The Radio Counterpart to the Fast X-ray Transient EP240414a
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2024
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866909874241142784 |
|---|---|
| author | Bright, Joe S. Carotenuto, Francesco Fender, Rob Choza, Carmen Mummery, Andrew Jonker, Peter G. Smartt, Stephen J. DeBoer, David R. Farah, Wael Matthews, James Pollak, Alexander W. Rhodes, Lauren Siemion, Andrew |
| author_facet | Bright, Joe S. Carotenuto, Francesco Fender, Rob Choza, Carmen Mummery, Andrew Jonker, Peter G. Smartt, Stephen J. DeBoer, David R. Farah, Wael Matthews, James Pollak, Alexander W. Rhodes, Lauren Siemion, Andrew |
| contents | Despite being operational for only a short time, the Einstein Probe mission, with its large field of view and rapid localisation capabilities, has already significantly advanced the study of rapid variability in the soft X-ray sky. We report the discovery of luminous and variable radio emission from the Einstein Probe fast X-ray transient EP240414a, the second such source with a radio counterpart. The radio emission at $3\,\rm{GHz}$ peaks at $\sim30$ days post explosion and with a spectral luminosity $\sim2\times10^{30}\,\rm{erg}\,\rm{s}^{-1}\,\rm{Hz}^{-1}$, similar to what is seen from long gamma-ray bursts, and distinct from other extra-galactic transients including supernovae and tidal disruption events, although we cannot completely rule out emission from engine driven stellar explosions e.g. the fast blue optical transients. An equipartition analysis of our radio data reveals that an outflow with at least a moderate bulk Lorentz factor ($Γ\gtrsim1.6$) with a minimum energy of $\sim10^{48}\,\rm{erg}$ is required to explain our observations. The apparent lack of reported gamma-ray counterpart to EP240414a could suggest that an off-axis or choked jet could be responsible for the radio emission, although a low luminosity gamma-ray burst may have gone undetected. Our observations are consistent with the hypothesis that a significant fraction of extragalactic fast X-ray transients are associated with the deaths of massive stars. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2409_19055 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | The Radio Counterpart to the Fast X-ray Transient EP240414a Bright, Joe S. Carotenuto, Francesco Fender, Rob Choza, Carmen Mummery, Andrew Jonker, Peter G. Smartt, Stephen J. DeBoer, David R. Farah, Wael Matthews, James Pollak, Alexander W. Rhodes, Lauren Siemion, Andrew High Energy Astrophysical Phenomena Despite being operational for only a short time, the Einstein Probe mission, with its large field of view and rapid localisation capabilities, has already significantly advanced the study of rapid variability in the soft X-ray sky. We report the discovery of luminous and variable radio emission from the Einstein Probe fast X-ray transient EP240414a, the second such source with a radio counterpart. The radio emission at $3\,\rm{GHz}$ peaks at $\sim30$ days post explosion and with a spectral luminosity $\sim2\times10^{30}\,\rm{erg}\,\rm{s}^{-1}\,\rm{Hz}^{-1}$, similar to what is seen from long gamma-ray bursts, and distinct from other extra-galactic transients including supernovae and tidal disruption events, although we cannot completely rule out emission from engine driven stellar explosions e.g. the fast blue optical transients. An equipartition analysis of our radio data reveals that an outflow with at least a moderate bulk Lorentz factor ($Γ\gtrsim1.6$) with a minimum energy of $\sim10^{48}\,\rm{erg}$ is required to explain our observations. The apparent lack of reported gamma-ray counterpart to EP240414a could suggest that an off-axis or choked jet could be responsible for the radio emission, although a low luminosity gamma-ray burst may have gone undetected. Our observations are consistent with the hypothesis that a significant fraction of extragalactic fast X-ray transients are associated with the deaths of massive stars. |
| title | The Radio Counterpart to the Fast X-ray Transient EP240414a |
| topic | High Energy Astrophysical Phenomena |
| url | https://arxiv.org/abs/2409.19055 |