Unveiling the enigma of ATLAS17aeu

DOI: 
10.1051/0004-6361/201833814
Publication date: 
01/01/2019
Main author: 
Melandri, A.
IAA authors: 
Castro-Tirado, A. J.;Hu, Y. -D.;Della Valle, M.
Authors: 
Melandri, A.;Rossi, A.;Benetti, S.;D'Elia, V.;Piranomonte, S.;Palazzi, E.;Levan, A. J.;Branchesi, M.;Castro-Tirado, A. J.;D'Avanzo, P.;Hu, Y. -D.;Raimondo, G.;Tanvir, N. R.;Tomasella, L.;Amati, L.;Campana, S.;Carini, R.;Covino, S.;Cusano, F.;Dadina, M.;Della Valle, M.;Fan, X.;Garnavich, P.;Grado, A.;Greco, G.;Hjorth, J.;Lyman, J. D.;Masetti, N.;O'Brien, P.;Pian, E.;Perego, A.;Salvaterra, R.;Stella, L.;Stratta, G.;Yang, S.;di Paola, A.;Caballero-García, M. D.;Fruchter, A. S.;Giunta, A.;Longo, F.;Pinamonti, M.;Sokolov, V. V.;Testa, V.;Valeev, A. F.;Brocato, E.
Journal: 
Astronomy and Astrophysics
Refereed: 
Yes
Publication type: 
Article
Volume: 
621
Pages: 
A81
Abstract: 
<BR /> Aims: The unusual transient ATLAS17aeu was serendipitously detected within the sky localisation of the gravitational wave trigger GW 170104. The importance of a possible association with gravitational waves coming from a binary black hole merger led to an extensive follow-up campaign, with the aim of assessing a possible connection with GW 170104. <BR /> Methods: With several telescopes, we carried out both photometric and spectroscopic observations of ATLAS17aeu, for several epochs, between ̃3 and ̃230 days after the first detection. <BR /> Results: We studied in detail the temporal and spectroscopic properties of ATLAS17aeu and its host galaxy. Although at low significance and not conclusive, we found similarities to the spectral features of a broad-line supernova superposed onto an otherwise typical long-GRB afterglow. Based on analysis of the optical light curve, spectrum, and host galaxy spectral energy distribution, we conclude that the redshift of the source is probably z ≃ 0.5 ± 0.2. <BR /> Conclusions: While the redshift range we have determined is marginally compatible with that of the gravitational wave event, the presence of a supernova component and the consistency of this transient with the E<SUB>p</SUB>-E<SUB>iso</SUB> correlation support the conclusion that ATLAS17aeu was associated with the long gamma-ray burst GRB 170105A. This rules out the association of the GRB 170105A/ATLAS17aeu transient with the gravitational wave event GW 170104, which was due to a binary black hole merger. Based on observations made with the following telescopes: Copernico, TNG (under programme A34TAC_24), GTC (under programmes GTCMULTIPLE2D-16B and GTCMULTIPLE2G-17A), LBT (under programme 2016_2017_19), and HST (under programme GO14270).Spectral data for this source shown on this paper are available on the Weizmann Interactive Supernova Data Repository (WISeREP, <A href='https://wiserep.weizmann.ac.il/'>http://https://wiserep.weizmann.ac.il/</A>).
Database: 
ADS
SCOPUS
URL: 
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85059963528&doi=10.1051%2f0004-6361%2f201833814&partnerID=40&md5=7b33f32b557c658b24751f6680b428b0
ADS Bibcode: 
2019A&A...621A..81M
Keywords: 
gamma-ray burst: individual: GRB 170105A;supernovae: general;gravitational waves;Astrophysics - High Energy Astrophysical Phenomena