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Open Access Publications from the University of California


  • Author(s): Kasliwal, MM
  • Cenko, SB
  • Singer, LP
  • Corsi, A
  • Cao, Y
  • Barlow, T
  • Bhalerao, V
  • Bellm, E
  • Cook, D
  • Duggan, GE
  • Ferretti, R
  • Frail, DA
  • Horesh, A
  • Kendrick, R
  • Kulkarni, SR
  • Lunnan, R
  • Palliyaguru, N
  • Laher, R
  • Masci, F
  • Manulis, I
  • Miller, AA
  • Nugent, PE
  • Perley, D
  • Prince, TA
  • Quimby, RM
  • Rana, J
  • Rebbapragada, U
  • Sesar, B
  • Singhal, A
  • Surace, J
  • Sistine, A Van
  • et al.

© 2016. The American Astronomical Society. All rights reserved.. The intermediate Palomar Transient Factory (iPTF) autonomously responded to and promptly tiled the error region of the first gravitational-wave event GW150914 to search for an optical counterpart. Only a small fraction of the total localized region was immediately visible in the northern night sky, due both to Sun-angle and elevation constraints. Here, we report on the transient candidates identified and rapid follow-up undertaken to determine the nature of each candidate. Even in the small area imaged of 126 deg2, after extensive filtering, eight candidates were deemed worthy of additional follow-up. Within two hours, all eight were spectroscopically classified by the Keck II telescope. Curiously, even though such events are rare, one of our candidates was a superluminous supernova. We obtained radio data with the Jansky Very Large Array and X-ray follow-up with the Swift satellite for this transient. None of our candidates appear to be associated with the gravitational-wave trigger, which is unsurprising given that GW150914 came from the merger of two stellar-mass black holes. This end-to-end discovery and follow-up campaign bodes well for future searches in this post-detection era of gravitational waves.

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