Radio Continuum Imaging of the Massive Edge-on Galaxy NGC 2613

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Desouza, Amanda
Galactic astronomy , Astronomy , Extra-galactic astronomy
We present the results of new, high sensitivity continuum imaging of NGC 2613, a massive edge-on galaxy 23.4 Mpc away. The high-resolution EVLA maps of NGC 2613 were observed at C-band (C-array and D-array) and L-band (B-array, C-array and D-array), as part of the Continuum Halos in Nearby Galaxies (CHANG-ES) survey. Using new techniques during the imaging process, we successfully generate in-band combination maps for all arrays at each band. We also create a combined array and frequency map (C-band and L-band); with an intermediate frequency of 4.13 GHz, it is one of the few known images for a galaxy generated using multiple data sets at different frequency bands. High resolution maps of NGC 2613 reveal the presence of a compact nuclear source at the centre of the galaxy. We and evidence for the presence of an AGN, as predicted in Li et al. (2006), as the source of this feature. Gaussian fits to the radio core allow us to constrain the position of the galactic centre, with RA = 08h33m22.776s \pm 0.004s & DEC = -22 58'24.86" \pm 016" and a core size of ~200pc. We detect the presence of several continuum features embedded in the disk of the galaxy, including the detection of a complex spiral feature in the eastern edge of the galaxy. We also uncover the existence of a broad continuum ring along which we and the presence of several continuum "hotspots", including the eastern spiral feature. The broad ring width suggests an older ring formed by the collision of the galaxy with its companion, ESO 495-G017, with the eastern spiral feature being an artifact of the collision. We also detect the presence of large extensions surrounding the disk of the galaxy, some of which reach heights of 12 kpc making them among the largest such extensions found. The extensions are believed to have formed through internal mechanisms, like supernovae, and appear to be connected to the continuum features detected in the galaxy. The presence of large loop-like extensions above and below the radio core hints at the existence of early AGN activity.
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