High Sensitivity Array Observations of the $z=4.4$ QSO BRI 1335-0417

Abstract

We present sensitive phase-referenced VLBI results on the radio continuum emission from the $z=4.4$ QSO BRI 1335--0417. The observations were carried out at 1.4 GHz using the High Sensitivity Array (HSA). Our sensitive VLBI image at $189\times 113$ mas ($1.25\times 0.75$ kpc) resolution shows continuum emission in BRI 1335--0417 with a total flux density of $208\pm 46\mu$Jy, consistent with the flux density measured with the VLA. The size of the source at FWHM is $255\times 138$ mas ($1.7\times 0.9$ kpc) and the derived intrinsic brightness temperature is $\sim 3.5\times 10^4$ K. No continuum emission is detected at the full VLBI resolution ($32\times 7$ mas, $211\times 46$ pc), with a 4$\sigma$ point source upper limit of 34 $\mu$Jy beam${}^{-1}$, or an upper limit to the intrinsic brightness temperature of $5.6\times 10^5$ K. The highest angular resolution with at least a 4.5$\sigma$ detection of the radio continuum emission is $53\times 27$ mas ($0.35\times 0.18$ kpc). At this resolution, the image shows a continuum feature in BRI 1335--0417 with a size of $64\times 35$ mas ($0.42\times 0.23$ kpc) at FWHM, and intrinsic brightness temperature of $\sim 2\times 10^5$ K. The extent of the observed continuum sources at 1.4 GHz and the derived brightness temperatures show that the radio emission (and thus presumably the far-infrared emission) in BRI 1335--0417 is powered by a major starburst, with a massive star formation rate of order a few thousand M_{\odot} {\rm yr}^{-1}$.Moreover,theabsenceofanycompacthigh-brightnesstemperaturesourcesuggeststhatthereisnoradio-loudAGNinthis$z=4.4$ QSO.

13 pages, 3 figures, AJ accepted

References in corpus (20)

• The Sloan Digital Sky Survey: Technical Summary
• Molecular Gas at High Redshift
• Observational constraints on Cosmic Reionization
• Evolution of the Ionizing Background and the Epoch of Reionization from the Spectra of z~6 Quasars
• Dust emission from the most distant quasars
• 350 Micron Dust Emission from High Redshift Quasars
• Molecular Gas in the Host Galaxy of a Quasar at Redshift z=6.42
• CO(1-0) in z >/~ 4 Quasar Host Galaxies: No Evidence for Extended Molecular Gas Reservoirs
• High resolution imaging of molecular line emission from high redshift QSOs
• APM z>4 QSO Survey: Spectra and Intervening Absorption Systems
• A 1.2mm MAMBO/IRAM-30m Study of Dust Emission from optically luminous z~2 Quasars
• The Extreme Compact Starburst in MRK 273
• Radio continuum imaging of FIR luminous QSOs at z>6
• Sensitive Radio Observations of High Redshift Dusty QSOs
• Detection of CO (2-1) and Radio Continuum Emission from the z = 4.4 QSO BRI 1335-0417
• Radio structure of the most distant radio-detected quasar at the ten milli- arcsecond scale
• Starburst activity in the host galaxy of the z=2.58 quasar J1409+5628
• Sensitive VLBI Observations of the z = 4.7 QSO BRI 1202-0725
• VLBA Continuum and H I Absorption Observations of the Ultra-Luminous Infrared Galaxy IRAS 17208-0014
• VLBA observations of z > 4 radio-loud quasars

Cited by in corpus (10)

• Cool Gas in High Redshift Galaxies
• Thermal Emission from Warm Dust in the Most Distant Quasars
• Assessing Radiation Pressure as a Feedback Mechanism in Star-Forming Galaxies
• Imaging Atomic and Highly Excited Molecular Gas in a z=6.42 Quasar Host Galaxy: Copious Fuel for an Eddington-Limited Starburst at the End of Cosmic Reionization
• Formation of a Quasar Host Galaxy through a Wet Merger 1.4 Billion Years after the Big Bang
• [CII] line emission in BRI1335-0417 at z=4.4
• VLA and VLBA Observations of the Highest Redshift Radio-Loud QSO J1427+3312 at z = 6.12
• Deep, ultra-high-resolution radio imaging of submillimetre galaxies using Very Long Baseline Interferometry
• New Constraints on the Molecular Gas in the Prototypical HyLIRGs BRI1202-0725 & BRI1335-0417
• Ground-state 12CO emission and a resolved jet at 115 GHz (rest-frame) in the radio loud quasar 3C318