Herschel-ATLAS: A Binary HyLIRG Pinpointing a Cluster of Starbursting Protoellipticals
R. J. Ivison
(1)
,
A. M. Swinbank
(2)
,
Ian Smail
(2)
,
A. I. Harris
(3)
,
R. S. Bussmann
(4)
,
A. Cooray
(5)
,
P. Cox
(6)
,
H. Fu
(7)
,
A. Kovács
(8)
,
M. Krips
(6)
,
D. Narayanan
(4)
,
M. Negrello
(4)
,
R. Neri
(6)
,
J. Peñarrubia
(4)
,
J. Richard
(9)
,
D. A. Riechers
(4)
,
K. Rowlands
(4)
,
J. G. Staguhn
(4)
,
T. A. Targett
(10, 5)
,
S. Amber
(4)
,
A. J. Baker
(11)
,
N. Bourne
(4)
,
F. Bertoldi
(11)
,
M. Bremer
(4)
,
J. A. Calanog
(4)
,
D. L. Clements
(4)
,
H. Dannerbauer
(12)
,
A. Dariush
(4)
,
G. de Zotti
(4)
,
L. Dunne
(4)
,
S. A. Eales
(4)
,
D. Farrah
(13)
,
S. Fleuren
(4)
,
A. Franceschini
(4)
,
J. E. Geach
(2)
,
R. D. George
(4)
,
J. C. Helly
(4)
,
R. Hopwood
(14)
,
E. Ibar
(4)
,
M. J. Jarvis
(15)
,
J.-P. Kneib
(16)
,
S. Maddox
(4)
,
A. Omont
(17)
,
D. Scott
(4)
,
S. Serjeant
(4)
,
M. W. L. Smith
(4)
,
M. A. Thompson
(4)
,
E. Valiante
(4)
,
I. Valtchanov
(4)
,
J. Vieira
(18)
,
P. van Der Werf
(19)
1
ROE -
Royal Observatory Edinburgh
2 Department of Physics
3 Department of Astronomy
4 AUTRES
5 CALTECH - California Institute of Technology
6 IRAM - Institut de RadioAstronomie Millimétrique
7 Earthquake Administration of Yunnan Province
8 Department of Pathology
9 CRAL - Centre de Recherche Astrophysique de Lyon
10 UAB - University of Alabama at Birmingham [ Birmingham]
11 MPIFR - Max-Planck-Institut für Radioastronomie
12 MPIA - Max-Planck-Institut für Astronomie
13 Astronomy Centre
14 Department of Physics and Astronomy [Milton Keynes]
15 Physical Sciences Division
16 LAM - Laboratoire d'Astrophysique de Marseille
17 IAP - Institut d'Astrophysique de Paris
18 GoLP/Instituto Plasmas e Fusa˜o Nuclear
19 Leiden Observatory [Leiden]
2 Department of Physics
3 Department of Astronomy
4 AUTRES
5 CALTECH - California Institute of Technology
6 IRAM - Institut de RadioAstronomie Millimétrique
7 Earthquake Administration of Yunnan Province
8 Department of Pathology
9 CRAL - Centre de Recherche Astrophysique de Lyon
10 UAB - University of Alabama at Birmingham [ Birmingham]
11 MPIFR - Max-Planck-Institut für Radioastronomie
12 MPIA - Max-Planck-Institut für Astronomie
13 Astronomy Centre
14 Department of Physics and Astronomy [Milton Keynes]
15 Physical Sciences Division
16 LAM - Laboratoire d'Astrophysique de Marseille
17 IAP - Institut d'Astrophysique de Paris
18 GoLP/Instituto Plasmas e Fusa˜o Nuclear
19 Leiden Observatory [Leiden]
P. Cox
- Fonction : Auteur
- PersonId : 748983
- IdHAL : cox-pierre
- ORCID : 0000-0003-2027-8221
H. Fu
- Fonction : Auteur
- PersonId : 760693
- ORCID : 0000-0002-4701-7219
R. Neri
- Fonction : Auteur
- PersonId : 755572
- ORCID : 0000-0002-7176-4046
J. Richard
- Fonction : Auteur
- PersonId : 84
- IdHAL : johan-richard
- ORCID : 0000-0001-5492-1049
- IdRef : 095319204
Résumé
Panchromatic observations of the best candidate hyperluminous infrared galaxies from the widest Herschel extragalactic imaging survey have led to the discovery of at least four intrinsically luminous z = 2.41 galaxies across an ≈100 kpc region--a cluster of starbursting protoellipticals. Via subarcsecond interferometric imaging we have measured accurate gas and star formation surface densities. The two brightest galaxies span ~3 kpc FWHM in submillimeter/radio continuum and CO J = 4-3, and double that in CO J = 1-0. The broad CO line is due partly to the multitude of constituent galaxies and partly to large rotational velocities in two counter-rotating gas disks--a scenario predicted to lead to the most intense starbursts, which will therefore come in pairs. The disks have M dyn of several × 1011 M ⊙, and gas fractions of ~40%. Velocity dispersions are modest so the disks are unstable, potentially on scales commensurate with their radii: these galaxies are undergoing extreme bursts of star formation, not confined to their nuclei, at close to the Eddington limit. Their specific star formation rates place them >~ 5 × above the main sequence, which supposedly comprises large gas disks like these. Their high star formation efficiencies are difficult to reconcile with a simple volumetric star formation law. N-body and dark matter simulations suggest that this system is the progenitor of a B(inary)-type ≈1014.6-M ⊙ cluster.