Ultra-luminous quasars at redshift z &amp;gt; 4.5 from SkyMapper

Wolf, Christian; Hon, Wei Jeat; Bian, Fuyan; Onken, Christopher A.; Alonzi, Noura; Bessell, Michael A.; Li, Zefeng; Schmidt, B. P.; Tisserand, Patrick

doi:10.1093/mnras/stz2955

Cited by 22 publications

(24 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Checking carefully Table 1, however, it is evident that our sample is limited to slightly brighter magnitudes (M 1450 ≤ −28.3) than their limit. If the Wolf et al (2020) sample is restricted to M 1450 ≤ −28.3, 19 QSOs are left, reducing the discrepancy with our sample within the mutual statistical uncertainties.…”

Section: Completeness Of Z ∼ 5 Qso Samplementioning

confidence: 77%

“…The spectroscopic confirmation of these high-z QSOs have been carried out by the QUBRICS team (Pa-perI, PaperII), as well as by other independent observations (e.g. Véron-Cetty & Véron 2010;Schindler et al 2019a,b;Wolf et al 2020). It is worth noting that all these different groups carried out independent surveys; nonetheless, several high-z QSOs in the southern hemisphere have been recently confirmed in multiple surveys, as indicated in the last column of Table 1.…”

Section: The Qubrics Surveymentioning

confidence: 81%

“…In order to estimate the completeness of the QSO sample in Table 1, it is useful to consider the results obtained by similar surveys. Wolf et al (2020) searched for bright QSOs at z > 4.5 using data from SkyMapper, Gaia, and WISE. They found 23 QSOs at 4.5 ≤ z spec ≤ 5.0 and M 1450 ≤ −28.0 in 12,500 sq.…”

Section: Completeness Of Z ∼ 5 Qso Samplementioning

confidence: 99%

“…Of the 23 QSOs by Wolf et al (2020) with 4.5 < z < 5.0 and M 1450 ≤ −28.0, only 12 objects are part of our QUBRICS sample. Nine QSOs of Wolf et al (2020) have an i-band magnitude in SkyMapper DR1.1 fainter than 18.0, so out of the QUBRICS selection criteria. Two QSOs of Wolf et al (2020) have i psf < 18.0 but they are not part of our sample.…”

Section: Completeness Of Z ∼ 5 Qso Samplementioning

confidence: 99%

“…Nine QSOs of Wolf et al (2020) have an i-band magnitude in SkyMapper DR1.1 fainter than 18.0, so out of the QUBRICS selection criteria. Two QSOs of Wolf et al (2020) have i psf < 18.0 but they are not part of our sample. For one of these two QSOs (J151443.82-325024.8) the galactic latitude is below the adopted threshold in PaperI and PaperII, i.e.…”

Section: Completeness Of Z ∼ 5 Qso Samplementioning

confidence: 99%

See 4 more Smart Citations

The space density of ultra-luminous QSOs at the end of reionization epoch by the QUBRICS Survey and the AGN contribution to the hydrogen ionizing background

Grazian,

Giallongo,

Boutsia

et al. 2021

Preprint

View full text Add to dashboard Cite

Motivated by evidences favoring a rapid and late hydrogen reionization process completing at z ∼ 5.2 − 5.5 and mainly driven by rare and luminous sources, we have reassessed the estimate of the space density of ultra-luminous QSOs at z ∼ 5 in the framework of the QUBRICS survey. A ∼ 90% complete sample of 14 spectroscopically confirmed QSOs at M 1450 ≤ −28.3 and 4.5 ≤ z ≤ 5.0 has been derived in an area of 12, 400 sq. deg., thanks to multi-wavelength selection and GAIA astrometry. The space density of z ∼ 5 QSOs within −29.3 ≤ M 1450 ≤ −28.3 is three times higher than previous determinations. Our results suggest a steep bright-end slope for the QSO luminosity function at z ∼ 5 and a mild redshift evolution of the space density of ultra-bright QSOs (M 1450 ∼ −28.5) at 3 < z < 5.5, in agreement with the redshift evolution of the much fainter AGN population at M 1450 ∼ −23. These findings are consistent with a pure density evolution for the AGN population at z > 3. Adopting our z ∼ 4 QSO luminosity function and applying a mild density evolution in redshift, a photo-ionization rate of Γ HI = 0.46 +0.17 −0.09 × 10 −12 s −1 has been obtained at z = 4.75, assuming an escape fraction of ∼ 70% and a steep faint-end slope of the AGN luminosity function. The derived photo-ionization rate is ∼ 50 − 100% of the ionizing background measured at the end of the reionization epoch, suggesting that AGNs could play an important role in the cosmological reionization process.

show abstract

Section: Completeness Of Z ∼ 5 Qso Samplementioning

confidence: 77%

Section: The Qubrics Surveymentioning

confidence: 81%

Section: Completeness Of Z ∼ 5 Qso Samplementioning

confidence: 99%

Section: Completeness Of Z ∼ 5 Qso Samplementioning

confidence: 99%

Section: Completeness Of Z ∼ 5 Qso Samplementioning

confidence: 99%

See 3 more Smart Citations

The space density of ultra-luminous QSOs at the end of reionization epoch by the QUBRICS Survey and the AGN contribution to the hydrogen ionizing background

Grazian,

Giallongo,

Boutsia

et al. 2021

Preprint

View full text Add to dashboard Cite

show abstract

SkyMapper Southern Survey: Second data release (DR2)

Onken

Wolf

Bessell

et al. 2019

Publ. Astron. Soc. Aust.

Self Cite

239

157

View full text Add to dashboard Cite

We present the second data release (DR2) of the SkyMapper Southern Survey, a hemispheric survey carried out with the SkyMapper Telescope at Siding Spring Observatory in Australia, using six optical filters: u, v, g, r, i, z. DR2 is the first release to go beyond the $\sim\!18$ mag (10 $\sigma$ ) limit of the Shallow Survey released in the first data release (DR1), and includes portions of the sky at full survey depth that reach $>\!21$ mag in g and r filters. The DR2 photometry has a precision as measured by internal reproducibility of 1% in u and v, and 0.7% in griz. More than 21 000 $\deg^2$ have data in some filters (at either Shallow or Main Survey depth) and over 7 000 $\deg^2$ have deep Main Survey coverage in all six filters. Finally, about 18 000 $\deg^2$ have Main Survey data in i and z filters, albeit not yet at full depth. The release contains over 120 000 images, as well as catalogues with over 500 million unique astrophysical objects and nearly 5 billion individual detections. It also contains cross-matches with a range of external catalogues such as Gaia DR2, Pan-STARRS1 DR1, GALEX GUVcat, 2MASS, and AllWISE, as well as spectroscopic surveys such as 2MRS, GALAH, 6dFGS, and 2dFLenS.

show abstract

AllBRICQS: The All-sky BRIght, Complete Quasar Survey

Onken

Wolf

Hon

et al. 2023

Publ. Astron. Soc. Aust.

Self Cite

View full text Add to dashboard Cite

We describe the first results from the All-sky BRIght, Complete Quasar Survey (AllBRICQS), which aims to discover the last remaining optically bright quasars. We present 156 spectroscopically confirmed quasars (140 newly identified) having $|b|>10^{\circ}$ . 152 of the quasars have Gaia DR3 magnitudes brighter than $B_{P}=16.5$ or $R_{P}=16$ mag, while four are slightly fainter. The quasars span a redshift range of $z=0.07-3.93$ . In particular, we highlight the properties of J0529-4351 at $z=3.93$ , which, if unlensed, is one of the most intrinsically luminous quasars in the Universe. The AllBRICQS sources have been selected by combining data from the Gaia and WISE all-sky satellite missions, and we successfully identify quasars not flagged as candidates by Gaia Data Release 3. We expect the completeness to be $\approx$ 96% within our magnitude and latitude limits, while the preliminary results indicate a selection purity of $\approx$ 96%. The optical spectroscopy used for source classification will also enable detailed quasar characterisation, including black hole mass measurements and identification of foreground absorption systems. The AllBRICQS sources will greatly enhance the number of quasars available for high-signal-to-noise follow-up with present and future facilities.

show abstract

Ultra-luminous quasars at redshift z > 4.5 from SkyMapper

Cited by 22 publications

References 49 publications

The space density of ultra-luminous QSOs at the end of reionization epoch by the QUBRICS Survey and the AGN contribution to the hydrogen ionizing background

The space density of ultra-luminous QSOs at the end of reionization epoch by the QUBRICS Survey and the AGN contribution to the hydrogen ionizing background

SkyMapper Southern Survey: Second data release (DR2)

AllBRICQS: The All-sky BRIght, Complete Quasar Survey

Contact Info

Product

Resources

About