.127751 | \n", "19.484145 | \n", "0.078967 | \n", "0.271126 | \n", "... | \n", "0.007900 | \n", "0.107100 | \n", "200111.0 | \n", "0.720208 | \n", "0.648146 | \n", "0.763561 | \n", "0.256345 | \n", "0.214092 | \n", "0.296318 | \n", "0.368741 | \n", "
50% | \n", "0.947206 | \n", "1.635721e+18 | \n", "6.618324e+17 | \n", "8.466956e+08 | \n", "2015.5 | \n", "130.012563 | \n", "0.398032 | \n", "19.976029 | \n", "0.243634 | \n", "0.745938 | \n", "... | \n", "0.041700 | \n", "0.200700 | \n", "200111.0 | \n", "0.937876 | \n", "0.855817 | \n", "1.002790 | \n", "0.667259 | \n", "0.584672 | \n", "0.758724 | \n", "0.902737 | \n", "
75% | \n", "1.212239 | \n", "1.635721e+18 | \n", "6.643895e+17 | \n", "1.278397e+09 | \n", "2015.5 | \n", "130.762424 | \n", "1.011944 | \n", "20.469638 | \n", "0.617917 | \n", "1.485823 | \n", "... | \n", "0.125500 | \n", "0.351800 | \n", "200111.0 | \n", "1.269365 | \n", "1.156431 | \n", "1.379006 | \n", "1.830126 | \n", "1.586210 | \n", "2.058991 | \n", "1.769543 | \n", "
max | \n", "1.727997 | \n", "1.635721e+18 | \n", "6.648629e+17 | \n", "1.692899e+09 | \n", "2015.5 | \n", "131.524907 | \n", "92.941017 | \n", "20.983283 | \n", "56.658432 | \n", "23.376402 | \n", "... | \n", "1.238700 | \n", "1.553000 | \n", "200111.0 | \n", "150.389877 | \n", "136.227798 | \n", "151.835205 | \n", "2420.168213 | \n", "2245.128906 | \n", "2595.207520 | \n", "3075.737473 | \n", "
8 rows × 92 columns
\n", "\n", " | ra | \n", "dec | \n", "
---|---|---|
mean | \n", "130.015400 | \n", "19.976328 | \n", "
min | \n", "128.525007 | \n", "18.983352 | \n", "
max | \n", "131.524907 | \n", "20.983283 | \n", "