Bibcode
Friedrich, S.; Davies, R. I.; Hicks, E. K. S.; Engel, H.; Müller-Sánchez, F.; Genzel, R.; Tacconi, L. J.
Referencia bibliográfica
Astronomy and Astrophysics, Volume 519, id.A79
Fecha de publicación:
9
2010
Revista
Número de citas
20
Número de citas referidas
20
Descripción
Aims: NGC 2992 is an intermediate Seyfert 1 galaxy showing
outflows on kilo parsec scales which might be due either to AGN or
starburst activity. We therefore aim at investigating its central region
for a putative starburst in the past and its connection to the AGN and
the outflows. Methods: Observations were performed with the
adaptive optics near infrared integral field spectrograph SINFONI on the
VLT, complemented by longslit observations with ISAAC on the VLT, as
well as N- and Q-band data from the Spitzer archive. The spatial and
spectral resolutions of the SINFONI data are 50 pc and 83 km
s-1, respectively. The field of view of 3 arcsec × 3
arcsec corresponds to 450 pc × 450 pc. Brγ equivalent width
and line fluxes from PAHs were compared to stellar population models to
constrain the age of the putative recent star formation. A simple
geometric model of two mutually inclined disks and an additional cone to
describe an outflow was developed to explain the observed complex
velocity field in H2 1-0S(1). Results: The
morphologies of the Brγ and the stellar continuum are different
suggesting that at least part of the Brγ emission comes from the
AGN. This is confirmed by PAH emission lines at 6.2 μm and 11.2 μm
and the strength of the silicon absorption feature at 9.7 μm, which
point to dominant AGN activity with a relatively minor starburst
contribution. We find a starburst age of 40-50 Myr from Brγ line
diagnostics and the radio continuum; ongoing star formation can be
excluded. Both the energetics and the timescales indicate that the
outflows are driven by the AGN rather than the starburst. The complex
velocity field observed in H2 1-0S(1) in the central 450 pc
can be explained by the superposition of the galaxy rotation and an
outflow.
Based on observations collected at the European Southern Observatory,
Chile (074.B-9012).
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