Follow-up of the Neutron Star Bearing Gravitational-wave Candidate Events S190425z and S190426c with MMT and SOAR
G. Hosseinzadeh, P. S. Cowperthwaite, S. Gomez, V. A. Villar, M. Nicholl, R. Margutti, E. Berger, R. Chornock, K. Paterson, W. Fong, V. Savchenko, P. Short, K. D. Alexander, P. K. Blanchard, J. Braga, M. L. Calkins, R. Cartier, D. L. Coppejans, T. Eftekhari, T. Laskar
C. Ly, L. Patton, I. Pelisoli, D. E. Reichart, G. Terreran, P. K.G. Williams
Astronomy & Astrophysics
On 2019 April 25.346 and 26.640 UT the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo gravitational-wave (GW) observatory announced the detection of the first candidate events in Observing Run 3 that contained at least one neutron star (NS). S190425z is a likely binary neutron star (BNS) merger at dL = 156 ± 41 Mpc, while S190426c is possibly the first NS-black hole (BH) merger ever detected, at dL = 377 ± 100 Mpc, although with marginal statistical significance. Here we report our optical follow-up observations for both events using the MMT 6.5 m telescope, as well as our spectroscopic follow-up of candidate counterparts (which turned out to be unrelated) with the 4.1 m SOAR telescope. We compare to publicly reported searches, explore the overall areal coverage and depth, and evaluate those in relation to the optical/near-infrared (NIR) kilonova emission from the BNS merger GW170817, to theoretical kilonova models, and to short gamma-ray burst (SGRB) afterglows. We find that for a GW170817-like kilonova, the partial volume covered spans up to about 40% for S190425z and 60% for S190426c. For an on-axis jet typical of SGRBs, the search effective volume is larger, but such a configuration is expected in at most a few percent of mergers. We further find that wide-field γ-ray and X-ray limits rule out luminous on-axis SGRBs, for a large fraction of the localization regions, although these searches are not sufficiently deep in the context of the γ-ray emission from GW170817 or off-axis SGRB afterglows. The results indicate that some optical follow-up searches are sufficiently deep for counterpart identification to about 300 Mpc, but that localizations better than 1000 deg2 are likely essential.
10.3847/2041-8213/ab271c
Hosseinzadeh, G., Cowperthwaite, P. S., Gomez, S., Villar, V. A., Nicholl, M., Margutti, R., Berger, E., Chornock, R., Paterson, K., Fong, W., Savchenko, V., Short, P., Alexander, K. D., Blanchard, P. K., Braga, J., Calkins, M. L., Cartier, R., Coppejans, D. L., Eftekhari, T., ... Williams, P. K. G. (2019). Follow-up of the Neutron Star Bearing Gravitational-wave Candidate Events S190425z and S190426c with MMT and SOAR. Astrophysical Journal Letters, 880(1), [L4]. https://doi.org/10.3847/2041-8213/ab271c
Hosseinzadeh, G. ; Cowperthwaite, P. S. ; Gomez, S. ; Villar, V. A. ; Nicholl, M. ; Margutti, R. ; Berger, E. ; Chornock, R. ; Paterson, K. ; Fong, W. ; Savchenko, V. ; Short, P. ; Alexander, K. D. ; Blanchard, P. K. ; Braga, J. ; Calkins, M. L. ; Cartier, R. ; Coppejans, D. L. ; Eftekhari, T. ; Laskar, T. ; Ly, C. ; Patton, L. ; Pelisoli, I. ; Reichart, D. E. ; Terreran, G. ; Williams, P. K.G. / Follow-up of the Neutron Star Bearing Gravitational-wave Candidate Events S190425z and S190426c with MMT and SOAR. In: Astrophysical Journal Letters. 2019 ; Vol. 880, No. 1.
@article{b54ad1ca735e484092af82c5532554e8,
title = "Follow-up of the Neutron Star Bearing Gravitational-wave Candidate Events S190425z and S190426c with MMT and SOAR",
abstract = "On 2019 April 25.346 and 26.640 UT the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo gravitational-wave (GW) observatory announced the detection of the first candidate events in Observing Run 3 that contained at least one neutron star (NS). S190425z is a likely binary neutron star (BNS) merger at dL = 156 ± 41 Mpc, while S190426c is possibly the first NS-black hole (BH) merger ever detected, at dL = 377 ± 100 Mpc, although with marginal statistical significance. Here we report our optical follow-up observations for both events using the MMT 6.5 m telescope, as well as our spectroscopic follow-up of candidate counterparts (which turned out to be unrelated) with the 4.1 m SOAR telescope. We compare to publicly reported searches, explore the overall areal coverage and depth, and evaluate those in relation to the optical/near-infrared (NIR) kilonova emission from the BNS merger GW170817, to theoretical kilonova models, and to short gamma-ray burst (SGRB) afterglows. We find that for a GW170817-like kilonova, the partial volume covered spans up to about 40% for S190425z and 60% for S190426c. For an on-axis jet typical of SGRBs, the search effective volume is larger, but such a configuration is expected in at most a few percent of mergers. We further find that wide-field γ-ray and X-ray limits rule out luminous on-axis SGRBs, for a large fraction of the localization regions, although these searches are not sufficiently deep in the context of the γ-ray emission from GW170817 or off-axis SGRB afterglows. The results indicate that some optical follow-up searches are sufficiently deep for counterpart identification to about 300 Mpc, but that localizations better than 1000 deg2 are likely essential.",
author = "G. Hosseinzadeh and Cowperthwaite, {P. S.} and S. Gomez and Villar, {V. A.} and M. Nicholl and R. Margutti and E. Berger and R. Chornock and K. Paterson and W. Fong and V. Savchenko and P. Short and Alexander, {K. D.} and Blanchard, {P. K.} and J. Braga and Calkins, {M. L.} and R. Cartier and Coppejans, {D. L.} and T. Eftekhari and T. Laskar and C. Ly and L. Patton and I. Pelisoli and Reichart, {D. E.} and G. Terreran and Williams, {P. K.G.}",
note = "Funding Information: The Berger Time-Domain Group is supported in part by NSF grant AST-1714498 and NASA grant NNX15AE50G. G.H. thanks the LSSTC Data Science Fellowship Program, which is funded by LSSTC, NSF Cybertraining Grant #1829740, the Brinson Foundation, and the Moore Foundation; his participation in the program has benefited this work. P.S.C. is grateful for support provided by NASA through the NASA Hubble Fellowship grant #HST-HF2-51404.001-A 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. M.N. is supported by a Royal Astronomical Society Research Fellowship. W.F. and K.P. acknowledge support by the National Science Foundation under award No. AST-1814782. I.P. acknowledges funding by the Deutsche Forschungsgemeinschaft under grant GE2506/ 12-1. R.M. acknowledges support for this work provided by the National Aeronautics and Space Administration through Chandra award No. DD8-19101A and DDT-18096A issued by the Chandra X-ray Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of the National Aeronautics Space Administration under contract NAS8-03060. K.D.A. is grateful for support provided by NASA through the NASA Hubble Fellowship grant #HSTHF2- 51403.001-A 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. 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. Funding Information: 2019-07-20 2019-07-18 08:37:43 cgi/release: Article released bin/incoming: New from .zip National Science Foundation AST-1714498 AST-1814782 National Aeronautics and Space Administration HST-HF-51404.001-A HST-HF2-51403.001-A Deutsche Forschungsgemeinschaft GE2506/12-1 yes Publisher Copyright: {\textcopyright} 2019. The American Astronomical Society. All rights reserved.",
doi = "10.3847/2041-8213/ab271c",
Hosseinzadeh, G, Cowperthwaite, PS, Gomez, S, Villar, VA, Nicholl, M, Margutti, R, Berger, E, Chornock, R, Paterson, K, Fong, W, Savchenko, V, Short, P, Alexander, KD, Blanchard, PK, Braga, J, Calkins, ML, Cartier, R, Coppejans, DL, Eftekhari, T, Laskar, T, Ly, C, Patton, L, Pelisoli, I, Reichart, DE, Terreran, G & Williams, PKG 2019, 'Follow-up of the Neutron Star Bearing Gravitational-wave Candidate Events S190425z and S190426c with MMT and SOAR', Astrophysical Journal Letters, vol. 880, no. 1, L4. https://doi.org/10.3847/2041-8213/ab271c
Follow-up of the Neutron Star Bearing Gravitational-wave Candidate Events S190425z and S190426c with MMT and SOAR. / Hosseinzadeh, G.; Cowperthwaite, P. S.; Gomez, S.; Villar, V. A.; Nicholl, M.; Margutti, R.; Berger, E.; Chornock, R.; Paterson, K.; Fong, W.; Savchenko, V.; Short, P.; Alexander, K. D.; Blanchard, P. K.; Braga, J.; Calkins, M. L.; Cartier, R.; Coppejans, D. L.; Eftekhari, T.; Laskar, T.; Ly, C.; Patton, L.; Pelisoli, I.; Reichart, D. E.; Terreran, G.; Williams, P. K.G.
In: Astrophysical Journal Letters, Vol. 880, No. 1, L4, 20.07.2019.
T1 - Follow-up of the Neutron Star Bearing Gravitational-wave Candidate Events S190425z and S190426c with MMT and SOAR
AU - Hosseinzadeh, G.
AU - Cowperthwaite, P. S.
AU - Gomez, S.
AU - Villar, V. A.
AU - Nicholl, M.
AU - Margutti, R.
AU - Berger, E.
AU - Chornock, R.
AU - Paterson, K.
AU - Fong, W.
AU - Savchenko, V.
AU - Short, P.
AU - Alexander, K. D.
AU - Blanchard, P. K.
AU - Braga, J.
AU - Calkins, M. L.
AU - Cartier, R.
AU - Coppejans, D. L.
AU - Eftekhari, T.
AU - Laskar, T.
AU - Ly, C.
AU - Patton, L.
AU - Pelisoli, I.
AU - Reichart, D. E.
AU - Terreran, G.
AU - Williams, P. K.G.
N1 - Funding Information: The Berger Time-Domain Group is supported in part by NSF grant AST-1714498 and NASA grant NNX15AE50G. G.H. thanks the LSSTC Data Science Fellowship Program, which is funded by LSSTC, NSF Cybertraining Grant #1829740, the Brinson Foundation, and the Moore Foundation; his participation in the program has benefited this work. P.S.C. is grateful for support provided by NASA through the NASA Hubble Fellowship grant #HST-HF2-51404.001-A 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. M.N. is supported by a Royal Astronomical Society Research Fellowship. W.F. and K.P. acknowledge support by the National Science Foundation under award No. AST-1814782. I.P. acknowledges funding by the Deutsche Forschungsgemeinschaft under grant GE2506/ 12-1. R.M. acknowledges support for this work provided by the National Aeronautics and Space Administration through Chandra award No. DD8-19101A and DDT-18096A issued by the Chandra X-ray Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of the National Aeronautics Space Administration under contract NAS8-03060. K.D.A. is grateful for support provided by NASA through the NASA Hubble Fellowship grant #HSTHF2- 51403.001-A 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. 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. Funding Information: 2019-07-20 2019-07-18 08:37:43 cgi/release: Article released bin/incoming: New from .zip National Science Foundation AST-1714498 AST-1814782 National Aeronautics and Space Administration HST-HF-51404.001-A HST-HF2-51403.001-A Deutsche Forschungsgemeinschaft GE2506/12-1 yes Publisher Copyright: © 2019. The American Astronomical Society. All rights reserved.
N2 - On 2019 April 25.346 and 26.640 UT the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo gravitational-wave (GW) observatory announced the detection of the first candidate events in Observing Run 3 that contained at least one neutron star (NS). S190425z is a likely binary neutron star (BNS) merger at dL = 156 ± 41 Mpc, while S190426c is possibly the first NS-black hole (BH) merger ever detected, at dL = 377 ± 100 Mpc, although with marginal statistical significance. Here we report our optical follow-up observations for both events using the MMT 6.5 m telescope, as well as our spectroscopic follow-up of candidate counterparts (which turned out to be unrelated) with the 4.1 m SOAR telescope. We compare to publicly reported searches, explore the overall areal coverage and depth, and evaluate those in relation to the optical/near-infrared (NIR) kilonova emission from the BNS merger GW170817, to theoretical kilonova models, and to short gamma-ray burst (SGRB) afterglows. We find that for a GW170817-like kilonova, the partial volume covered spans up to about 40% for S190425z and 60% for S190426c. For an on-axis jet typical of SGRBs, the search effective volume is larger, but such a configuration is expected in at most a few percent of mergers. We further find that wide-field γ-ray and X-ray limits rule out luminous on-axis SGRBs, for a large fraction of the localization regions, although these searches are not sufficiently deep in the context of the γ-ray emission from GW170817 or off-axis SGRB afterglows. The results indicate that some optical follow-up searches are sufficiently deep for counterpart identification to about 300 Mpc, but that localizations better than 1000 deg2 are likely essential.
AB - On 2019 April 25.346 and 26.640 UT the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo gravitational-wave (GW) observatory announced the detection of the first candidate events in Observing Run 3 that contained at least one neutron star (NS). S190425z is a likely binary neutron star (BNS) merger at dL = 156 ± 41 Mpc, while S190426c is possibly the first NS-black hole (BH) merger ever detected, at dL = 377 ± 100 Mpc, although with marginal statistical significance. Here we report our optical follow-up observations for both events using the MMT 6.5 m telescope, as well as our spectroscopic follow-up of candidate counterparts (which turned out to be unrelated) with the 4.1 m SOAR telescope. We compare to publicly reported searches, explore the overall areal coverage and depth, and evaluate those in relation to the optical/near-infrared (NIR) kilonova emission from the BNS merger GW170817, to theoretical kilonova models, and to short gamma-ray burst (SGRB) afterglows. We find that for a GW170817-like kilonova, the partial volume covered spans up to about 40% for S190425z and 60% for S190426c. For an on-axis jet typical of SGRBs, the search effective volume is larger, but such a configuration is expected in at most a few percent of mergers. We further find that wide-field γ-ray and X-ray limits rule out luminous on-axis SGRBs, for a large fraction of the localization regions, although these searches are not sufficiently deep in the context of the γ-ray emission from GW170817 or off-axis SGRB afterglows. The results indicate that some optical follow-up searches are sufficiently deep for counterpart identification to about 300 Mpc, but that localizations better than 1000 deg2 are likely essential.
U2 - 10.3847/2041-8213/ab271c
DO - 10.3847/2041-8213/ab271c
M1 - L4
Hosseinzadeh G, Cowperthwaite PS, Gomez S, Villar VA, Nicholl M, Margutti R et al. Follow-up of the Neutron Star Bearing Gravitational-wave Candidate Events S190425z and S190426c with MMT and SOAR. Astrophysical Journal Letters. 2019 Jul 20;880(1). L4. https://doi.org/10.3847/2041-8213/ab271c