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Min S. Yun

2000

Galaxies: evolution

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Full-Text Articles in Physical Sciences and Mathematics

The Scatter In The Relationship Between Redshift And The Radio-To-Submm Spectral Index, C L. Carilli, Min S. Yun Feb 2000

The Scatter In The Relationship Between Redshift And The Radio-To-Submm Spectral Index, C L. Carilli, Min S. Yun

Min S. Yun

We derive the scatter in the relationship between redshift and the radio-to-submillimeter spectral index, a135.40, using the observed spectral energy distributions of 17 low-redshift star-forming galaxies. A mean galaxy model is derived, along with the rms scatter in a13.540. The scatter is roughly constant with redshift. Constant rms scatter, combined with the Ñattening of the mean a13.540-z relationship with increasing redshift, leads to increasing uncertainty for redshift estimates at high redshifts. Normalizing by the dust temperature in the manner proposed by Blain decreases the scatter in a13.540 for most of the sample, but does not remove outliers, and free-free absorption …


Sensitive Radio Observations Of High-Redshift Dusty Qsos, Min S. Yun, C L. Carilli, R Kawabe, Y Tutui, K Kohno, K Ohta Jan 2000

Sensitive Radio Observations Of High-Redshift Dusty Qsos, Min S. Yun, C L. Carilli, R Kawabe, Y Tutui, K Kohno, K Ohta

Min S. Yun

We present sensitive radio continuum imaging at 1.4 and 4.9 GHz of seven high-redshift QSOs selected for having a 240 GHz continuum detection, which is thought to be thermal dust emission. We detect radio continuum emission from four of the sources: BRI 0952-0115, BR 1202-0725, LBQS 1230+1627B, and BRI 1335-0417. The radio source in BR 1202-0725 is resolved into two components, coincident with the double millimeter and CO sources. We compare the results at 1.4 and 240 GHz to empirical and semianalytic spectral models based on star-forming galaxies at low redshift. The radio-to-submillimeter spectral energy distribution (SED) for BR 1202-0725, …