Sample Selection Tutorial

Select Main Sample Galaxies

To select the Main Sample galaxies (Primary + Secondary + Color Enhanced samples), we can use the MaNGA DRPall summary file. You can use the get_drpall_table utility to load the full DRPall table. By default this will load the DRPall file for the current release set in Marvin.

Let’s open the DRPall file:

from marvin.utils.general import get_drpall_table
data = get_drpall_table()

The Main Sample consists of the Primary, Secondary, and Color-Enhanced Samples, which correspond to MNGTARG1 bits 10, 11, and 12, respectively.

import numpy as np
primary        = data['mngtarg1'] & 2**10
secondary      = data['mngtarg1'] & 2**11
color_enhanced = data['mngtarg1'] & 2**12

main_sample = np.logical_or.reduce((primary, secondary, color_enhanced))

plateifus = data['plateifu'][main_sample]

Now we can use the downloadList() function to download all of the files of type map (other valid dltypes: map, image, rss, mastar, default, or plate).

from marvin.utils.general.general import downloadList
downloadList(plateifus, dltype='map')