"Spitzer Space Telescope Infrared Observations of the Binary Neutron St" by V. A. Villar, P. S. Cowperthwaite et al.
 

Title

Spitzer Space Telescope Infrared Observations of the Binary Neutron Star Merger GW170817

Document Type

Article

Publication Date

7-20-2018

Keywords

gravitational waves, infrared: general, stars: neutron

Abstract

© 2018. The American Astronomical Society. We present Spitzer Space Telescope 3.6 and 4.5 μm observations of the binary neutron star merger GW170817 at 43, 74, and 264 days post-merger. Using the final observation as a template, we uncover a source at the position of GW170817 at 4.5 μm with a brightness of 22.9 0.3 AB mag at 43 days and 23.8 0.3 AB mag at 74 days (the uncertainty is dominated by systematics from the image subtraction); no obvious source is detected at 3.6 μm to a 3σ limit of >23.3 AB mag in both epochs. The measured brightness is dimmer by a factor of about 2-3 times compared to our previously published kilonova model, which is based on UV, optical, and near-infrared data at ≲30 days. However, the observed fading rate and color (m 3.6-m 4.5 0 AB mag) are consistent with our model. We suggest that the discrepancy is likely due to a transition to the nebular phase, or a reduced thermalization efficiency at such late time. Using the Spitzer data as a guide, we briefly discuss the prospects of observing future binary neutron star mergers with Spitzer (in the Laser Interferometer Gravitational-Wave Observatory (LIGO)/Virgo Observing Run 3) and the James Webb Space Telescope (in LIGO/Virgo Observing Run 4 and beyond).

Link to Full Text

Plum Print visual indicator of research metrics
PlumX Metrics
  • Usage
    • Abstract Views: 1
see details

COinS