A 100 kpc INVERSE COMPTON X-RAY HALO AROUND 4C 60.07 AT z = 3.79

Journal Article · Thu Sep 10 04:00:00 EDT 2009 · Astrophysical Journal (Online)

DOI:https://doi.org/10.1088/0004-637X/702/2/L114; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21336039

Smail, Ian; Lehmer, B D; Alexander, D M; Bower, R G; Geach, J E; Coppin, K E. K. ^[1]; Ivison, R J ^[2]; Stevens, J A ^[3]; Scharf, C A ^[4]

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1. Institute for Computational Cosmology, Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom)
2. UK Astronomy Technology Centre, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)
3. Centre for Astrophysics Research, Science and Technology Research Centre, University of Hertfordshire, College Lane, Herts AL10 9AB (United Kingdom)
4. Columbia Astrophysics Laboratory, Columbia University, 550 W. 120th Street, MC 5247, New York, NY 10027 (United States)

We analyze a 100 ks Chandra observation of the powerful radio galaxy, 4C 60.07 at z = 3.79. We identify extended X-ray emission with L {sub X} {approx} 10{sup 45} erg s{sup -1} across a {approx}90 kpc region around the radio galaxy. The energetics of this X-ray halo and its morphological similarity to the radio emission from the galaxy suggest that it arises from inverse Compton (IC) scattering, by relativistic electrons in the radio jets, of cosmic microwave background photons and potentially far-infrared photons from the dusty starbursts around this galaxy. The X-ray emission has a similar extent and morphology to the Ly{alpha} halo around the galaxy, suggesting that it may be ionizing this halo. Indeed, we find that the GHz-radio and X-ray and Ly{alpha} luminosities of the halo around 4C 60.07 are identical to those of 4C 41.17 (also at z = 3.8) implying that these three components are linked by a single physical process. This is only the second example of highly extended IC emission known at z>3, but it underlines the potential importance of IC emission in the formation of the most massive galaxies at high redshifts. In addition, we detect two X-ray luminous active galactic nuclei (AGNs) within {approx}30 kpc of the radio galaxy. These two companion AGNs imply that the radio and starburst activity in the radio galaxy is triggered through multiple mergers of massive progenitors on a short timescale, {approx}<100 Myr. These discoveries demonstrate the wealth of information which sensitive X-ray observations can yield into the formation of massive galaxies at high redshifts.

• OSTI ID: 21336039
• Journal Information: Astrophysical Journal (Online), Journal Name: Astrophysical Journal (Online) Journal Issue: 2 Vol. 702; ISSN 1538-4357
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COSMOLOGY
ELECTRONS
GALACTIC EVOLUTION
GALAXY NUCLEI
GHZ RANGE
LUMINOSITY
PHOTON EMISSION
PHOTONS
RADIO GALAXIES
RED SHIFT
RELATIVISTIC RANGE
RELICT RADIATION
X RADIATION