High-redshift quasar discovered by Pan-STARRS

December 21, 2016 by Tomasz Nowakowski report
The spectrum of PSO J006.1240+39.2219. The spectrum and spectrum error are combined into upper and lower panels, respectively. Credit: Tang et al., 2016.

(Phys.org)—A new luminous high-redshift quasar has been detected by one of the telescopes of the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS). The newly discovered quasi-stellar object received designation PSO J006.1240+39.2219 and is the seventh highest redshift quasar known to date. The findings are presented in a paper published Dec. 19 on arXiv.org.

Quasars are supermassive black holes with accretion disks in the center of a galaxy. Their redshifts are measured from the strong spectral lines that dominate their visible and ultraviolet spectra. These lines are brighter than the continuous spectrum, so they are called 'emission' lines. All observed quasar spectra have redshifts between 0.056 and 7.085.

Quasars with high redshift (over 6.0) are of special interest for astronomers because their ultraviolet light is absorbed by the neutral hydrogen along the line of sight; thus, they can be used to probe the intergalactic medium in the early universe. They are the most luminous and most distant, compact objects in the observable universe. Their spectrum can be used to estimate the mass of a supermassive black hole, which constrains the evolution and formation model of a quasar. Therefore, high-redshift quasars could serve as a powerful tool to probe the early universe.

Recently, a team of researchers led by Ji-Jia Tang of the National Taiwan University in Taipei, Taiwan, has searched for such quasars using the first Pan-STARRS telescope (PS1) located in Hawaii. In particular, they tried to find red-color objects between two adjacent broad bands caused by the strong intergalactic medium absorption on the blue side of the redshifted Lyman-alpha line emission.

They detected a new luminous high-redshift quasar at redshift of 6.61. The discovery was later confirmed by the team during a follow-up observation campaign carried out with the Subaru Faint Object Camera and Spectrograph (FOCAS) mounted on the Subaru Telescope in Hawaii.

According to the paper, PSO J006.1240+39.2219, besides being the seventh highest redshift quasar known to date, is also one of nine quasars above the redshift of 6.5.

"We report a discovery of a new quasar at z 6.6 select from PS1 with a spectroscopic confirmation. This is the seventh highest quasar among nine z-dropout quasar (z>6.5) known to date," the paper reads.

The researchers found that the rest-frame ultraviolet luminosity of PSO J006.1240+39.2219 is comparable to other z-dropout quasars, though its Lyman-alpha line emission is much stronger when compared to typical quasars obtained from low redshift.

"J006.1240+39.2219 is consistent with other comparably distant quasars, although it has much stronger Lyman-alpha line. (…) The spectral resolution is adjusted to match for a fair comparison. This shows that Lyman-alpha line emission of PSO J006.1240+39.2219 is much stronger than those quasars at low redshifts," the astronomers wrote.

The team also noted that after decades of searching, more than 100 were found with redshifts between 5.7 and 6.5 from various kind of surveys. So far, ULAS J112001.48+064124 is the highest redshift quasar with a redshift of 7.085. It was found in 2011 using UK Infrared Telescope (UKIRT) Infrared Deep Sky Survey (UKIDSS).

Explore further: Astronomers find universe's most distant quasar (w/ video)

More information: A Quasar Discovered at redshift 6.6 from Pan-STARRS1, arXiv:1612.06148 [astro-ph.GA] arxiv.org/abs/1612.06148

Abstract
Luminous high-redshift quasars can be used to probe of the intergalactic medium (IGM) in the early universe because their UV light is absorbed by the neutral hydrogen along the line of sight. They help us to measure the neutral hydrogen fraction of the high-z universe, shedding light on the end of reionization epoch. In this paper, we present a discovery of a new quasar (PSO J006.1240+39.2219) at redshift z = 6.61 +- 0.02 from Panoramic Survey Telescope & Rapid Response System 1. Including this quasar, there are nine quasars above z > 6.5 up to date. The estimated continuum brightness is M1450= 25.96 +- 0.08. PSO J006.1240+39.2219 has a strong Ly alpha emission compared with typical low-redshift quasars, but the measured near-zone region size is RNZ = 3.2 +- 1.1 proper megaparsecs, which is consistent with other quasars at z~6.

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cantdrive85
2 / 5 (8) Dec 22, 2016
They are the most luminous and most distant, compact objects in the observable universe. Their spectrum can be used to estimate the mass of a supermassive black hole, which constrains the evolution and formation model of a quasar. Therefore, high-redshift quasars could serve as a powerful tool to probe the early universe.

Speculation based upon speculation. A speculation that has been shown to be falsified by Hal Arp. He has shown beyond a reasonable doubt that redshift is likely intrinsic, especially in QSO's.
IMP-9
5 / 5 (4) Dec 22, 2016
He has shown beyond a reasonable doubt that redshift is likely intrinsic, especially in QSO's.


Not only are you wrong but you've clearly never actually read Arp's papers. The models by Bell and Karlsson that Arp worked on had only an intrinsic component. These models of ejection are dead, debunked by the cross-correlation of low-z galaxies with QSOs in SDSS.
Bigbangcon
2.1 / 5 (7) Dec 23, 2016
Halton (Chip) Arp's idea of the intrinsic nature of redshift is very much alive and well, even though Arp is no more. The single study of two Chinese astronomers (Tang and Zhang) who claimed to have refuted Arp (and was touted by official cosmology as the irreversible refutation of Arp's challenge of the Big Bang) is now debunked in a recent publication by Bell and McDiarmid. : http://iopscience...ulltext/

GR and the whole edifice of Big Bang cosmology built on it; are coming undone! The claims of "Dark Energy" and "Dark Matter" are in serious doubt. Even the recent "Discovery of the century if not of all times" failed to get attention from the Nobel Committee and the Guardian list of the year!--- "The Times They Are A Changin'"!
IMP-9
5 / 5 (4) Dec 23, 2016
is now debunked in a recent publication by Bell and McDiarmid


You realise you're quoting a paper which was refuted by Bell himself?: http://adsabs.har...26...11B

"Because this [selection] effect cannot be rigorously corrected for, astronomers need to be aware of it in any investigation that uses the SDSS N( z) distribution. Its presence also means that the SDSS quasar data cannot be used either to confirm or to rule out the Δ z~0.6 redshift period reported previously in other, unrelated quasar data."

Even Hartnett perhaps the most extreme follower of redshift periodicity made a similar admission:
http://adsabs.har...24...13H

"It does not signal any intrinsic (quantized) redshifts in the quasars in Sloan survey data."
IMP-9
5 / 5 (4) Dec 23, 2016
You clearly haven't read either paper. Firstly the paper is not recent, it's 10 years old. Secondly they do not address the cross-correlation results which are so damning. How can QSO's be ejected flow low-z galaxies and not cluster? The ejection models say they should cluster and yet they don't. This result is independent of selection effects which ruin the study you quote as it deals with clustering not the redshift distribution.

Bell & McDiarmid instead only look at periodicity in the DR3 QSO sample. You claim this "refutes" this paper but they aren't even doing the same test. However the more recent DR7 QSO paper showed the periodicity in the QSO sample was due to a cut in redshift confidence (i.e. a selection effect) and when a bright sample was selected the redshift distribution was smooth and there was no evidence of periodicity. The virtual retraction of this paper in Bell & Comeau puts this to bed. Tang and Zhang is not the only paper critical of redshift periodicity.
Bigbangcon
1 / 5 (5) Dec 23, 2016
"You realise you're quoting a paper which was refuted by Bell himself?: http://adsabs.har...26...11B

This cited paper refers to one Delta z˜0.6 redshift period only and says, "Its presence also means that the SDSS quasar data cannot be used either to confirm or to rule out the Delta z˜0.6 redshift period reported previously in other, unrelated quasar data." The second reference says, "However this result does not rule out the possibility as found in earlier studies of other data." These do not refute Arp!

In any case, Arp's view of the Big Bang is not based on one issue only, it has observational support of recent studies on the "Dark Energy", "Dark Matter" (little basis for either one) and disappointing results from the LHC. It has deeper philosophical basis as well

"No trace of dark matter in gamma-ray background":
http://phys.org/n...und.html

https://www.amazo...4041884X
IMP-9
5 / 5 (3) Dec 23, 2016
These do not refute Arp!


I didn't claim they did, please don't misrepresent my words. It does refute Bell & McDiarmid who claimed the detection of a deltaz ~ 0.7 feature in SDSS DR3 QSO. Tang & Zhang refutes ejection models.

You should look at this holistically to. QSO surveys are always selected, you can't do them otherwise. SDSS is the largest and most well understood redshift survey to date. It's large sample size allows for selection effects to be studied. I don't for a second believe that sample's of ~500 objects is more robust than 50,000 just because nobody looked closely enough at the systematics. People studied systematics in SDSS, that doesn't mean there were none in previous studied where people claimed to see periodicity. This is why the cross-correlation work is superior, because the selection effects are irrelevant.

And now you're shifting the argument event further. Arp's work was specific to this controversy.

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