TY - JOUR
T1 - Optimized Radio Follow-up of Binary Neutron-star Mergers
AU - Carbone, Dario
AU - Corsi, Alessandra
N1 - Funding Information:
D.C. and A.C. acknowledge support from the National Science Foundation CAREER Award No. 1455090, and partial support from the Swift Cycle 12 GI program (grant No. NNX17AF93G).
Publisher Copyright:
© 2018. The American Astronomical Society. All rights reserved.
PY - 2018/11/10
Y1 - 2018/11/10
N2 - Motivated by the recent discovery of the binary neutron-star (BNS) merger GW170817, we determine the optimal observational setup for detecting and characterizing radio counterparts of nearby (d L ∼ 40 Mpc) BNS mergers. We simulate GW170817-like radio transients, and radio afterglows generated by fast jets with isotropic energy erg, expanding in a low-density interstellar medium (ISM; cm-3), observed from different viewing angles (from slightly off-axis to largely off-axis). We then determine the optimal timing of GHz radio observations following the precise localization of the BNS radio counterpart candidate, assuming a sensitivity comparable to that of the Karl G. Jansky Very Large Array. The optimization is done so as to ensure that properties such as viewing angle and circumstellar density can be correctly reconstructed with the minimum number of observations. We show that radio is the optimal band to explore the fastest ejecta from BNSs in the low-density ISM, since the optical emission is likely to be dominated by the so-called "kilonova" component, while X-rays from the jet are detectable only for a small subset of the BNS models considered here. Finally, we discuss how future radio arrays like the next-generation VLA would improve the detectability of BNS mergers with physical parameters similar to those explored here.
AB - Motivated by the recent discovery of the binary neutron-star (BNS) merger GW170817, we determine the optimal observational setup for detecting and characterizing radio counterparts of nearby (d L ∼ 40 Mpc) BNS mergers. We simulate GW170817-like radio transients, and radio afterglows generated by fast jets with isotropic energy erg, expanding in a low-density interstellar medium (ISM; cm-3), observed from different viewing angles (from slightly off-axis to largely off-axis). We then determine the optimal timing of GHz radio observations following the precise localization of the BNS radio counterpart candidate, assuming a sensitivity comparable to that of the Karl G. Jansky Very Large Array. The optimization is done so as to ensure that properties such as viewing angle and circumstellar density can be correctly reconstructed with the minimum number of observations. We show that radio is the optimal band to explore the fastest ejecta from BNSs in the low-density ISM, since the optical emission is likely to be dominated by the so-called "kilonova" component, while X-rays from the jet are detectable only for a small subset of the BNS models considered here. Finally, we discuss how future radio arrays like the next-generation VLA would improve the detectability of BNS mergers with physical parameters similar to those explored here.
KW - gravitational waves
KW - methods: numerical
KW - methods: statistical
KW - surveys
UR - http://www.scopus.com/inward/record.url?scp=85056634792&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/aae583
DO - 10.3847/1538-4357/aae583
M3 - Article
AN - SCOPUS:85056634792
VL - 867
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2
M1 - 135
ER -