#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# lenz2017.py
# Reads the Lenz, Hensley & Doré (2017) dust reddening map.
# http://arxiv.org/abs/1706.00011
#
# Copyright (C) 2018 Gregory M. Green
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
from __future__ import print_function, division
import os
import numpy as np
import healpy as hp
import astropy.io.fits as fits
import astropy.units as units
from .std_paths import *
from .healpix_map import HEALPixFITSQuery
from . import fetch_utils
from . import dustexceptions
[docs]class Lenz2017Query(HEALPixFITSQuery):
"""
Queries the Lenz, Hensley & Doré (2017) dust map:
http://arxiv.org/abs/1706.00011
"""
[docs] def __init__(self, map_fname=None):
"""
Args:
map_fname (Optional[:obj:`str`]): Filename for the Lenz map. Defaults to
``None``, meaning that the default location is used.
"""
if map_fname is None:
map_fname = os.path.join(
data_dir(),
'lenz2017',
'ebv_lhd.hpx.fits')
try:
super(Lenz2017Query, self).__init__(
map_fname, 'galactic',
hdu=1,
field='EBV')
except IOError as error:
print(dustexceptions.data_missing_message('lenz2017',
'Lenz et al. (2017)'))
raise error
[docs] def query(self, coords, **kwargs):
"""
Returns E(B-V), in mags, at the specified location(s) on the sky.
Args:
coords (:obj:`astropy.coordinates.SkyCoord`): The coordinates to query.
Returns:
A float array of the reddening, in magnitudes of E(B-V), at the
selected coordinates.
"""
return super(Lenz2017Query, self).query(coords, **kwargs)
[docs]def fetch():
"""
Downloads the Lenz, Hensley & Doré (2017) dust map, placing it in the
default :obj:`dustmaps` data directory.
"""
doi = '10.7910/DVN/AFJNWJ'
fname = os.path.join(
data_dir(),
'lenz2017',
'ebv_lhd.hpx.fits')
fetch_utils.dataverse_download_doi(
doi, fname,
file_requirements={'filename': 'ebv_lhd.hpx.fits'})
def main():
from astropy.coordinates import SkyCoord
q = Lenz2017Query()
c = SkyCoord([0., 180., 0.], [0., 0., 90.], frame='galactic', unit='deg')
print(q(c))
if __name__ == '__main__':
main()