Astronomy and Astrophysics – Astrophysics
Scientific paper
Aug 1993
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993apj...413l..77s&link_type=abstract
Astrophysical Journal, Part 2 - Letters (ISSN 0004-637X), vol. 413, no. 2, p. L77-L80.
Astronomy and Astrophysics
Astrophysics
13
Blue Stars, Dwarf Galaxies, Emission Spectra, Quasars, Star Formation, Faint Objects, Line Of Sight
Scientific paper
We report the discovery of a dwarf galaxy (MB = -17.2 for H0 = 50 km/s per Mpc) at z = 0.072 which is only 4 arcsec (3.7/h(100) kpc) in projection from the line of sight to the bright quasar PKS 0454+0356 (z(em) = 1.345). The dwarf has very blue optical and optical/IR colors and exhibits line emission indicative of ongoing or recent star formation. However, there is no detection of Ca II 3934 A, 3969 A absorption at z(abs) = 0.072 to equivalent width limits (3 sigma) of about 40 mA, which would suggest an H I column density along the line of sight of less than 5 x 10 exp 19/sq cm, if the Ca II/H I ratio is similar to sight lines in the Galaxy. Based on the absence of Ca II absorption and the unusually weak line emission given the very blue color of the dwarf, we speculate that it may be close to exhausting its supply of gas. As its star formation rate declines, the galaxy's blue magnitude should fade substantially, eventually reaching a quiescent state in accord with its K luminosity of about 0.005 L*. Future observations of the sight line to PKS 0454+0356 using HST in search of Mg II resonance lines, or a search for 21 cm absorption against the quasar radio continuum, could place even more stringent limits on the extent of the gas associated with an intrinsically faint, star-forming dwarf.
Bowen David V.
Dickinson Mark
Steidel Charles C.
No associations
LandOfFree
A dwarf galaxy near the sight line to PKS 0454+0356 - A fading 'faint blue galaxy'? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A dwarf galaxy near the sight line to PKS 0454+0356 - A fading 'faint blue galaxy'?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A dwarf galaxy near the sight line to PKS 0454+0356 - A fading 'faint blue galaxy'? will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1491427