A CO-rich merger shaping a powerful and hyperluminous infrared radio galaxy at z=2: the Dragonfly Galaxy
Artikel i vetenskaplig tidskrift, 2015

In the low-redshift Universe, the most powerful radio sources are often associated with gasrich galaxy mergers or interactions. We here present evidence for an advanced, gas-rich ('wet') merger associated with a powerful radio galaxy at a redshift of z similar to 2. This radio galaxy, MRC 0152-209, is the most infrared-luminous high-redshift radio galaxy known in the Southern hemisphere. Using the Australia Telescope Compact Array, we obtained highresolution CO(1-0) data of cold molecular gas, which we complement with Hubble Space Telescope (HS7)IWide Field Planetaiy Camera 2 (WFPC2) imaging and William Herschel Telescope long-slit spectroscopy. We find that, while roughly M-H2 x 10(10) Me of molecular gas coincides with the central host galaxy, another M-H2 similar to 3 x 10(10) Me is spread across a total extent of'-60 kpc. Most of this widespread CO(1-0) appears to follow prominent tidal features visible in the rest-frame near-UV HSTIWFPC2 imaging. Lya emission shows an excess over He II, but a deficiency over LIR, which is likely the result of photoionization by enhanced but very obscured star formation that was triggered by the merger. In terms of feedback, the radio source is aligned with widespread CO(1-0) emission, which suggests that there is a physical link between the propagating radio jets and the presence of cold molecular gas on scales of the galaxy's halo. Its optical appearance, combined with the transformational stage at which we witness the evolution of MRC 0152-209, leads us to adopt the name 'Dragonfly Galaxy'.

ISM: jets and outflows

galaxies: high-redshift

ACTIVE GALACTIC NUCLEI

galaxies: active

STAR-FORMING GALAXIES

GALAXIES

GALAXIES

BAND BACK-END

FORMATION HISTORY

MASSIVE DISK

HIGH-REDSHIFT GALAXIES

QUASAR HOST GALAXIES

MOLECULAR GAS-RESERVOIRS

galaxies: individual: MRC 0152-209

SCALING RELATIONS

LUMINOUS SUBMILLIMETER

Författare

B. Emonts

Centro de Astrobiologia (CAB)

M. Y. Mao

National Radio Astronomy Observatory

A. Stroe

Universiteit Leiden

L. Pentericci

Osservatorio Astronomico di Roma

M. Villar-Martin

Universidad Autonoma de Madrid (UAM)

Centro de Astrobiologia (CAB)

R. P. Norris

Australia Telescope National Facility

G. Miley

Universiteit Leiden

C. De Breuck

European Southern Observatory (ESO)

G. A. van Moorsel

National Radio Astronomy Observatory

M. Lehnert

Université Pierre et Marie Curie (UPMC)

C. L. Carilli

University of Cambridge

National Radio Astronomy Observatory

H. Rottgering

Universiteit Leiden

N. Seymour

University of Western Australia

E. M. Sadler

The University of Sydney

R. D. Ekers

Australia Telescope National Facility

Guillaume Drouart

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

I. Feain

The University of Sydney

L. Colina

Centro de Astrobiologia (CAB)

Universidad Autonoma de Madrid (UAM)

J. Stevens

Australia Telescope National Facility

J. Holt

ESTEC

Monthly Notices of the Royal Astronomical Society

0035-8711 (ISSN) 1365-2966 (eISSN)

Vol. 451 1 1025-1035

Ämneskategorier

Astronomi, astrofysik och kosmologi

DOI

10.1093/mnras/stv930