ADS Astronomy Abstract Service

Title:		HST images of very compact blue galaxies at z approximately 0.2
Authors:		KOO, DAVID C.; BERSHADY, MATTHEW A.; WIRTH, GREGORY D.; STANFORD, S. ADAM; MAJEWSKI, STEVEN R.
Affiliation:		AAUniv. of California, Santa Cruz, CA, US ABUniv. of California, Santa Cruz, CA, US ACUniv. of California, Santa Cruz, CA, US ADUniv. of California, Berkeley, CA, US AEThe Observatories of the Carnegie Inst. of Washington, Pasadena, CA, US
Journal:		Astrophysical Journal, Part 2 - Letters, vol. 427, no. 1, p. L9-L12
Publication Date:		05/1994
Category:		Astronomy
Origin:		STI
NASA/STI Keywords:		BLUE STARS, COMPACT GALAXIES, COSMOLOGY, GALACTIC EVOLUTION, GALACTIC STRUCTURE, IMAGES, IONIZATION, RED SHIFT, STARBURST GALAXIES, STELLAR LUMINOSITY, ASTRONOMICAL OBSERVATORIES, CAMERAS, HUBBLE SPACE TELESCOPE, ISOPHOTES, SPECTRAL RESOLUTION, SPECTROSCOPIC TELESCOPES, WIDE ANGLE LENSES
Bibliographic Code:		1994ApJ...427L...9K

Abstract

We present the results of Hubble Space Telescope (HST) Wide-Field Camera (WFC) imaging of seven very compact, very blue galaxies with B less than or equal to 21 and redshifts z approximately 0.1 to 0.35. Based on deconvolved images, we estimate typical half-light diameters of approximately 0.65 sec, corresponding to approximately 1.4 h(exp -1) kpc at redshifts z approximately 0.2. The average rest frame surface brightness within this diameter is mu(sub v) approximately 20.5 mag arcsec(exp -2), approximately 1 mag brighter than that of typical late-type blue galaxies. Ground-based spectra show strong, narrow emission lines indicating high ionization; their very blue colors suggest recent bursts of star-formation; their typical luminosities are approximately 4 times fainter than that of field galaxies. These characteristics suggest H II galaxies as likely local counterparts of our sample, though our most luminous targets appear to be unusually compact for their luminosities.