Kinematics and stellar population of NGC 4486A

2011 
Context. NGC 4486A is a low-luminosity elliptical galaxy harbouring an edge-on nuclear disk of stars and dust. It is known to host a super-massive black hole. Aims. We study its large-scale kinematics and stellar population along the major axis to investigate the link between the nuclear and global properties. Methods. We use long-slit medium-resolution optical spectra that we fit against stellar population models. Results. The SSP-equivalent age is about 12 Gyr old throughout the body of the galaxy, and its metallicity decreases from [Fe/H] = 0.18 near the centre to sub-solar values in the outskirts. The metallicity gradient is −0.24 dex per decade of radius within the effective isophote. The velocity dispersion is 132 ± 3k m s −1 at 1.3 �� from the centre and decreases outwards. The rotation velocity reaches a maximum Vmax 115 ± 5k m s −1 at a radius 1.3 < rmax < 2 �� . Conclusions. NGC 4486A appears to be a typical low-luminosity elliptical galaxy. There is no signature in the stellar population of the possible ancient accretion/merging event that produced the disk.
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