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IDL MAPS HOW TO
IDL MAPS SOFTWARE

Xy = mrdfits(file,'BIN_LWSKYCOO') coordinates of each spaxel Let's now use this information to plot the position of each unique bin and color-code it by the measured stellar velocity: Since the unique bins are returned as an ordered array, we can just remove the first elements to get rid of -1: If a spaxel has a bin ID of -1, then it was not included in any bins. Unique_bin_indices = uniq(stellar_kin_bins,sort(stellar_kin_bins)) For instance, to find the indices of the unique bins where stellar kinematics were fit:

4: any binned spectrum with spectral-index measurements.įor any analysis, you'll want to extract the unique spectra and/or maps values.

3: any binned spectrum with an attempted emission-line fit.

2: any binned spectrum with emission-line moment measurements.

1: any binned spectrum with an attempted stellar kinematics fit.

Any spaxel with BINID=-1 as not included in any bin. There are 5 channels providing the IDs of spaxels associated with The BINID extension provides information about which spaxels are in which bins. This binning means that two spaxels can belong the same bin, and therefore a derived quantity at those locations will be identical. The spaxels are binned in different ways depending on the measurement being made (the DAP documentation provides more information). Hb_vdc(where(hb_mask ne 0))=-30 choose -30 so the plot is more legible Since Hβ spectral index is in Angstroms, we can corrected in like this: Now we can apply the velocity dispersion correction. Specindex_corr=mrdfits(file,'SPECINDEX_CORR',/silent) Specindex_mask=mrdfits(file,'SPECINDEX_MASK',/silent) We will also get the masks and the corrections for the velocity dispersion for the Hβ spectral index. We see that Hβ is in channel 9 and the units are in Angstrom (C09='Hb' and U09='ang'). Also the units for each index is given which is important for the corrections done below. Like with the emission line header, in the spectral indices header we can see which spectral indices are in which channel. Specindex=mrdfits(file,'SPECINDEX',spechdr,/silent) We will follow a similar procedure as before with the emission line fluxes. The spectral indices are stored in the “SPECINDEX” extension of the maps file.

IDL MAPS HOW TO

Next we’ll show how to plot spectral indices and correct them for velocity dispersion. The calculation below will ignore any points where the correction is larger than the measured dispersion.ĭisp_stars_corr=sqrt(disp_raw^2-disp_inst^2)ĭisp_mask=mrdfits(file,'STELLAR_SIGMA_MASK',/silent) reading in maskĭisp_stars_corr(where(disp_mask ne 0 or finite(disp_stars_corr) eq 0))=-99 applying mask and removing NaN values Let’s apply the correction and plot the results (also removing masked values). We need to correct the stellar velocity dispersion for the instrumental resolution.ĭisp_inst=mrdfits(file,'STELLAR_SIGMACORR',/silent) First we need to read in the raw stellar velocities.ĭisp_raw=mrdfits(file,'STELLAR_SIGMA',/silent) In this section we will plot the stellar velocity dispersion. You cannot reduce the uncertainty on the measured velocity by averaging the velocities of several lines together. Image_plot,ha_flux,x,y replot with the new color tableĪn important note regarding gas velocity fields: The velocities of the emission lines are tied together, so for example, the velocity of the -5007 line is the same as the Hα line, as are the uncertainties. If you have not already downloaded this file, see this tutorial for help with downloading MaNGA data.įile= to 35. For this tutorial, we'll use the maps file for MaNGA object (plate-ifu) 7443-12703 with the MAPS-HYB10-GAU-MILESHC type map. It assumes you're using IDL and have the IDL Astronomy User's Library, the Coyote Graphics Library, and image_plot.pro from the ppxf package. The goal of this introductory tutorial will be to show you the basics of loading and visualizing MaNGA DAP products.

However, we highly recommend you consider using Marvin, a python package designed specifically for downloading, visualizing, and analyzing MaNGA data.

IDL MAPS SOFTWARE

Disclaimer: This tutorial teaches you how to look at the DAP output files using the software IDL.