A Comprehensive Observational Study of the FRB 121102 Persistent Radio Source
FRB 121102 is the first fast radio burst to be spatially associated with a persistent radio source (QRS 121102), the nature of which remains unknown. We constrain the physical size of QRS 121102 by measuring its flux-density variability with the VLA from 12 to 26 GHz. Any such variability would like...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ad02f3 |
| _version_ | 1827632349294100480 |
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| author | Ge Chen Vikram Ravi Gregg W. Hallinan |
| author_facet | Ge Chen Vikram Ravi Gregg W. Hallinan |
| author_sort | Ge Chen |
| collection | DOAJ |
| description | FRB 121102 is the first fast radio burst to be spatially associated with a persistent radio source (QRS 121102), the nature of which remains unknown. We constrain the physical size of QRS 121102 by measuring its flux-density variability with the VLA from 12 to 26 GHz. Any such variability would likely be due to Galactic refractive scintillation and would require the source radius to be ≲10 ^17 cm at the host-galaxy redshift. We found the radio variability to be lower than the scintillation theory predictions for such a small source, leaving open the possibility for non-AGN models for QRS 121102. In addition, we roughly estimated the mass of any potential supermassive black hole (BH) associated with QRS 121102 from the line width of the host-galaxy H α emission using a new optical spectrum from the Keck Observatory. The line width indicates a supermassive BH mass of ≲10 ^4∼5 M _⊙ , too low for the observed radio luminosity and X-ray luminosity constraints, if QRS 121102 were an AGN. Finally, some dwarf galaxies that host supermassive BHs may be the stripped cores of massive galaxies during tidal interactions with companion systems. We find no nearby galaxy at the same redshift as the QRS 121102 host from low-resolution Keck spectra or the PanSTARRS catalog. In conclusion, we find no evidence supporting the hypothesis that QRS 121102 is an AGN. We instead argue that the inferred size and flat radio spectrum favor a plerion interpretation. We urge continued broadband radio monitoring of QRS 121102 to search for long-term evolution. |
| first_indexed | 2024-03-09T14:43:43Z |
| format | Article |
| id | doaj.art-a567fa9ed0d143be8f89c59b56456349 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-09T14:43:43Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-a567fa9ed0d143be8f89c59b564563492023-11-27T12:03:40ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-01958218510.3847/1538-4357/ad02f3A Comprehensive Observational Study of the FRB 121102 Persistent Radio SourceGe Chen0https://orcid.org/0000-0003-2867-4544Vikram Ravi1https://orcid.org/0000-0002-7252-5485Gregg W. Hallinan2https://orcid.org/0000-0002-7083-4049Cahill Center for Astronomy and Astrophysics , MC 249-17, California Institute of Technology, Pasadena, CA 91125, USA ; gcchen@caltech.eduCahill Center for Astronomy and Astrophysics , MC 249-17, California Institute of Technology, Pasadena, CA 91125, USA ; gcchen@caltech.eduCahill Center for Astronomy and Astrophysics , MC 249-17, California Institute of Technology, Pasadena, CA 91125, USA ; gcchen@caltech.eduFRB 121102 is the first fast radio burst to be spatially associated with a persistent radio source (QRS 121102), the nature of which remains unknown. We constrain the physical size of QRS 121102 by measuring its flux-density variability with the VLA from 12 to 26 GHz. Any such variability would likely be due to Galactic refractive scintillation and would require the source radius to be ≲10 ^17 cm at the host-galaxy redshift. We found the radio variability to be lower than the scintillation theory predictions for such a small source, leaving open the possibility for non-AGN models for QRS 121102. In addition, we roughly estimated the mass of any potential supermassive black hole (BH) associated with QRS 121102 from the line width of the host-galaxy H α emission using a new optical spectrum from the Keck Observatory. The line width indicates a supermassive BH mass of ≲10 ^4∼5 M _⊙ , too low for the observed radio luminosity and X-ray luminosity constraints, if QRS 121102 were an AGN. Finally, some dwarf galaxies that host supermassive BHs may be the stripped cores of massive galaxies during tidal interactions with companion systems. We find no nearby galaxy at the same redshift as the QRS 121102 host from low-resolution Keck spectra or the PanSTARRS catalog. In conclusion, we find no evidence supporting the hypothesis that QRS 121102 is an AGN. We instead argue that the inferred size and flat radio spectrum favor a plerion interpretation. We urge continued broadband radio monitoring of QRS 121102 to search for long-term evolution.https://doi.org/10.3847/1538-4357/ad02f3Radio transient sourcesHigh energy astrophysicsRadio burstsExtragalactic radio sources |
| spellingShingle | Ge Chen Vikram Ravi Gregg W. Hallinan A Comprehensive Observational Study of the FRB 121102 Persistent Radio Source The Astrophysical Journal Radio transient sources High energy astrophysics Radio bursts Extragalactic radio sources |
| title | A Comprehensive Observational Study of the FRB 121102 Persistent Radio Source |
| title_full | A Comprehensive Observational Study of the FRB 121102 Persistent Radio Source |
| title_fullStr | A Comprehensive Observational Study of the FRB 121102 Persistent Radio Source |
| title_full_unstemmed | A Comprehensive Observational Study of the FRB 121102 Persistent Radio Source |
| title_short | A Comprehensive Observational Study of the FRB 121102 Persistent Radio Source |
| title_sort | comprehensive observational study of the frb 121102 persistent radio source |
| topic | Radio transient sources High energy astrophysics Radio bursts Extragalactic radio sources |
| url | https://doi.org/10.3847/1538-4357/ad02f3 |
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