A radio transient 0.1 parsecs from sagittarius A*

Geoffrey C. Bower*, Doug A. Roberts, Farhad Yusef-Zadeh, Donald C. Backer, W. D. Cotton, W. M. Goss, Cornelia C. Lang, Yoram Lithwick

*Corresponding author for this work

Research output: Contribution to journalArticle

33 Scopus citations


We report the discovery of a transient radio source 2″.7 (0.1 pc projected distance) south of the Galactic center massive black hole, Sgr A*. The source flared with a peak of at least 80 mJy in 2004 March. The source was resolved by the Very Large Array into two components with a separation of ∼0″.7 and characteristic sizes of ∼0″.2. The two components of the source faded with a power-law index of 1.1 ± 0.1. We detect an upper limit to the proper motion of the eastern component of ∼3 × 103 km s-1 relative to Sgr A*. We detect a proper motion of ∼104 km s-1 for the western component relative to Sgr A*. The transient was also detected at X-ray wavelengths with the Chandra X-Ray Observatory and XMM-Newton and given the designation CXOGC J174540.0-290031. The X-ray source falls in between the two radio components. The maximum luminosity of the X-ray source is ∼1036 ergs s-1, significantly sub-Eddington. The radio jet flux density predicted by the X-ray/radio correlation for X-ray binaries is orders of magnitude less than the measured flux density. We conclude that the radio transient is the result of a bipolar jet originating in a single impulsive event from the X-ray source and interacting with the dense interstellar medium of the Galactic center.

Original languageEnglish (US)
Pages (from-to)218-227
Number of pages10
JournalAstrophysical Journal
Issue number1 I
StatePublished - Nov 1 2005



  • Galaxy: center
  • ISM: jets and outflows
  • Radio continuum: general
  • X-rays: binaries

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Bower, G. C., Roberts, D. A., Yusef-Zadeh, F., Backer, D. C., Cotton, W. D., Goss, W. M., Lang, C. C., & Lithwick, Y. (2005). A radio transient 0.1 parsecs from sagittarius A*. Astrophysical Journal, 633(1 I), 218-227. https://doi.org/10.1086/444587