Dynamical signature of a stellar bulge in a quasar host galaxy at z≃6z\simeq 6

We present a dynamical analysis of a quasar-host galaxy at $z\simeq 6$ (SDSS J2310+1855) using a high-resolution ALMA observation of the [CII] emission line. The observed rotation curve was fitted with mass models that considered the gravitational contribution of a thick gas disc, a thick star-forming stellar disc, and a central mass concentration, which is likely due to a combination of a spheroidal component (i.e. a stellar bulge) and a supermassive black hole (SMBH). The SMBH mass of $5\times 10^9\ \rm M_{\odot}$, previously measured using the CIV and MgII emission lines, is not sufficient to explain the high velocities in the central regions. Our dynamical model suggests the presence of a stellar bulge with a mass of $\rm M_{bulge}\sim 10^{10}\ \rm M_{\odot}$ in this object, when the Universe was younger than 1 Gyr. To finally be located on the local $M_{\rm SMBH}-M_{\rm bulge}$ relation, the bulge mass should increase by a factor of $\sim$40 from $z=6$ to 0, while the SMBH mass should grow by a factor of 4 at most. This points towards asynchronous galaxy-BH co-evolution. Imaging with the JWST will allow us to validate this scenario.Comment: 8 pages, 4 figures, 3 tables. Accepted by A&

NGC 2992: The interplay between the multiphase disk, wind and radio bubbles

We present an analysis of the gas kinematics in NGC 2992, based on VLT/MUSE, ALMA and VLA data, aimed at characterising the disk, the wind and their interplay in the cold molecular and warm ionised phases. CO(2-1) and H$\rm \alpha~$ arise from a multiphase disk with inclination 80 deg and radii 1.5 and 1.8 kpc, respectively. We find that the velocity dispersion of the cold molecular phase is consistent with that of star forming galaxies at the same redshift, except in the inner 600 pc region, and in the region between the cone walls and the disk. This suggests that a disk-wind interaction locally boosts the gas turbulence. We detect a clumpy ionised wind distributed in two wide opening angle ionisation cones reaching scales of 7 kpc. The [O III] wind expands with velocity exceeding -1000 km/s in the inner 600 pc, a factor of 5 larger than the previously reported wind velocity. Based on spatially resolved electron density and ionisation parameter maps, we infer an ionised outflow mass of $M_{\rm of,ion} = (3.2 \pm 0.3) \times \, 10^7 \, M_{\odot}$, and a total ionised outflow rate of $\dot M_{\rm of,ion}=13.5\pm1$ \sfr. We detected clumps of cold molecular gas located above and below the disk reaching maximum projected distances and velocities of 1.7 kpc and 200 km/s, respectively. On these scales, the wind is multiphase, with a fast ionised component and a slower molecular one, and a total mass of $M_{\rm of, ion+mol}= 5.8 \times 10^7 \, M_{\odot}$, of which the molecular component carries the bulk of the mass. The dusty molecular outflowing clumps and the turbulent ionised gas are located at the edges of the radio bubbles, suggesting that the bubbles interact with the surrounding medium through shocks. We detect a dust reservoir co-spatial with the molecular disk, with a cold dust mass $M_{\rm dust} = (4.04 \pm 0.03) \times \, 10^{6} \, M_{\odot}$.Comment: 19 pages, 17 figures, 6 tables; Accepted by A&

The IBISCO survey: I. Multiphase discs and winds in the Seyfert galaxy Markarian 509

We present the analysis of the ALMA CO(2 1) emission line and the underlying 1.2mm continuum of Mrk 509 with spatial resolution of similar to 270 pc. This local Seyfert 1.5 galaxy, optically classified as a spheroid, is known to host an ionised disc, a starburst ring, and ionised gas winds on both nuclear (ultra-fast outflows) and galactic scales. From CO(2 1) we estimate a molecular gas reservoir of M-H2 = 1.7 x10(9) M-circle dot, located within a disc of size similar to 5.2 kpc, with M-dyn = (2.0 +/- 1.1) x 10(10) M-circle dot inclined at 44 +/- 10 deg. The molecular gas fraction within the disc is mu(gas) = 5%, consistent with that of local star-forming galaxies with similar stellar mass. The gas kinematics in the nuclear region within r similar to 700 pc, that is only marginally resolved at the current angular resolution, suggests the presence of a warped nuclear disc. Both the presence of a molecular disc with ongoing star formation in a starburst ring, and the signatures of a minor merger, are in agreement with the scenario where galaxy mergers produce gas destabilisation, feeding both star formation and AGN activity. The spatially resolved Toomre Q-parameter across the molecular disc is in the range Q(gas) = 0.5-10, and shows that the disc is marginally unstable across the starburst ring, and stable against fragmentation at nucleus and in a lopsided ring-like structure located inside of the starburst ring. We find complex molecular gas kinematics and significant kinematics perturbations at two locations, one within 300 pc of the nucleus and one 1.4 kpc away close to the region with high Q(gas), that we interpret as molecular winds with velocity v(98) = 200-250 km s(-1). The total molecular outflow rate is in the range 6.4-17.0 M-circle dot yr(-1) for the optically thin and thick cases, respectively. The molecular wind total kinetic energy is consistent with a multiphase momentum-conserving wind driven by the AGN with P-of/P-rad in the range 0.06-0.5. The spatial overlap of the inner molecular wind with the ionised wind, and their similar velocity suggest a cooling sequence within a multiphase wind driven by the AGN. The second outer molecular wind component overlaps with the starburst ring, and its energy is consistent with a supernova-driven wind arising from the starburst ring

Star formation efficiency and AGN feedback in narrow-line Seyfert 1 galaxies with fast X-ray nuclear winds

We present the first systematic study of the molecular gas and star formation efficiency in a sample of ten narrow-line Seyfert 1 galaxies selected to have X-ray Ultra Fast Outflows and, therefore, to potentially show AGN feedback effects. CO observations were obtained with the IRAM 30m telescope in six galaxies and from the literature for four galaxies. We derived the stellar mass, star formation rate, AGN and FIR dust luminosities by fitting the multi-band spectral energy distributions with the CIGALE code. Most of the galaxies in our sample lie above the main sequence (MS) and the molecular depletion time is one to two orders of magnitude shorter than the one typically measured in local star-forming galaxies. Moreover, we found a promising correlation between the star formation efficiency and the Eddington ratio, as well as a tentative correlation with the AGN luminosity. The role played by the AGN activity in the regulation of star formation within the host galaxies of our sample remains uncertain (little or no effect? positive feedback?). Nevertheless, we can conclude that quenching by the AGN activity is minor and that star formation will likely stop in a short time due to gas exhaustion by the current starburst episode.Comment: Published in MNRAS, Volume 524, Issue 2, Pages 3130-314

First constraints of dense molecular gas at z~7.5 from the quasar P\=oniu\=a'ena

We report the detection of CO(6-5) and CO(7-6) and their underlying continua from the host galaxy of quasar J100758.264+211529.207 (P\=oniu\=a'ena) at z=7.5419, obtained with the NOrthern Extended Millimeter Array (NOEMA). P\=oniu\=a'ena belongs to the HYPerluminous quasars at the Epoch of ReionizatION (HYPERION) sample of 17 $z>6$ quasars selected to be powered by supermassive black holes (SMBH) which experienced the fastest mass growth in the first Gyr of the Universe. The one reported here is the highest-redshift measurement of the cold and dense molecular gas to date. The host galaxy is unresolved and the line luminosity implies a molecular reservoir of $\rm M(H_2)=(2.2\pm0.2)\times 10^{10}$ $\rm M_\odot$, assuming a CO spectral line energy distribution typical of high-redshift quasars and a conversion factor $\alpha=0.8$ $\rm M_{\odot} (K\,km \, s^{-1} \,pc^{2})^{-1}$. We model the cold dust spectral energy distribution (SED) to derive a dust mass of M$_{\rm dust} =(2.1\pm 0.7)\times 10^8$ $\rm M_\odot$, and thus a gas to dust ratio $\sim100$. Both the gas and dust mass are not dissimilar from the reservoir found for luminous quasars at $z\sim6$. We use the CO detection to derive an estimate of the cosmic mass density of $\rm H_2$, $\Omega_{H_2} \simeq 1.31 \times 10^{-5}$. This value is in line with the general trend suggested by literature estimates at $z < 7$ and agrees fairly well with the latest theoretical expectations of non-equilibrium molecular-chemistry cosmological simulations of cold gas at early times.Comment: Submitted to ApJ Letter

Accurate dust temperature and star formation rate in the most luminous z>6z>6 quasar in the HYPerluminous quasars at the Epoch of ReionizatION (HYPERION) sample

We present ALMA Band 9 continuum observation of the ultraluminous quasi-stellar object (QSO) SDSS J0100+2802, providing a $\sim 10\sigma$ detection at $\sim 670$ GHz. SDSS J0100+2802 is the brightest QSO with the most massive super massive black hole (SMBH) known at $z>6$, and we study its dust spectral energy distribution in order to determine the dust properties and the star formation rate (SFR) of its host-galaxy. We obtain the most accurate estimate so far of the temperature, mass and emissivity index of the dust, having $T_{\rm dust}=48.4\pm2.3$ K, $M_{\rm dust}=(2.29\pm0.83)\times 10^7$ M$_\odot$, $\beta=2.63\pm 0.23$. This allows us to measure the SFR with the smallest statistical error for this QSO, SFR$=265\pm 32\ \rm M_\odot yr^{-1}$. Our results enable us to evaluate the relative growth of the SMBH and host galaxy of J0100+2802, finding that the SMBH is dominating the process of BH-galaxy growth in this QSO at $z=6.327$, when the Universe was $865$ Myr old. Such unprecedented constraints on the host galaxy SFR and dust temperature can only be obtained through high frequency observations, and highlight the importance of ALMA Band 9 to obtain a robust overview of the build-up of the first quasars' host galaxies at $z>6$.Comment: 10 pages, 4 figures, 1 table. Accepted for publication in ApJ

The XQR-30 Metal Absorber Catalog: 778 Absorption Systems Spanning 2 < z < 6.5

Intervening metal absorption lines in the spectra of z > 6 quasars are fundamental probes of the ionization state and chemical composition of circumgalactic and intergalactic gas near the end of the reionization epoch. Large absorber samples are required to robustly measure typical absorber properties and to refine models of the synthesis, transport, and ionization of metals in the early Universe. The "Ultimate XSHOOTER legacy survey of quasars at z~5.8-6.6" (XQR-30) has obtained high signal-to-noise spectra of 30 luminous quasars, nearly quadrupling the existing sample of 12 high quality z~6 quasar spectra. We use this unprecedented sample to construct a catalog of 778 systems showing absorption in one or more of MgII (360 systems), FeII (184), CII (46), CIV (479), SiIV (127), and NV (13) which span 2 < z < 6.5. This catalog significantly expands on existing samples of z > 5 absorbers, especially for CIV and SiIV which are important probes of the ionizing photon background at high redshift. The sample is 50% (90%) complete for rest-frame equivalent widths W > 0.03AA (0.09AA). We publicly release the absorber catalog along with completeness statistics and a Python script to compute the absorption search path for different ions and redshift ranges. This dataset is a key legacy resource for studies of enriched gas from the era of galaxy assembly to cosmic noon, and paves the way for even higher redshift studies with the James Webb Space Telescope and 30m-class telescopes.Comment: 29 pages and 14 figures including 2 appendices. Accepted for publication in MNRAS. The metal absorber catalogue can be downloaded from https://github.com/XQR-30/Metal-catalogue. Contents unchanged from v1 apart from change to author lis

The WISSH quasars project XI. The mean Spectral Energy Distribution and Bolometric Corrections of the most luminous quasars

Hyper-luminous Quasi-Stellar Objects (QSOs) represent the ideal laboratory to investigate Active Galactic Nuclei (AGN) feedback mechanism since their formidable energy release causes powerful winds at all scales and thus the maximum feedback is expected. We aim at deriving the mean Spectral Energy Distribution (SED) of a sample of 85 WISE-SDSS Selected Hyper-luminous (WISSH) quasars. Since the SED provides a direct way to investigate the AGN structure, our goal is to understand if quasars at the bright end of the luminosity function have peculiar properties compared to the bulk of the population. We built a mean intrinsic SED after correcting for the dust extinction, absorption and emission lines and intergalactic medium absorption. We also derived bolometric, IR band and monochromatic luminosities together with bolometric corrections at lambda = 5100 A and 3 micron. We define a new relation for the 3 micron bolometric correction. We find that the mean SED of hyper-luminous WISSH QSOs is different from that of less luminous sources, i.e. a relatively lower X-ray emission and a near and mid IR excess which can be explained assuming a larger dust contribution. WISSH QSOs have stronger emission from both warm and very hot dust, the latter being responsible for shifting the typical dip of the AGN SED from 1.3 to 1.1 micron. We also derived the mean SEDs of two sub-samples created according to the presence of Broad Absorption Lines and equivalent width of CIV line. We confirm that BALs are X-ray weak and that they have a reddened UV-optical continuum. We also find that BALs tend to have stronger emission from the hot dust component. This analysis suggests that hyper-luminous QSOs have a peculiar SED compared to less luminous objects. It is therefore critical to use SED templates constructed exclusively from very bright quasars samples when dealing with particularly luminous sources.Comment: Accepted for publication in A&A. 20 pages, 15 figure

New quasar proximity zone size measurements at z∼6z\sim 6 using the enlarged XQR-30 sample

Proximity zones of high-redshift quasars are unique probes of their central supermassive black holes as well as the intergalactic medium in the last stages of reionization. We present 22 new measurements of proximity zones of quasars with redshifts between 5.8 and 6.6, using the enlarged XQR-30 sample of high-resolution, high-SNR quasar spectra. The quasars in our sample have UV magnitudes of $M_{1450}\sim -27$ and black hole masses of $10^9$\unicode{x2013}$10^{10}$ M$_\odot$. Our inferred proximity zone sizes are 2\unicode{x2013}7 physical Mpc, with a typical uncertainty of less than 0.5 physical Mpc, which, for the first time, also includes uncertainty in the quasar continuum. We find that the correlation between proximity zone sizes and the quasar redshift, luminosity, or black hole mass, indicates a large diversity of quasar lifetimes. Two of our proximity zone sizes are exceptionally small. The spectrum of one of these quasars, with $z=6.02$, displays, unusually for this redshift, damping wing absorption without any detectable metal lines, which could potentially originate from the IGM. The other quasar has a high-ionization absorber $\sim$0.5 pMpc from the edge of the proximity zone. This work increases the number of proximity zone measurements available in the last stages of cosmic reionization to 87. This data will lead to better constraints on quasar lifetimes and obscuration fractions at high redshift, which in turn will help probe the seed mass and formation redshift of supermassive black holes.Comment: 16 pages, 9 figures, Accepted in MNRA

The fraction and kinematics of broad absorption line quasars across cosmic time

Luminous quasars are powerful targets to investigate the role of feedback from supermassive black-holes (BHs) in regulating the growth phases of BHs themselves and of their host galaxies, up to the highest redshifts. Here we investigate the cosmic evolution of the occurrence and kinematics of BH-driven outflows, as traced by broad absorption line (BAL) features, due to the C IV ionic transition. We exploit a sample of 1935 quasars quasars at $z=2.1-6.6$ with bolometric luminosity log($L_{\rm bol}/$erg s$^{-1})\gtrsim46.5$, drawn from the Sloan Digital Sky Survey and from the X-shooter legacy survey of Quasars at Reionisation (XQR-30). We consider rest-frame optical bright quasars to minimise observational biases due to quasar selection criteria. We apply a homogeneous BAL identification analysis, based on employing composite template spectra to estimate the quasar intrinsic emission. We find a BAL quasar fraction close to 20\% at $z\sim2-4$, while it increases to almost 50\% at $z\sim6$. The velocity and width of the BAL features also increase at $z\gtrsim4.5$. We exclude that the redshift evolution of the BAL properties is due to differences in terms of quasar luminosity and accretion rate. These results suggest significant BH feedback occurring in the 1 Gyr old Universe, likely affecting the growth of BHs and, possibly, of their host galaxies, as supported by models of early BH and galaxy evolution.Comment: Accepted for publication in Ap