WISE DISCOVERY OF LOW-METALLICITY BLUE COMPACT DWARF GALAXIES
- Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States)
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109 (United States)
- Department of Physics and Astronomy, University of Leicester, LE1 7RH Leicester (United Kingdom)
- Space Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States)
- Department of Physics, University of California Davis, One Shields Avenue, Davis, CA 95616 (United States)
- Astronomy Department, University of California Los Angeles, P.O. Box 951547, Los Angeles, CA 90095 (United States)
We report two new low-metallicity blue compact dwarf galaxies (BCDs), WISEP J080103.93+264053.9 (hereafter W0801+26) and WISEP J170233.53+180306.4 (hereafter W1702+18), discovered using the Wide-field Infrared Survey Explorer (WISE). We identified these two BCDs from their extremely red colors at mid-infrared wavelengths and obtained follow-up optical spectroscopy using the Low Resolution Imaging Spectrometer on Keck I. The mid-infrared properties of these two sources are similar to the well-studied, extremely low metallicity galaxy SBS 0335-052E. We determine metallicities of 12 + log (O/H) = 7.75 and 7.63 for W0801+26 and W1702+18, respectively, placing them among a very small group of very metal deficient galaxies (Z {<=} 1/10 Z{sub sun}). Their >300 A H{beta} equivalent widths, similar to SBS 0335-052E, imply the existence of young (<5 Myr) star-forming regions. We measure star formation rates of 2.6 and 10.9 M{sub sun} yr{sup -1} for W0801+26 and W1702+18, respectively. These BCDs, showing recent star formation activity in extremely low metallicity environments, provide new laboratories for studying star formation in extreme conditions and are low-redshift analogs of the first generation of galaxies to form in the universe. Using the all-sky WISE survey, we discuss a new method to identify similar star-forming, low-metallicity BCDs.
- OSTI ID:
- 21562519
- Journal Information:
- Astrophysical Journal Letters, Vol. 736, Issue 1; Other Information: DOI: 10.1088/2041-8205/736/1/L22; ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
Similar Records
SHELS: OPTICAL SPECTRAL PROPERTIES OF WISE 22 {mu}m SELECTED GALAXIES
ON THE ORIGIN OF THE RED EXCESS IN VERY YOUNG SUPER STAR CLUSTERS: THE CASE OF SBS 0335-052E