Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-01-13
Astronomy & Astrophysics 431, 793-812 (2005)
Astronomy and Astrophysics
Astrophysics
23 Pages, including 20 PostScript figures. Publiced in Astronomy & Astrophysics. v2: typo fixed and Journal reference added
Scientific paper
10.1051/0004-6361:20042038
Observations of the radio galaxy MRC 0316-257 at z=3.13 and the surrounding field are presented. Using narrow- and broad-band imaging obtained with the VLT, 77 candidate Ly-alpha emitters with a rest-frame equivalent width of > 15 A were selected in a ~7'x7' field around the radio galaxy. Spectroscopy of 40 candidate emitters resulted in the discovery of 33 emission line galaxies of which 31 are Ly-alpha emitters with redshifts similar to that of the radio galaxy, while the remaining two galaxies turned out to be [OII] emitters. The Ly-alpha profiles have widths (FWHM) in the range of 120-800 km/s, with a median of 260 km/s. Where the signal-to-noise was large enough, the Ly-alpha profiles were found to be asymmetric, with apparent absorption troughs blueward of the profile peaks, indicative of absorption along the line of sight of an HI mass of at least 2x10^2 - 5x10^4 M_sun. The properties of the Ly-alpha galaxies (faint, blue and small) are consistent with young star forming galaxies which are still nearly dust free. The volume density of Ly-alpha emitting galaxies in the field around MRC 0316-257 is a factor of 3.3+0.5-0.4 larger compared with the density of field Ly-alpha emitters at that redshift. The velocity distribution of the spectroscopically confirmed emitters has a FWHM of 1510 km/s, which is substantially smaller than the width of the narrow-band filter (FWHM ~ 3500 km/s). The peak of the velocity distribution is located within 200 km/s of the redshift of the radio galaxy. We conclude that the confirmed Ly-alpha emitters are members of a protocluster of galaxies at z~3.13. The size of the protocluster is larger than 3.3x3.3 Mpc^2. The mass of this structure is estimated to be > 3-6x10^14 M_sun and could be the progenitor of a cluster of galaxies similar to e.g. the Virgo cluster. (Abridged)
Carilli Chris L.
de Breuck Carlos
Ford Holland
Heckman Tim
Kurk Jaron Daniel
No associations
LandOfFree
Properties of Ly-alpha emitters around the radio galaxy MRC 0316-257 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 Properties of Ly-alpha emitters around the radio galaxy MRC 0316-257, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Properties of Ly-alpha emitters around the radio galaxy MRC 0316-257 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-273644