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strong gravitational lenses with measured time delays between the multiple images allow a direct measurement of the time-delay distance to the lens, and thus a measure of cosmological parameters, particularly the hubble constant, h0. we present a blind lens model analysis of the quadruply imaged quasar lens he 0435-122... | h0licow - iv. lens mass model of he 0435-1223 and blind measurement of its time-delay distance for cosmology |
we present a new investigation of the thermal history of the intergalactic medium (igm) during and after reionization using the lyα forest flux power spectrum at 4.0 ≲ z ≲ 5.2. using a sample of 15 high-resolution spectra, we measure the flux power down to the smallest scales ever probed at these redshifts (-1 ≲ log(k/... | revealing reionization with the thermal history of the intergalactic medium: new constraints from the lyα flux power spectrum |
aims: integral field spectroscopy (ifs) with jwst nirspec will significantly improve our understanding of the first quasars, by providing spatially resolved, infrared spectroscopic capabilities that cover key rest-frame optical emission lines that have been previously unobservable.methods: here we present our results f... | ga-nifs: black hole and host galaxy properties of two z ≃ 6.8 quasars from the nirspec ifu |
we present a void clustering analysis in configuration-space using the completed sloan digital sky survey iv (sdss-iv) extended baryon oscillation spectroscopic survey (eboss) dr16 samples. these samples consist of luminous red galaxies (lrgs) combined with the high-redshift tail of the sdss-iii baryon oscillation spec... | the completed sdss-iv extended baryon oscillation spectroscopic survey: growth rate of structure measurement from cosmic voids |
aims: outflows driven by active galactic nuclei (agn) are invoked by galaxy evolutionary models to quench star formation and to explain the origin of the relations observed locally between super-massive black holes and their host galaxies. we here aim to detect extended ionised outflows in luminous quasars, where we ex... | ionised outflows in z ~ 2.4 quasar host galaxies |
we present chemical abundance ratios of 70 star-forming galaxies at z ~ 4-10 observed by the jwst/nirspec early release observations, glass, and ceers programs. among the 70 galaxies, we have pinpointed two galaxies, ceers_01019 at z = 8.68 and glass_150008 at z = 6.23, with extremely low c/n ([c/n] ≲ -1), evidenced wi... | jwst identification of extremely low c/n galaxies with [n/o] ≳ 0.5 at z 6-10 evidencing the early cno-cycle enrichment and a connection with globular cluster formation |
we present the clustering measurements of quasars in configuration space based on the data release 14 (dr14) of the sloan digital sky survey iv extended baryon oscillation spectroscopic survey (eboss). this data set includes 148 659 quasars spread over the redshift range 0.8 ≤ z ≤ 2.2 and spanning 2112.9 deg2. we use t... | the clustering of the sdss-iv extended baryon oscillation spectroscopic survey dr14 quasar sample: measurement of the growth rate of structure from the anisotropic correlation function between redshift 0.8 and 2.2 |
massive disk galaxies like the milky way are expected to form at late times in traditional models of galaxy formation1,2, but recent numerical simulations suggest that such galaxies could form as early as a billion years after the big bang through the accretion of cold material and mergers3,4. observationally, it has b... | a cold, massive, rotating disk galaxy 1.5 billion years after the big bang |
we reinvestigate a claimed sample of 22 x-ray detected active galactic nuclei (agn) at redshifts z > 4, which has reignited the debate as to whether young galaxies or agn reionized the universe. these sources lie within the great observatories origins deep survey-south (goods-s)/cosmic assembly near-infrared deep ex... | no evidence for a significant agn contribution to cosmic hydrogen reionization |
jwst is discovering star-forming 'candidate' galaxies with photometric redshifts z > 9 and little attenuation. we model presumptive massive black holes (mbhs) in such galaxies and find that their unobscured emission is fainter than the galaxy starlight in jwst filters, and difficult to be detected via colour-colour ... | what if young z > 9 jwst galaxies hosted massive black holes? |
we introduce the abacushod model and present two applications of abacushod and the abacussummit simulations to observations. abacushod is a halo occupation distribution (hod) framework written in python that is particle-based, multitracer, highly generalized, and highly efficient. it is designed specifically with multi... | abacushod: a highly efficient extended multitracer hod framework and its application to boss and eboss data |
we present deep near-infrared spectroscopy of six quasars at 6.1 ≤ z ≤ 6.7 with very large telescope/x-shooter and gemini-n/gnirs. our objects, originally discovered through a wide-field optical survey with the hyper suprime-cam (hsc) subaru strategic program (hsc-ssp), have the lowest luminosities (-25.5 mag ≤ m 1450 ... | subaru high-z exploration of low-luminosity quasars (shellqs). vi. black hole mass measurements of six quasars at 6.1 ≤ z ≤ 6.7 |
we present a new investigation of the intergalactic medium near reionization using dark gaps in the lyβ forest. with its lower optical depth, lyβ offers a potentially more sensitive probe to any remaining neutral gas compared to the commonly used lyα line. we identify dark gaps in the lyβ forest using spectra of 42 qso... | long dark gaps in the lyβ forest at z < 6: evidence of ultra-late reionization from xqr-30 spectra |
we have completed two years of photometric and spectroscopic monitoring of a large number of active galactic nuclei (agns) with very high accretion rates. in this paper, we report on the result of the second phase of the campaign, during 2013-2014, and the measurements of five new hβ time lags out of eight monitored ag... | supermassive black holes with high accretion rates in active galactic nuclei. iv. hβ time lags and implications for super-eddington accretion |
motivated by the discovery of rare enormous lyman α nebulae (elan) around z ∼ 2 quasars, we initiated a long-term campaign with the muse/vlt instrument to directly uncover the astrophysics of the gas around quasars. we present here the first 61 targets under the acronym qso museum. these quasars are characterized by a ... | qso museum i: a sample of 61 extended ly α-emission nebulae surrounding z ∼ 3 quasars |
quasar feedback in the form of powerful outflows is invoked as a key mechanism to quench star formation in galaxies, although direct observational evidence is still scarce and debated. here we present early release science jwst nirspec ifu observations of the z = 1.59 prototypical obscured active galactic nucleus (agn)... | bubbles and outflows: the novel jwst/nirspec view of the z = 1.59 obscured quasar xid2028 |
the mean free path of ionizing photons, λ mfp, is a critical parameter for modeling the intergalactic medium (igm) both during and after reionization. we present direct measurements of λ mfp from qso spectra over the redshift range 5 < z < 6, including the first measurements at z ≃ 5.3 and 5.6. our sample include... | probing ultralate reionization: direct measurements of the mean free path over 5 < z < 6 |
the cosmic ionizing emissivity from star-forming galaxies has long been anchored to uv luminosity functions. here, we introduce an emissivity framework based on lyα emitters (laes), which naturally hones in on the subset of galaxies responsible for the ionizing background due to the intimate connection between producti... | (re)solving reionization with lyα: how bright lyα emitters account for the z ≈ 2-8 cosmic ionizing background |
aims: the sinfoni survey for unveiling the physics and effect of radiative feedback (super) aims to trace and characterise ionised gas outflows and their impact on star formation in a statistical sample of x-ray selected active galactic nuclei (agn) at z ∼ 2. we present the first sinfoni results for a sample of 21 type... | super. ii. spatially resolved ionised gas kinematics and scaling relations in z ∼ 2 agn host galaxies |
prevalent around luminous accreting black holes, thin discs are challenging to resolve in numerical simulations. when the disc and black hole angular momentum vectors are misaligned, the challenge becomes extreme, requiring adaptive meshes to follow the disc proper as it moves through the computational grid. with our n... | bardeen-petterson alignment, jets, and magnetic truncation in grmhd simulations of tilted thin accretion discs |
dark matter (dm) could be a relic of freeze-in through a light mediator, where the dm is produced by extremely feeble, ir-dominated processes in the thermal standard model plasma. in the simplest viable models with dm lighter than 1 mev, the dm has a small effective electric charge and is born with a nonthermal phase-s... | cosmology of sub-mev dark matter freeze-in |
we present the quasar luminosity function (lf) at z = 7, measured with 35 spectroscopically confirmed quasars at 6.55 < z < 7.15. the sample of 22 quasars from the subaru high-z exploration of low-luminosity quasars (shellqs) project, combined with 13 brighter quasars in the literature, covers an unprecedentedly ... | quasar luminosity function at z = 7 |
models and observations suggest that both the power and effects of agn feedback should be maximised in hyper-luminous (lbol > 1047 erg s-1) quasars, i.e. objects at the brightest end of the agn luminosity function. in this paper, we present the first results of a multiwavelength observing programme, focusing on a sa... | the wissh quasars project. i. powerful ionised outflows in hyper-luminous quasars |
almost 10 yr of γ-ray observations with the fermi large area telescope have revealed extreme γ-ray outbursts from flat spectrum radio quasars (fsrqs), temporarily making these objects the brightest γ-ray emitters in the sky. yet, the location and mechanisms of the γ-ray emission remain elusive. we characterize long-ter... | characterizing the gamma-ray variability of the brightest flat spectrum radio quasars observed with the fermi lat |
quiescent galaxies with little or no ongoing star formation dominate the population of galaxies with masses above 2 × 1010 times that of the sun; the number of quiescent galaxies has increased by a factor of about 25 over the past ten billion years (refs 1, 2, 3, 4). once star formation has been shut down, perhaps duri... | suppressing star formation in quiescent galaxies with supermassive black hole winds |
the c ivλλ1498,1501 broad emission line is visible in optical spectra to redshifts exceeding z ∼ 5. c iv has long been known to exhibit significant displacements to the blue and these `blueshifts' almost certainly signal the presence of strong outflows. as a consequence, single-epoch virial black hole (bh) mass estimat... | correcting c iv-based virial black hole masses |
bright quasars, powered by accretion onto billion-solar-mass black holes, already existed at the epoch of reionization, when the universe was 0.5-1 billion years old1. how these black holes formed in such a short time is the subject of debate, particularly as they lie above the correlation between black-hole mass and g... | suppression of black-hole growth by strong outflows at redshifts 5.8-6.6 |
we analyse some open debates in cosmology in light of the most updated quasar (qso) sample, covering a wide redshift range up to $\mathit{ z}$ ~ 7.5, combined with type ia supernovae (sne) and baryon acoustic oscillations (baos). indeed, extending the cosmological analyses with high-redshift data is key to distinguishi... | quasar cosmology: dark energy evolution and spatial curvature |
we quantify the presence of lyα damping wing absorption from a partially neutral intergalactic medium (igm) in the spectrum of the z = 7.08 qso, ulasj1120+0641. using a bayesian framework, we simultaneously account for uncertainties in: (i) the intrinsic qso emission spectrum; and (ii) the distribution of cosmic h i pa... | are we witnessing the epoch of reionisation at z = 7.1 from the spectrum of j1120+0641? |
we present a measurement of the 1d lyα forest flux power spectrum, using the complete baryon oscillation spectroscopic survey (boss) and first extended-boss (eboss) quasars at zqso > 2.1, corresponding to the fourteenth data release (dr14) of the sloan digital sky survey (sdss). our results cover thirteen bins in re... | the one-dimensional power spectrum from the sdss dr14 lyα forests |
we study the interaction of feedback from active galactic nuclei (agn) and a multiphase interstellar medium (ism), in simulations including explicit stellar feedback, multiphase cooling, accretion-disc winds, and compton heating. we examine radii ∼0.1-100 pc around a black hole (bh), where the accretion rate on to the ... | stellar and quasar feedback in concert: effects on agn accretion, obscuration, and outflows |
we study metal depletion due to dust in the interstellar medium (ism) to infer the properties of dust grains and characterize the metal and dust content of galaxies down to low metallicity and intermediate redshift z. we provide metal column densities and abundances of a sample of 70 damped lyman-α absorbers (dlas) tow... | dust-depletion sequences in damped lyman-α absorbers. a unified picture from low-metallicity systems to the galaxy |
we present a new investigation of the intergalactic medium (igm) near the end of reionization using "dark gaps" in the lyα forest. using spectra of 55 qsos at z em > 5.5, including new data from the xqr-30 vlt large programme, we identify gaps in the lyα forest where the transmission averaged over 1 comoving h -1 mp... | chasing the tail of cosmic reionization with dark gap statistics in the lyα forest over 5 < z < 6 |
this is the fourth paper in a series of publications aiming at discovering quasars at the epoch of reionization. in this paper, we expand our search for z ∼ 7 quasars to the footprint of the dark energy survey (des) data release one (dr1), covering ∼5000 deg2 of a new area. we select z ∼ 7 quasar candidates using deep ... | exploring reionization-era quasars. iv. discovery of six new z ≳ 6.5 quasars with des, vhs, and unwise photometry |
dust-obscured galaxies are thought to represent an early evolutionary phase of massive galaxies in which the active galactic nucleus (agn) is still deeply buried in significant amounts of dusty material and its emission is strongly suppressed. the unprecedented sensitivity of the james webb space telescope enables us f... | ga-nifs: early-stage feedback in a heavily obscured agn at $z=4.76$ |
we present band 6 alma observations of a heavily obscured radio-loud (l1.4 ghz = 1025.4 w hz-1) active galactic nucleus (agn) candidate at zphot = 6.83 ± 0.06 found in the 1.5 deg2 cosmos field. the alma data reveal detections of exceptionally strong [c ii]158 $\mu$m (z[c ii] = 6.8532) and underlying dust continuum emi... | alma confirmation of an obscured hyperluminous radio-loud agn at z = 6.853 associated with a dusty starburst in the 1.5 deg2 cosmos field |
we present the one-dimensional ly α forest power spectrum measurement using the first data provided by the dark energy spectroscopic instrument (desi). the data sample comprises 26 330 quasar spectra, at redshift z > 2.1, contained in the desi early data release and the first 2 months of the main survey. we employ a... | the dark energy spectroscopic instrument: one-dimensional power spectrum from first ly α forest samples with fast fourier transform |
the origin and properties of the initial black hole seeds that grow to produce the observed population of accreting sources remain to be determined. it is a challenge to uniquely disentangle signatures of seeding from fuelling and dynamics that shapes the assembly history of growing black holes. to address this, we use... | the observational signatures of supermassive black hole seeds |
we present 15 ghz stacked vlba images of 373 jets associated with active galactic nuclei (agns) having at least five observing epochs within a 20 yr time interval 1994-2015 from the monitoring of jets in active galactic nuclei with vlba experiments (mojave) programme and/or its precursor, the 2-cm vlba survey. these da... | mojave - xiv. shapes and opening angles of agn jets |
the prevalence and properties of kiloparsec-scale outflows in nearby type 1 quasars have been the subject of little previous attention. this work presents gemini integral field spectroscopy of 10 type 1 radio-quiet quasars at z< 0.3. the excellent image quality, coupled with a new technique to remove the point-sprea... | quasar-mode feedback in nearby type 1 quasars: ubiquitous kiloparsec-scale outflows and correlations with black hole properties |
strong lensing provides a powerful means of investigating the nature of dark matter as it probes dark matter structure on sub-galactic scales. we present an extension of a forward modelling framework that uses flux ratios from quadruply imaged quasars (quads) to measure the shape and amplitude of the halo mass function... | probing dark matter structure down to 107 solar masses: flux ratio statistics in gravitational lenses with line-of-sight haloes |
previous studies have noted difficulties in modelling the highest opacities of the z > 5.5 ly α forest, epitomized by the extreme lyα trough observed towards quasar ulas j0148 + 0600. one possibility is that the most opaque regions at these redshifts contain significant amounts of neutral hydrogen. this explanation,... | observing the tail of reionization: neutral islands in the z = 5.5 lyman-α forest |
recent observations have shown that the scatter in opacities amongst coeval segments of the ly α forest increases rapidly at z > 5. in this paper, we assess whether the large scatter can be explained by fluctuations in the ionizing background in the post-reionization intergalactic medium. we find that matching the o... | large fluctuations in the high-redshift metagalactic ionizing background |
we use idealized 3d hydrodynamic simulations to study the dynamics and thermal structure of the circumgalactic medium (cgm). our simulations quantify the role of cooling, stellar feedback driven galactic winds and cosmological gas accretion in setting the properties of the cgm in dark matter haloes ranging from 1011 to... | the impact of star formation feedback on the circumgalactic medium |
context. the recent early third data release (edr3) from the gaia mission has produced parallaxes for 1.468 × 109 sources with better quality than those reported in the previous data release. nevertheless, there are calibration issues with the data that require corrections to the published values and uncertainties.aims... | validation of the accuracy and precision of gaia edr3 parallaxes with globular clusters |
we use high-quality, medium-resolution hubble space telescope/cosmic origins spectrograph (hst/cos) observations of 82 uv-bright active galactic nuclei (agns) at redshifts zagn < 0.85 to construct the largest survey of the low-redshift intergalactic medium (igm) to date: 5138 individual extragalactic absorption line... | an hst/cos survey of the low-redshift intergalactic medium. i. survey, methodology, and overall results |
massive black holes are fundamental constituents of our cosmos, from the big bang to today. understanding their formation from cosmic dawn, their growth, and the emergence of the first, rare quasars in the early universe remains one of our greatest theoretical and observational challenges. hydrodynamic cosmological sim... | massive black holes in galactic nuclei: theory and simulations |
context. identifying the most likely sources for high-energy neutrino emission has been one of the main topics in high-energy astrophysics ever since the first observation of high-energy neutrinos by the icecube neutrino observatory. active galactic nuclei with relativistic jets, also known as blazars, have been consid... | association of icecube neutrinos with radio sources observed at owens valley and metsähovi radio observatories |
x-ray quasi-periodic eruptions (qpes) represent a recently discovered example of extreme x-ray variability associated with supermassive black holes. these are high-amplitude bursts recurring every few hours that are detected in the soft x-ray band from the nuclei of nearby galaxies whose optical spectra lack the broad ... | quasi-periodic eruptions from impacts between the secondary and a rigidly precessing accretion disc in an extreme mass-ratio inspiral system |
using a suite of three large cosmological hydrodynamical simulations, horizon-agn, horizon-noagn (no agn feedback) and horizon-dm (no baryons), we investigate how a typical sub-grid model for agn feedback affects the evolution of the inner density profiles of massive dark matter haloes and galaxies. based on direct obj... | density profile of dark matter haloes and galaxies in the horizon-agn simulation: the impact of agn feedback |
the detection of starlight from the host galaxies of quasars during the reionization epoch (z > 6) has been elusive, even with deep hubble space telescope observations1,2. the current highest redshift quasar host detected3, at z = 4.5, required the magnifying effect of a foreground lensing galaxy. low-luminosity qua... | detection of stellar light from quasar host galaxies at redshifts above 6 |
the origin of thermal optical and uv emission from stellar tidal disruption flares (tdfs) remains an open question. we present hubble space telescope far-uv (fuv) observations of eight optical/uv-selected tdfs 5-10 yr post-peak. six sources are cleanly detected, showing point-like fuv emission ({10}41.5{--42.5} {erg} {... | late-time uv observations of tidal disruption flares reveal unobscured, compact accretion disks |
we present results from our on-going muse gas flow and wind (megaflow) survey, which consists of 22 quasar lines of sight, each observed with the integral field unit muse and the uves spectrograph at the eso very large telescopes (vlt). the goals of this survey are to study the properties of the circumgalactic medium a... | muse gas flow and wind (megaflow) - iii. galactic wind properties using background quasars |
motivated by the recent discovery of the near-ubiquity of lyα emission around z ≳ 3 qsos, we performed a systematic study of qso circumgalactic lyα emission at z ≈ 2 utilizing the unique capability of the keck cosmic web imager (kcwi)—a new wide-field, blue sensitive integral field spectrograph. in this paper, we prese... | evolution of the cool gas in the circumgalactic medium of massive halos: a keck cosmic web imager survey of lyα emission around qsos at z ≈ 2 |
quasar emission lines are often shifted from the systemic velocity due to various dynamical and radiative processes in the line-emitting region. the level of these velocity shifts depends both on the line species and on quasar properties. we study velocity shifts for the line peaks (not the centroids) of various narrow... | the sloan digital sky survey reverberation mapping project: velocity shifts of quasar emission lines |
as part of the sloan digital sky survey (sdss) iv the extended baryon oscillation spectroscopic survey (eboss) will improve measurements of the cosmological distance scale by applying the baryon acoustic oscillation (bao) method to quasar samples. eboss will adopt two approaches to target quasars over 7500 deg2. first,... | the sdss-iv extended baryon oscillation spectroscopic survey: quasar target selection |
we study quasar proximity zones in the redshift range 5.77≤slant z≤slant 6.54 by homogeneously analyzing 34 medium-resolution spectra, encompassing both archival and newly obtained data, and exploiting recently updated systemic redshift and magnitude measurements. whereas previous studies found strong evolution of prox... | implications of z ∼ 6 quasar proximity zones for the epoch of reionization and quasar lifetimes |
despite their factor of ∼108 difference in black hole mass, several lines of evidence suggest possible similarities between black hole accretion flows in active galactic nuclei (agn) and galactic x-ray binaries. however, it is still unclear whether the geometry of the disk-corona system in x-ray binaries directly scale... | the analogous structure of accretion flows in supermassive and stellar mass black holes: new insights from faded changing-look quasars |
in a companion paper, we reported the self-consistent formation of quasar accretion disks with inflow rates $\sim 10\,{\rm m_{\odot}\,yr^{-1}}$ down to <300 schwarzschild radii from cosmological radiation-magneto-thermochemical-hydrodynamical galaxy and star formation simulations. we see the formation of a well-defi... | forge'd in fire ii: the formation of magnetically-dominated quasar accretion disks from cosmological initial conditions |
strongly lensed quasar systems with time delay measurements provide “time delay distances,” which are a combination of three angular diameter distances and serve as powerful tools to determine the hubble constant h 0. however, current results often rely on the assumption of the λcdm model. here we use a model-independe... | a model-independent determination of the hubble constant from lensed quasars and supernovae using gaussian process regression |
in 2019 july, the icecube experiment detected a high-energy neutrino from the direction of the powerful blazar pks 1502+106. we perform multiwavelength and multimessenger modeling of this source, using a fully selfconsistent one-zone model that includes the contribution of external radiation fields typical of flat-spec... | multiwavelength and neutrino emission from blazar pks 1502 + 106 |
in this work, we establish and test methods for implementing dynamical friction (df) for massive black hole pairs that form in large volume cosmological hydrodynamical simulations that include galaxy formation and black hole growth. we verify our models and parameters both for individual black hole dynamics and for the... | dynamical friction modelling of massive black holes in cosmological simulations and effects on merger rate predictions |
we report the results of a multiband observing campaign on the famous blazar 3c 279 conducted during a phase of increased activity from 2013 december to 2014 april, including first observations of it with nustar. the γ-ray emission of the source measured by fermi-lat showed multiple distinct flares reaching the highest... | rapid variability of blazar 3c 279 during flaring states in 2013-2014 with joint fermi-lat, nustar, swift, and ground-based multiwavelength observations |
short-lived intermittent phases of super-critical (super-eddington) growth, coupled with star formation via positive feedback, may account for early growth of massive black holes (mbh) and coevolution with their host spheroids. we estimate the possible growth rates and duty cycles of these episodes, both assuming slim ... | the case for supercritical accretion onto massive black holes at high redshift |
we use updated type ia pantheon +supernova , baryon acoustic oscillation, and hubble parameter (now also accounting for correlations) data, as well as new reverberation-measured c iv quasar data, and quasar angular size, h ii starburst galaxy, reverberation-measured mg ii quasar, and amati-correlated gamma-ray burst da... | h0=69.8 ±1.3 km s-1 mpc-1 , ωm 0=0.288 ±0.017 , and other constraints from lower-redshift, non-cmb, expansion-rate data |
we use cosmological hydrodynamical simulations to examine the physical properties of the gas in the circumgalactic media (cgm) of star-forming galaxies as a function of angular orientation. we utilize tng50 of the illustristng project, as well as the eagle simulation to show that observable properties of cgm gas correl... | predictions for the angular dependence of gas mass flow rate and metallicity in the circumgalactic medium |
quasar feedback in the form of powerful outflows is invoked as a key mechanism to quench star formation in galaxies, preventing massive galaxies to overgrow and producing the red colors of ellipticals. on the other hand, some models are also requiring "positive" active galactic nucleus feedback, inducing star formation... | blowin\' in the wind: both "negative" and "positive" feedback in an obscured high-z quasar |
a quasar catalogue is presented with a total of 510 764 objects including 424 748 type 1 qsos and 26 623 type 1 agn complete from the literature to 2015 january 25. also included are 25015 high-confidence sdss-based photometric quasars with radio/x-ray associations, 1595 bl lac objects, and 32783 type 2 objects. each o... | the half million quasars (hmq) catalogue |
we use the 2015 risaliti and lusso compilation of 808 x-ray and uv flux measurements of quasars (qsos) in the redshift range 0.061 ≤ z ≤ 6.28, alone and in conjunction with baryon acoustic oscillation (bao) and hubble parameter [h(z)] measurements, to constrain cosmological parameters in six cosmological models. the qs... | quasar x-ray and uv flux, baryon acoustic oscillation, and hubble parameter measurement constraints on cosmological model parameters |
we present constraints on local primordial non-gaussianity (png), parametrized through fnlloc, using the sloan digital sky survey iv extended baryon oscillation spectroscopic survey data release 14 quasar sample. we measure and analyze the anisotropic clustering of the quasars in fourier space, testing for the scale-de... | redshift-weighted constraints on primordial non-gaussianity from the clustering of the eboss dr14 quasars in fourier space |
observational studies of collimation in jets in active galactic nuclei (agn) are a key to understanding their formation and acceleration processes. we have performed an automated search for jet shape transitions in a sample of 367 agn using vlba data at 15 and 1.4 ghz. this search has found 10 out of 29 nearby jets at ... | a transition from parabolic to conical shape as a common effect in nearby agn jets |
in this work we investigate the properties of the sources that reionized the intergalactic medium (igm) in the high-redshift universe. using a semi-analytical model aimed at reproducing galaxies and black holes in the first ∼1.5 gyr of the universe, we revisit the relative role of star formation and black hole accretio... | reionization with galaxies and active galactic nuclei |
context. gaia-crf3 is the celestial reference frame for positions and proper motions in the third release of data from the gaia mission, gaia dr3 (and for the early third release, gaia edr3, which contains identical astrometric results). the reference frame is defined by the positions and proper motions at epoch 2016.0... | gaia early data release 3. the celestial reference frame (gaia-crf3) |
we present the first rest-frame optical spectrum of a high-redshift quasar observed with jwst/nircam in wide field slitless mode. the observed quasar, j0100+2802, is the most luminous quasar known at z > 6. we measure the mass of the central supermassive black hole (smbh) by means of the rest-frame optical h β emiss... | eiger. iii. jwst/nircam observations of the ultraluminous high-redshift quasar j0100+2802 |
we present the first results from romulusc, the highest resolution cosmological hydrodynamic simulation of a galaxy cluster run to date. romulusc, a zoom-in simulation of a halo with z = 0 mass 1014 m⊙, is run with the same sub-grid physics and resolution as romulus25. with unprecedented mass and spatial resolution, ro... | introducing romulusc: a cosmological simulation of a galaxy cluster with an unprecedented resolution |
supermassive primordial stars forming in atomically cooled haloes at z ∼ 15-20 are currently thought to be the progenitors of the earliest quasars in the universe. in this picture, the star evolves under accretion rates of 0.1-1 m⊙ yr-1 until the general relativistic instability triggers its collapse to a black hole at... | the evolution of supermassive population iii stars |
we use the large boss dr9 sample of quasar spectra to constrain two cases of non-thermal dark matter models: cold-plus-warm dark matter (c+wdm) where the warm component is a thermal relic, and sterile neutrinos resonantly produced in the presence of a lepton asymmetry (rpsn). we establish constraints on the thermal rel... | constraints from ly-α forests on non-thermal dark matter including resonantly-produced sterile neutrinos |
we present a new, all-sky quasar catalog, quaia, that samples the largest comoving volume and has the cleanest selection function of any existing spectroscopic quasar sample. the catalog draws on the 6,649,162 quasar candidates identified by the gaia mission that have redshift estimates from the space observatory's low... | quaia, the gaia-unwise quasar catalog: an all-sky spectroscopic quasar sample |
we have conducted a search for new strong gravitational lensing systems in the dark energy spectroscopic instrument legacy imaging surveys' data release 8. we use deep residual neural networks, building on previous work presented by huang et al. these surveys together cover approximately one-third of the sky visible fr... | discovering new strong gravitational lenses in the desi legacy imaging surveys |
the broad line region (blr) in active galactic nuclei (agns) is composed of dense gas (∼1011 cm-3) on sub-pc scale, which absorbs about 30 per cent of the ionizing continuum. the outer size of the blr is likely set by dust sublimation, and its density by the incident radiation pressure compression (rpc). but, what is t... | dust inflated accretion disc as the origin of the broad line region in active galactic nuclei |
we introduce a new set of large-scale, high-resolution hydrodynamical simulations of the intergalactic medium: the sherwood simulation suite. these are performed in volumes of 103-1603h-3 comoving mpc3, span almost four orders of magnitude in mass resolution with up to 17.2 billion particles, and employ a variety of ph... | the sherwood simulation suite: overview and data comparisons with the lyman α forest at redshifts 2 ≤ z ≤ 5 |
we present reverberation-mapping (rm) lags and black hole mass measurements using the c iv λ1549 broad emission line from a sample of 348 quasars monitored as a part of the sloan digital sky survey rm project. our data span four years of spectroscopic and photometric monitoring for a total baseline of 1300 days, allowi... | the sloan digital sky survey reverberation mapping project: initial c iv lag results from four years of data |
negative feedback from active galactic nuclei (agn) is the leading mechanism for the quenching of massive galaxies in the vast majority of modern galaxy evolution models. however, direct observational evidence that agn feedback causes quenching on a population scale is lacking. studies have shown that luminous agn are ... | cosmological simulations predict that agn preferentially live in gas-rich, star-forming galaxies despite effective feedback |
we present the to-date largest parameter space exploration of binaries in circumbinary discs (cbds), deriving orbital evolution prescriptions for eccentric, unequal mass binaries from our suite of hydrodynamic simulations. in all cases, binary eccentricities evolve towards steady state values that increase with mass ra... | orbital evolution of binaries in circumbinary discs |
we measure the mean free path ($\lambda _{\rm mfp,h\, \small {i}}$), photoionization rate ($\langle \gamma _{\rm h\, \small {i}} \rangle$), and neutral fraction ($\langle f_{\rm h\, \small {i}} \rangle$) of hydrogen in 12 redshift bins at 4.85 < z < 6.05 from a large sample of moderate resolution xshooter and esi... | measuring the photoionization rate, neutral fraction, and mean free path of h i ionizing photons at 4.9 ≤ z ≤ 6.0 from a large sample of xshooter and esi spectra |
molecular gas serves as a key probe of the complex interplay between black hole accretion and star formation in the host galaxies of active galactic nuclei (agns). we use co(2-1) observations from a new atacama large millimeter/submillimeter array survey, in conjunction with literature measurements, to investigate the ... | agn feedback and star formation of quasar host galaxies: insights from the molecular gas |
core formation and runaway core collapse in models with self-interacting dark matter (sidm) significantly alter the central density profiles of collapsed haloes. using a forward modelling inference framework with simulated data-sets, we demonstrate that flux ratios in quadruple image strong gravitational lenses can det... | strong lensing signatures of self-interacting dark matter in low-mass haloes |
this paper reports results of the third-year campaign of monitoring super-eddington accreting massive black holes (seambhs) in active galactic nuclei (agns) between 2014 and 2015. ten new targets were selected from the quasar sample of the sloan digital sky survey (sdss), which have generally been more luminous than th... | supermassive black holes with high accretion rates in active galactic nuclei. v. a new size-luminosity scaling relation for the broad-line region |
luminous distant quasars are unique probes of the high-redshift intergalactic medium (igm) and of the growth of massive galaxies and black holes in the early universe. absorption due to neutral hydrogen in the igm makes quasars beyond a redshift of z≃ 6.5 very faint in the optical z band, thus locating quasars at highe... | the identification of z-dropouts in pan-starrs1: three quasars at 6.5< z< 6.7 |
in a multiwavelength survey of 13 quasars at 5.8 ≲ z ≲ 6.5, which were preselected to be potentially young, we find five objects with extremely small proximity zone sizes that may imply uv-luminous quasar lifetimes of ≲100,000 yr. proximity zones are regions of enhanced transmitted flux in the vicinity of quasars that ... | detecting and characterizing young quasars. i. systemic redshifts and proximity zone measurements |
we report the discovery of 28 quasars and 7 luminous galaxies at 5.7 ≤ z ≤ 7.0. this is the tenth in a series of papers from the subaru high-z exploration of low-luminosity quasars (shellqs) project, which exploits the deep multiband imaging data produced by the hyper suprime-cam (hsc) subaru strategic program survey. ... | subaru high-z exploration of low-luminosity quasars (shellqs). x. discovery of 35 quasars and luminous galaxies at 5.7 ≤ z ≤ 7.0 |
radio sources at the highest redshifts can provide unique information on the first massive galaxies and black holes, the densest primordial environments, and the epoch of reionization. the number of astronomical objects identified at z > 6 has increased dramatically over the last few years, but previously only three... | the discovery of a highly accreting, radio-loud quasar at z = 6.82 |
as matter accretes onto the central supermassive black holes in active galactic nuclei (agns), x-rays are emitted. we present a population synthesis model that accounts for the summed x-ray emission from growing black holes; modulo the efficiency of converting mass to x-rays, this is effectively a record of the accrete... | the accretion history of agns. i. supermassive black hole population synthesis model |
blazars are a sub-class of quasars with doppler boosted jets oriented close to the line of sight, and thus efficient probes of supermassive black hole growth and their environment, especially at high redshifts. here we report on very long baseline interferometry observations of a blazar j0906 + 6930 at z = 5.47, which ... | evolving parsec-scale radio structure in the most distant blazar known |
extended lyman alpha emission is now commonly detected around high-redshift galaxies through stacking and even on individual basis. despite recent observational advances, the physical origin of these lyman alpha haloes (lahs), as well as their relationships to galaxies, quasars, circumgalactic gas, and other environmen... | the physical origins and dominant emission mechanisms of lyman alpha haloes: results from the tng50 simulation in comparison to muse observations |
we present co(2−1) and adjacent continuum observations of seven nearby radio-quiet type-2 quasars (qso2s) obtained with alma at ∼0.2″ resolution (370 pc at z ∼ 0.1). these qso2s are luminous (l[oiii] > 108.5 l⊙ ∼ mb < −23), and their host galaxies massive (m* ∼ 1011 m⊙). the co morphologies are diverse, including... | the diverse cold molecular gas contents, morphologies, and kinematics of type-2 quasars as seen by alma |
we present results from the keck baryonic structure survey (kbss) including the first detailed measurements of the column densities, kinematics, and internal energy of metal-bearing gas within the virial radius (35-100 physical kpc) of eight ∼l* galaxies at z ∼ 2. from our full sample of 130 metal-bearing absorbers, we... | column density, kinematics, and thermal state of metal-bearing gas within the virial radius of z ∼ 2 star-forming galaxies in the keck baryonic structure survey |
we use the muse gas flow and wind (megaflow) survey to study the kinematics of extended disc-like structures of cold gas around z ≈ 1 star-forming galaxies. the combination of vlt/muse and vlt/uves observations allows us to connect the kinematics of the gas measured through mg ii quasar absorption spectroscopy to the k... | muse gas flow and wind (megaflow) ii. a study of gas accretion around z ≈ 1 star-forming galaxies with background quasars |
the detection of quasars at z > 6 unveils the presence of supermassive black holes of a few billion solar masses. the rapid formation process of these extreme objects remains a fascinating and open issue. such discovery implies that seed black holes must have formed early on, and grown via either rapid accretion or ... | formation of supermassive black hole seeds |
in this work, we study different types of dark energy (de) models in the framework of the cosmographic approach, with emphasis on the running vacuum models (rvms). we assess their viability using different information criteria and compare them with the so-called ghost de models (gdes) as well as with the concordance la... | cosmographic approach to running vacuum dark energy models: new constraints using baos and hubble diagrams at higher redshifts |
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