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Post Info TOPIC: CFHQS J2329-0301


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Title: Redshift 6.4 host galaxies of 10^8 solar mass black holes: low star formation rate and dynamical mass
Authors: Chris J. Willott, Alain Omont, Jacqueline Bergeron

We present ALMA observations of rest-frame far-infrared continuum and [CII] line emission in two z=6.4 quasars with black hole masses of ~10^8 solar masses. CFHQS J0210-0456 is detected in the continuum with a 1.2 mm flux of 12035 microJy, whereas CFHQS J2329-0301 is undetected at a similar noise level. J2329-0301 has a star formation rate limit of <36 solar masses/yr, considerably below the typical value at all redshifts for this bolometric luminosity. We speculate that this quasar is observed at a relatively rare phase where quasar feedback has effectively shut down star formation in the host galaxy. [CII] emission is also detected only in J0210-0456. The ratio of [CII] to far-infrared luminosity is similar to at low redshift, suggesting the offset in the relationships between this ratio and far-infrared luminosity at low- and high-redshift may be partially due to a selection effect from the limited sensitivity of previous observations. The [CII] line of J0210-0456 is relatively narrow (FWHM=18918 km/s), indicating a dynamical mass substantially lower than the local black hole - velocity dispersion correlation. The [CII] line is marginally resolved at 0.7" resolution with the blue and red wings spatially offset by 0.5" (3 kpc) and a smooth velocity gradient of 100 km/s across a scale of 6 kpc, possibly due to rotation of a galaxy-wide disk. These observations are consistent with the idea that stellar mass growth lags black hole accretion for quasars at this epoch with respect to more recent times.

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Title: A Lyman alpha halo around a quasar at redshift z=6.4
Authors: Chris J. Willott, Savironi Chet, Jacqueline Bergeron, John B. Hutchings

We present long-slit spectroscopic data which reveals extended Lyman alpha emission around the z=6.417 radio-quiet quasar CFHQS J2329-0301. The Lyman alpha emission is extended over 15 kpc and has a luminosity of > 8 x 10^36 W, comparable to the most luminous Lyman alpha halos known. The emission has complex kinematics, in part due to foreground absorption which only partly covers the extended nebula. The velocity ranges from -500 km/s to +500 km/s, with a peak remarkably close to the systemic velocity identified by broad MgII emission of the quasar. There is no evidence for infall or outflow of the halo gas. We speculate that the Lyman alpha emission mechanism is recombination after quasar photo-ionisation of gas sitting within a high-mass dark matter halo. The immense Lyman alpha luminosity indicates a higher covering factor of cold gas compared to typical radio-quiet quasars at lower redshift.

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Title: A QSO host galaxy and its Ly emission at z=6.43?
Authors: Tomotsugu Goto, Yousuke Utsumi, Hisanori Furusawa, Satoshi Miyazaki, and Yutaka Komiyama

Host galaxies of highest redshift QSOs are of interest; they provide us with a valuable opportunity to investigate physics relevant to the starburst-AGN connection at the earliest epoch of the Universe, with the most luminous black holes.
Here we report an optical detection of an extended structure around a QSO at z=6.43 in deep z0 and z_r-band images of the Subaru/Suprime-Cam. Our target is CFHQSJ2329-0301 (z=6.43), the highest redshift QSO currently known. We have carefully subtracted a PSF constructed using nearby stars from the images. After the PSF (QSO) subtraction, a structure in the z0 -band extends more than 4" on the sky (R_e=11 kpc), and thus, is well-resolved (16 sigma detection). The PSF-subtracted z_r-band structure is in a similar shape to that in the z0 -band, but less significant with a 3 sigma detection. In the z0 -band, a radial profile of the QSO+host shows a clear excess over that of the averaged PSF in 0.8-3" radius.
Since the z0 -band includes a Ly emission at z=6.43, we suggest the z0
flux is a mixture of the host (continuum light) and its Ly emission, whereas the z_r-band flux is from the host. Through a SED modelling, we estimate 40% of the PSF-subtracted z0 -band light is from the host (continuum) and 60% is from Ly emission. The absolute magnitude of the host is M_1450=-23.9 (c.f.M1450=-26.4 for the QSO). A lower limit of the SFR(Ly) is 1.6 solar masses yr^-1 with stellar mass ranging 6.2 x 10^8 to 1.1 x 10^10 solar masses when 100 Myrs of age is assumed. The detection shows that a luminous QSO is already harboured by a large, star-forming galaxy in the early Universe only after ~840 Myr after the big bang. The host may be a forming giant galaxy, co-evolving with a super massive black hole.

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Astronomers have found a supermassive black hole so far away it's almost as old as the universe itself. It may provide new clues to investigate the evolution of galaxies.
The huge galaxy that surrounds the black hole is similar in size to the Milky Way, but is so distant that the light we see from it is 12.8 billion years old.

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QSO (CFHQSJ2329-0301)
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A careful analysis of the colours revealed that 40 percent of light around 9100 is from the host galaxy itself and 60 percent is from the surrounding ionised nebulae illuminated by the black hole.

"We have witnessed a supermassive black hole and its host galaxy forming together. This discovery has opened a new window for investigating galaxy-black hole co-evolution at the dawn of the universe" - Dr. Yousuke Utsumi (Graduate University for Advanced Studies/NAOJ), a member of the project team.


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Astronomers have discovered a supermassive black hole near the edge of the known universe.
It lies within a galaxy the size of the Milky Way, which is 12.8billion light-years from Earth. The light from this galaxy has travelled for most of the universe's 13.7billion-year lifespan to reach us.

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Most Distant Supermassive Black Hole
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University of Hawaii Astronomer Finds Giant Galaxy Hosting the Most Distant Supermassive Black Hole
University of Hawaii astronomer Dr. Tomotsugu Goto and colleagues have discovered a giant galaxy surrounding the most distant black hole ever found. The galaxy, which is 12.8 billion light-years from Earth, is as large as the Milky Way galaxy and harbours a supermassive black hole that contains at least a billion times as much matter as does our Sun.

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CFHQS J2329-0301
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Chris Willott (University of Ottawa) and a large international research team identified four new quasars at redshift greater than z = 6 from MegaCam imaging at the Canada-France-Hawaii Telescope (CFHT). Follow-up spectroscopy with GMOS at the Gemini South telescope (and the Marcario LRS at the Hobby-Ebbberly Telescope) allowed the team to determine accurate redshifts. The team found what is now the most distant known quasar, CFHQS J2329-0301 at z = 6.43.
Willott et al. also used the spectra to investigate constraints on the ionisation sate of the intergalactic medium at that early age of the universe. Analysis of two of these quasar spectra revealed evidence that the reionisation period is considerably longer than predicted by most theoretical models.

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