Began stellar streams tutorial

Author: ojustino

tutorials/stellar_streams.ipynb

@@ -0,0 +1,176 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "(under construction)\n",
+    "\n",
+    "Adapted from [a notebook](https://nbviewer.jupyter.org/github/marksubbarao/pyWWT_AAS225/blob/master/SgrStream.ipynb) by Mark SubbaRao that uses files from [here](http://www.astro.virginia.edu/~srm4n/Sgr/data.html) and visualizes the tidal disruption of the Sagittarius Dwarf Galaxy described in [Law & Majewski 2010](https://iopscience.iop.org/article/10.1088/0004-637X/714/1/229)."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import time\n",
+    "\n",
+    "from astropy.coordinates import SkyCoord\n",
+    "from astropy import units as u\n",
+    "from astropy.table import Table, Column\n",
+    "from astropy.time import Time, TimeDelta\n",
+    "\n",
+    "import numpy as np\n",
+    "\n",
+    "from astroquery.vizier import Vizier\n",
+    "from astroquery.nasa_exoplanet_archive import NasaExoplanetArchive\n",
+    "\n",
+    "from pywwt.jupyter import WWTJupyterWidget"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "wwt = WWTJupyterWidget()\n",
+    "#wwt"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# import and manipulate a table with stellar stream data\n",
+    "stars = Table.read('https://raw.githubusercontent.com/WorldWideTelescope/pywwt-notebooks/137d6a398b4ba0b6de332cd4603e8e40c74bedcf/tutorials/data/SgrTriax_DYN.dat',\n",
+    "                   format='ascii.basic')\n",
+    "#stars = Table.read('SgrTriax_DYN.dat', format='ascii.basic')\n",
+    "stars.keep_columns([\"ra\",\"dec\",\"dist\",\"Pcol\"])\n",
+    "stars['ra'].unit = u.deg\n",
+    "stars['dec'].unit = u.deg\n",
+    "stars['dist'] *= 1000\n",
+    "stars['dist'].unit = u.pc\n",
+    "#stars.rename_column('dist','distance')\n",
+    "\n",
+    "# add a column of colors for each point for pywwt to read\n",
+    "stars['colormap'] = '#000000'\n",
+    "for i, val in enumerate(stars['Pcol']):\n",
+    "    if val == -1:\n",
+    "        stars['colormap'][i] = '#c0c0c0' # silver\n",
+    "    elif val == 0 or val == 1:\n",
+    "        stars['colormap'][i] = '#ffa500' # orange\n",
+    "    elif val == 2 or val == 3:\n",
+    "        stars['colormap'][i] = '#ff00ff' # magenta\n",
+    "    elif val == 4 or val == 5:\n",
+    "        stars['colormap'][i] = '#00ffff' # cyan\n",
+    "    elif val == 6 or val == 7:\n",
+    "        stars['colormap'][i] = '#228b22' # forest green"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "stars"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# display the stellar streams in the viewer\n",
+    "star_ly = wwt.layers.add_data_layer(table=stars, frame='Sky',\n",
+    "                                    lon_att='ra', lat_att='dec',\n",
+    "                                    alt_att='dist', alt_type='distance',\n",
+    "                                    cmap_att='depth', size_scale=20)\n",
+    "\n",
+    "star_ly.far_side_visible = True"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# import and manipulate a table containing Sgr Dwarf's orbital data\n",
+    "orbit = Table.read('https://raw.githubusercontent.com/WorldWideTelescope/pywwt-notebooks/137d6a398b4ba0b6de332cd4603e8e40c74bedcf/tutorials/data/SgrTriax_orbit.dat',\n",
+    "                   format='ascii.basic')\n",
+    "#orbit = Table.read('SgrTriax_orbit.dat', format='ascii.basic')\n",
+    "orbit.keep_columns(['time', 'ra', 'dec', 'dist'])\n",
+    "orbit['ra'].unit = u.deg\n",
+    "orbit['dec'].unit = u.deg\n",
+    "orbit['time'].unit = u.Gyr\n",
+    "orbit['dist'] *= 1000\n",
+    "#orbit.rename_column('dist', 'distance')"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# translate times from gigayears, which are too large for pywwt, ...\n",
+    "# to days -- so 1 day in the viewer translates to 1 gigayear real-time\n",
+    "base = Time('2019-01-01', format='iso').jd\n",
+    "orbit['wwt_times'] = base\n",
+    "orbit['wwt_times'] += orbit['time']"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "orbit"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# display Sgr Dwarf in the viewer\n",
+    "orb_ly = wwt.layers.add_data_layer(table=orbit[:300], frame='Sky',\n",
+    "                                   lon_att='ra', lat_att='dec',\n",
+    "                                   alt_att='dist', alt_type='distance',\n",
+    "                                   size_scale=20)\n",
+    "\n",
+    "orb_ly.far_side_visible = True"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.6.3"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}