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we present the drastic transformation of the x-ray properties of the active galactic nucleus (agn) 1es 1927+654, following a changing-look event. after the optical/ultraviolet outburst the power-law component, produced in the x-ray corona, disappeared, and the spectrum of 1es 1927+65 instead became dominated by a black... | the destruction and recreation of the x-ray corona in a changing-look active galactic nucleus |
as one paper in a series reporting on a large reverberation mapping campaign of super-eddington accreting massive black holes (seambhs) in active galactic nuclei (agns), we present the results of 10 seambhs monitored spectroscopically during 2015-2017. six of them are observed for the first time, and have generally hig... | supermassive black holes with high accretion rates in active galactic nuclei. ix. 10 new observations of reverberation mapping and shortened hβ lags |
we present atacama large millimeter/submillimeter array (alma) band 7 observations of a remarkably bright galaxy candidate at ${z}_{\mathrm{phot}}={16.7}_{-0.3}^{+1.9}$ (m uv = -21.6), s5-z17-1, identified in james webb space telescope (jwst) early release observation data of stephen's quintet. we do not detect the dus... | alma fir view of ultra-high-redshift galaxy candidates at z 11-17: blue monsters or low-z red interlopers? |
observations of the redshift z=7.085 quasar j1120+0641 have been used to search for variations of the fine structure constant, alpha, over the redshift range 5.5 to 7.1. observations at z=7.1 probe the physics of the universe when it was only 0.8 billion years old. these are the most distant direct measurements of alph... | four direct measurements of the fine-structure constant 13 billion years ago |
the extended baryon oscillation spectroscopic survey (eboss) data release 14 sample includes 80,118 luminous red galaxies (lrgs). by combining these galaxies with the high-redshift tail of the boss galaxy sample, we form a sample of lrgs at an effective redshift z = 0.72, covering an effective volume of 0.9 gpc3. we ac... | the sdss-iv extended baryon oscillation spectroscopic survey: baryon acoustic oscillations at redshift of 0.72 with the dr14 luminous red galaxy sample |
nearly every massive galaxy harbors a supermassive black hole (smbh) in its nucleus. smbh masses are millions to billions of solar mass, and they correlate with properties of spheroids of their host galaxies. while the smbh growth channels, mergers, and gas accretion are well established, their origin remains uncertain... | a population of bona fide intermediate-mass black holes identified as low-luminosity active galactic nuclei |
mergers of galaxies are thought to cause significant gas inflows to the inner parsecs, which can activate rapid accretion on to supermassive black holes (smbhs), giving rise to active galactic nuclei (agn). during a significant fraction of this process, smbhs are predicted to be enshrouded by gas and dust. studying 52 ... | growing supermassive black holes in the late stages of galaxy mergers are heavily obscured |
we report on the design and performance of the keck cosmic web imager (kcwi), a general purpose optical integral field spectrograph that has been installed at the nasmyth port of the 10 m keck ii telescope on maunakea, hawaii. the novel design provides blue-optimized seeing-limited imaging from 350-560 nm with configur... | the keck cosmic web imager integral field spectrograph |
a system of 5020 robotic fiber positioners was installed in 2019 on the mayall telescope, at kitt peak national observatory. the robots automatically retarget their optical fibers every 10-20 minutes, each to a precision of several microns, with a reconfiguration time of fewer than 2 minutes. over the next 5 yr, they w... | the robotic multiobject focal plane system of the dark energy spectroscopic instrument (desi) |
context. lbqs 0302−0019 is a blue quasar (qso) at z ∼ 3.3 that hosts powerful outflows and resides in a complex environment consisting of an obscured active galactic nucleus (agn) candidate and multiple companions, all within 30 kpc in projection.aims: we aim to characterise this complex system using jwst nirspec integ... | ga-nifs: the ultra-dense, interacting environment of a dual agn at z ∼ 3.3 revealed by jwst/nirspec ifs |
context. as part of the third gaia data release, we present the contributions of the non-stellar and classification modules from the eighth coordination unit (cu8) of the data processing and analysis consortium, which is responsible for the determination of source astrophysical parameters using gaia data. this is the t... | gaia data release 3. apsis. iii. non-stellar content and source classification |
we present the first results from the jwst program a spectroscopic survey of biased halos in the reionization era (aspire). this program represents an imaging and spectroscopic survey of 25 reionization-era quasars and their environments by utilizing the unprecedented capabilities of nircam wide field slitless spectros... | a spectroscopic survey of biased halos in the reionization era (aspire): jwst reveals a filamentary structure around a z = 6.61 quasar |
we present the results from a full polarization study carried out with the atacama large millimeter/submillimeter array (alma) during the first very long baseline interferometry (vlbi) campaign, which was conducted in 2017 april in the λ3 mm and λ1.3 mm bands, in concert with the global mm-vlbi array (gmva) and the eve... | polarimetric properties of event horizon telescope targets from alma |
we aim to constrain the evolution of active galactic nuclei (agns) as a function of obscuration using an x-ray-selected sample of ~2000 agns from a multi-tiered survey including the cdfs, aegis-xd, cosmos, and xmm-xxl fields. the spectra of individual x-ray sources are analyzed using a bayesian methodology with a physi... | obscuration-dependent evolution of active galactic nuclei |
we study the sudden optical and ultraviolet (uv) brightening of 1es 1927+654, which until now was known as a narrow-line active galactic nucleus (agn). 1es 1927+654 was part of the small and peculiar class of “true type-2” agns that lack broad emission lines and line-of-sight obscuration. our high-cadence spectroscopic... | 1es 1927+654: an agn caught changing look on a timescale of months |
we present two large catalogs of active galactic nucleus (agn) candidates identified across 30,093 deg2 of extragalactic sky from the wide-field infrared survey explorer’s allwise data release. both catalogs are selected purely using the wide-field infrared survey explorer (wise) w1 and w2 bands. the r90 catalog consis... | the wise agn catalog |
there have recently been several reports of apparently periodic variations in the light curves of quasars, e.g. pg 1302-102 by graham et al. any quasar showing periodic oscillations in brightness would be a strong candidate to be a close binary supermassive black hole and, in turn, a candidate for gravitational wave st... | false periodicities in quasar time-domain surveys |
we develop a new spectral model for the broad-band spectral energy distribution (sed) of active galactic nuclei (agn). this includes an outer standard disc, an inner warm comptonizing region to produce the soft x-ray excess and a hot corona. we tie these together energetically by assuming novikov-thorne emissivity, and... | a physical model of the broad-band continuum of agn and its implications for the uv/x relation and optical variability |
we investigate black hole-host galaxy scaling relations in cosmological simulations with a self-consistent black hole growth and feedback model. our sub-grid accretion model captures the key scalings governing angular momentum transport by gravitational torques from galactic scales down to parsec scales, while our kine... | gravitational torque-driven black hole growth and feedback in cosmological simulations |
massive black hole (mbh) coalescences are powerful sources of low-frequency gravitational waves. to study these events in the cosmological context, we need to trace the large-scale structure and cosmic evolution of a statistical population of galaxies, from dim dwarfs to bright galaxies. to cover such a large range of ... | black hole mergers from dwarf to massive galaxies with the newhorizon and horizon-agn simulations |
the radius-luminosity ({r}{{h}β }{--}{l}5100) relationship of active galactic nuclei (agns) established by the reverberation mapping (rm) observations has been widely used as a single-epoch black hole mass estimator in the research of large agn samples. however, the recent rm campaigns discovered that the agns with hig... | the radius-luminosity relationship depends on optical spectra in active galactic nuclei |
context. the erosita final equatorial depth survey (efeds), observed with erosita ahead of its planned 4-yr all-sky survey, is the largest contiguous-field x-ray survey at present. it yielded a large sample of x-ray sources with very rich multiband photometric and spectroscopic coverage.aims: we present here the efeds ... | the erosita final equatorial-depth survey (efeds). the agn catalog and its x-ray spectral properties |
we report the discovery of a quasar at z = 7.07, which was selected from the deep multi-band imaging data collected by the hyper suprime-cam (hsc) subaru strategic program survey. this quasar, hsc j124353.93+010038.5, has an order of magnitude lower luminosity than do the other known quasars at z > 7. the rest-frame... | discovery of the first low-luminosity quasar at z > 7 |
we have analyzed the parsec-scale jet kinematics of 447 bright radio-loud active active galactic nuclei (agn), based on 15 ghz very long baseline array (vlba) data obtained between 1994 august 31 and 2019 august 4. we present new total intensity and linear polarization maps obtained between 2017 january 1 and 2019 augu... | monitoring of jets in active galactic nuclei with vlba experiments. xviii. kinematics and inner jet evolution of bright radio-loud active galaxies |
we present two new large-scale datasets aimed at evaluating systems designed to comprehend a natural language query and extract its answer from a large corpus of text. the quasar-s dataset consists of 37000 cloze-style (fill-in-the-gap) queries constructed from definitions of software entity tags on the popular website... | quasar: datasets for question answering by search and reading |
the observation of quasars at very high redshift such as pōniuā'ena is a challenge for models of supermassive black hole (smbh) formation. this work presents a study of smbh formation via known physical processes in starburst clusters formed at the onset of the formation of their hosting galaxy. while at the early stag... | very high redshift quasars and the rapid emergence of supermassive black holes |
galaxy-scale strong gravitational lensing can not only provide a valuable probe of the dark matter distribution of massive galaxies, but also provide valuable cosmological constraints, either by studying the population of strong lenses or by measuring time delays in lensed quasars. due to the rarity of galaxy-scale str... | cmu deeplens: deep learning for automatic image-based galaxy-galaxy strong lens finding |
active galactic nuclei (agns) that show strong rest-frame optical/uv variability in their blue continuum and broad line emission are classified as changing-look agn, or at higher luminosities, changing-look quasars (clqs). these surprisingly large and sometimes rapid transitions challenge accepted models of quasar phys... | changing-look quasar candidates: first results from follow-up spectroscopy of highly optically variable quasars |
the recent detection of ulasj1342+0928, a bright qso at z = 7.54, provides a powerful probe of the ionization state of the intervening intergalactic medium, potentially allowing us to set strong constraints on the epoch of reionization (eor). here we quantify the presence of ly α damping wing absorption from the eor in... | constraints on reionization from the z = 7.5 qso ulasj1342+0928 |
images of the linear polarizations of synchrotron radiation around active galactic nuclei (agns) highlight their projected magnetic field lines and provide key data for understanding the physics of accretion and outflow from supermassive black holes. the highest-resolution polarimetric images of agns are produced with ... | high-resolution linear polarimetric imaging for the event horizon telescope |
we present the evolution of ly$\alpha$ emission derived from 53 galaxies at $z=6.6-13.2$ that are identified by multiple jwst/nirspec spectroscopy programs of ero, ers, go, ddt, and gto. these galaxies fall on the star-formation main sequence and are the typical star-forming galaxies with uv magnitudes of $-22.5\leq m_... | ly$\\alpha$ emission at $z=7-13$: clear ly$\\alpha$ equivalent width evolution indicating the late cosmic reionization history |
the ionizing continuum from active galactic nuclei is fundamental for interpreting their broad emission lines and understanding their impact on the surrounding gas. furthermore, it provides hints on how matter accretes on to supermassive black holes. using hubble space telescope's wide field camera 3, we have construct... | the first ultraviolet quasar-stacked spectrum at z ≃ 2.4 from wfc3 |
we present a jwst/mrs spectrum of the quasar j1120+0641 at z=7.0848, the first spectroscopic observation of a reionisation-era quasar in the rest-frame infrared ($0.6<\lambda<3.4\mu$m). in the context of the mysterious fast assembly of the first supermassive black holes at z>7, our observations enable for the ... | first rest-frame infrared spectrum of a z>7 quasar: jwst/mrs observations of j1120+0641 |
multiple pulsar timing array (pta) collaborations have recently reported the first detection of gravitational waves (gws) of nanohertz frequencies. the signal is expected to be primarily sourced by inspiralling supermassive black hole binaries (smbhbs) and these first results are broadly consistent with the expected gw... | where are nanograv's big black holes? |
we present an analysis of a sample of robust high-redshift galaxies selected from the 'blank' fields of the prime extragalactic areas for reionization science (pearls) survey and early release observations (ero) data from jwst with the aim of selecting candidate high-redshift active galactic nuclei (agn). sources were ... | epochs vii: discovery of high-redshift (6.5 < z < 12) agn candidates in jwst ero and pearls data |
we present a detailed characterization of the 849 broad-line quasars from the sloan digital sky survey reverberation mapping (sdss-rm) project. our quasar sample covers a redshift range of 0.1 < z < 4.5 and is flux-limited to i psf < 21.7 without any other cuts on quasar properties. the main sample characteriz... | the sloan digital sky survey reverberation mapping project: sample characterization |
in the current paper, a dark energy (de) model reconstructed from the well‑motivated deceleration parameter (dp) is analyzed. a flat frw universe filled with radiation, dark matter (dm), and dark energy fluids is considered. the free parameters are constrained using measurements from supernovae, hubble, gamma ray burst... | observational constraining study of new deceleration parameters in frw universe |
this paper introduces a novel cosmological model aimed at probing the accelerated expansion of the late universe through a unique parametrization of the deceleration parameter. we aim to constrain key cosmic parameters by integrating recent measurements of the hubble parameter obtained from various observational method... | addressing the $r_{d}$ tension using late-time observational measurements in a novel deceleration parametrization |
gravitational time delays, observed in strong lens systems where the variable background source is multiply imaged by a massive galaxy in the foreground, provide direct measurements of cosmological distance that are very complementary to other cosmographic probes. the success of the technique depends on the availabilit... | time delay cosmography |
concerted effort is currently ongoing to open up the epoch of reionization (eor) ($z\sim$15-6) for studies with ir and radio telescopes. whereas ir detections have been made of sources (lyman-$\alpha$ emitters, quasars and drop-outs) in this redshift regime in relatively small fields of view, no direct detection of neu... | the cosmic dawn and epoch of reionisation with ska |
we review current understanding of the population of radio galaxies and radio-loud quasars from an observational perspective, focusing on their large-scale structures and dynamics. we discuss the physical conditions in radio galaxies, their fuelling and accretion modes, host galaxies and large-scale environments, and t... | radio galaxies and feedback from agn jets |
recently we have shown that high-energy neutrinos above 200 tev detected by icecube are produced within several parsecs in the central regions of radio-bright blazars, that is active galactic nuclei with jets pointing toward us. to independently test this result and extend the analysis to a wider energy range, we use p... | directional association of tev to pev astrophysical neutrinos with radio blazars |
context. the low frequency array (lofar) is the only radio telescope that is presently capable of high-sensitivity, high-resolution (i.e. < 1 mjy beam−1 and < 15″) observations at ultra-low frequencies (< 100 mhz). to utilise these capabilities, the lofar surveys key science project is undertaking a large surv... | the lofar lba sky survey. i. survey description and preliminary data release |
we present x-shooter near-ir spectroscopy of a large sample of 38 luminous (m1450 = -29.0 to -24.4) quasars at 5.78 < z < 7.54, which have complementary [c ii]158μm observations from alma. this x-shooter/alma sample provides us with the most comprehensive view of reionization-era quasars to date, allowing us to c... | the x-shooter/alma sample of quasars in the epoch of reionization. i. nir spectral modeling, iron enrichment, and broad emission line properties |
we explore the abundance, spatial distribution, and physical properties of the o vi, o vii, and o viii ions of oxygen in circumgalactic and intergalactic media (the cgm, igm, and whim). we use the tng100 and tng300 large volume cosmological magnetohydrodynamical simulations. modelling the ionization states of simulated... | the abundance, distribution, and physical nature of highly ionized oxygen o vi, o vii, and o viii in illustristng |
on 2015 june 16, fermi-lat observed a giant outburst from the flat spectrum radio quasar 3c 279 with a peak >100 mev flux of ∼3.6 × 10-5 photons cm-2 s-1, averaged over orbital period intervals. it is historically the highest γ-ray flux observed from the source, including past egret observations, with the γ-ray isot... | minute-timescale >100 mev γ-ray variability during the giant outburst of quasar 3c 279 observed by fermi-lat in 2015 june |
relativistic jets are associated with extreme astrophysical phenomena, like the core collapse of massive stars in gamma-ray bursts (grbs) and the accretion on to supermassive black holes in active galactic nuclei. it is generally accepted that these jets are powered electromagnetically, by the magnetized rotation of a ... | relativistic mhd simulations of core-collapse grb jets: 3d instabilities and magnetic dissipation |
we examine the connection between the properties of the circumgalactic medium (cgm) and the quenching and morphological evolution of central galaxies in the eagle and illustristng simulations. the simulations yield very different median cgm mass fractions, fcgm, as a function of halo mass, m200, with low-mass haloes be... | the quenching and morphological evolution of central galaxies is facilitated by the feedback-driven expulsion of circumgalactic gas |
understanding how super-massive black holes form and grow in the early universe has become a major challenge1,2 since it was discovered that luminous quasars existed only 700 million years after the big bang3,4. simulations indicate an evolutionary sequence of dust-reddened quasars emerging from heavily dust-obscured s... | a dusty compact object bridging galaxies and quasars at cosmic dawn |
we present 1-7 ghz high-resolution radio imaging (vla and e-merlin) and spatially resolved ionized gas kinematics for 10 z < 0.2 type 2 `obscured' quasars (log [lagn/erg s-1] ≳ 45) with moderate radio luminosities (log [l_{1.4 ghz}/w hz-1] = 23.3-24.4). these targets were selected to have known ionized outflows base... | prevalence of radio jets associated with galactic outflows and feedback from quasars |
the gaia galactic survey mission is designed and optimized to obtain astrometry, photometry, and spectroscopy of nearly two billion stars in our galaxy. yet as an all-sky multi-epoch survey, gaia also observes several million extragalactic objects down to a magnitude of g ∼ 21 mag. due to the nature of the gaia onboard... | gaia data release 3. the extragalactic content |
the milky way hosts a hot (≈2 × 106 k), diffuse, gaseous halo based on detections of z = 0 o vii and o viii absorption lines in quasar spectra and emission lines in blank-sky spectra. here we improve constraints on the structure of the hot gas halo by fitting a radial model to a much larger sample of o vii and o viii e... | constraining the milky way's hot gas halo with o vii and o viii emission lines |
the bolometric luminosity of active galactic nuclei (agns) is difficult to determine, and various approximations have been used to calibrate it against different observed properties. here, i combine theoretical calculations of optically thick, geometrically thin accretion discs, and observed x-ray properties of agn, to... | bolometric correction factors for active galactic nuclei |
we characterize the thermal state of the intergalactic medium (igm) in 10 redshift bins in the range 2 ≤ z ≤ 4 with a sample of 103 high-resolution, high s/n ly α forest spectra using four different flux distribution statistics. our measurements are calibrated with mock spectra from a large suite of hydrodynamical simu... | a consistent and robust measurement of the thermal state of the igm at 2 ≤ z ≤ 4 from a large sample of ly α forest spectra: evidence for late and rapid he ii reionization |
we present a systematic investigation of the circumgalactic medium (cgm) within projected distances d < 160 kpc of luminous red galaxies (lrgs). the sample comprises 16 intermediate-redshift (z = 0.21-0.55) lrgs of stellar mass m_star> 10^{11} m_\odot. combining far-ultraviolet cosmic origin spectrograph spectra ... | characterizing circumgalactic gas around massive ellipticals at z ∼ 0.4 - ii. physical properties and elemental abundances |
we conduct global three-dimensional radiation magnetohydrodynamic simulations of the inner regions of accretion flows around a 5 × 108 m ⊙ black hole, with mass accretion rates reaching 7% and 20% of the eddington value. we choose initial field topologies that result in an inner disk supported by magnetic pressure, wit... | global radiation magnetohydrodynamic simulations of sub-eddington accretion disks around supermassive black holes |
we analyse the clustering of the sloan digital sky survey iv extended baryon oscillation spectroscopic survey data release 14 quasar sample (dr14q). we measure the redshift space distortions using the power-spectrum monopole, quadrupole, and hexadecapole inferred from 148 659 quasars between redshifts 0.8 and 2.2, cove... | the clustering of the sdss-iv extended baryon oscillation spectroscopic survey dr14 quasar sample: structure growth rate measurement from the anisotropic quasar power spectrum in the redshift range 0.8 < z < 2.2 |
we analyze the parsec-scale jet kinematics from 2007 june to 2018 december of a sample of γ-ray bright blazars monitored roughly monthly with the very long baseline array (vlba) at 43 ghz under the vlba-bu-blazar program. we implement a novel piecewise linear fitting method to derive the kinematics of 521 distinct emis... | kinematics of parsec-scale jets of gamma-ray blazars at 43 ghz during 10 yr of the vlba-bu-blazar program |
we use updated hubble parameter and baryon acoustic oscillation data, as well as other lower redshift type ia supernova, mg ii reverberation-measured quasar, quasar angular size, h ii starburst galaxy, and amati-correlated gamma-ray burst data, to jointly constrain cosmological parameters in six cosmological models. th... | using lower redshift, non-cmb, data to constrain the hubble constant and other cosmological parameters |
the next two decades are expected to open the door to the first coincident detections of electromagnetic (em) and gravitational-wave (gw) signatures associated with massive black-hole (mbh) binaries heading for coalescence. these detections will launch a new era of multimessenger astrophysics by expanding this growing ... | electromagnetic counterparts to massive black-hole mergers |
context. understanding the physics and geometry of accretion and ejection around super massive black holes (smbhs) is important to understand the evolution of active galactic nuclei (agn) and therefore of the large scale structures of the universe.aims: we aim at providing a simple, coherent, and global view of the sub... | a global view of the inner accretion and ejection flow around super massive black holes. radiation-driven accretion disk winds in a physical context |
we report the discovery of 15 quasars and bright galaxies at 5.7 < z < 6.9. this is the initial result from the subaru high-z exploration of low-luminosity quasars project, which exploits the exquisite multiband imaging data produced by the subaru hyper suprime-cam (hsc) strategic program survey. the candidate se... | subaru high-z exploration of low-luminosity quasars (shellqs). i. discovery of 15 quasars and bright galaxies at 5.7 < z < 6.9 |
we present the active galactic nucleus (agn) catalog and optical spectroscopy for the second data release of the swift bat agn spectroscopic survey (bass dr2). with this dr2 release we provide 1449 optical spectra, of which 1182 are released for the first time, for the 858 hard-x-ray-selected agns in the swift bat 70-m... | bass. xxii. the bass dr2 agn catalog and data |
the existence of massive (1011 solar masses) elliptical galaxies by redshift z ≈ 4 (refs 1, 2, 3; when the universe was 1.5 billion years old) necessitates the presence of galaxies with star-formation rates exceeding 100 solar masses per year at z > 6 (corresponding to an age of the universe of less than 1 billion y... | rapidly star-forming galaxies adjacent to quasars at redshifts exceeding 6 |
we report a new changing-look quasar, wise j105203.55+151929.5 at z = 0.303, found by identifying highly mid-ir-variable quasars in the wide-field infrared survey explorer (wise)/near-earth object wise reactivation (neowise) data stream. compared to multiepoch mid-ir photometry of a large sample of sdss-confirmed quasa... | a mid-ir selected changing-look quasar and physical scenarios for abrupt agn fading |
we present a new method to test the λcdm cosmological model and to estimate cosmological parameters based on the nonlinear relation between the ultraviolet and x-ray luminosities of quasars. we built a data set of 1138 quasars by merging several samples from the literature with x-ray measurements at 2 kev and sdss phot... | a hubble diagram for quasars |
galaxies are surrounded by large reservoirs of gas, mostly hydrogen, that are fed by inflows from the intergalactic medium and by outflows from galactic winds. absorption-line measurements along the lines of sight to bright and rare background quasars indicate that this circumgalactic medium extends far beyond the star... | nearly all the sky is covered by lyman-α emission around high-redshift galaxies |
in the current framework, the standard parametrization of our universe is the so-called lambda cold dark matter (λcdm) model. recently, a ∼4σ tension with the λcdm model was shown to exist via a model-independent parametrization of a hubble diagram of type ia supernovae (sne ia) from the jla survey and quasars. model-i... | tension with the flat λcdm model from a high-redshift hubble diagram of supernovae, quasars, and gamma-ray bursts |
we present the first version of the automatic learning for the rapid classification of events (alerce) broker light curve classifier. alerce is currently processing the zwicky transient facility (ztf) alert stream, in preparation for the vera c. rubin observatory. the alerce light curve classifier uses variability feat... | alert classification for the alerce broker system: the light curve classifier |
risaliti and lusso have compiled x-ray and uv flux measurements of 1598 quasars (qsos) in the redshift range 0.036 ≤ z ≤ 5.1003, part of which, z ~ 2.4 - 5.1, is largely cosmologically unprobed. in this paper we use these qso measurements, alone and in conjunction with baryon acoustic oscillation (bao) and hubble param... | using quasar x-ray and uv flux measurements to constrain cosmological model parameters |
announcing the release v6.4 of the milliquas (million quasars) quasar catalogue which presents all published quasars to 11 december 2019, including sdss-dr16. its totals are 757,991 type-i qsos/agn and approx 1.1m high-confidence (80%+ likelihood) quasar candidates from sdss-based & allwise photometric quasar catal... | the million quasars (milliquas) catalogue, v6.4 |
black hole feedback is now a standard component of galaxy formation models. these models predict that the impact of black hole activity on its host galaxy likely peaked at z = 2-3, the epoch of strongest star formation activity and black hole accretion activity in the universe. we used xshooter on the very large telesc... | discovery of extreme [o iii] λ5007 å outflows in high-redshift red quasars |
we present constraints on masses of active and sterile neutrinos in the context of the λcdmν and λwdm models, respectively. we use the one-dimensional lyα-forest power spectrum from the baryon oscillation spectroscopic survey (boss) of the sloan digital sky survey (sdss-iii) measured by palanque-delabrouille et al. [1]... | constraints on neutrino masses from lyman-alpha forest power spectrum with boss and xq-100 |
the free-streaming of kev-scale particles impacts structure growth on scales that are probed by the lyman-alpha forest of distant quasars. using an unprecedentedly large sample of medium-resolution qso spectra from the ninth data release of sdss, along with a state-of-the-art set of hydrodynamical simulations to model ... | lyman-alpha forests cool warm dark matter |
gravitational waves (gws) have now been detected from stellar-mass black hole binaries, and the first observations of gws from massive black hole (mbh) binaries are expected within the next decade. pulsar timing arrays (pta), which can measure the years long periods of gws from mbh binaries (mbhbs), have excluded many ... | massive black hole binary mergers in dynamical galactic environments |
all galaxies once passed through a hyperluminous quasar phase powered by accretion onto a supermassive black hole. but because these episodes are brief, quasars are rare objects typically separated by cosmological distances. in a survey for lyman-α emission at redshift z ≈ 2, we discovered a physical association of fou... | quasar quartet embedded in giant nebula reveals rare massive structure in distant universe |
the recent compilation of quasar (qso) x-ray and ultraviolet (uv) flux measurements include qsos that appear to not be standardizable via the x-ray luminosity and uv luminosity (lx-luv) relation and so should not be used to constrain cosmological model parameters. here, we show that the largest of seven sub-samples in ... | do quasar x-ray and uv flux measurements provide a useful test of cosmological models? |
axion-like particles (alps) are predicted by several beyond the standard model theories, in particular, string theory. in the presence of an external magnetic field perpendicular to the direction of propagation, alps can couple to photons. therefore, if an x-ray source is viewed through a magnetized plasma, such as a l... | new constraints on light axion-like particles using chandra transmission grating spectroscopy of the powerful cluster-hosted quasar h1821+643 |
the total contribution of diffuse halo gas to the galaxy baryon budget strongly depends on its dominant ionization state. in this paper, we address the physical conditions in the highly ionized circumgalactic medium (cgm) traced by {{o}} {{vi}} absorption lines observed in cos-halos spectra. we analyze the observed ion... | the cos-halos survey: origins of the highly ionized circumgalactic medium of star-forming galaxies |
the observed relation between the soft x-ray and the optical-ultraviolet emission in active galactic nuclei (agns) is nonlinear and it is usually parametrized as a dependence between the logarithm of the monochromatic luminosity at 2500 å and at 2 kev. previous investigations have found that the dispersion of this rela... | the tight relation between x-ray and ultraviolet luminosity of quasars |
scaling relations between black hole (bh) masses and their host galaxy properties have been studied extensively over the last two decades, and point toward co-evolution of central massive bhs and their hosts. however, these relations remain poorly constrained for bh masses below ∼ {10}6 {m}⊙ . here we present optical a... | a ∼50,000 m⊙ solar mass black hole in the nucleus of rgg 118 |
an incremental version of the fourth catalog of active galactic nuclei (agns) detected by the fermi large area telescope is presented. this version (4lac-dr3) derives from the third data release of the 4fgl catalog based on 12 yr of e > 50 mev gamma-ray data, where the spectral parameters, spectral energy distributi... | the fourth catalog of active galactic nuclei detected by the fermi large area telescope: data release 3 |
quasars (qsos) are extremely luminous active galactic nuclei currently observed up to redshift z = 7.642. as such, they have the potential to be the next rung of the cosmic distance ladder beyond type ia supernovae, if they can reliably be used as cosmological probes. the main issue in adopting qsos as standard candles... | quasar standardization: overcoming selection biases and redshift evolution |
in this paper, we use all available baryon acoustic oscillation, hubble parameter, and quasar angular size data to constrain six dark energy cosmological models, both spatially flat and non-flat. depending on the model and data combination considered, these data mildly favour closed spatial hypersurfaces (by as much as... | baryon acoustic oscillation, hubble parameter, and angular size measurement constraints on the hubble constant, dark energy dynamics, and spatial curvature |
the advent of high-angular-resolution ir and submillimeter interferometry allows for spatially resolved observations of the parsec-scale environment of active galactic nuclei (agns), commonly referred to as the “torus.” while molecular lines show the presence of large, massive disks, the ir observations appear to be do... | redefining the torus: a unifying view of agns in the infrared and submillimeter |
it is well known that reverberation mapping of active galactic nuclei (agns) reveals a relationship between agn luminosity and the size of the broad-line region, and that use of this relationship, combined with the doppler width of the broad emission line, enables an estimate of the mass of the black hole at the center... | the sloan digital sky survey reverberation mapping project: estimating masses of black holes in quasars with single-epoch spectroscopy |
the evolution of galaxies is connected to the growth of supermassive black holes in their centers. during the quasar phase, a huge luminosity is released as matter falls onto the black hole, and radiation-driven winds can transfer most of this energy back to the host galaxy. over five different epochs, we detected the ... | black hole feedback in the luminous quasar pds 456 |
studies of rest-frame optical emission in quasars at z > 6 have historically been limited by the wavelengths accessible by ground-based telescopes. the james webb space telescope (jwst) now offers the opportunity to probe this emission deep into the reionization epoch. we report the observations of eight quasars at ... | a spectroscopic survey of biased halos in the reionization era (aspire): a first look at the rest-frame optical spectra of z > 6.5 quasars using jwst |
following the recent discovery of x-ray quasi-periodic eruptions (qpes) coming from the nucleus of the galaxy gsn 069, here we report on the detection of qpes in the active galaxy named rx j1301.9+2747. qpes are rapid and recurrent increases of the x-ray count-rate by more than one order of magnitude with respect to a ... | x-ray quasi-periodic eruptions from the galactic nucleus of rx j1301.9+2747 |
we present alma detections of the [c ii] 158 μm emission line and the underlying far-infrared (fir) continuum of three quasars at 6.6 < z < 6.9 selected from the viking survey. the [c ii] line fluxes range between 1.6 and 3.4 jy km s-1 ([c ii] luminosities ∼(1.9-3.9) × 109 l⊙). we measure continuum flux densities... | bright [c ii] and dust emission in three z > 6.6 quasar host galaxies observed by alma |
we combine results from deep alma observations of massive (m* > 1010 m⊙) galaxies at different redshifts to show that the column density of their interstellar medium (ism) rapidly increases toward early cosmic epochs. our analysis includes objects from the aspecs and alpine large programs, as well as individual obse... | supermassive black holes at high redshift are expected to be obscured by their massive host galaxies' interstellar medium |
we improve the dynamical black hole (bh) mass estimates in three nearby low-mass early-type galaxies: ngc 205, ngc 5102, and ngc 5206. we use new hubble space telescope (hst)/stis spectroscopy to fit the star formation histories of the nuclei in these galaxies, and use these measurements to create local color-mass-to-l... | improved dynamical constraints on the masses of the central black holes in nearby low-mass early-type galactic nuclei and the first black hole determination for ngc 205 |
we compute synthetic, rest-frame optical and ultraviolet (uv) emission-line properties of galaxy populations at redshifts from z ≈ 0 to = 8 in a full cosmological framework. we achieve this by coupling, in post-processing, the cosmological illustristng simulations with new-generation nebular-emission models, accounting... | emission-line properties of illustristng galaxies: from local diagnostic diagrams to high-redshift predictions for jwst |
we introduce a series of 20 cosmological hydrodynamical simulations of l* (m200 = 1011.7-1012.3 m⊙) and group-sized (m200 = 1012.7-1013.3 m⊙) haloes run with the model used for the eagle project, which additionally includes a non-equilibrium ionization and cooling module that follows 136 ions. the simulations reproduce... | bimodality of low-redshift circumgalactic o vi in non-equilibrium eagle zoom simulations |
we present new synthesis models of the extragalactic background light (ebl) from far infra-red (fir) to tev γ-rays, with an emphasis on the extreme ultraviolet (uv) background that is responsible for the observed ionization and thermal state of the intergalactic medium across the cosmic time. our models use updated val... | new synthesis models of consistent extragalactic background light over cosmic time |
warm dark matter has recently become increasingly constrained by observational inferences about the low-mass end of the subhalo mass function, which would be suppressed by dark matter free streaming in the early universe. in this work, we point out that a constraint can be placed on ultralight bosonic dark matter (ofte... | subhalo mass function and ultralight bosonic dark matter |
we use six different cosmological models to study the recently released compilation of x-ray and uv flux measurements of 2038 quasars (qsos) which span the redshift range 0.009 ≤ z ≤ 7.5413. we find, for the full qso data set, that the parameters of the x-ray and uv luminosities lx-luv relation used to standardize thes... | determining the range of validity of quasar x-ray and uv flux measurements for constraining cosmological model parameters |
we publicly release a new sample of 34 medium resolution quasar spectra at 5.77 ≤ z em ≤ 6.54 observed with the echellette spectrograph and imager on the keck telescope. this quasar sample represents an ideal laboratory to study the intergalactic medium (igm) during the end stages of the epoch of reionization, and cons... | the opacity of the intergalactic medium measured along quasar sightlines at z ∼ 6 |
past observations of quasar host galaxies at z> 6 have found cold gas and star formation on compact scales of a few kiloparsecs. we present new high sensitivity iram plateau de bure interferometer follow-up observations of the [c ii] 158 μm emission line and far-infrared (fir) continuum in the host galaxy of sdss j1... | very extended cold gas, star formation and outflows in the halo of a bright quasar at z > 6 |
we present evidence that txs 0506+056, the first plausible non-stellar neutrino source, despite appearances, is not a blazar of the bl lac type but is instead a masquerading bl lac, i.e. intrinsically a flat-spectrum radio quasar with hidden broad lines and a standard accretion disc. this reclassification is based on: ... | txs 0506+056, the first cosmic neutrino source, is not a bl lac |
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