The CO line SED and atomic carbon in IRAS F10214+4724

TL;DR

This study detects and analyzes multiple carbon and CO emission lines in the high-redshift galaxy IRAS F10214+4724, revealing detailed physical conditions of its interstellar medium and the spatial distribution of dust and gas.

Contribution

First detection of the extcstwo line in IRAS F10214+4724, providing new insights into the galaxy's carbon excitation and gas conditions at high redshift.

Findings

Carbon excitation temperature of 42 K derived from line ratio

Gas density estimated at 10^{3.6-4.0} cm^{-3}

Dust continuum is more compact than line emission regions

Abstract

Using the IRAM 30m telescope and the Plateau de Bure interferometer we have detected the \ctwo and the CO 3$-$2, 4$-$3, 6$-$5, 7$-$6 transitions as well as the dust continuum at 3 and 1.2 mm towards the distant luminous infrared galaxy IRAS F10214+4724 at $z=2.286$. The \ctwo line is detected for the first time towards this source and IRAS F10214+4724 now belongs to a sample of only 3 extragalactic sources at any redshift where both of the carbon fine structure lines have been detected. The source is spatially resolved by our \ctwo\ observation and we detect a velocity gradient along the east-west direction. The CI line ratio allows us to derive a carbon excitation temperature of 42$^{+12}_{-9}$ K. The carbon excitation in conjunction with the CO ladder and the dust continuum constrain the gas density to $n(\hh)$ = $10^{3.6-4.0}$ cm$^{-3}$ and the kinetic temperature to $T\rm_{kin}$ = 45--80 K, similar to the excitation conditions found in nearby starburst galaxies. The rest-frame 360 $\mu$m dust continuum morphology is more compact than the line emitting region, which supports previous findings that the far infrared luminosity arises from regions closer to the active galactic nucleus at the center of this system.