English

Probing Planets in Extragalactic Galaxies Using Quasar Microlensing

Astrophysics of Galaxies 2018-02-14 v1 Earth and Planetary Astrophysics

Abstract

Previously, planets have been detected only in the Milky Way galaxy. Here, we show that quasar microlensing provides a means to probe extragalactic planets in the lens galaxy, by studying the microlensing properties of emission close to the event horizon of the supermassive black hole of the background quasar, using the current generation telescopes. We show that a population of unbound planets between stars with masses ranging from Moon to Jupiter masses is needed to explain the frequent Fek line energy shifts observed in the gravitationally lensed quasar RXJ1131-1231 at a lens redshift of z=0.295z=0.295 or 3.8 billion light-years away. We constrain the planet mass fraction to be larger than 0.0001 of the halo mass, which is equivalent to 2,000 objects ranging from Moon to Jupiter mass per main sequence star.

Keywords

Cite

@article{arxiv.1802.00049,
  title  = {Probing Planets in Extragalactic Galaxies Using Quasar Microlensing},
  author = {Xinyu Dai and Eduardo Guerras},
  journal= {arXiv preprint arXiv:1802.00049},
  year   = {2018}
}

Comments

8 preprint pages, 4 figures, accepted by ApJ Letters

R2 v1 2026-06-23T00:06:47.035Z