journal contribution posted on 15.08.2018, 15:18 by Michał J. Michałowski, Dong Xu, Jamie Stevens, Andrew Levan, Jun Yang, Zsolt Paragi, Atish Kamble, An-Li Tsai, Helmut Dannerbauer, Alexander J. van der Horst, Lang Shao, David Crosby, Gianfranco Gentile, Elizabeth Stanway, Klaas Wiersema, Johan P. U. F Fynbo, Nial R. Tanvir, Peter Kamphuis, Michael Garrett, Przemysław Bartczak
We report the detection of the radio afterglow of a long gamma-ray burst (GRB) 111005A at 5-345 GHz, including the very long baseline interferometry observations with the positional error of 0.2 mas. The afterglow position is coincident with the disk of a galaxy ESO 580-49 at z= 0.01326 (~1" from its center), which makes GRB 111005A the second closest GRB known to date, after GRB 980425. The radio afterglow of GRB 111005A was an order of magnitude less luminous than those of local low-luminosity GRBs, and obviously than those of cosmological GRBs. The radio flux was approximately constant and then experienced an unusually rapid decay a month after the GRB explosion. Similarly to only two other GRBs, we did not find the associated supernovae (SN), despite deep near- and mid-infrared observations 1-9 days after the GRB explosion, reaching ~20 times fainter than other SNe associated with GRBs. Moreover, we measured twice solar metallicity for the GRB location. The low gamma-ray and radio luminosities, rapid decay, lack of a SN, and super-solar metallicity suggest that GRB 111005A represents a different rare class of GRBs than typical core-collapse events. We modelled the spectral energy distribution of the GRB 111005A host finding that it is a dwarf, moderately star-forming galaxy, similar to the host of GRB 980425. The existence of two local GRBs in such galaxies is still consistent with the hypothesis that the GRB rate is proportional to the cosmic star formation rate (SFR) density, but suggests that the GRB rate is biased towards low SFRs. Using the far-infrared detection of ESO 580-49, we conclude that the hosts of both GRBs 111005A and 980425 exhibit lower dust content than what would be expected from their stellar masses and optical colours.
We thank Joanna Baradziej and our referee for
help with improving this paper; the staff at the ATCA, EVN, VLBA,
WSRT, PdBI, APEX, VLT, WHT, Spitzer and HST for scheduling
these observations. Axel Weiss for help with the APEX observations;
and Jan Martin Winters for help with the PdBI observations.
M.J.M. and A.-L.T. acknowledge the support of the
National Science Centre, Poland through the POLONEZ grant
2015/19/P/ST9/04010. M.J.M. acknowledges the support of the UK
Science and Technology Facilities Council, the SUPA Postdoctoral
and Early Career Researcher Exchange Program, and the hospitality
at the Harvard-Smithsonian Center for Astrophysics and the
National Astronomical Observatories, Chinese Academy of Sciences.
This project has received funding from the European Union’s
Horizon 2020 research and innovation programme under the Marie
Sk lodowska-Curie grant agreement No. 665778. The Dark Cosmology
Centre is funded by the Danish National Research Foundation.
H.D. acknowledges financial support from the Spanish Ministry of
Economy and Competitiveness (MINECO) under the 2014 Ramon
y Cajal program MINECO RYC-2014-15686. L.S. acknowledges
the support by National Basic Research Program of China (No. 2014CB845800) and the National Natural Science Foundation of
China (No. 11361140349 and No. 11103083).
The Australia Telescope is funded by the Commonwealth of
Australia for operation as a National Facility managed by CSIRO.
The National Radio Astronomy Observatory is a facility of the
National Science Foundation operated under cooperative agreement
by Associated Universities, Inc. This work made use of the Swinburne
University of Technology software correlator, developed as part of
the Australian Major National Research Facilities Programme and
operated under licence. The European VLBI Network is a joint facility
of independent European, African, Asian, and North American
radio astronomy institutes. Scientific results from data presented in
CitationAstronomy and Astrophysics, 2018
Author affiliation/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy
VersionVoR (Version of Record)
Published inAstronomy and Astrophysics
PublisherEDP Sciences for European Southern Observatory (ESO)