Serendipitous discovery of an optical emission line jet in NGC\,232
| Autor: | Lopez-Coba, C., Sanchez, S. F., Cruz-Gonzalez, I., Binette, L., Galbany, L., Kruhler, T., Rodrıguez, L. F., Barrera-Ballesteros, J. K., Sanchez-Menguiano, L., Walcher, C. J., Aquino-Ortız, E., Anderson, J. P. |
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| Rok vydání: | 2017 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.3847/2041-8213/aa98db |
| Popis: | We report the detection of a highly collimated linear emission-line structure in the spiral galaxy NGC\,232 through the use of integral field spectroscopy data from the All-weather MUse Supernova Integral field Nearby Galaxies (AMUSING) survey. This jet--like feature extends radially from the nucleus and is primarily detected in [oiii]$\lambda$5007 without clear evidence of an optical continuum counterpart. The length of the radial structure projected on sky reaches $\sim 3$ kpc, which makes NGC\,232 the second longest emission-line jet reported. The ionized gas presents extreme [Oiii]/H$\beta$ and [Nii]/H$\alpha$ line ratios, increasing along the jet-like structure. We discuss three possible scenarios to explain the observed structure: (i) direct ionization of in-falling material from the intergalactic medium by the AGN; (ii) photo-ionization by an un-detected optical counter-part of the radio jet and (iii) fast shocks ionization due to the lateral expansion of the radio jet across the ISM. Our analysis favors in-situ ionization. Comment: 7 pages, 2 figures, accepted for publishing in ApJL |
| Databáze: | arXiv |
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