A multi-wavelength view of the central kiloparsec region in the luminous infrared galaxy NGC 1614
- Instituto de Astrofísica de Andalucía-CSIC, P.O. Box 3004, E-18008 Granada (Spain)
- Instituto de Física de Cantabria, CSIC-Universidad de Cantabria, E-39005 Santander (Spain)
- Centro de Astrobiología (INTA-CSIC), Ctra. de Torrejón a Ajalvir, km 4, E-28850 Torrejón de Ardoz, Madrid (Spain)
- School of Sciencies, European University Cyprus, Diogenes Street, Engomi, 1516 Nicosia (Cyprus)
- Instituto de Física Teórica, Universidad Autónoma de Madrid, E-28049 Madrid (Spain)
- South African Astronomical Observatory, P.O. Box 9, Observatory 7935 Cape Town (South Africa)
- Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249 (United States)
- Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom)
- Jodrell Bank Centre for Astrophysics, University of Manchester, Manchester M13 9PL (United Kingdom)
The Luminous Infrared Galaxy NGC 1614 hosts a prominent circumnuclear ring of star formation. However, the nature of the dominant emitting mechanism in its central ∼100 pc is still under debate. We present sub-arcsecond angular resolution radio, mid-infrared, Paα, optical, and X-ray observations of NGC 1614, aimed at studying in detail both the circumnuclear ring and the nuclear region. The 8.4 GHz continuum emission traced by the Very Large Array and the Gemini/T-ReCS 8.7 μm emission, as well as the Paα line emission, show remarkable morphological similarities within the star-forming ring, suggesting that the underlying emission mechanisms are tightly related. We used a Hubble Space Telescope/NICMOS Paα map of similar resolution to our radio maps to disentangle the thermal free-free and non-thermal synchrotron radio emission, from which we obtained the intrinsic synchrotron power law for each individual region within the central kiloparsec of NGC 1614. The radio ring surrounds a relatively faint, steep-spectrum source at the very center of the galaxy, suggesting that the central source is not powered by an active galactic nucleus (AGN), but rather by a compact (r ≲ 90 pc) starburst (SB). Chandra X-ray data also show that the central kiloparsec region is dominated by SB activity, without requiring the existence of an AGN. We also used publicly available infrared data to model-fit the spectral energy distribution of both the SB ring and a putative AGN in NGC 1614. In summary, we conclude that there is no need to invoke an AGN to explain the observed bolometric properties of the galaxy.
- OSTI ID:
- 22356911
- Journal Information:
- Astrophysical Journal, Vol. 786, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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