James Webb Space Telescope can Detect Kilonovae in Gravitational Wave Follow-up Search [HEAP]


Kilonovae represent an important electromagnetic counterpart for compact binary mergers, which could become the most commonly detected gravitational wave (GW) source. Follow-up observations, triggered by GW sources, of kilonovae are nevertheless difficult due to poor localization by GW detectors and due to their faint near-infrared peak emission that has limited observational capability. We show that the Near-Infrared Camera (NIRCam) on the James Webb Space Telescope (JWST) will be able to detect kilonovae within the relevant GW-detection range of $\sim300$ Mpc, in less than NIRCam’s minimum exposure time, for over a week following the merger. Despite this sensitivity, a kilonova search in all galaxies within 300 Mpc in the GW-localized sky area will not be viable with NIRCam because of JWST slew rates. However, targeted surveys may be developed to optimize the likelihood of discovering kilonovae efficiently within limited observing time. We estimate that a targeted survey focused on galaxies within 200 Mpc in a fiducial localized area of $10 \mbox{deg}^2$ would require $\sim$ 6.0 hours, dominated by overhead times; a targeted survey further focused on galaxies exhibiting high star-formation rates would require $\sim$ 2.8 hours. Required times may be reduced by as much as 40%, without compromising the likelihood of detecting kilonovae, in a targeted survey of localized areas associated with 50%, rather than 90%, confidence regions. On detection and identification of a kilonova, a limited number of NIRCam follow-up observations could constrain the properties of matter ejected by the binary and the equation of state of dense nuclear matter.

Read this paper on arXiv…

I. Bartos, T. Huard and S. Marka
Fri, 27 Feb 15

Comments: 8 pages, 2 figures