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galaxy strategy for ligo-virgo gravitational wave counterpart searchesIn this work we continue a line of inquiry begun in Kanner et al. which detailed a strategy for utilizing telescopes with narrow fields of view, such as the Swift X-Ray Telescope (XRT), to localize gravity wave (GW) triggers from LIGO (Laser Interferometer Gravitational-Wave Observatory) / Virgo. If one considers the brightest galaxies that produce 50 percent of the light, then the number of galaxies inside typical GW error boxes will be several tens. We have found that this result applies both in the early years of Advanced LIGO when the range is small and the error boxes large, and in the later years when the error boxes will be small and the range large. This strategy has the beneficial property of reducing the number of telescope pointings by a factor 10 to 100 compared with tiling the entire error box. Additional galaxy count reduction will come from a GW rapid distance estimate which will restrict the radial slice in search volume. Combining the bright galaxy strategy with a convolution based on anticipated GW localizations, we find that the searches can be restricted to about 18 plus or minus 5 galaxies for 2015, about 23 plus or minus 4 for 2017, and about 11 plus or minus for 2020. This assumes a distance localization at the putative neutron star-neutron star (NS-NS) merger range mu for each target year, and these totals are integrated out to the range. Integrating out to the horizon would roughly double the totals. For localizations with r (rotation) greatly less than mu the totals would decrease. The galaxy strategy we present in this work will enable numerous sensitive optical and X-ray telescopes with small fields of view to participate meaningfully in searches wherein the prospects for rapidly fading afterglow place a premium on a fast response time.
Document ID
Document Type
Reprint (Version printed in journal)
Gehrels, Neil
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Cannizzo, John K.
(Maryland Univ. Baltimore County Baltimore, MD, United States)
Kanner, Jonah
(California Inst. of Tech. Pasadena, CA, United States)
Kasliwal, Mansi M.
(Carnegie Institution for Science Pasadena, CA, United States)
Nissanke, Samaya
(Radboud Univ. Nijmegen, Netherlands)
Singer, Leo P.
(Universities Space Research Association Greenbelt, MD, United States)
Date Acquired
February 12, 2016
Publication Date
February 8, 2016
Subject Category
Report/Patent Number
Funding Number(s)
Distribution Limits
galaxies: statistics aEuro" gamma-ray burst: general aEuro" gravitational waves