Absorption of Millimeter-band CO and CN in the Early Universe: Molecular Clouds in the Radio Galaxy B2 0902+ 34 at Redshift 3.4
The Astrophysical Journal, 2024•iopscience.iop.org
Abstract Using the Karl G. Jansky Very Large Array, we have detected absorption lines due
to carbon monoxide, CO (J= 0→ 1), and the cyano radical, CN (N= 0→ 1), associated with
radio galaxy B2 0902+ 34 at redshift z= 3.4. The detection of millimeter-band absorption
observed 1.5 Gyr after the Big Bang facilitates studying molecular clouds down to gas
masses inaccessible to emission-line observations. The CO absorption in B2 0902+ 34 has
a peak optical depth of τ≥ 8.6% and consists of two components, one of which has the …
to carbon monoxide, CO (J= 0→ 1), and the cyano radical, CN (N= 0→ 1), associated with
radio galaxy B2 0902+ 34 at redshift z= 3.4. The detection of millimeter-band absorption
observed 1.5 Gyr after the Big Bang facilitates studying molecular clouds down to gas
masses inaccessible to emission-line observations. The CO absorption in B2 0902+ 34 has
a peak optical depth of τ≥ 8.6% and consists of two components, one of which has the …
Abstract
Using the Karl G. Jansky Very Large Array, we have detected absorption lines due to carbon monoxide, CO (J= 0→ 1), and the cyano radical, CN (N= 0→ 1), associated with radio galaxy B2 0902+ 34 at redshift z= 3.4. The detection of millimeter-band absorption observed 1.5 Gyr after the Big Bang facilitates studying molecular clouds down to gas masses inaccessible to emission-line observations. The CO absorption in B2 0902+ 34 has a peak optical depth of τ≥ 8.6% and consists of two components, one of which has the same redshift as previously detected 21 cm absorption of neutral hydrogen (H i) gas. Each CO component traces an integrated H 2 column density of
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