[seminar] Astro Journal Club on 19 Nov

[Oskari Miettinen]

Dear all,

We will meet on Wednesday at 10 am for our Astro Journal Club in the
seminar room F-201 of the Physics Department. This week we will discuss
about quasar feedback.

Presenter: Nikola Baran
Paper title: Blowin' in the wind: both 'negative' and 'positive' feedback
in an obscured high-z Quasar
Authors: Cresci, G., Mainieri, V., Brusa, M., et al.
Reference: ApJ, in press, arXiv:1411.4208

Abstract:
Quasar feedback in the form of powerful outflows is invoked as a key
mechanism to quench star formation in galaxies, preventing massive
galaxies to over-grow and producing the red colors of ellipticals. On the
other hand, some models are also requiring 'positive' AGN feedback,
inducing star formation in the host galaxy through enhanced gas pressure
in the interstellar medium. However, finding observational evidence of the
effects of both types of feedback is still one of the main challenges of
extragalactic astronomy, as few observations of energetic and extended
radiatively-driven winds are available. Here we present SINFONI near
infrared integral field spectroscopy of XID2028, an obscured, radio-quiet
z=1.59 QSO detected in the XMM-COSMOS survey, in which we clearly resolve
a fast (1500 km/s) and extended (up to 13 kpc from the black hole) outflow
in the [OIII] lines emitting gas, whose large velocity and outflow rate
are not sustainable by star formation only. The narrow component of Ha
emission and the rest frame U band flux from HST-ACS imaging enable to map
the current star formation in the host galaxy: both tracers independently
show that the outflow position lies in the center of an empty cavity
surrounded by star forming regions on its edge. The outflow is therefore
removing the gas from the host galaxy ('negative feedback'), but also
triggering star formation by outflow induced pressure at the edges
('positive feedback'). XID2028 represents the first example of a host
galaxy showing both types of feedback simultaneously at work.

Link to the paper: http://adsabs.harvard.edu/abs/2014arXiv1411.4208C

Hope to see you all on Wednesday.

Best regards,
Oskari