Caustic crossings in giant arcs with extended dark matter objects
Fuente:
arXiv
Gespeichert in:
| Hauptverfasser: | , , , , |
|---|---|
| Format: | Preprint |
| Veröffentlicht: |
2025
|
| Schlagworte: | |
| Online-Zugang: | |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| _version_ | 1866915877283168256 |
|---|---|
| author | Croon, Djuna Crossey, Benedict Diego, Jose Maria Kavanagh, Bradley J. Palencia, Jose Maria |
| author_facet | Croon, Djuna Crossey, Benedict Diego, Jose Maria Kavanagh, Bradley J. Palencia, Jose Maria |
| contents | Caustic-crossing stars observed in giant arcs behind galaxy clusters provide a powerful probe of dark matter substructure. While previous work has focused on point-like lenses such as primordial black holes, we extend this framework to extended dark objects (EDOs), including ultracompact minihalos formed from the collapse of primordial overdensities. We develop an analytic model of microlensing by EDOs embedded in a macrolensing cluster potential and derive the resulting caustics and light curves. Depending on the EDO size relative to the effective Einstein radius, we show that they may generate additional narrow caustics, leading to novel features in the light curve. Applying our framework to the MACS J1149 LS1 ``Icarus'' event, we constrain EDOs with radii up to $10^7 R_\odot$. Our results demonstrate that caustic-crossing events complement galactic microlensing searches, as they can probe EDOs with larger physical size. We discuss the implications for current and future observations, which promise to deliver a statistical sample of caustic transients and correspondingly sharper constraints on dark objects. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2511_20761 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Caustic crossings in giant arcs with extended dark matter objects Croon, Djuna Crossey, Benedict Diego, Jose Maria Kavanagh, Bradley J. Palencia, Jose Maria Cosmology and Nongalactic Astrophysics Astrophysics of Galaxies High Energy Physics - Phenomenology Caustic-crossing stars observed in giant arcs behind galaxy clusters provide a powerful probe of dark matter substructure. While previous work has focused on point-like lenses such as primordial black holes, we extend this framework to extended dark objects (EDOs), including ultracompact minihalos formed from the collapse of primordial overdensities. We develop an analytic model of microlensing by EDOs embedded in a macrolensing cluster potential and derive the resulting caustics and light curves. Depending on the EDO size relative to the effective Einstein radius, we show that they may generate additional narrow caustics, leading to novel features in the light curve. Applying our framework to the MACS J1149 LS1 ``Icarus'' event, we constrain EDOs with radii up to $10^7 R_\odot$. Our results demonstrate that caustic-crossing events complement galactic microlensing searches, as they can probe EDOs with larger physical size. We discuss the implications for current and future observations, which promise to deliver a statistical sample of caustic transients and correspondingly sharper constraints on dark objects. |
| title | Caustic crossings in giant arcs with extended dark matter objects |
| topic | Cosmology and Nongalactic Astrophysics Astrophysics of Galaxies High Energy Physics - Phenomenology |
| url | https://arxiv.org/abs/2511.20761 |