2006/02/20 by Yuichi Matsuda, Toru Yamada, Tōru Yamada +4 · 1 citation
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Emission spectrum #Galaxies: Formation, Evolution, Phenomena #Galaxy #Line (geometry) #Physics #Redshift #Spectral line #Spectrograph #Spectroscopy #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/503362
published as Astrophys.J. 640 (2006) L123-L126 · Accepted for publication in ApJL
arxiv created 2006/02/20 · openalex publication_date 2006/03/06 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present the results of an intermediate resolution ( ∼ 2 ˚A) spectroscopy of a sample of 37 candidate Lyα blobs and emitters at redshift z = 3.1 using the DEIMOS spectrograph on the 10 m Keck telescope. The emission lines are detected for all the 37 objects and have variety in their line profiles. The Lyα velocity widths (FWHM) of the 28 objects with higher quality spectra, measured by fitting a single Gaussian profile, are in the range of 150 − 1700 km s −1 and correlate with the Lyα spatial extents. All the 12 Lyα blobs ( ≥ 16 arcsec 2) have large velocity widths of � 500 km s −1. While there are several possible physical interpretations of the Lyα velocity widths (motion of gravitationallybound gas clouds, inflows, merging of clumps, or outflows from superwinds), the large velocity widths of the Lyα blobs suggest that they are the sites of massive galaxy formation. If we assume gravitationally-bound gas clouds, the dynamical masses of the Lyα blobs are estimated to be ∼ 10 12 −10 13 M⊙. Even for the case of outflows, the outflow velocities are likely to be the same order of the rotation velocities as inferred from the observational evidence for local starburst galaxies.