| Title: |
Searching for Electromagnetic Counterparts to Gravitational-wave Merger Events with the Prototype Gravitational-wave Optical Transient Observer (GOTO-4) |
| Authors: |
Gompertz, B. P., Cutter, R., Steeghs, D., Galloway, D. K., Lyman, J., Ulaczyk, K., Dyer, M. J., Ackley, K., Dhillon, V. S., O'Brien, P. T., Ramsay, G., Poshyachinda, S., Kotak, R., Nuttall, L., Breton, R. P., Pallé, E., Pollacco, D., Thrane, E., Aukkaravittayapun, S., Awiphan, S., Brown, M. J. I., Burhanudin, U., Chote, P., Chrimes, A. A., Daw, E., Duffy, C., Eyles-Ferris, R. A. J., Heikkilä, T., Irawati, P., Kennedy, M. R., Killestein, T., Levan, A. J., Littlefair, S., Makrygianni, L., Marsh, T., Sánchez, D. Mata, Mattila, S., Maund, J., McCormac, J., Mkrtichian, D., Mong, Y. -L., Mullaney, J., Müller, B., Obradovic, A., Rol, E., Sawangwit, U., Stanway, E. R., Starling, R. L. C., Strøm, P., Tooke, S., West, R., Wiersema, K. |
| Publication Year: |
2020 |
| Collection: |
Astrophysics |
| Subject Terms: |
Astrophysics - High Energy Astrophysical Phenomena |
| More Details: |
We report the results of optical follow-up observations of 29 gravitational-wave triggers during the first half of the LIGO-Virgo Collaboration (LVC) O3 run with the Gravitational-wave Optical Transient Observer (GOTO) in its prototype 4-telescope configuration (GOTO-4). While no viable electromagnetic counterpart candidate was identified, we estimate our 3D (volumetric) coverage using test light curves of on- and off-axis gamma-ray bursts and kilonovae. In cases where the source region was observable immediately, GOTO-4 was able to respond to a GW alert in less than a minute. The average time of first observation was $8.79$ hours after receiving an alert ($9.90$ hours after trigger). A mean of $732.3$ square degrees were tiled per event, representing on average $45.3$ per cent of the LVC probability map, or $70.3$ per cent of the observable probability. This coverage will further improve as the facility scales up alongside the localisation performance of the evolving gravitational-wave detector network. Even in its 4-telescope prototype configuration, GOTO is capable of detecting AT2017gfo-like kilonovae beyond 200~Mpc in favourable observing conditions. We cannot currently place meaningful electromagnetic limits on the population of distant ($\hat{D}_L = 1.3$~Gpc) binary black hole mergers because our test models are too faint to recover at this distance. However, as GOTO is upgraded towards its full 32-telescope, 2 node (La Palma \& Australia) configuration, it is expected to be sufficiently sensitive to cover the predicted O4 binary neutron star merger volume, and will be able to respond to both northern and southern triggers.
Comment: 15 pages, 7 figures, 3 tables. Accepted for publication in MNRAS. Author's final submitted version |
| Document Type: |
Working Paper |
| DOI: |
10.1093/mnras/staa1845 |
| Access URL: |
http://arxiv.org/abs/2004.00025 |
| Accession Number: |
edsarx.2004.00025 |
| Database: |
arXiv |
