Issue 
A&A
Volume 572, December 2014



Article Number  A40  
Number of page(s)  13  
Section  Extragalactic astronomy  
DOI  https://doi.org/10.1051/00046361/201423805  
Published online  26 November 2014 
Online material
Appendix A: Properties H_{2} transitions
In this Appendix we provide the spectra and line fluxes derived from fitting two Gaussian components to the emissionline spectra of the various H_{2} transitions in regions A, B and C.
Appendix A.1: Method
For each of the seven H_{2} transitions in our SINFONI data we extracted an emissionline spectrum from a circular aperture of 13 spaxels centered around the peak flux in regions A, B and C (similar to what is shown in Fig. 1 for H_{2} 1−0 S(1)).
As mentioned in Sect. 2, we used an IDL routine based on the MPFIT package to perform the linefitting. We used a threecomponent model to simultaneously fit the continuum and both the narrow and broad component of the emission lines. The continuum was fitted using a linear term, whereas a Gaussian profile was used for each emissionline component.
As can be seen in Fig. A.1, the signaltonoise of some of the lines is too low to derive accurate results when using this multicomponent analysis without placing any constraints on the linefitting procedure. To reduce the uncertainties of the fitting and obtain more robust measurements of the line fluxes, we assume that all transitions share the same kinematics. We first performed
the fitting routine on the strong 1−0 S(1) 2.1218 μm line without placing constraints on the linefitting parameters. Subsequently, we used these results to fix the position and line width (both in km s^{1}) of the narrow and broad component of the other emission lines.
The uncertainties of the flux measurements were calculated using a Monte Carlo technique. This method consists of measuring the noise in the spectra as the rootmeansquare of the residuals after the subtraction of our multicomponent model. Taking this estimation of the noise into account, we construct a total of 500 independent simulations/realizations of the spectra, where the lines are again fitted. These simulations yield distributions of each free parameter of our model. The uncertainty of each parameter is then defined as the standard deviation of its corresponding distribution.
Appendix A.2: Results
In Fig. A.1 we show the results of the linefitting procedure. In Table A.1 we summarize the line ratios for the broad and narrow component with respect to the flux of the 1−0 S(1) 2.1218 μm line. The upper limits are defined as 1sigma detections, using the noise estimation from the Monte Carlo method described in Sect. A.1.
Flux ratios of the broad and narrow components of all seven H_{2} lines in our SINFONI data with respect to 1−0 S(1) in regions A, B and C.
Fig. A.1
Emissionline spectra and 2component Gaussian fit of the various H_{2} transitions in regions A, B and C. The spectra were extracted from a circular aperture of 13 spaxels, centered on the broadcomponent H_{2} feature in each region. The line width and shift between the peak of the narrow and broad component were constrained in velocity to those of the strong 1−0 S(1) line. A straight line was fitted to the continuum across a wide velocity range of −1800 to +1800 km s^{1} in order to handle potential features in the continuum (see, e.g., the H_{2} 1−0S(3) transition in region B). However, a smaller velocity range is plotted in the figures to highlight the details of the fits to the emission lines. After extracting flux measurements, for visualisation purposes the spectra in the plots were normalized to the fitted continuum. 

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