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The Needle in the 100 deg² Haystack: The Hunt for Binary Neutron Star Mergers with LIGO and Palomar Transient Factory


Singer, Leo Pound (2015) The Needle in the 100 deg² Haystack: The Hunt for Binary Neutron Star Mergers with LIGO and Palomar Transient Factory. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/Z9ZP442V.


The Advanced LIGO and Virgo experiments are poised to detect gravitational waves (GWs) directly for the first time this decade. The ultimate prize will be joint observation of a compact binary merger in both gravitational and electromagnetic channels. However, GW sky locations that are uncertain by hundreds of square degrees will pose a challenge. I describe a real-time detection pipeline and a rapid Bayesian parameter estimation code that will make it possible to search promptly for optical counterparts in Advanced LIGO. Having analyzed a comprehensive population of simulated GW sources, we describe the sky localization accuracy that the GW detector network will achieve as each detector comes online and progresses toward design sensitivity. Next, in preparation for the optical search with the intermediate Palomar Transient Factory (iPTF), we have developed a unique capability to detect optical afterglows of gamma-ray bursts (GRBs) detected by the Fermi Gamma-ray Burst Monitor (GBM). Its comparable error regions offer a close parallel to the Advanced LIGO problem, but Fermi's unique access to MeV-GeV photons and its near all-sky coverage may allow us to look at optical afterglows in a relatively unexplored part of the GRB parameter space. We present the discovery and broadband follow-up observations (X-ray, UV, optical, millimeter, and radio) of eight GBM-IPTF afterglows. Two of the bursts (GRB 130702A / iPTF13bxl and GRB 140606B / iPTF14bfu) are at low redshift (z=0.145 and z = 0.384, respectively), are sub-luminous with respect to "standard" cosmological bursts, and have spectroscopically confirmed broad-line type Ic supernovae. These two bursts are possibly consistent with mildly relativistic shocks breaking out from the progenitor envelopes rather than the standard mechanism of internal shocks within an ultra-relativistic jet. On a technical level, the GBM--IPTF effort is a prototype for locating and observing optical counterparts of GW events in Advanced LIGO with the Zwicky Transient Facility.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Laser Interferometer Gravitational-Wave Observatory; LIGO; PTF; gravitational waves; compact binary coalescence; CBC; binary neutron star mergers; BNS; gamma-ray bursts; GRB; signal processing; Bayesian inference; parameter estimation; optical transients; optical counterparts; multimessenger
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Weinstein, Alan Jay (advisor)
  • Kulkarni, Shrinivas R. (co-advisor)
Group:LIGO, Palomar Transient Factory, Astronomy Department
Thesis Committee:
  • Weinstein, Alan Jay (chair)
  • Kulkarni, Shrinivas R.
  • Ott, Christian D.
  • Reitze, David H.
Defense Date:24 November 2014
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Funding AgencyGrant Number
NSF Graduate Research FellowshipUNSPECIFIED
John and Ursula Kanel Foundation Charitable ScholarshipUNSPECIFIED
Swift Guest Investigator Program Cycle 9NNX14AC24G
Swift Guest Investigator Program Cycle 10NNX14AI99G
Projects:LIGO, Virgo, Palomar Transient Factory, Zwicky Transient Facility
Record Number:CaltechTHESIS:12102014-223122387
Persistent URL:
Related URLs:
URLURL TypeDescription publication corresponding to Chapter 3 publication corresponding to Chapter 5 publication corresponding to Chapter 6 DocumentOnline supplemental data corresponding to Appendix D
Singer, Leo Pound0000-0001-9898-5597
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:8739
Deposited By: Leo Singer
Deposited On:12 Dec 2014 22:33
Last Modified:26 Oct 2021 18:25

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