Radio continuum and X-ray emission from the most extreme far-IR-excess galaxy NGC 1377: An extremely obscured AGN revealed

• Context. Galaxies which strongly deviate from the radio-far infrared (FIR) correlation are of great importance for studies of galaxy evolution as they may be tracing early, short-lived stages of starbursts and active galactic nuclei (AGNs). The most extreme FIR-excess galaxy NGC 1377 has long been interpreted as a young dusty starburst, but millimeter observations of CO lines revealed a powerful collimated molecular outflow which cannot be explained by star formation alone. Aims. This paper aims to determine the nature of the energy source in the nucleus of NGC 1377 and to study the driving mechanism of the collimated CO outflow. Methods. We present new radio observations of NGC 1377 at 1.5 and 10 GHz obtained with the Jansky Very Large Array (JVLA) and Chandra X-ray observations. The observations are compared to synthetic starburst models to constrain the properties of the central energy source. Results. We obtained the first detection of the cm radio continuum and X-ray emission in NGC 1377. We found that the radio emission is distributed in two components, one on the nucleus and another offset by 4?5 to the south-west. We confirm the extreme FIR-excess of the galaxy, with a qFIR ? 4.2, which deviates by more than 7? from the radio-FIR correlation. Soft X-ray emission is detected on the off-nucleus component. From the radio emission we estimated for a young (

Ämnesord

NATURVETENSKAP  -- Fysik -- Atom- och molekylfysik och optik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Atom and Molecular Physics and Optics (hsv//eng)

Nyckelord

Galaxies: starburst

Radio continuum: galaxies

Galaxies: jets

X-rays: galaxies

Galaxies: individual: NGC 1377

Galaxies: active

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