masks.ipynb

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    "# Author: M. Riley Owens (GitHub: mrileyowens)\n",
    "\n",
    "# This file makes masks of the MagE slit projections\n",
    "# and the two largest arcs of the Sunburst Arc\n",
    "# matching the WCS of the v5 reductions of the HST\n",
    "# observations of the Sunburst Arc"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "id": "bb33997a",
   "metadata": {},
   "outputs": [],
   "source": [
    "import os\n",
    "\n",
    "from datetime import date\n",
    "\n",
    "import numpy as np\n",
    "\n",
    "from astropy.io import fits\n",
    "\n",
    "import astropy.units as u\n",
    "\n",
    "from astropy.wcs import WCS\n",
    "from astropy.coordinates import SkyCoord\n",
    "from regions import RectangleSkyRegion\n",
    "from reproject.interpolation import reproject_interp"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "1c285dfd",
   "metadata": {},
   "outputs": [],
   "source": [
    "def make():\n",
    "\n",
    "    '''\n",
    "    Make masks of the MagE slit apertures and the two largest arcs of the\n",
    "    Sunburst Arc in the WCS projection of the v5 HST data reduction\n",
    "    '''\n",
    "\n",
    "    # Dictionary containing information about the position,\n",
    "    # size, and orientation of the MagE slit apertures\n",
    "    slits = {\n",
    "        'm5' : ['15:50:01.1649 -78:11:07.822', 0.850, 313],\n",
    "        'm4' : ['15:50:04.9279 -78:10:59.032', 0.850, 0],\n",
    "        'm6' : ['15:50:06.6389 -78:10:57.412', 0.850, 12],\n",
    "        'm3' : ['15:50:00.6009 -78:11:09.912', 0.850, 298],\n",
    "        'm0' : ['15:50:04.4759 -78:10:59.652', 1.0, 349],\n",
    "        'm2' : ['15:49:59.7480 -78:11:13.482', 0.850, 52],\n",
    "        'm7' : ['15:50:07.3959 -78:10:56.962', 0.850, 0],\n",
    "        'm8' : ['15:49:59.9499 -78:11:12.242', 0.850, 330],\n",
    "        'm9' : ['15:50:00.3719 -78:11:10.512', 0.850, 302]\n",
    "        }\n",
    "\n",
    "    # Establish common directories\n",
    "    home = os.getcwd()\n",
    "    data = f'{home}/data'\n",
    "    results = f'{home}/results'\n",
    "\n",
    "    # File path to a v5 reduced HST observation. We just need this for the WCS, so it shouldn't matter\n",
    "    # which v5 file we grab, since the v5 reductions should all have the same WCS\n",
    "    file = f'{data}/hst/V5.0_PSZ1G311.65-18.48_F814W_0.03g0.6_crsc1.2_0.7crsn3.5_3.0_drc_sci.fits'\n",
    "\n",
    "    # Get the header of the reference file\n",
    "    header = fits.getheader(file)\n",
    "\n",
    "    # Extract the WCS from the header\n",
    "    wcs = WCS(header)\n",
    "\n",
    "    # For each slit\n",
    "    for i, slit_id in enumerate(slits):\n",
    "\n",
    "        # The coordinates of the center of the slit aperture\n",
    "        coords = SkyCoord(slits[slit_id][0], unit=(u.hourangle, u.deg), frame='fk5')\n",
    "\n",
    "        # Instantiate the slit aperture as a RectangleSkyRegion with the aperture's size and orientation\n",
    "        region = RectangleSkyRegion(center=coords, width=slits[slit_id][1] * u.arcsecond, height=10 * u.arcsecond, angle=slits[slit_id][2] * u.deg)\n",
    "\n",
    "        # Get the slit in pixel coordinates using the WCS\n",
    "        pixel_region = region.to_pixel(wcs)\n",
    "\n",
    "        # Make a mask from the pixel region\n",
    "        mask = pixel_region.to_mask().to_image((header['NAXIS2'], header['NAXIS1']))\n",
    "\n",
    "        # Make a new header from the WCS projection\n",
    "        slit_mask_header = wcs.to_header()\n",
    "\n",
    "        # Insert new keycards in the header to add additional information\n",
    "        slit_mask_header.insert(1, ('CREATOR', 'M. Riley Owens', 'Creator of this file'))\n",
    "        slit_mask_header.insert(2, ('EMAIL', 'm.riley.owens@gmail.com', 'Email of the creator of this file'))\n",
    "        slit_mask_header['GENFILE'] = ('masks.ipynb', 'The file used to create this file')\n",
    "        slit_mask_header['DATE'] = (date.today().strftime('%d %B %Y'), 'The date this file was created')\n",
    "        slit_mask_header['FILENAME'] = (f'{slit_id}_mask_v5.fits', 'Name of file')\n",
    "        slit_mask_header['DESC'] = (f'This file is a binary mask of the slit {slit_id.upper()} MagE aperture of the \\\n",
    "            Sunburst Arc, aligned to the WCS of the v5 reduction of the HST observations.', 'Description of file')\n",
    "\n",
    "        # Save the mask with the new header\n",
    "        fits.writeto(f'{results}/masks/{slit_id}_mask_v5.fits', mask, header=slit_mask_header, overwrite=True)\n",
    "\n",
    "    # The file path to the mask of the two largest arcs in a VLT/MUSE IFU footprint\n",
    "    arc_mask_file = f'{data}/arc_mask_v4.fits'\n",
    "\n",
    "    # Reproject and interpolate the mask to the v5 HST reduction WCS\n",
    "    arc_mask, _ = reproject_interp(arc_mask_file, header, hdu_in=0)\n",
    "    \n",
    "    # Where the interpolation produces values 0 - 1, reassign them as 1 to maintain\n",
    "    # binary structure\n",
    "    arc_mask = np.where(arc_mask > 0, 1, 0)\n",
    "\n",
    "    # Create a new header from the v5 HST reduction WCS\n",
    "    arc_mask_header = wcs.to_header()\n",
    "\n",
    "    # Insert new keycards in the header to add additional information\n",
    "    arc_mask_header.insert(1, ('CREATOR', 'M. Riley Owens', 'Creator of this file'))\n",
    "    arc_mask_header.insert(2, ('EMAIL', 'm.riley.owens@gmail.com', 'Email of the creator of this file'))\n",
    "    arc_mask_header['GENFILE'] = ('masks.ipynb', 'The file used to create this file')\n",
    "    arc_mask_header['DATE'] = (date.today().strftime('%d %B %Y'), 'The date this file was created')\n",
    "    arc_mask_header['FILENAME'] = (f'arc_mask_v5.fits', 'Name of file')\n",
    "    arc_mask_header['DESC'] = ('This file is a binary mask of the Sunburst Arc, aligned to the WCS of the \\\n",
    "        v5 reduction of the HST observations. The original mask was made for the VLT/MUSE footprint.', \n",
    "        'Description of file')\n",
    "\n",
    "    # Save the new arc mask\n",
    "    hdu = fits.PrimaryHDU(data=arc_mask, header=header)\n",
    "    hdul = fits.HDUList([hdu])\n",
    "    hdul.writeto(f'{results}/masks/arc_mask_v5.fits', overwrite=True)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "1a038523",
   "metadata": {},
   "outputs": [],
   "source": [
    "make()"
   ]
  }
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