Keck observations of candidate ultra-luminous X-ray sources

Diane Sonya Wong*, Ryan Chornock, Alexei V. Filippenko

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


We present results of optical follow-up observations of candidate ultra-luminous X-ray sources (ULXs). Using Keck optical spectroscopy, 17 of the candidates from the Colbert & Ptak (2002) catalog have been identified; this is one of the largest sets of optical identifications of such objects thus far. 15 are background active galactic nuclei (AGN); 2 are foreground stars in our Galaxy. These findings are compared with background and foreground object expectations, as derived from log N-log S relations. Also, the results are briefly discussed in terms of the spiral-galaxy/ULX connection.

Original languageEnglish (US)
Pages (from-to)306-307
Number of pages2
JournalProceedings of the International Astronomical Union
Issue numberS230
StatePublished - 2005


  • Black hole physics
  • Catalogs
  • Galaxies: distances and redshifts
  • Galaxies: individual (NGC 720, NGC 1316, NGC 1365, NGC 1399, NGC 2775, NGC 3266, IC 2597, NGC 3923, NGC 4151, NGC 4373, NGC 5128)
  • Quasars: general
  • X-rays: galaxies

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Astronomy and Astrophysics
  • Nutrition and Dietetics
  • Public Health, Environmental and Occupational Health
  • Space and Planetary Science


Dive into the research topics of 'Keck observations of candidate ultra-luminous X-ray sources'. Together they form a unique fingerprint.

Cite this