X-rays from Green Pea Analogs

Abstract

X-ray observations of two metal-deficient luminous compact galaxies (LCG) (SHOC~486 and SDSS J084220.94+115000.2) with properties similar to the so-called Green Pea galaxies were obtained using the {\emph{Chandra X-ray Observatory}}. Green Pea galaxies are relatively small, compact (a few kpc across) galaxies that get their green color from strong [OIII]$\lambda$5007Å emission, an indicator of intense, recent star formation. These two galaxies were predicted to have the highest observed count rates, using the X-ray luminosity -- star formation rate ($L_X$--SFR) relation for X-ray binaries, from a statistically complete sample drawn from optical criteria. We determine the X-ray luminosity relative to star-formation rate and metallicity for these two galaxies. Neither exhibit any evidence of active galactic nuclei and we suspect the X-ray emission originates from unresolved populations of high mass X-ray binaries. We discuss the $L_X$--SFR--metallicity plane for star-forming galaxies and show that the two LCGs are consistent with the prediction of this relation. This is the first detection of Green Pea analogs in X-rays.

7 pages, 5 figures

References in corpus (3)

• Galaxies with Wolf-Rayet signatures in the low-redshift Universe - A survey using the Sloan Digital Sky Survey
• X-ray binary formation in low-metallicity blue compact dwarf galaxies
• Metallicity dependence of HMXB populations

Cited by in corpus (1)

• Resolving the X-ray emission from the Lyman continuum emitting galaxy Tol 1247-232