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we present glade+, an extended version of the glade galaxy catalogue introduced in our previous paper for multimessenger searches with advanced gravitational-wave detectors. glade+ combines data from six separate but not independent astronomical catalogues: the gwgc, 2mpz, 2mass xsc, hyperleda, and wisexscospz galaxy c... | glade+ : an extended galaxy catalogue for multimessenger searches with advanced gravitational-wave detectors |
we present a comprehensive analysis of 21 light curves of type 1 active galactic nuclei (agn) from the kepler spacecraft. first, we describe the necessity and development of a customized pipeline for treating kepler data of stochastically variable sources like agn. we then present the light curves, power spectral densi... | the kepler light curves of agn: a detailed analysis |
with a projected size of about 450 kpc at z ≃ 2.3, the slug ly α nebula is a rare laboratory to study, in emission, the properties of the intergalactic gas in the cosmic web. since its discovery, the slug has been the subject of several spectroscopic follow-ups to constrain the properties of the emitting gas. here we r... | the large- and small-scale properties of the intergalactic gas in the slug ly α nebula revealed by muse he ii emission observations |
we present the first model-agnostic analysis of the complete set of sloan digital sky survey iii (boss) and -iv (eboss) catalogues of luminous red galaxy and quasar clustering in the redshift range 0.2 ≤ z ≤ 2.2 (10 billion years of cosmic evolution), which consistently includes the baryon acoustic oscillations (bao), ... | model-agnostic interpretation of 10 billion years of cosmic evolution traced by boss and eboss data |
the discovery of galaxies with regularly rotating discs at redshifts ≥4 has been a puzzling challenge to galaxy formation models that tend to predict chaotic gas kinematics in the early universe as a consequence of gas accretion, mergers, and efficient feedback. in this work, we investigated the kinematics of five high... | regular rotation and low turbulence in a diverse sample of z 4.5 galaxies observed with alma |
we present a study of the metal-enriched cool halo gas traced by mg ii absorption around 228 galaxies at z ~ 0.8-1.5 within 28 quasar fields from the muse analysis of gas around galaxies survey. we observe no significant evolution in the mg ii equivalent width versus impact parameter relation and in the mg ii covering ... | muse analysis of gas around galaxies (magg) - ii: metal-enriched halo gas around z ∼ 1 galaxies |
reverberation mapping (rm) measurements of broad-line region (blr) lags in z\gt 0.3 quasars are important for directly measuring black hole masses in these distant objects, but so far there have been limited attempts and success given the practical difficulties of rm in this regime. here we report preliminary results o... | the sloan digital sky survey reverberation mapping project: first broad-line hβ and mg ii lags at z ≳0.3 from six-month spectroscopy |
we perform a systematic search for long-term extreme variability quasars (evqs) in the overlapping sloan digital sky survey and 3 year dark energy survey imaging, which provide light curves spanning more than 15 years. we identified ∼1000 evqs with a maximum change in g-band magnitude of more than 1 mag over this perio... | extreme variability quasars from the sloan digital sky survey and the dark energy survey |
we present multiwavelength observations of the tidal disruption event (tde) iptf15af, discovered by the intermediate palomar transient factory survey at redshift z = 0.07897. the optical and ultraviolet (uv) light curves of the transient show a slow decay over 5 months, in agreement with previous optically discovered t... | the broad absorption line tidal disruption event iptf15af: optical and ultraviolet evolution |
we present a systematic search for periodically varying quasar and supermassive black hole binary (smbhb) candidates in the pan-starrs1 medium deep survey (mds). from ∼9000 color-selected quasars in an ∼50 °2 sky area, we initially identify 26 candidates with more than 1.5 cycles of variation. we extend the baseline of... | supermassive black hole binary candidates from the pan-starrs1 medium deep survey |
the relationship between quasars and their host galaxies provides clues on how supermassive black holes (smbhs) and massive galaxies are jointly assembled. to elucidate this connection, we measure the structural and photometric properties of the host galaxies of ~5000 sloan digital sky survey quasars at 0.2 < z <... | the sizes of quasar host galaxies in the hyper suprime-cam subaru strategic program |
we present the discovery and spectroscopic confirmation with the european southern observatory new technology telescope (ntt) and gemini south telescopes of eight new, and the rediscovery of two previously known, 6.0 < z < 6.5 quasars with zab < 21.0. these quasars were photometrically selected without any mor... | eight new luminous z ≥ 6 quasars discovered via sed model fitting of vista, wise and dark energy survey year 1 observations |
in this letter, we present a cosmic bell experiment with polarization-entangled photons, in which measurement settings were determined based on real-time measurements of the wavelength of photons from high-redshift quasars, whose light was emitted billions of years ago; the experiment simultaneously ensures locality. a... | cosmic bell test using random measurement settings from high-redshift quasars |
ss 433 is a binary system containing a supergiant star that is overflowing its roche lobe with matter accreting onto a compact object (either a black hole or neutron star)1-3. two jets of ionized matter with a bulk velocity of approximately 0.26c (where c is the speed of light in vacuum) extend from the binary, perpend... | very-high-energy particle acceleration powered by the jets of the microquasar ss 433 |
we study the link between galaxies and h i-selected absorption systems at z ~ 3-4 in the muse analysis of gas around galaxies (magg) survey, an eso large programme consisting of integral field spectroscopic observations of 28 quasar fields hosting 61 strong absorbers with $\rm n_{\rm h\,{\small i}}\gtrsim 10^{16.5}~\rm... | muse analysis of gas around galaxies (magg) - iv. the gaseous environment of z 3-4 ly α emitting galaxies |
we analyse the full shape of anisotropic clustering measurements from the extended baryon oscillation spectroscopic survey quasar sample together with the combined galaxy sample from the baryon oscillation spectroscopic survey. we obtain constraints on the cosmological parameters independent of the hubble parameter h f... | beyond - λcdm constraints from the full shape clustering measurements from boss and eboss |
multiply imaged time-variable sources can be used to measure absolute distances as a function of redshifts and thus determine cosmological parameters, chiefly the hubble constant h0. in the two decades up to 2020, through a number of observational and conceptual breakthroughs, this so-called time-delay cosmography has ... | strong lensing time-delay cosmography in the 2020s |
the bulk of the x-ray emission in active galactic nuclei (agns) is produced very close to the accreting supermassive black hole (smbh), in a corona of hot electrons which up scatters optical and ultraviolet photons from the accretion flow. the cut-off energy (ec) of the primary x-ray continuum emission carries importan... | bat agn spectroscopic survey - xii. the relation between coronal properties of active galactic nuclei and the eddington ratio |
we report the results from a search for z > 6.5 quasars using the dark energy survey (des) year 3 data set combined with the vista hemisphere survey (vhs) and wise all-sky survey. our photometric selection method is shown to be highly efficient in identifying clean samples of high-redshift quasars, leading to spectr... | three new vhs-des quasars at 6.7 < z < 6.9 and emission line properties at z > 6.5 |
we present cosmological radiation-hydrodynamic simulations, performed with the code ramses-rt, of radiatively-driven outflows in a massive quasar host halo at z = 6. our simulations include both single- and multiscattered radiation pressure on dust from a quasar and are compared against simulations performed with therm... | quenching star formation with quasar outflows launched by trapped ir radiation |
we present a catalog of central engine properties, i.e., black hole mass (mbh) and accretion luminosity (ldisk), for a sample of 1077 blazars detected with the fermi large area telescope. this includes broad emission-line systems and blazars whose optical spectra lack emission lines but are dominated by the absorption ... | the central engines of fermi blazars |
we present the spectroscopic discovery of 69 quasars at 5.8 < z < 7.0, drawn from the hyper suprime-cam (hsc) subaru strategic program (ssp) imaging survey data. this is the 16th publication from the subaru high-z exploration of low-luminosity quasars (shellqs) project, and it completes identification of all but ... | subaru high-z exploration of low-luminosity quasars (shellqs). xvi. 69 new quasars at 5.8 < z < 7.0 |
we characterize the stellar mass of j2239+0207, a z ~ 6.25 sub-eddington quasar (m 1450 = -24.6), using dedicated jwst/nircam medium-band observations of a nearby point-spread function star to remove the central point source and reveal the underlying galaxy emission. we detect the host galaxy in two bands longward of t... | detection of the low-stellar-mass host galaxy of a z 6.25 quasar with jwst |
recent observations suggest that there are violations of the isotropy of the universe at large scales, which is an important part of the cosmological principle. in this paper, we use the cosmic microwave background (cmb) data to search for spatial variations of the cosmological parameters in the λ cdm model. we fit the... | directional variations of cosmological parameters from the planck cmb data |
supermassive primordial stars are suspected to be the progenitors of the most massive quasars at z ∼ 6. previous studies of such stars were either unable to resolve hydrodynamical timescales or considered stars in isolation, not in the extreme accretion flows in which they actually form. therefore, they could not self-... | on the maximum mass of accreting primordial supermassive stars |
we present observations of 50 pairs of redshift z ≈ 0.2 star-forming galaxies and background quasars. these sightlines probe the circumgalactic medium (cgm) out to half the virial radius, and we describe the circumgalactic gas kinematics relative to the reference frame defined by the galactic disks. we detect halo gas ... | kinematics of circumgalactic gas: feeding galaxies and feedback |
strong gravitational lensing provides a powerful probe of the physical properties of quasars and their host galaxies. a high fraction of the most luminous high-redshift quasars was predicted to be lensed due to magnification bias. however, no multiple imaged quasar was found at z > 5 in previous surveys. we report t... | the discovery of a gravitationally lensed quasar at z = 6.51 |
we present alma [c ii] line and far-infrared (fir) continuum observations of three z > 6 low-luminosity quasars (m_1450 > -25 mag) discovered by our subaru hyper suprime-cam (hsc) survey. the [c ii] line was detected in all three targets with luminosities of (2.4-9.5) × 10^8 l_{⊙}, about one order of magnitude sm... | subaru high-z exploration of low-luminosity quasars (shellqs). viii. a less biased view of the early co-evolution of black holes and host galaxies |
we use higher redshift gamma-ray burst (grb), h ii starburst galaxy (h iig), and quasar angular size (qso-as) measurements to constrain six spatially flat and non-flat cosmological models. these three sets of cosmological constraints are mutually consistent. cosmological constraints from a joint analysis of these data ... | cosmological constraints from higher redshift gamma-ray burst, h ii starburst galaxy, and quasar (and other) data |
we report the discovery and analysis of the most metal-poor damped lyα (dla) system currently known, which also displays the lyman series absorption lines of neutral deuterium. the average [o/h] abundance of this system is [o/h] = -2.804 ± 0.015, which includes an absorption component with [o/h] = -3.07 ± 0.03. despite... | the primordial deuterium abundance of the most metal-poor damped lyman-α system |
in this work, we obtain measurements of the hubble constant in the context of modified gravity theories. we set up our theoretical framework by considering viable cosmological f (r ) and f (t ) models, and we analyzed them through the use of geometrical datasets obtained in a model-independent way, namely, gravitationa... | measurements of h0 in modified gravity theories: the role of lensed quasars in the late-time universe |
direct collapse black hole (dcbh) formation with mass ≳105 m⊙ is a promising scenario for the origin of high-redshift supermassive black holes. it has usually been supposed that the dcbh can only form in the primordial gas since the metal enrichment enhances the cooling ability and causes the fragmentation into smaller... | supermassive star formation via super competitive accretion in slightly metal-enriched clouds |
recent breakthroughs of pretrained language models have shown the effectiveness of self-supervised learning for a wide range of natural language processing (nlp) tasks. in addition to standard syntactic and semantic nlp tasks, pretrained models achieve strong improvements on tasks that involve real-world knowledge, sug... | pretrained encyclopedia: weakly supervised knowledge-pretrained language model |
cosmic reionization holds the key to understand structure formation in the universe, and can inform us about the properties of the first sources, as their star formation efficiency and escape fraction of ionizing photons. by combining the recent release of planck electron scattering optical depth data with observations... | cosmic reionization after planck. |
context. the existence of tight correlations between supermassive black holes (bhs) and their host galaxies' properties in the local universe suggests a closely linked evolution. investigating these relations up to the high redshifts (z ≳ 6) is crucial in order to understand the interplay between star formation and bh ... | the alma view of the high-redshift relation between supermassive black holes and their host galaxies |
recent studies have revealed intense ultraviolet (uv) metal emission lines in a modest sample of z > 7 lyman-α emitters, indicating a hard ionizing spectrum is present. if such high ionization features are shown to be common, it may indicate that extreme radiation fields play a role in regulating the visibility of l... | spectroscopic constraints on uv metal line emission at z ≃ 6-9: the nature of lyα emitting galaxies in the reionization era |
we present atacama large millimeter array 1 mm observations of the rest-frame far-infrared (fir) dust continuum in 27 quasars at redshifts 6.0 ≲ z < 6.7. we detect fir emission at ≳3σ in all quasar host galaxies with flux densities at ∼1900 ghz in the rest-frame of 0.12 < s rest,1900 ghz < 5.9 mjy, with a medi... | dust emission in an accretion-rate-limited sample of z ≳ 6 quasars |
observations of hyper-luminous quasars at z>6 reveal the rapid growth of supermassive black holes (smbhs ${\gt}10^9 \,\rm m_{\odot }$) whose origin is still difficult to explain. their progenitors may have formed as remnants of massive, metal-free stars (light seeds), via stellar collisions (medium-weight seeds) and... | light, medium-weight, or heavy? the nature of the first supermassive black hole seeds |
we present new near-infrared vlti/gravity interferometric spectra that spatially resolve the broad brγ emission line in the nucleus of the active galaxy iras 09149-6206. we use these data to measure the size of the broad line region (blr) and estimate the mass of the central black hole. using an improved phase calibrat... | the spatially resolved broad line region of iras 09149-6206 |
we present a radio-quiet quasar at z = 0.237 discovered “turning on” by the intermediate palomar transient factory (iptf). the transient, iptf 16bco, was detected by iptf in the nucleus of a galaxy with an archival sloan digital sky survey spectrum with weak narrow-line emission characteristic of a low-ionization nucle... | iptf discovery of the rapid “turn-on” of a luminous quasar |
we report new observations of the cool diffuse gas around 29, $2.3<z<6.3$ galaxies, using deep jwst/nircam slitless grism spectroscopy around the sightline to the quasar j0100+2802. the galaxies span a stellar mass range of $7.1 \leq \log m_{*}/m_{sun} \leq 10.7$, and star-formation rates of $-0.1 < \log \; sf... | eiger iv: the cool 10$^4$k circumgalactic environment of high-$z$ galaxies reveals remarkably efficient igm enrichment |
cosmic reionization was the last major phase transition of hydrogen from neutral to highly ionized in the intergalactic medium (igm). current observations show that the igm is significantly neutral at z > 7 and largely ionized by z ~ 5.5. however, most methods to measure the igm neutral fraction are highly model dep... | (nearly) model-independent constraints on the neutral hydrogen fraction in the intergalactic medium at z 5-7 using dark pixel fractions in lyα and lyβ forests |
aims: the demographics of the production and escape of ionizing photons from uv-faint early galaxies is a key unknown that has hindered attempts to discover the primary drivers of reionization. with the advent of jwst, it is finally possible to observe the rest-frame optical nebular emission from individual sub-l*z >... | the production of ionizing photons in uv-faint z ∼ 3-7 galaxies |
we present an independent examination of the parallax zero-point of the third gaia early data release (hereafter edr3), using the lamost primary red clump (prc) stellar sample. a median parallax offset of around 26 μas, slightly larger than that found by examination of distant quasars, is found for both the five- and s... | the parallax zero-point of gaia early data release 3 from lamost primary red clump stars |
machine learning (ml) algorithms have revolutionized the way we interpret data in astronomy, particle physics, biology, and even economics, since they can remove biases due to a priori chosen models. here we apply a particular ml method, the genetic algorithms (ga), to cosmological data that describes the background ex... | what can machine learning tell us about the background expansion of the universe? |
this paper is the first in a series of preparing and analyzing spectral and other properties for a database of already discovered changing-look active galactic nuclei (cl agns). here, we focus on the spectral fitting and analysis of broad emission lines in an exhaustive sample of 112 cl agns available in the literature... | changing-look agns -- i. tracking the transition on the main sequence of quasars |
we introduce arepo-rt, a novel radiation hydrodynamic (rhd) solver for the unstructured moving-mesh code arepo. our method solves the moment-based radiative transfer equations using the m1 closure relation. we achieve second-order convergence by using a slope-limited linear spatial extrapolation and a first-order time ... | arepo-rt: radiation hydrodynamics on a moving mesh |
because most large galaxies contain a central black hole, and galaxies often merge, black-hole binaries are expected to be common in galactic nuclei. although they cannot be imaged, periodicities in the light curves of quasars have been interpreted as evidence for binaries, most recently in pg 1302-102, which has a sho... | relativistic boost as the cause of periodicity in a massive black-hole binary candidate |
we use atacama large millimeter array observations of the host galaxy of the quasar ulas j1342+0928 at z = 7.54, to study the dust continuum and far-infrared lines emitted from its interstellar medium (ism). the rayleigh-jeans tail of the dust continuum is well sampled with eight different spectral setups, and from a m... | an alma multiline survey of the interstellar medium of the redshift 7.5 quasar host galaxy j1342+0928 |
context. ultra-compact structure in radio sources (especially in quasars that can be observed up to very high redshifts), with milliarcsecond angular sizes measured by very-long-baseline interferometry (vlbi), is becoming an important astrophysical tool for probing both cosmology and the physical properties of agn.aims... | ultra-compact structure in intermediate-luminosity radio quasars: building a sample of standard cosmological rulers and improving the dark energy constraints up to z 3 |
ss433 is the only galactic binary system known to persistently accrete at highly super-critical (or hyper-critical) rates, similar to those in tidal disruption events, and likely needed to explain the rapid growth of those very high redshift quasars containing massive smbhs. probing the inner regions of ss433 in the x-... | nustar reveals the hidden nature of ss433 |
we interpret recent alma observations of z > 6 normal star-forming galaxies by means of a seminumerical method, which couples the output of a cosmological hydrodynamical simulation with a chemical evolution model which accounts for the contribution to dust enrichment from supernovae, asymptotic giant branch stars an... | the dust mass in z > 6 normal star-forming galaxies. |
we measure the host galaxy properties of five quasars with z ~ 1.6-3.5 selected from the sloan digital sky survey (sdss) and aegis, which fall within the jwst/hubble space telescope (hst) ceers survey area. a point-spread function library is constructed based on stars in the full field of view of the data and used with... | opening the era of quasar-host studies at high redshift with jwst |
we present x-shooter at very large telescope observations of a sample of 10 luminous, x-ray obscured quasi-stellar objects (qsos) at z ∼ 1.5 from the xmm-cosmos survey, expected to be caught in the transitioning phase from starburst to active galactic nucleus (agn)-dominated systems. the main selection criterion is x-r... | x-shooter reveals powerful outflows in z ∼ 1.5 x-ray selected obscured quasi-stellar objects |
models that address both the hubble and s8 tensions with the same mechanism generically cause a prerecombination suppression of the small scale matter power spectrum. here we focus on two such models. both models introduce a self-interacting dark radiation fluid scattering with dark matter, which has a step in its abun... | comparative analysis of interacting stepped dark radiation |
identifying and characterizing reionized bubbles enables us to track both their size distribution, which depends on the primary ionizing sources, and the relationship between reionization and galaxy evolution. we demonstrate that spectrally resolved z ≳ 6 lyman-alpha (lyα) emission can constrain properties of reionized... | measuring the properties of reionized bubbles with resolved lyα spectra |
we present and validate the catalog of lyman-α forest fluctuations for 3d analyses using the early data release (edr) from the dark energy spectroscopic instrument (desi) survey. we used 88,511 quasars collected from desi survey validation (sv) data and the first two months of the main survey (m2). we present several i... | the lyman-α forest catalog from the dark energy spectroscopic instrument early data release |
the forest of lyman-α absorption lines detected in the spectra of distant quasars encodes information on the nature and properties of dark matter and the thermodynamics of diffuse baryonic material. its main observable—the 1d flux power spectrum (fps)—should exhibit a suppression on small scales and an enhancement on l... | new constraints on warm dark matter from the lyman-α forest power spectrum |
we present the first results from the kmos (k-band multi-object spectrograph) agn (active galactic nuclei) survey at high redshift (kashz), a vlt/kmos integral-field spectroscopic (ifs) survey of z ≳ 0.6 agn. we present galaxy-integrated spectra of 89 x-ray agn (l2-10 kev = 1042-1045 erg s-1), for which we observed [o ... | the kmos agn survey at high redshift (kashz): the prevalence and drivers of ionized outflows in the host galaxies of x-ray agn |
we employ cosmological hydrodynamical simulations to investigate the effects of agn feedback on the formation of massive galaxies with present-day stellar masses of m_stel= 8.8 × 10^{10}-6.0 × 10^{11} m_{⊙}. using smoothed particle hydrodynamics simulations with a pressure-entropy formulation that allows an improved tr... | the impact of mechanical agn feedback on the formation of massive early-type galaxies |
we use 78 reverberation-measured mg ii time-lag quasars (qsos) in the redshift range 0.0033 ≤ z ≤ 1.89 to constrain cosmological parameters in six different cosmological models. the basis of our method is the use of the radius-luminosity or r-l relation to standardize these 78 mg ii qsos. in each cosmological model, we... | standardizing reverberation-measured mg ii time-lag quasars, by using the radius-luminosity relation, and constraining cosmological model parameters |
we present a study of metal-enriched halo gas traced by mg ii and c iv absorption at z < 2 in the muse analysis of gas around galaxies survey and the quasar sightline and galaxy evolution survey. using these large and complete galaxy surveys in quasar fields, we study the dependence of the metal distribution on gala... | metal-enriched halo gas across galaxy overdensities over the last 10 billion years |
we present reverberation mapping (rm) results for 17 high-redshift, high-luminosity quasars with good-quality r-band and emission-line light curves. we are able to measure statistically significant lags for lyα (11 objects), si iv (5 objects), c iv (11 objects), and c iii] (2 objects). using our results and previous la... | reverberation mapping of luminous quasars at high z |
we use 317,000 emission-line galaxies from the sloan digital sky survey to investigate line-ratio selection of active galactic nuclei (agns). in particular, we demonstrate that “star formation (sf) dilution” by h ii regions causes a significant bias against agn selection in low-mass, blue, star-forming, disk-dominated ... | the biases of optical line-ratio selection for active galactic nuclei and the intrinsic relationship between black hole accretion and galaxy star formation |
we present an x-ray and multiwavelength study of 33 weak emission-line quasars (wlqs) and 18 quasars that are analogs of the extreme wlq, phl 1811, at z≈ 0.5-2.9. new chandra 1.5-9.5 ks exploratory observations were obtained for 32 objects while the others have archival x-ray observations. significant fractions of thes... | x-ray insights into the nature of phl 1811 analogs and weak emission-line quasars: unification with a geometrically thick accretion disk? |
the global influence of agn-driven outflows remains uncertain, due to a lack of large samples with accurately determined outflow properties. in the second paper of this series, we determine the mass and energetics of ionized outflows in 234 type ii agn, the largest such sample to date, by combining the infrared emissio... | discovering agn-driven winds through their infrared emission - ii. mass outflow rate and energetics |
we study how runaway stellar collisions in high-redshift, metal-poor star clusters form very massive stars (vmss) that can directly collapse to intermediate-mass black holes (imbhs). we follow the evolution of a pair of neighbouring high-redshift mini-haloes with high-resolution, cosmological hydrodynamical zoom-in sim... | seeding high-redshift qsos by collisional runaway in primordial star clusters |
we have initiated a new survey for local extremely metal-poor galaxies (empgs) with subaru/hyper suprime-cam (hsc) large-area (∼500 deg2) optical images reaching a 5σ limit of ∼26 mag, about 100 times deeper than the sloan digital sky survey (sdss). to select z/z⊙ < 0.1 empgs from ∼40 million sources detected in the... | extremely metal-poor representatives explored by the subaru survey (empress). i. a successful machine-learning selection of metal-poor galaxies and the discovery of a galaxy with m* < 106 m⊙ and 0.016 z⊙ |
we present an in-depth and systematic variability study of a sample of 20 powerful blazars, including 12 bl lacs and 8 flat-spectrum radio quasars, applying various analysis tools such as flux distribution, symmetry analysis, and time-series analysis on the decade-long fermi/lat observations. the results show that blaz... | the nature of γ-ray variability in blazars |
project amiga (absorption maps in the gas of andromeda) is a survey of the circumgalactic medium (cgm) of andromeda (m31, ${r}_{\mathrm{vir}}$ ≃ 300 kpc) along 43 qso sightlines at impact parameters 25 ≤ r ≤ 569 kpc (25 at r ≲ ${r}_{\mathrm{vir}}$). we use ultraviolet absorption measurements of si ii, si iii, si iv, c ... | project amiga: the circumgalactic medium of andromeda |
the last 25 years saw a major step forward in the analysis of optical and uv spectroscopic data of large quasar samples. multivariate statistical approaches have led to the definition of systematic trends in observational properties that are the basis of physical and dynamical modeling of quasar structure. we discuss t... | a main sequence for quasars |
this review describes the events leading up to the discovery of the kerr metric in 1963 and the enormous impact the discovery has had in the subsequent 50 years. the review discusses the penrose process, the four laws of black hole mechanics, uniqueness of the solution, and the no-hair theorems. it also includes kerr p... | the kerr metric |
quasi-stellar object (qso) spectral templates are important both to qso physics and for investigations that use qsos as probes of intervening gas and dust. however, combinations of various qso samples obtained at different times and with different instruments so as to expand a composite and to cover a wider rest frame ... | an x-shooter composite of bright 1 < z < 2 quasars from uv to infrared |
recent data released by james webb space telescope (jwst) and, somewhat earlier, the data presented by hubble space telescope (hst) are commonly understood as a strong indication for breaking of the canonical $\lambda$cdm cosmology. it is argued in the presented work that massive primordial black holes (pbh) could seed... | tension between hst/jwst and $\\lambda$cdm cosmology, pbh, and antimatter in the galaxy |
we investigate the steady spherically symmetric accretion in the combined potential of a central black hole and a dark matter halo. for the halo, we consider a hernquist and an nfw potential and calculate the critical points of the flow. we find that the trans-sonic solution to the centre is not possible without a blac... | the origin of supermassive black holes at cosmic dawn |
we present an empirical analysis of the properties of dust-continuum emission in a sample of 17 galaxies in the early universe (4 < z < 8) with well-sampled far-infrared spectral energy distributions (seds) compiled from the literature. we place our results into context by self-consistently comparing to samples o... | an empirical study of dust properties at the earliest epochs |
the apparent position of jet base (core) in radio-loud active galactic nuclei changes with frequency because of synchrotron self-absorption. studying this `core shift' effect enables us to reconstruct properties of the jet regions close to the central engine. we report here results from core shift measurements in agns ... | significant core shift variability in parsec-scale jets of active galactic nuclei |
stream-stream collisions play an important role in the circularization of highly eccentric streams that result from tidal disruption events (tdes). we perform three-dimensional radiation hydrodynamic simulations to show that stream collisions can contribute significant optical and ultraviolet light to the flares produc... | prompt radiation and mass outflows from the stream-stream collisions of tidal disruption events |
in the light of the recent planck downward revision of the electron scattering optical depth, and of the discovery of a faint active galactic nuclei (agn) population at z > 4, we reassess the actual contribution of quasars to cosmic reionization. to this aim, we extend our previous markov chain monte carlo based dat... | cosmic reionization after planck ii: contribution from quasars |
we present results from a spectroscopic survey of z ∼ 5 quasars in the cfht legacy survey. using both optical color selection and a likelihood method, we select 97 candidates over an area of 105 deg2 to a limit of i ab < 23.2, and 7 candidates in the range 23.2 < i ab < 23.7 over an area of 18.5 deg2. spectros... | the faint end of the z = 5 quasar luminosity function from the cfhtls |
we use vlti/gravity near-infrared interferometry measurements of eight bright type 1 agn to study the size and structure of hot dust that is heated by the central engine. we partially resolve each source, and report gaussian full width at half-maximum sizes in the range 0.3-0.8 mas. in all but one object, we find no ev... | the resolved size and structure of hot dust in the immediate vicinity of agn |
we introduce a sub-grid force correction term to better model the dynamical friction experienced by a supermassive black hole (smbh) as it orbits within its host galaxy. this new approach accurately follows an smbh's orbital decay and drastically improves over commonly used `advection' methods. the force correction int... | off the beaten path: a new approach to realistically model the orbital decay of supermassive black holes in galaxy formation simulations |
this is the second in a series of papers aiming to test how the mass (mbh), accretion rate (ṁ) and spin (a*) of supermassive black holes (smbhs) determine the observed properties of type i active galactic nuclei (agn). our project utilizes a sample of 39 unobscured agn at z ≃ 1.55 observed by very large telescope/x-sho... | active galactic nuclei at z ∼ 1.5 - ii. black hole mass estimation by means of broad emission lines |
based on spectroscopy and multiband wide-field observations of the gravitationally lensed quasar he 0435-1223, we determine the probability distribution function of the external convergence κext for this system. we measure the under/overdensity of the line of sight towards the lens system and compare it to the average ... | h0licow - iii. quantifying the effect of mass along the line of sight to the gravitational lens he 0435-1223 through weighted galaxy counts★ |
we use a sample of powerful $z\, \approx \, 0.1$ type 2 quasars ('obscured'; log [lagn/erg s $^{-1}]\, \gtrsim \, 45$ ), which host kpc-scale ionized outflows and jets, to identify possible signatures of agn feedback on the total molecular gas reservoirs of their host galaxies. specifically, we present atacama pathfind... | high molecular gas content and star formation rates in local galaxies that host quasars, outflows, and jets |
the extents of proximity zones of high-redshift quasars enable constraints on the timescales of quasar activity, which are fundamental for understanding the growth of the supermassive black holes (smbhs) that power the quasars' emission. in this study, we obtain precise estimates for the ultraviolet (uv) luminous lifet... | detecting and characterizing young quasars. ii. four quasars at z 6 with lifetimes < 104 yr |
the gamma-ray emission in broad-line blazars is generally explained as inverse compton (ic) radiation of relativistic electrons in the jet scattering optical-uv photons from the broad-line region (blr), the so-called blr external compton (ec) scenario. we test this scenario on the fermi gamma-ray spectra of 106 broad-l... | on the origin of gamma-rays in fermi blazars: beyondthe broad-line region |
periodically variable quasars have been suggested as close binary supermassive black holes. we present a systematic search for periodic light curves in 625 spectroscopically confirmed quasars with a median redshift of 1.8 in a 4.6 deg2 overlapping region of the dark energy survey supernova (des-sn) fields and the sloan... | candidate periodically variable quasars from the dark energy survey and the sloan digital sky survey |
cosmological simulations suggest a strong correlation between high optical-depth lyα absorbers, which arise from the intergalactic medium, and 3d mass overdensities on scales of 10-30 {h}-1 comoving mpc. by examining the absorption spectra of ∼80,000 qso sight lines over a volume of 0.1 gpc3 in the sloan digital sky su... | mapping the most massive overdensities through hydrogen (mammoth). ii. discovery of the extremely massive overdensity boss1441 at z = 2.32 |
we survey the properties of stars destroyed in tidal disruption events (tdes) as a function of black hole (bh) mass, stellar mass and evolutionary state, star formation history and redshift. for m_{bh} ≲ 10^7 m_{⊙}, the typical tde is due to a m* ∼ 0.3 m⊙ m-dwarf, although the mass function is relatively flat for m_{as... | tidal disruption event demographics |
we measure the two-point clustering of spectroscopically confirmed quasars from the final sample of the baryon oscillation spectroscopic survey (boss) on comoving scales of 4 ≲ s ≲ 22 h-1 mpc. the sample covers 6950 deg2 [ ∼ 19 (h- 1gpc)3] and, over the redshift range 2.2 ≤ z ≤ 2.8, contains 55 826 homogeneously select... | clustering of intermediate redshift quasars using the final sdss iii-boss sample |
we present a new implementation for active galactic nucleus (agn) feedback through small-scale, ultrafast winds in the moving-mesh hydrodynamic code arepo. the wind is injected by prescribing mass, momentum, and energy fluxes across a spherical boundary centred on a supermassive black hole according to available constr... | powering galactic superwinds with small-scale agn winds |
x-ray cavities are key tracers of mechanical (or radio mode) heating arising from the active galactic nuclei (agns) in brightest cluster galaxies (bcgs). we report on a survey for x-ray cavities in 83 massive, high-redshift (0.4\lt z\lt 1.2) clusters of galaxies selected by their sunyaev-zel’dovich signature in the sou... | x-ray cavities in a sample of 83 spt-selected clusters of galaxies: tracing the evolution of agn feedback in clusters of galaxies out to z=1.2 |
galaxy interactions are thought to be one of the main triggers of active galactic nuclei (agn), especially at high luminosities, where the accreted gas mass during the agn lifetime is substantial. evidence for a connection between mergers and agn, however, remains mixed. possible triggering mechanisms remain particular... | host galaxies of luminous z ∼ 0.6 quasars: major mergers are not prevalent at the highest agn luminosities |
we present the luminosity function of z ∼ 4 quasars based on the hyper suprime-cam subaru strategic program wide layer imaging data in the g, r, i, z, and y bands covering 339.8 deg2. from stellar objects, 1666 z ∼ 4 quasar candidates are selected via the g-dropout selection down to i = 24.0 mag. their photometric reds... | the quasar luminosity function at redshift 4 with the hyper suprime-cam wide survey |
we present a study of extended galaxy halo gas through h i and o vi absorption over two decades in projected distance at z ≈ 0.2. the study is based on a sample of 95 galaxies from a highly complete (>80 per cent) survey of faint galaxies (l > 0.1l*) with archival quasar absorption spectra and 53 galaxies from th... | on the possible environmental effect in distributing heavy elements beyond individual gaseous haloes |
quasars have recently been used as an absolute distance indicator, extending the hubble diagram to high redshift to reveal a deviation from the expansion history predicted for the standard, λ cdm cosmology. here we show that the laser interferometer space antenna (lisa) will efficiently test this claim with standard si... | testing the quasar hubble diagram with lisa standard sirens |
we present a new measurement of the systemic proper motion of the small magellanic cloud (smc), based on an expanded set of 30 fields containing background quasars and spanning a ∼3 year baseline, using the hubble space telescope (hst) wide field camera 3. combining this data with our previous five hst fields, and an a... | the proper motion field of the small magellanic cloud: kinematic evidence for its tidal disruption |
oj 287 is a quasi-periodic quasar with roughly 12 year optical cycles. it displays prominent outbursts that are predictable in a binary black hole model. the model predicted a major optical outburst in 2015 december. we found that the outburst did occur within the expected time range, peaking on 2015 december 5 at magn... | primary black hole spin in oj 287 as determined by the general relativity centenary flare |
context. before the publication of the gaia catalogue, the contents of the first data release have undergone multiple dedicated validation tests.aims: these tests aim to provide in-depth analysis of the catalogue content in order to detect anomalies and individual problems in specific objects or in overall statistical ... | gaia data release 1. catalogue validation |
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