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- Ciroletti, M., et al.
(författare)
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FRB 150418: clues to its nature from European VLBI Network and e-MERLIN observations
- 2016
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 593, s. L16-L19
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Tidskriftsartikel (refereegranskat)abstract
- Aims: We investigate the nature of the compact and possibly variable nuclear radio source in the centre of WISE J0716-19, the proposed host galaxy of the fast radio burst FRB 150418. Methods: We observed WISE J0716-19 at 5.0 GHz with the European VLBI Network (EVN) four times between 2016 March 16 and June 2. At three epochs, we simultaneously observed the source with e-MERLIN at the same frequency. Results: We detected a compact source in the EVN data in each epoch with a significance of up to ~8σ. The four epochs yielded consistent results within their uncertainties for the peak surface intensity and positions. The mean values for these quantities are Ipeak = (115 ± 9)μJy beam-1 and RA = 07h16m34.55496(7)s, Dec = -19°00'39.4754(8)''. The e-MERLIN data provided ~3-5σ detections at a position consistent with those of the EVN data. The emission on angular scales intermediate between the EVN and e-MERLIN is consistent with being null. The brightness temperature of the EVN core is Tb ≳ 108.5 K, close to the value previously required to explain the short-term radio variability properties of WISE J0716-19 in terms of interstellar scintillation. Conclusions: Our observations provide direct and independent evidence of a nuclear compact source in WISE J0716-19, a physical scenario without evident connection with FRB 150418. However, the EVN data do not indicate the variability observed with the VLA.
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| 2. |
- Marcote, B., et al.
(författare)
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The origin of Fast Radio Bursts, still an open question
- 2016
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Ingår i: Proceedings of the 12th Scientific Meeting of the Spanish Astronomical Society - Highlights of Spanish Astrophysics IX, SEA 2016.
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Konferensbidrag (refereegranskat)abstract
- FRB 150418 is the first Fast Radio Burst (FRB) with a proposed counterpart. Keane et al. (2016) claimed that the galaxy WISE J0716-19 is the host of this event. Such association would provide extremely important clues about the possible extragalactic origin of the FRBs. It is still a mystery what kind of events produces the FRBs. We observed the proposed host galaxy with the European VLBI Network (EVN) during four epochs at 5 GHz, revealing a compact and persistent radio source located in the center of the galaxy. These data, together with contemporaneous observations, strongly support the presence of an active galactic nuclei (AGN) in the galaxy with variability on short timescales due to refractive scintillation. Therefore, WISE J0716-19 would not be related with FRB 150418.
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