Bibcode
Oteo, I.; Zhang, Z.-Y.; Yang, C.; Ivison, R. J.; Omont, A.; Bremer, M.; Bussmann, S.; Cooray, A.; Cox, P.; Dannerbauer, H.; Dunne, L.; Eales, S.; Furlanetto, C.; Gavazzi, R.; Gao, Y.; Greve, T. R.; Nayyeri, H.; Negrello, M.; Neri, R.; Riechers, D.; Tunnard, R.; Wagg, J.; Van der Werf, P.
Bibliographical reference
The Astrophysical Journal, Volume 850, Issue 2, article id. 170, 10 pp. (2017).
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12
2017
Journal
Citations
42
Refereed citations
39
Description
We present ALMA J=3{--}2 and VLA J=1{--}0 observations of the dense
molecular gas tracers HCN, HCO+, and HNC in two lensed,
high-redshift starbursts selected from the Herschel-ATLAS survey:
H-ATLAS J090740.0‑004200 (SDP.9, {z}{spec}=1.575) and
H-ATLAS J091043.1‑000321 (SDP.11, {z}{spec}=1.786). In
SDP.9 we have detected all J=3{--}2 transitions and also HCN(1–0)
and HCO+(1–0). In SDP.11 we have detected
HCN(3–2) and HCO+(3–2). The amplification factors
for both galaxies have been determined from subarcsecond-resolution CO
and dust emission observations carried out with NOEMA and the SMA. The
HNC(1–0)/HCN(1–0) line ratio in SDP.9 suggests the presence
of photon-dominated regions, as happens in most local (U)LIRGs. The CO,
HCN, and HCO+ spectral line energy distribution (SLEDs) of
SDP.9 are compatible to those found for many local, IR-bright galaxies,
indicating that the molecular gas in local and high-redshift dusty
starbursts can have similar excitation conditions. We obtain that the
correlation between total IR ({L}{IR}) and dense line
({L}{dense}) luminosity in SDP.9 and SDP.11 and local
star-forming galaxies can be represented by a single relation. We argue
that the scatter of the {L}{IR}{--}{L}{dense}
correlation, together with the lack of sensitive dense molecular gas
tracer observations for a homogeneous sample of high-redshift galaxies,
prevents us from distinguishing differential trends with redshift. Our
results suggest that the intense star formation found in some
high-redshift, dusty, luminous starbursts is associated with more
massive dense molecular gas reservoirs and higher dense molecular gas
fractions.
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Molecular Gas and Dust in Galaxies Across Cosmic Time
Two of the most fundamental questions in astrophysics are the conversion of molecular gas into stars and how this physical process is a function of environments on all scales, ranging from planetary systems, stellar clusters, galaxies to galaxy clusters. The main goal of this internal project is to get insight into the formation and evolution of
Helmut
Dannerbauer