skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: THE NATURE OF A GALAXY ALONG THE SIGHT LINE TO PKS 0454+039

Journal Article · · Astronomical Journal (New York, N.Y. Online)
 [1];  [2]; ;  [3]
  1. Physics and Astronomy Department, University of Hawaii Hilo, Hilo, HI 96720 (United States)
  2. Institute for Astronomy, University of Hawaii Manoa, HI 96822 (United States)
  3. Department of Physics and Astronomy, University of South Carolina, SC 29208 (United States)

We report on the properties of a faint blue galaxy (G1) along the line of sight to the QSO PKS 0454+039 from spectroscopic and imaging data. We measured emission lines of H{alpha}, [S II] {lambda}{lambda}6716, 6732, and [N II] {lambda}6584 in the spectrum of G1 obtained with the Gemini/GMOS instrument. The spectroscopic redshift of G1 is z = 0.0715 {+-} 0.0002. From the extinction-corrected H{alpha} flux, we determine a modest star formation rate of SFR = 0.07 M{sub Sun} yr{sup -1} and a specific SFR of log (sSFR) -8.4. Using three different abundance indicators, we determine a nebular abundance 12 + log (O/H) ranging from 7.6 to 8.2. Based on the velocity dispersion inferred from the emission line widths and the observed surface brightness profile, we estimate the virial mass of G1 to be M{sub vir} {approx} 6.7 Multiplication-Sign 10{sup 9} M{sub Sun} with an effective radius of 2.0 kpc. We estimate the stellar mass of G1 using spectral energy distribution fitting to be M{sub *} Almost-Equal-To 1.2 Multiplication-Sign 10{sup 7} M{sub Sun} and an r'-luminosity of L{sub r'} = 1.5x10{sup 8} L{sub Sun }. Overall, G1 is a faint, low-mass, low-metallicity Im/H II galaxy. We also report on the line flux limits of another source (G3) which is the most likely candidate for the absorber system at z = 0.8596. From the spectrum of the QSO itself, we report a previously undetected Mg II {lambda}{lambda}2796, 2803 absorption line system at z = 1.245.

OSTI ID:
22089854
Journal Information:
Astronomical Journal (New York, N.Y. Online), Vol. 144, Issue 4; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1538-3881
Country of Publication:
United States
Language:
English