Discovery of Eight New Extremely Metal--Poor Galaxies in the Sloan Digital Sky Survey

Details Discovery of Eight New Extremely Metal--Poor Galaxies in the Sloan Digital Sky Survey Discovery of Eight New Extremely Metal--Poor Galaxies in the Sloan Digital Sky Survey

2003-07-23

arxiv.org/abs/astro-ph/0307401v1

Astrophys.J.593:L73-L76,2003

Astronomy and Astrophysics

Astrophysics

To appear in August 20 issue of ApJ Letters, 6 pages, 2 figures

Scientific paper

10.1086/378259

We report the discovery of eight new extremely metal-poor galaxies (XMPGs; 12+log(O/H) < 7.65) and the recovery of four previously known or suspected XMPGs (IZw18, HS0822+3542, HS0837+4717 and A1116+517) using Sloan Digital Sky Survey (SDSS) spectroscopy. These new objects were identified after an analysis of 250,000 galaxy spectra within an area of ~3000 deg^2 on the sky. Our oxygen abundance determinations have an accuracy of $\le$ 0.1 dex and are based on the temperature-sensitive [O {\sc iii}] $\lambda$4363 \AA line and on the direct calculation of the electron temperature. We briefly discuss a new method of oxygen abundance determinations using the [O {\sc ii}] $\lambda$7319,7330 \AA\ lines, which is particularly useful for SDSS emission-line spectra with redshifts $\le$~0.024 since the [O {\sc ii}] $\lambda$3727 \AA emission line falls outside of the SDSS wavelength range. We detect XMPGs with redshifts ranging from 0.0005 to 0.0443 and $M_g$ luminosities from $-$12\fm4 to $-$18\fm6. Our eight new XMPGs increase the number of known metal-deficient galaxies by approximately one quarter. The estimated surface density of XMPGs is 0.004 deg$^{-2}$ for $r$ $\le$ 17\fm77.

Affiliated with

Also associated with

No associations

Rating

Discovery of Eight New Extremely Metal--Poor Galaxies in the Sloan Digital Sky Survey 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 Discovery of Eight New Extremely Metal--Poor Galaxies in the Sloan Digital Sky Survey, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Discovery of Eight New Extremely Metal--Poor Galaxies in the Sloan Digital Sky Survey will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-165664