# Could dark matter have gamma-ray absorption lines?

by johne1618
Tags: absorption, dark, gammaray, lines, matter
 P: 373 Are there sky surveys that perform gamma-ray absorption spectroscopy? I was wondering if dark matter might absorb gamma radiation. I have done a simple Bohr-atom type calculation assuming a dark matter model of a bound state of a North and South magnetic monopole and found a Rydberg energy of about a MeV. I assume that the mass of the monopoles is 1 Tev; masses less than this limit have apparently been excluded by particle accelerator experiments (to a confidence of 95%). I also assume that the monopoles have the minimum magnetic charge.
P: 373
 Quote by johne1618 I have done a simple Bohr-atom type calculation assuming a dark matter model of a bound state of a North and South magnetic monopole and found a Rydberg energy of about a MeV. I assume that the mass of the monopoles is 1 Tev; masses less than this limit have apparently been excluded by particle accelerator experiments (to a confidence of 95%). I also assume that the monopoles have the minimum magnetic charge.
Actually I retract this calculation - I think I got my fine structure constant upside-down! And also GUT theories think the mass of the monopole is probably bigger than $10^{16}$ GeV!
P: 4,782
 Quote by johne1618 Are there sky surveys that perform gamma-ray absorption spectroscopy? I was wondering if dark matter might absorb gamma radiation. I have done a simple Bohr-atom type calculation assuming a dark matter model of a bound state of a North and South magnetic monopole and found a Rydberg energy of about a MeV. I assume that the mass of the monopoles is 1 Tev; masses less than this limit have apparently been excluded by particle accelerator experiments (to a confidence of 95%). I also assume that the monopoles have the minimum magnetic charge.
It's somewhat difficult to do spectroscopy in general with gamma rays, as least where astronomy is concerned. The number counts are just too low. But I think the general expectation is that we'd see gamma rays from dark matter annihilation, but that the dark matter won't do much if any absorption.

That said, I don't think that magnetic monopoles can work as dark matter. They'd interact far too strongly with one another and normal matter.

 Quote by johne1618 Actually I retract this calculation - I think I got my fine structure constant upside-down! And also GUT theories think the mass of the monopole is probably bigger than $10^{16}$ GeV!