@article{f0f5a3d5e1a04a01a1b751a1c9a05e76,
title = "GRB 190114C in the nuclear region of an interacting galaxy: A detailed host analysis using ALMA, the HST, and the VLT",
abstract = "Context. For the first time, very high energy emission up to the TeV range has been reported for a gamma-ray burst (GRB). It is still unclear whether the environmental properties of GRB 190114C might have contributed to the production of these very high energy photons, or if it is solely related to the released GRB emission. Aims. The relatively low redshift of the GRB (z = 0.425) allows us to study the host galaxy of this event in detail, and to potentially identify idiosyncrasies that could point to progenitor characteristics or environmental properties that might be responsible for this unique event. Methods. We used ultraviolet, optical, infrared, and submillimetre imaging and spectroscopy obtained with the HST, the VLT, and ALMA to obtain an extensive dataset on which the analysis of the host galaxy is based. Results. The host system is composed of a close pair of interacting galaxies (Δv = 50 km s-1), both of which are well detected by ALMA in CO(3-2). The GRB occurred within the nuclear region (∼170 pc from the centre) of the less massive but more star-forming galaxy of the pair. The host is more massive (log(M/M⊙ ) = 9.3) than average GRB hosts at this redshift, and the location of the GRB is rather unique. The higher star formation rate was probably triggered by tidal interactions between the two galaxies. Our ALMA observations indicate that both host galaxy and companion have a high molecular gas fraction, as has been observed before in interacting galaxy pairs. Conclusions. The location of the GRB within the core of an interacting galaxy with an extinguished line of sight is indicative of a denser environment than typically observed for GRBs and could have been crucial for the generation of the very high energy photons that were observed.",
author = "{De Ugarte Postigo}, A. and Th{\"o}ne, {C. C.} and S. Mart{\'i}n and J. Japelj and Levan, {A. J.} and Micha{\l}owski, {M. J.} and J. Selsing and Kann, {D. A.} and S. Schulze and Palmerio, {J. T.} and Vergani, {S. D.} and Tanvir, {N. R.} and K. Bensch and S. Covino and V. D'Elia and {De Pasquale}, M. and Fruchter, {A. S.} and Fynbo, {J. P.U.} and D. Hartmann and Heintz, {K. E.} and {Van Der Horst}, {A. J.} and L. Izzo and P. Jakobsson and Ng, {K. C.Y.} and Perley, {D. A.} and A. Rossi and B. Sbarufatti and R. Salvaterra and R. S{\'a}nchez-Ram{\'i}rez and D. Watson and D. Xu",
note = "Funding Information: Acknowledgements. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2018.A.00020.T. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. CT, AdUP, DAK, MB, and LI acknowledge support from the Spanish research project AYA2017-89384-P. CT and AdUP acknowledge support from funding associated to Ram{\'o}n y Cajal fellowships (RyC-2012-09984 and RyC-2012-09975). DAK acknowledges support from the Spanish research project RTI2018-098104-J-I00. M.J.M. acknowledges the support of the National Science Centre, Poland through the SONATA BIS grant 2018/30/E/ST9/00208. JPUF thanks the Carlsberg Foundation for support. KEH and PJ acknowledge support by a Project Grant (162948–051) from The Icelandic Research Fund. JS and DW are supported in part by Independent Research Fund Denmark grant DFF-7014-00017. The Cosmic Dawn Center is supported by the Danish National Research Foundation under grant No. 140. Funding Information: This paper makes use of the following ALMA data: ADS/JAO.ALMA#2018.A.00020.T. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. CT, AdUP, DAK, MB, and LI acknowledge support from the Spanish research project AYA2017-89384-P. CT and AdUP acknowledge support from funding associated to Ram?n y Cajal fellowships (RyC-2012-09984 and RyC-2012-09975). DAK acknowledges support from the Spanish research project RTI2018-098104-J-I00. M.J.M. acknowledges the support of the National Science Centre, Poland through the SONATA BIS grant 2018/30/E/ST9/00208. JPUF thanks the Carlsberg Foundation for support. KEH and PJ acknowledge support by a Project Grant (162948?051) from The Icelandic Research Fund. JS and DW are supported in part by Independent Research Fund Denmark grant DFF-7014-00017. The Cosmic Dawn Center is supported by the Danish National Research Foundation under grant No. 140. Publisher Copyright: {\textcopyright} ESO 2020.",
year = "2020",
month = jan,
day = "1",
doi = "10.1051/0004-6361/201936668",
language = "English (US)",
volume = "633",
journal = "Astronomy and Astrophysics",
issn = "0004-6361",
publisher = "EDP Sciences",
}