Milliarcsecond Imaging of the Radio Emission from the Quasar with the Most Massive Black Hole at Reionization

Journal Article · Wed Feb 01 04:00:00 EST 2017 · Astrophysical Journal Letters

DOI:https://doi.org/10.3847/2041-8213/835/2/L20· OSTI ID:22654556

Wang, Ran; Wu, Xue-Bing; Jiang, Linhua ^[1]; Momjian, Emmanuel; Carilli, Chris L. ^[2]; Fan, Xiaohui ^[3]; Walter, Fabian ^[4]; Strauss, Michael A. ^[5]; Wang, Feige ^[6]

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1. Kavli Institute of Astronomy and Astrophysics at Peking University, No. 5 Yiheyuan Road, Haidian District, Beijing 100871 (China)
2. National Radio Astronomy Observatory, P.O. Box 0, Socorro, NM 87801 (United States)
3. Steward Observatory, University of Arizona, 933 N Cherry Avenue, Tucson, AZ 85721 (United States)
4. Max-Planck-Institute for Astronomy, Königsstuhl 17, D-69117 Heidelberg (Germany)
5. Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)
6. Department of Astronomy, School of Physics, Peking University, No. 5 Yiheyuan Road, Haidian District, Beijing 100871 (China)

We report Very Long Baseline Array (VLBA) observations of the 1.5 GHz radio continuum emission of the z = 6.326 quasar SDSS J010013.02+280225.8 (hereafter J0100+2802). J0100+2802 is by far the most optically luminous and is a radio-quiet quasar with the most massive black hole known at z > 6. The VLBA observations have a synthesized beam size of 12.10 mas ×5.36 mas (FWHM), and detected the radio continuum emission from this object with a peak surface brightness of 64.6 ± 9.0 μ Jy beam{sup −1} and a total flux density of 88 ± 19 μ Jy. The position of the radio peak is consistent with that from SDSS in the optical and Chandra in the X-ray. The radio source is marginally resolved by the VLBA observations. A 2D Gaussian fit to the image constrains the source size to (7.1 ± 3.5) mas × (3.1 ± 1.7) mas. This corresponds to a physical scale of (40 ± 20) pc × (18 ± 10) pc. We estimate the intrinsic brightness temperature of the VLBA source to be T {sub B} = (1.6 ± 1.2) × 10{sup 7} K. This is significantly higher than the maximum value in normal star-forming galaxies, indicating an active galactic nucleus (AGN) origin for the radio continuum emission. However, it is also significantly lower than the brightness temperatures found in highest-redshift radio-loud quasars. J0100+2802 provides a unique example for studying the radio activity in optically luminous and radio-quiet AGNs in the early universe. Further observations at multiple radio frequencies will accurately measure the spectral index and address the dominant radiation mechanism of the radio emission.

• OSTI ID: 22654556
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 835; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BEAMS
BLACK HOLES
BRIGHTNESS
EMISSION
FLUX DENSITY
GALAXIES
GHZ RANGE
QUASARS
RADIOWAVE RADIATION
RED SHIFT
STARS
SURFACES
UNIVERSE
X RADIATION