_version_ 1866912972117377024
author Vieira, Nicholas
Franz, Noah
Subrayan, Bhagya
Kilpatrick, Charles D.
Sand, David J.
Fong, Wen-fai
Hosseinzadeh, Griffin
Alexander, Kate D.
Bostroem, K. Azalee
Rastinejad, Jillian
Paterson, Kerry
Shrestha, Manisha
Noel, Phillip
Darc, P.
Pearson, Jeniveve
Aamer, Aysha
Santos, A. Souza
Santana-Silva, Luidhy
Bom, Clecio R.
Cartier, Regis
Bommireddy, Hemanth
Rodríguez, Ósmar
Andrews, Jennifer E.
Ransome, Conor
Paschalidis, Vasileios
Strader, Jay
Grichener, Aldana
Quirola-Vásquez, J.
Vasylyev, Sergiy
Soares-Santos, Marcelle
Christy, Collin T.
Hsu, Brian
Fuls, D. Carson
Dong, Yize
Reichart, Daniel E.
Pineda-García, Jonathan
Daniel, Kathryne J.
Janzen, Daryl
Fields, C. E.
Zabludoff, Ann
Meza, Nicolas
E., Felipe Olivares
Spekkens, Kristine
Weiner, Benjamin
Williams, Maia
Gibbs, Alex R.
Shelly, Frank
Ravi, Aravind P.
Jha, Saurabh W.
Valenti, Stefano
Haislip, Joshua
Trilling, David E.
author_facet Vieira, Nicholas
Franz, Noah
Subrayan, Bhagya
Kilpatrick, Charles D.
Sand, David J.
Fong, Wen-fai
Hosseinzadeh, Griffin
Alexander, Kate D.
Bostroem, K. Azalee
Rastinejad, Jillian
Paterson, Kerry
Shrestha, Manisha
Noel, Phillip
Darc, P.
Pearson, Jeniveve
Aamer, Aysha
Santos, A. Souza
Santana-Silva, Luidhy
Bom, Clecio R.
Cartier, Regis
Bommireddy, Hemanth
Rodríguez, Ósmar
Andrews, Jennifer E.
Ransome, Conor
Paschalidis, Vasileios
Strader, Jay
Grichener, Aldana
Quirola-Vásquez, J.
Vasylyev, Sergiy
Soares-Santos, Marcelle
Christy, Collin T.
Hsu, Brian
Fuls, D. Carson
Dong, Yize
Reichart, Daniel E.
Pineda-García, Jonathan
Daniel, Kathryne J.
Janzen, Daryl
Fields, C. E.
Zabludoff, Ann
Meza, Nicolas
E., Felipe Olivares
Spekkens, Kristine
Weiner, Benjamin
Williams, Maia
Gibbs, Alex R.
Shelly, Frank
Ravi, Aravind P.
Jha, Saurabh W.
Valenti, Stefano
Haislip, Joshua
Trilling, David E.
contents The recent gravitational-wave (GW) alert from a compact object merger involving at least one subsolar mass (SSM) object has prompted questions about their origins. S251112cm is reported by LIGO/Virgo with a false alarm rate of 1 per 6.2 years, nearby luminosity distance $93 \pm 27$ Mpc, probability of containing a SSM object of 100%, and probability of containing a $1-3~M_\odot$ object of just 8%. Such a system likely did not involve the supersolar neutron stars or black holes invoked to explain kilonovae. One must then also invoke hitherto unobserved and speculative models to produce SSM mergers and the resultant electromagnetic (EM) counterparts. We introduce a framework which vets and scores candidate counterparts to SSM GW events to inform follow-up in search of any among the zoo of potential EM transients: kilonovae, kilonovae-within-supernovae, super-kilonovae, or AGN flares from binary black hole mergers. We use a suite of telescopes to perform tiling, galaxy-targeted observations, and photometric/spectroscopic follow-up of promising candidates. In near-real time, we ingest candidates reported by the community, including some of the first observations reported by the Vera C. Rubin Observatory. We vet and score a total of 248 candidates, including 67 from Rubin, but find no likely counterpart. We nonetheless highlight candidates which demonstrate the ability of our framework to distinguish between different transient types and describe strategies to maximize the chances of detecting a counterpart to the next SSM event. Our framework will be implemented in the forthcoming Multimessenger Tool for Rapid Object Vetting and Examination (TROVE).
format Preprint
id arxiv_https___arxiv_org_abs_2603_17009
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Search For a Counterpart to the Subsolar Mass Gravitational Wave Candidate S251112cm
Vieira, Nicholas
Franz, Noah
Subrayan, Bhagya
Kilpatrick, Charles D.
Sand, David J.
Fong, Wen-fai
Hosseinzadeh, Griffin
Alexander, Kate D.
Bostroem, K. Azalee
Rastinejad, Jillian
Paterson, Kerry
Shrestha, Manisha
Noel, Phillip
Darc, P.
Pearson, Jeniveve
Aamer, Aysha
Santos, A. Souza
Santana-Silva, Luidhy
Bom, Clecio R.
Cartier, Regis
Bommireddy, Hemanth
Rodríguez, Ósmar
Andrews, Jennifer E.
Ransome, Conor
Paschalidis, Vasileios
Strader, Jay
Grichener, Aldana
Quirola-Vásquez, J.
Vasylyev, Sergiy
Soares-Santos, Marcelle
Christy, Collin T.
Hsu, Brian
Fuls, D. Carson
Dong, Yize
Reichart, Daniel E.
Pineda-García, Jonathan
Daniel, Kathryne J.
Janzen, Daryl
Fields, C. E.
Zabludoff, Ann
Meza, Nicolas
E., Felipe Olivares
Spekkens, Kristine
Weiner, Benjamin
Williams, Maia
Gibbs, Alex R.
Shelly, Frank
Ravi, Aravind P.
Jha, Saurabh W.
Valenti, Stefano
Haislip, Joshua
Trilling, David E.
High Energy Astrophysical Phenomena
The recent gravitational-wave (GW) alert from a compact object merger involving at least one subsolar mass (SSM) object has prompted questions about their origins. S251112cm is reported by LIGO/Virgo with a false alarm rate of 1 per 6.2 years, nearby luminosity distance $93 \pm 27$ Mpc, probability of containing a SSM object of 100%, and probability of containing a $1-3~M_\odot$ object of just 8%. Such a system likely did not involve the supersolar neutron stars or black holes invoked to explain kilonovae. One must then also invoke hitherto unobserved and speculative models to produce SSM mergers and the resultant electromagnetic (EM) counterparts. We introduce a framework which vets and scores candidate counterparts to SSM GW events to inform follow-up in search of any among the zoo of potential EM transients: kilonovae, kilonovae-within-supernovae, super-kilonovae, or AGN flares from binary black hole mergers. We use a suite of telescopes to perform tiling, galaxy-targeted observations, and photometric/spectroscopic follow-up of promising candidates. In near-real time, we ingest candidates reported by the community, including some of the first observations reported by the Vera C. Rubin Observatory. We vet and score a total of 248 candidates, including 67 from Rubin, but find no likely counterpart. We nonetheless highlight candidates which demonstrate the ability of our framework to distinguish between different transient types and describe strategies to maximize the chances of detecting a counterpart to the next SSM event. Our framework will be implemented in the forthcoming Multimessenger Tool for Rapid Object Vetting and Examination (TROVE).
title Search For a Counterpart to the Subsolar Mass Gravitational Wave Candidate S251112cm
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2603.17009