2018A&A...620A..61C


Query : 2018A&A...620A..61C

2018A&A...620A..61C - Astronomy and Astrophysics, volume 620A, 61-61 (2018/12-1)

Planck's dusty GEMS. VI. Multi-J CO excitation and interstellar medium conditions in dusty starburst galaxies at z = 2-4.

CANAMERAS R., YANG C., NESVADBA N.P.H., BEELEN A., KNEISSL R., KOENIG S., LE FLOC'H E., LIMOUSIN M., MALHOTRA S., OMONT A. and SCOTT D.

Abstract (from CDS):

We present an extensive CO emission-line survey of the Planck's dusty Gravitationally Enhanced subMillimetre Sources, a small set of 11 strongly lensed dusty star-forming galaxies at z=2-4 discovered with Planck and Herschel satellites, using EMIR on theIRAM 30-m telescope. We detected a total of 45 CO rotational lines from Jup=3 to Jup=11, and up to eight transitions per source, allowing a detailed analysis of the gas excitation and interstellar medium conditions within these extremely bright (µLFIR=0.5-3.0x 1014L), vigorous starbursts. The peak of the CO spectral-line energy distributions (SLEDs) fall between Jup=4 and Jup=7 for nine out of 11 sources, in the same range as other lensed and unlensed submillimeter galaxies (SMGs) and the inner regions of local starbursts. We applied radiative transfer models using the large velocity gradient approach to infer the spatially-averaged molecular gas densities, nH2~=102.6-104.1cm–3, and kinetic temperatures, Tk~=30-1000K. In five sources, we find evidence of two distinct gas phases with different properties and model their CO SLED with two excitation components. The warm (70-320K) and dense gas reservoirs in these galaxies are highly excited, while the cooler (15-60K) and more extended low-excitation components cover a range of gas densities.In two sources, the latter is associated with diffuse Milky Way-like gas phases of density nH2~=102.4-102.8 cm–3, which provides evidence that a significant fraction of the total gas masses of dusty starburst galaxies can be embedded in cool, low-density reservoirs. The delensed masses of the warm star-forming molecular gas range from 0.6 to 12x1010M. Finally, we show that the CO line luminosity ratios are consistent with those predicted by models of photon-dominated regions (PDRs) and disfavor scenarios of gas clouds irradiated by intense X-ray fields from active galactic nuclei. By combining CO, [CI] and [CII] line diagnostics, we obtain average PDR gas densities significantly higher than in normal star-forming galaxies at low-redshift, as well as far-ultraviolet radiation fields 102-104 times more intense than in the Milky Way. These spatially-averaged conditions are consistent with those in high-redshift SMGs and in a range of low-redshift environments, from the central regions of ultra-luminous infrared galaxies and bluer starbursts to Galactic giant molecular clouds.

Abstract Copyright: © ESO 2018

Journal keyword(s): galaxies: high-redshift - galaxies: evolution - galaxies: star formation - galaxies: ISM - submillimeter: galaxies - ISM: molecules

Simbad objects: 16

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Number of rows : 16
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 QSO J0831+5245 QSO 08 31 41.7108197808 +52 45 17.616994560   19.2   14.5 13.9 ~ 513 1
2 SDP 81 G 09 03 11.574 +00 39 06.55           ~ 88 0
3 [CNG2015] PLCK G200.6+46.1 LeG 09 32 23.67 +27 25 00.0           ~ 4 0
4 M 82 IG 09 55 52.430 +69 40 46.93 9.61 9.30 8.41     ~ 5583 6
5 [CNG2015] PLCK G145.2+50.9 LeG 10 53 22.56 +60 51 49.0           ~ 7 0
6 [CNG2015] PLCK G244.8+54.9 LeG 10 53 53.04 +05 56 21.0           ~ 13 0
7 PCCS1 857 G165.65+67.01 LeG 11 27 14.60 +42 28 25.0           ~ 12 0
8 [CNG2015] PLCK G231.3+72.2 LeG 11 39 21.60 +20 24 53.0           ~ 3 0
9 [CNG2015] PLCK G138.6+62.0 LeG 12 02 07.68 +53 34 40.0           ~ 5 0
10 [CNG2015] PLCK G113.7+61.0 LeG 13 23 02.88 +55 36 01.0           ~ 4 0
11 [CNG2015] PLCK G102.1+53.6 LeG 14 29 17.98 +59 21 09.0           ~ 3 0
12 [CNG2015] PLCK G045.1+61.1 LeG 15 02 36.04 +29 20 51.0           ~ 6 0
13 IC 4553 SyG 15 34 57.22396 +23 30 11.6084   14.76 13.88     ~ 2822 4
14 [CNG2015] PLCK G080.2+49.8 LeG 15 44 32.40 +50 23 46.0           ~ 4 0
15 PCCS1 857 G092.47+42.88 G 16 09 17.76 +60 45 21.0           ~ 8 0
16 NAME Eyelash LeG 21 35 11.60 -01 02 52.0           ~ 208 0

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2022.05.24-11:36:22

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