The Pan-STARRS1 z>5.6 quasar survey II: Discovery of 55 Quasars at 5.6<z<6.5

Abstract

The identification of bright quasars at z>6 enables detailed studies of supermassive black holes, massive galaxies, structure formation, and the state of the intergalactic medium within the first billion years after the Big Bang. We present the spectroscopic confirmation of 55 quasars at redshifts 5.6<z<6.5 and UV magnitudes -24.5<M1450<-28.5 identified in the optical Pan-STARRS1 and near-IR VIKING surveys (48 and 7, respectively). Five of these quasars have been independently discovered in other studies. The quasar sample shows an extensive range of physical properties, including 17 objects with weak emission lines, ten broad absorption line quasars, and five with strong radio emission (radio-loud quasars). There are also a few notable sources in the sample, including a blazar candidate at z=6.23, a likely gravitationally lensed quasar at z=6.41, and a z=5.84 quasar in the outskirts of the nearby (D~3 Mpc) spiral galaxy M81. The blazar candidate remains undetected in NOEMA observations of the [CII] and underlying emission, implying a star-formation rate <30-70 Msun/yr. A significant fraction of the quasars presented here lies at the foundation of the first measurement of the z~6 quasar luminosity function from Pan-STARRS1 (introduced in a companion paper). The quasars presented here will enable further studies of the high-redshift quasar population with current and future facilities.

Version after addressing referee report. See companion paper by Schindler et al

References in corpus (52)

• Array Programming with NumPy
• The Gaia mission
• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• The LOFAR Two-metre Sky Survey -- V. Second data release
• GROND - a 7-channel imager
• The Pan-STARRS1 distant z>5.6 quasar survey: more than 100 quasars within the first Gyr of the universe
• The fourth data release of the Kilo-Degree Survey: ugri imaging and nine-band optical-IR photometry over 1000 square degrees
• The Dark Energy Survey Data Release 2
• Physical properties of 15 quasars at $z\gtrsim 6.5$
• 4MOST: Project overview and information for the First Call for Proposals
• Hydrogen reionisation ends by $z=5.3$: Lyman-$\alpha$ optical depth measured by the XQR-30 sample
• The Rapid ASKAP Continuum Survey I: Design and First Results
• Rapidly star-forming galaxies adjacent to quasars at redshifts exceeding 6
• The Rapid ASKAP Continuum Survey Paper II: First Stokes I Source Catalogue Data Release
• The UKIRT Hemisphere Survey: Definition and J-band Data Release
• Kiloparsec-scale ALMA Imaging of [CII] and Dust Continuum Emission of 27 Quasar Host Galaxies at z~6
• Discovery of eight z ~ 6 quasars from Pan-STARRS1
• Probing the thermal state of the intergalactic medium at $z>5$ with the transmission spikes in high-resolution Ly$\alpha$ forest spectra
• Constraining the radio-loud fraction of quasars at z>5.5
• The X-shooter/ALMA Sample of Quasars in the Epoch of Reionization. II. Black Hole Masses, Eddington Ratios, and the Formation of the First Quasars
• The REQUIEM Survey I: A Search for Extended Ly-Alpha Nebular Emission Around 31 z>5.7 Quasars
• The X-SHOOTER/ALMA sample of Quasars in the Epoch of Reionization. I. NIR spectral modeling, iron enrichment and broad emission line properties
• Detecting and Characterizing Young Quasars I: Systemic Redshifts and Proximity Zones Measurements
• Quasars That Have Transitioned from Radio-quiet to Radio-loud on Decadal Timescales Revealed by VLASS and FIRST
• The first blazar observed at z>6
• The discovery of a highly accreting, radio-loud quasar at z=6.82
• No evidence for [CII] halos or high-velocity outflows in z>6 quasar host galaxies
• Widespread, strong outflows in XQR-30 quasars at the Reionisation epoch
• The variability timescales and brightness temperatures of radio flares from stars to supermassive black holes
• New Constraints on Quasar Evolution: Broad Line Velocity Shifts over $1.5\lesssim z\lesssim 7.5$
• No overdensity of Lyman Alpha Emitting Galaxies around a quasar at z~5.7
• Mapping the Lyman-Alpha Emission Around a z~6.6 QSO with MUSE: Extended Emission and a Companion at Close Separation
• An ALMA multi-line survey of the ISM in two quasar host-companion galaxy pairs at $z>6$
• Molecular gas in z~6 quasar host galaxies
• Constraining the quasar radio-loud fraction at $z\sim 6$ with deep radio observations
• Discovery of 24 radio-bright quasars at $4.9\le z\le 6.6$ using low-frequency radio observations
• The Pan-STARRS1 $\mathbf{z}>5.6$ Quasar Survey: III. The $\mathbf{z}\approx 6$ Quasar Luminosity Function
• The space density of z>4 blazars
• Metallicity in Quasar Broad Line Regions at Redshift $\sim$ 6
• Constraining galaxy overdensities around three z~6.5 quasars with ALMA and MUSE
• Enhanced X-ray Emission from the Most Radio-Powerful Quasar in the Universe's First Billion Years
• Chemical Abundance of z~6 Quasar Broad-Line Regions in the XQR-30 Sample
• A search for faint high-redshift radio galaxy candidates at 150 MHz
• Resolving the Radio Emission from the Quasar P172+18 at $z=6.82$
• Chandra and Magellan/FIRE follow-up observations of PSO167-13: an X-ray weak QSO at $z=6.515$
• Constraining the Gravitational Lensing of $z\gtrsim 6$ Quasars from their Proximity Zones
• SCUBA2 High Redshift Bright Quasar Survey: Far-infrared Properties and Weak-line Features
• Unveiling the warm dense ISM in $z>6$ quasar host galaxies via water vapor emission
• Improvements to Pan-STARRS1 Astrometry Using Gaia
• The Decoupled Kinematics of high-z QSO Host Galaxies and their Lya halos
• The Impact of Powerful Jets on the Far-infrared Emission of an Extreme Radio Quasar at z~6
• Quasar clustering at redshift 6

Cited by in corpus (27)

• EIGER V. Characterizing the Host Galaxies of Luminous Quasars at $z\gtrsim 6$
• XQR-30: the ultimate XSHOOTER quasar sample at the reionization epoch
• GA-NIFS: Black hole and host galaxy properties of two z$\simeq$6.8 quasars from the NIRSpec IFU
• Metal enrichment and evolution in four z > 6.5 quasar sightlines observed with JWST/NIRSpec
• New quasar proximity zone size measurements at $z\sim 6$ using the enlarged XQR-30 sample
• GA-NIFS and EIGER: A merging quasar host at z=7 with an overmassive black hole
• The SRG/eROSITA All-Sky Survey: X-ray beacons at late cosmic dawn
• Radio Emission from the First Quasars at $z\sim$ 6-15
• Far-Infrared and [CII] observations of a z=7 blazar
• SHELLQs-JWST Unveils the Host Galaxies of 12 Quasars at z>6
• Discovery and characterization of 25 new quasars at 4.6 < z < 6.9 from wide-field multi-band surveys
• Multi-wavelength properties of three new radio-powerful $z\sim 5.6$ quasi-stellar objects discovered from RACS
• Prospects for Observing High-redshift Radio-loud Quasars in the SKA Era: Paving the Way for 21-cm Forest Observations
• The host galaxies of radio-loud quasars at z>5 with ALMA
• Comprehensive view on a $z\sim 6.5$ radio-loud QSO: from the radio to the optical/NIR to the X-ray band
• Euclid preparation. Observational expectations for redshift z<7 active galactic nuclei in the Euclid Wide and Deep surveys
• No strong radio absorption detected in the low-frequency spectra of radio-loud quasars at z > 5.6
• High-$z$ radio Quasars in RACS I: Selection, identification, and multi-wavelength properties
• The Noctua Suite of Simulations -- The Difficulty of Growing Massive Black Holes in Low-Mass Dwarf Galaxies
• Euclid: The potential of slitless infrared spectroscopy: A z=5.4 quasar and new ultracool dwarfs
• Prospects of a statistical detection of the 21-cm forest and its potential to constrain the thermal state of the neutral IGM during reionization
• JWST's PEARLS: A z=6 quasar in a train-wreck galaxy merger system
• Prospects for measuring neutrino mass with 21-cm forest
• Shedding the envelope: JWST reveals a kiloparsec-scale [OIII]-weak Balmer shell around a z=7.64 quasar
• High-redshift AGN population in radiation-hydrodynamics simulations
• QUEST (Quasar Unsupervised Encoder and Synthesis Tool): A machine learning framework to generate quasar spectra
• 4MOST ChANGES: Catalog of high-redshift quasar candidates (4.5 < $z$ < 7) selected with SED fitting