Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Possible Detection of Gamma-Rays from Epsilon Eridani
Show others and affiliations
2019 (English)In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 878, no 1, article id 8Article in journal (Refereed) Published
Abstract [en]

We use the Fermi Large Area Telescope gamma-ray observatory to search for gamma-ray emission from four nearby, debris disk-hosting main-sequence stars: τ Ceti, Eridani, Fomalhaut, and Vega. For three stars (τ Ceti, Fomalhaut, and Vega), we establish upper limits that are consistent with theoretical expectations. For Eridani, we find a possible spatially coincident source with a soft energy spectrum of dN/dE ∼ E -3.6. However, at this stage we are unable to rule out that this emission is due to a more extended feature in the diffuse background. In the interpretation that the emission is due to Eridani, the >100 MeV gamma-ray luminosity is ∼1027 erg s-1 ≃ 3 ×10-7 L o, which is ∼1010 times the gamma-ray luminosity from the disk of the quiet Sun. We find ≲2σ evidence of source variability over a ∼7 yr timescale. In the interpretation that the gamma-ray emission is from Eridani itself, we consider two possible models: (1) cosmic-ray collisions with solid bodies in the debris disk, which extends out ∼60 au from the host star, and (2) emission from the stellar activity. For the former model, assuming a total disk mass consistent with infrared measurements, we find that the size distribution of bodies is steeper than expected for a collisional cascade state. If confirmed as being associated with Eridani, this would be the first indication of gamma-ray emission from the vicinity of a main-sequence star other than the Sun.

Place, publisher, year, edition, pages
Institute of Physics Publishing (IOPP), 2019. Vol. 878, no 1, article id 8
Keywords [en]
gamma rays: stars, protoplanetary disks
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
URN: urn:nbn:se:kth:diva-262629DOI: 10.3847/1538-4357/ab1a3cISI: 000470862100008Scopus ID: 2-s2.0-85069435529OAI: oai:DiVA.org:kth-262629DiVA, id: diva2:1362280
Note

QC 20191018

Available from: 2019-10-18 Created: 2019-10-18 Last updated: 2019-10-18Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Jóhannesson, Gudlaugur
By organisation
Nordic Institute for Theoretical Physics NORDITA
In the same journal
Astrophysical Journal
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf