Volume 576, April 2015
|Number of page(s)||4|
|Published online||27 March 2015|
A hot bubble at the centre of M 81⋆
Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de
e-mail: firstname.lastname@example.org; email@example.com, firstname.lastname@example.org
Received: 11 December 2014
Accepted: 10 February 2015
Context. Messier 81 has the nearest active nucleus with broad Hα emission. A detailed study of this galaxy’s centre is important for understanding the innermost structure of the AGN phenomenon.
Aims. Our goal is to seek previously undetected structures using additional techniques to reanalyse a data cube obtained with the GMOS-IFU installed on the Gemini North telescope (Schnorr Müller et al. 2011, MNRAS, 413, 149).
Methods. We analysed the data cube using techniques of noise reduction, spatial deconvolution, starlight subtraction, PCA tomography, and comparison with HST images.
Results. We identified a hot bubble with T> 43 500 K that is associated with strong emission of [N II]λ5755 Å and a high [O I]λ6300/Hα ratio; the bubble displays a bluish continuum, surrounded by a thin shell of Hα + [N II] emission. We also reinterpret the outflow found by Schnorr Müller et al. (2011), showing that the blueshifted cone nearly coincides with the radio jet, as expected.
Conclusions. We interpret the hot bubble as having been caused by post starburst events that left one or more clusters of young stars, similar to the ones found at the centre of the Milky Way, such as the Arches and the IRS 16 clusters. Shocked structures from combined young stellar winds or supernova remnants are probably the cause of this hot gas and the low ionization emission.
Key words: techniques: imaging spectroscopy / galaxies: nuclei / galaxies: individual: M 81 / ISM: jets and outflows / ISM: bubbles / galaxies: active
The reduced datacube is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (18.104.22.168) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/576/A58
© ESO, 2015
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.