Constraints on high-J CO emission lines in $z\sim 6$ quasars

Abstract

We present Atacama Large Millimiter/submillimiter Array (ALMA) observations of eight highly excited CO (J${}_{\mathrm{up}}>8$) lines and continuum emission in two $z\sim 6$ quasars: SDSS J231038.88+185519.7 (hereafter J2310), for which CO(8-7), CO(9-8), and CO(17-16) lines have been observed, and ULAS J131911.29+095951.4 (J1319), observed in the CO(14-13), CO(17-16) and CO(19-18) lines. The continuum emission of both quasars arises from a compact region ($<0.9$ kpc). By assuming a modified black-body law, we estimate dust masses of Log$(M_{\mathrm{dust}}/M_{\odot })=8.75\pm 0.07$ and Log$(M_{\mathrm{dust}}/M_{\odot })=8.8\pm 0.2$ and dust temperatures of $T_{\mathrm{dust}}=76\pm 3\mathrm{K}$ and $T_{\mathrm{dust}}=66_{-10}^{+15}\mathrm{K}$, respectively for J2310 and J1319. Only CO(8-7) and CO(9-8) in J2310 are detected, while $3\sigma$ upper limits on luminosities are reported for the other lines of both quasars. The CO line luminosities and upper limits measured in J2310 and J1319 are consistent with those observed in local AGN and starburst galaxies, and other $z\sim 6$ quasars, except for SDSS J1148+5251 (J1148), the only quasar at $z=6.4$ with a previous CO(17-16) line detection. By computing the CO SLEDs normalised to the CO(6-5) line and FIR luminosities for J2310, J1319, and J1149, we conclude that different gas heating mechanisms (X-ray radiation and/or shocks) may explain the different CO luminosities observed in these $z\sim 6$ quasar. Future J${}_{\mathrm{up}}>8$ CO observations will be crucial to understand the processes responsible for molecular gas excitation in luminous high-$z$ quasars.

13 pages, 9 figures, 3 tables; MNRAS journal

References in corpus (39)

• An 800-million-solar-mass black hole in a significantly neutral Universe at redshift 7.5
• An ultra-luminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30
• Combined CO & Dust Scaling Relations of Depletion Time and Molecular Gas Fractions with Cosmic Time, Specific Star Formation Rate and Stellar Mass
• Dust Formation and Survival in Supernova Ejecta
• The Pan-STARRS1 distant z>5.6 quasar survey: more than 100 quasars within the first Gyr of the universe
• Diagnostics of irradiated dense gas in galaxy nuclei. II. A grid of XDR and PDR models
• 350 Micron Dust Emission from High Redshift Quasars
• The Final SDSS High-Redshift Quasar Sample of 52 Quasars at z>5.7
• Faint AGNs at z>4 in the CANDELS GOODS-S field: looking for contributors to the reionization of the Universe
• Physical properties of 15 quasars at $z\gtrsim 6.5$
• Formation of z ~ 6 quasars from hierarchical galaxy mergers
• Gemini Near-infrared Spectroscopy of Luminous z~6 Quasars: Chemical Abundances, Black Hole Masses, and MgII Absorption
• Black hole masses and enrichment of z ~ 6 SDSS quasars
• Rapidly star-forming galaxies adjacent to quasars at redshifts exceeding 6
• Star formation relations and CO SLEDs across the J-ladder and redshift
• GALARIO: a GPU Accelerated Library for Analysing Radio Interferometer Observations
• The origin of fast molecular outflows in quasars: molecule formation in AGN-driven galactic winds
• Zooming on the internal structure of $z\simeq 6$ galaxies
• The impact of chemistry on the structure of high-z galaxies
• Quenching star formation with quasar outflows launched by trapped IR radiation
• The compact, ~1 kpc host galaxy of a quasar at z=7.1
• Molecular outflow and feedback in the obscured Quasar XID2028 revealed by ALMA
• High-redshift quasars host galaxies: is there a stellar mass crisis?
• Fast cold gas in hot AGN outflows
• CO line emission from galaxies in the Epoch of Reionization
• High-J CO SLEDs in nearby infrared bright galaxies observed by Herschel-PACS
• First CO(17-16) emission line detected in a z > 6 quasar
• Quasar outflows at $z\ge 6$: the impact on the host galaxies
• Gas dynamics of a luminous $z$ = 6.13 quasar ULAS J1319$+$0950 revealed by ALMA high resolution observations
• ALMA observations of cold molecular gas in AGN hosts at z~1.5 - Evidence of AGN feedback?
• Quasar UV luminosity function evolution up to z=8
• On the Detection of High Redshift Black Holes with ALMA through CO and H2 Emission
• The dense molecular gas in the $\mathrm{z}\sim 6$ QSO SDSS J231038.88+185519.7 resolved by ALMA
• The Nature of CO Emission From z~6 Quasars
• Galaxy evolution studies with the SPace IR telescope for Cosmology and Astrophysics (SPICA): the power of IR spectroscopy
• Detections of [OIII] 88 $\mu$m in Two Quasars in the Reionization Epoch
• CO excitation in the Seyfert galaxy NGC 34: stars, shock or AGN driven?
• X-ray spectroscopy of the z=6.4 quasar J1148+5251
• Probing the High-Redshift Universe with SPICA: Toward the Epoch of Reionization and Beyond

Cited by in corpus (23)

• Missing [CII] emission from early galaxies
• The WISSH QSOs project IX. Cold gas content and environment of luminous QSOs at z~2.4-4.7
• High molecular gas content and star formation rates in local galaxies that host quasars, outflows and jets
• ALMA Lensing Cluster Survey: Bright [CII] 158 $\mu$m Lines from a Multiply Imaged Sub-$L^{\star }$ Galaxy at $z=6.0719$
• An ALMA multi-line survey of the ISM in two quasar host-companion galaxy pairs at $z>6$
• Host galaxies of high-redshift quasars: supermassive black hole growth and feedback
• An empirical study of dust properties at the earliest epochs
• Impact of X-rays on CO emission from high-z galaxies
• Infrared emission of $z\sim 6$ galaxies: AGN imprints
• Probing the full CO spectral line energy distribution (SLED) in the nuclear region of a quasar-starburst system at $z=6.003$
• AGN impact on the molecular gas in galactic centers as probed by CO lines
• The ALPINE-ALMA [CII] Survey: On the nature of an extremely obscured serendipitous galaxy
• Red quasars blow out molecular gas from galaxies during the peak of cosmic star formation
• Accurate dust temperature and star formation rate in the most luminous $z>6$ quasar in the HYPerluminous quasars at the Epoch of ReionizatION (HYPERION) sample
• The effect of active galactic nuclei on the cold interstellar medium in distant star-forming galaxies
• An ALMA view of 11 Dusty Star Forming Galaxies at the peak of Cosmic Star Formation History
• Molecular Outflows in z > 6 QSO Hosts Driven by Star Formation
• Looking for Signatures of AGN Feedback in Radio-Quiet AGN
• Is the star formation rate in $z\sim 6$ quasars overestimated?
• Dense and warm neutral gas in BR1202-0725 at z = 4.7 as traced by the [O I] 145 um line
• Gas and Star Formation from HD and Dust Emission in a Strongly Lensed Galaxy
• ALMA Observations for CO Emission from Luminous Lyman-break Galaxies at $z=6.0293$-$6.2037$
• Massive molecular gas reservoir in a luminous sub-millimeter galaxy during cosmic noon