Issue |
A&A
Volume 409, Number 3, October III 2003
|
|
---|---|---|
Page(s) | L47 - L50 | |
Section | Letters | |
DOI | https://doi.org/10.1051/0004-6361:20031345 | |
Published online | 17 November 2003 |
Letter to the Editor
High-excitation CO in a quasar host galaxy at z
*
1
Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
2
Institut d'Astrophysique Spatiale, Université de Paris XI, 91405 Orsay, France
3
IRAM, 300 rue de la Piscine, 38406 St-Martin-d'Hères, France
4
National Radio Astronomy Observatory, PO Box, Socorro, NM 87801, USA
5
Institut d'Astrophysique de Paris, CNRS & Université Paris 6, 98bis bd. Arago, 75014 Paris, France
6
Steward Observatory, The University of Arizona, Tucson, AZ 85721, USA
7
Princeton University Observatory, Princeton, NJ 08544, USA
Corresponding author: F. Bertoldi, bertoldi@mpifr-bonn.mpg.de
Received:
30
May
2003
Accepted:
2
September
2003
We report the detection of high excitation CO emission from
the most distant quasar currently known, SDSS J114816.64+525150.3
(hereafter J1148+5251), at a redshift . The CO (
)
and (
) lines were detected using the
IRAM Plateau de Bure interferometer, showing a width
of ≈
. An upper flux limit for
the CO (
) line was obtained from observations with the
Effelsberg 100-meter telescope. Assuming no gravitational
magnification, we estimate a molecular gas mass of ≈
.
Using the CO (
)
observations by Walter et al. (2003), a comparison of the
line flux ratios with predictions from a large velocity gradient model
suggests that the gas is likely of high excitation, at densities
~
and a temperature ~100 K.
Since in this case
the CO lines appear to have moderate optical depths, the gas
must be extended over a few kpc.
The gas mass detected in J1148+5251 can fuel star formation at the
rate implied by the far-infrared luminosity for less than 10 million years,
a time comparable to the dynamical time scale of the region. The gas must
therefore be replenished quickly, and metal and dust enrichment must
occur fast.
The strong dust emission and the massive, dense gas reservoir at
provide further evidence that vigorous star formation is co-eval
with the rapid growth of massive black holes at these early epochs of
the Universe.
Key words: galaxies: formation / galaxies: starburst / galaxies: high-redshift / quasars: emission lines / quasars: individual: SDSS J1148+5251 / cosmology: observations
© ESO, 2003
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