TY - JOUR
T1 - Improved Constraints on H 0 from a Combined Analysis of Gravitational-wave and Electromagnetic Emission from GW170817
AU - Guidorzi, C.
AU - Margutti, R.
AU - Brout, D.
AU - Scolnic, D.
AU - Fong, W.
AU - Alexander, K. D.
AU - Cowperthwaite, P. S.
AU - Annis, J.
AU - Berger, E.
AU - Blanchard, P. K.
AU - Chornock, R.
AU - Coppejans, D. L.
AU - Eftekhari, T.
AU - Frieman, J. A.
AU - Huterer, D.
AU - Nicholl, M.
AU - Soares-Santos, M.
AU - Terreran, G.
AU - Villar, V. A.
AU - Williams, P. K.G.
N1 - Funding Information:
We thank the anonymous reviewer for their constructive and detailed report that helped us improve the Letter. C.G. acknowledges University of Ferrara for use of the local HPC facility co-funded by the “Large-Scale Facilities 2010” project (grant 7746/2011). This research was supported in part through the computational resources and staff contributions provided for the Quest high performance computing facility at North-western University, which is jointly supported by the Office of the Provost, the Office for Research, and Northwestern University Information Technology. We gratefully acknowledge Piero Rosati for granting us usage of proprietary HPC facility. The Berger Time-Domain Group at Harvard is supported in part by the NSF through grants AST-1411763 and AST-1714498, and by NASA through grants NNX15AE50G and NNX16AC22G. D.A.B. is supported by NSF award PHY-1707954. Development of the BOXFIT code was supported in part by NASA through grant NNX10AF62G issued through the Astrophysics Theory Program and by the NSF through grant AST-1009863. Simulations for BOXFITv2 have been carried out in part on the computing facilities of the Computational Center for Particle and Astrophysics of the research cooperation “Excellence Cluster Universe” in Garch-ing, Germany. D.S. is supported by NASA through Hubble Fellowship grant HST-HF2-51383.001 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. We gratefully acknowledge the director of the Anglo-Australian Telescope for their discretionary time on the AAOmega Spectrograph. Based in part on data acquired through the Australian Astronomical Observatory. We acknowledge the traditional owners of the land on which the AAT stands, the Gamilaraay people, and pay our respects to elders past and present. We acknowledge members of the LIGO Scientific Collaboration and the Virgo Collaboration for contributions in formulating some of the ideas in this work, in particular through our collaborative efforts on Abbott et al. (2017a).
Publisher Copyright:
© 2017. The American Astronomical Society. All rights reserved..
PY - 2017/12/20
Y1 - 2017/12/20
N2 - The luminosity distance measurement of GW170817 derived from gravitational-wave analysis in Abbott et al. (2017a, hereafter A17:H0) is highly correlated with the measured inclination of the NS-NS system. To improve the precision of the distance measurement, we attempt to constrain the inclination by modeling the broadband X-ray-to-radio emission from GW170817, which is dominated by the interaction of the jet with the environment. We update our previous analysis and we consider the radio and X-ray data obtained at t < 40 days since merger. We find that the afterglow emission from GW170817 is consistent with an off-axis relativistic jet with energy E k ∼ 1048 -3 1050 erg propagating into an environment with density n ∼ 10-2-10-4 cm-3, with preference for wider jets (opening angle θ j = 15°). For these jets, our modeling indicates an off-axis angle θ obs ∼ 25°-50°. We combine our constraints on θ obs with the joint distance-inclination constraint from LIGO. Using the same ∼170 km s-1 peculiar velocity uncertainty assumed in A17:H0 but with an inclination constraint from the afterglow data, we get a value of km s-1 Mpc-1, which is higher than the value of km s-1 Mpc-1 found in A17:H0. Further, using a more realistic peculiar velocity uncertainty of 250 km s-1 derived from previous work, we find km s-1 Mpc-1 for H 0 from this system. This is in modestly better agreement with the local distance ladder than the Planck cosmic microwave background, though such a significant discrimination will require ∼50 such events. Measurements at t > 100 days of the X-ray and radio emission will lead to tighter constraints.
AB - The luminosity distance measurement of GW170817 derived from gravitational-wave analysis in Abbott et al. (2017a, hereafter A17:H0) is highly correlated with the measured inclination of the NS-NS system. To improve the precision of the distance measurement, we attempt to constrain the inclination by modeling the broadband X-ray-to-radio emission from GW170817, which is dominated by the interaction of the jet with the environment. We update our previous analysis and we consider the radio and X-ray data obtained at t < 40 days since merger. We find that the afterglow emission from GW170817 is consistent with an off-axis relativistic jet with energy E k ∼ 1048 -3 1050 erg propagating into an environment with density n ∼ 10-2-10-4 cm-3, with preference for wider jets (opening angle θ j = 15°). For these jets, our modeling indicates an off-axis angle θ obs ∼ 25°-50°. We combine our constraints on θ obs with the joint distance-inclination constraint from LIGO. Using the same ∼170 km s-1 peculiar velocity uncertainty assumed in A17:H0 but with an inclination constraint from the afterglow data, we get a value of km s-1 Mpc-1, which is higher than the value of km s-1 Mpc-1 found in A17:H0. Further, using a more realistic peculiar velocity uncertainty of 250 km s-1 derived from previous work, we find km s-1 Mpc-1 for H 0 from this system. This is in modestly better agreement with the local distance ladder than the Planck cosmic microwave background, though such a significant discrimination will require ∼50 such events. Measurements at t > 100 days of the X-ray and radio emission will lead to tighter constraints.
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U2 - 10.3847/2041-8213/aaa009
DO - 10.3847/2041-8213/aaa009
M3 - Article
AN - SCOPUS:85039743277
SN - 2041-8205
VL - 851
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 2
M1 - L36
ER -