Nature of 4FGL J2249.4+6229: Evidence for a redback system with a cool companion and low X-ray and γ-ray luminosities

Clicks: 2
ID: 314850
2026
Free PDF
Article Quality & Performance Metrics
Overall Quality
Not rated
Combines reader engagement with the AI quality analysis. This article has not been analysed, so there is no overall score — reader engagement is measured and shown alongside.
AI Quality Assessment
Not analyzed
Readership in this journal
Emerging

Ranked #287 of 900 articles by views in monthly notices of the royal astronomical society

Most read Least read

Bar heights use a square-root scale. Only the 120 most-read articles are drawn; the journal has 900 in total.

Mint this article as an NFT
Not yet minted

Create a permanent, verifiable on-chain record of this article on the Scimatic Network. The NFT is held in your Journament account, and you can withdraw it to your own wallet at any time.

5 SUSD one-off · no wallet required
Sign in to mint
Abstract
Abstract We report the identification of the likely X-ray and optical counterpart to the unassociated Fermi source 4FGL J2249.4+6229. To clarify its nature, we investigate the X-ray data from Swift/XRT and SRG/eROSITA as well as photometric data from optical catalogues and archival spectroscopic data from the Gemini-North telescope. Using Zwicky Transient Facility data spanning over 6.6 yr, we confirmed a period of ≈5.6 h likely associated with the orbital motion in a binary system. The folded light curves have a smooth sinusoidal shape with two peaks per period and the amplitude of ≈0.2 mag. The X-ray spectra of the source are well fitted by an absorbed power law with the photon index of ≈2.0 and unabsorbed flux of ≈1.4 × 10−13 erg s−1 cm−2. All these together with the X-ray to optical flux ratio of ~0.2 implies that 4FGL J2249.4+6229 is a promising redback candidate. Fitting the optical light curves with the direct heating model, we obtained the companion mass of ≈0.5 M⊙ and temperature of ≈3600 K implying an M-type star. This places it among the coldest and most massive companions known in redback systems. Optical spectra confirms the M-type star and shows the broad asymmetric Hα emission line. For the distance of 500–550 pc derived from the optical data, the source can be the redback with the lowest X-ray and γ-ray luminosities.
Reference Key
openalex_W7162284694 Use this key to autocite in the manuscript while using SciMatic Manuscript Manager or Thesis Manager
Authors A V Karpova, D A Zyuzin, S V Zharikov, M R Gilfanov
Journal monthly notices of the royal astronomical society
Year 2026
DOI
10.1093/mnras/stag971
URL
https://doi.org/10.1093/mnras/stag971
Keywords Keywords not found

Citations

No citations found. To add a citation, contact the admin at info@scimatic.org

Comments

No comments yet. Be the first to comment on this article.