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we present new ultraviolet, optical, and x-ray data on the phoenix galaxy cluster (spt-clj2344-4243). deep optical imaging reveals previously undetected filaments of star formation, extending to radii of ∼50-100 kpc in multiple directions. combined uv-optical spectroscopy of the central galaxy reveals a massive (2 × 10... | deep chandra, hst-cos, and megacam observations of the phoenix cluster: extreme star formation and agn feedback on hundred kiloparsec scales |
the intrinsic column density (nh) distribution of quasars is poorly known. at the high obscuration end of the quasar population and for redshifts z < 1, the x-ray spectra can only be reliably characterized using broad-band measurements that extend to energies above 10 kev. using the hard x-ray observatory nustar, al... | nustar reveals extreme absorption in z < 0.5 type 2 quasars |
in this work, we investigate the reliability of the bpt diagram for excluding galaxies that host an active galactic nucleus (agn). we determine the prevalence of x-ray agns in the star-forming region of the bpt diagram and discuss the reasons behind this apparent misclassification, focusing primarily on relatively mass... | crossing the line: active galactic nuclei in the star-forming region of the bpt diagram |
we present measurements of the large-scale (≈40 comoving mpc) effective optical depth of he ii lyα absorption, {τ }eff}, at 2.54 < z < 3.86 toward 16 he ii-transparent quasars observed with the cosmic origins spectrograph on the hubble space telescope, to characterize the ionization state of helium in the interga... | the evolution of the he ii-ionizing background at redshifts 2.3 < z < 3.8 inferred from a statistical sample of 24 hst/cos he ii lyα absorption spectra |
the lifetime of quasars can be estimated by means of their proximity zone sizes, which are regions of enhanced flux blueward of the lyα emission line observed in the rest-frame uv spectra of high-redshift quasars because the intergalactic gas has a finite response time to the quasars' radiation. we estimate the effecti... | estimating the effective lifetime of the z 6 quasar population from the composite proximity zone profile |
we present results from a polarization study of the radio-intermediate quasar, iii zw 2, at a redshift of 0.089, with the upgraded giant metrewave radio telescope (ugmrt) at 685 mhz and the karl g. jansky very large array (vla) at 5 and 34 ghz. we detect a kpc-scale outflow, exhibiting transverse magnetic (b-) fields. ... | outflows in the radio-intermediate quasar iii zw 2: a polarization study with the evla and ugmrt |
we broadly explore the effects of systematic errors on reverberation mapping lag uncertainty estimates from javelin and the interpolated cross-correlation function (iccf) method. we focus on simulated light curves from random realizations of the light curves of five intensively monitored agns. both methods generally wo... | on reverberation mapping lag uncertainties |
we review the properties of the established scaling relations (srs) of galaxies and active galactic nuclei (agn), focusing on their origin and expected evolution back in time, providing a short history of the most important progresses obtained up to now and discussing the possible future studies. we also try to connect... | past, present and future of the scaling relations of galaxies and active galactic nuclei |
we present a suite of high-resolution cosmological zoom-in simulations to z = 4 of a 1012 m⊙ halo at z = 0, obtained using seven contemporary astrophysical simulation codes (art-i, enzo, ramses, changa, gadget-3, gear, and gizmo) widely used in the numerical galaxy formation community. the physics prescriptions for gas... | the agora high-resolution galaxy simulations comparison project. iii. cosmological zoom-in simulation of a milky way-mass halo |
the late-time integrated sachs-wolfe (isw) imprint of $r\gtrsim 100~h^{-1}\, \mathrm{mpc}$ superstructures is sourced by evolving large-scale potentials due to a dominant dark energy component in the λcdm model. the aspect that makes the isw effect distinctly interesting is the repeated observation of stronger-than-exp... | evidence for a high-z isw signal from supervoids in the distribution of eboss quasars |
we present the results of our spatially resolved investigation into the interplay between the ages of the stellar populations and the kinematics of the warm ionized outflows in the well-studied type ii quasar markarian 34 (mrk 34). utilizing integral field spectroscopy data, we determine the spatial distribution of the... | spatially resolved evidence of the impact of quasar-driven outflows on recent star formation: the case of mrk 34 |
using bona-fide black hole (bh) mass estimates from reverberation mapping and the line ratio [si vi] 1.963$\rm{\mu m}$/brγbroad as tracer of the agn ionizing continuum, a novel bh-mass scaling relation of the form log(mbh) = (6.40 ± 0.17) - (1.99 ± 0.37) × log ([si vi]/brγbroad), dispersion 0.47 dex, over the bh mass i... | a novel black hole mass scaling relation based on coronal gas, and its dependence with the accretion disc |
quasar outflows may play a crucial role in regulating the host galaxy, although the spatial scale of quasar outflows remain a major enigma, with their acceleration mechanism poorly understood. the kinematic information of outflow is the key to understanding its origin and acceleration mechanism. here, we report the gal... | evidence for quasar fast outflows being accelerated at the scale of tens of parsecs |
we have recently found fundamental differences in the radio properties of red quasars when compared to typical blue quasars. in this paper, we use data from the x-shooter spectrograph on the very large telescope, providing spectral coverage from ~3000-$25\,000\,$ å, of a sample of 40 red and blue luminous quasars at 1.... | fundamental differences in the properties of red and blue quasars: measuring the reddening and accretion properties with x-shooter |
we present a strong lensing analysis of the galaxy cluster sdss j1029+2623 at z = 0.588, one of the few currently known lens clusters with multiple images of a background (z = 2.1992) quasar with a measured time delay. we use archival hubble space telescope multiband imaging and new multi unit spectroscopic explorer fo... | vlt/muse observations of sdss j1029+2623: toward a high-precision strong lensing model |
recent results of ground-based telescopes, giving high-quality measurements of the cosmic microwave background (cmb) temperature power spectrum on small scales (below 1 deg) motivate the need for an accurate model of foregrounds, which dominate the primary signal at these multipoles. in a previous work, we have shown t... | retrieving cosmological information from small-scale cmb foregrounds. ii. the kinetic sunyaev zel'dovich effect |
context. the strong asymmetry in the optical [o iii] λ5007 emission line is one of the best signatures of active galactic nuclei (agn) driven warm (∼104 k) ionized gas outflows on host galaxy scales. while large spectroscopic surveys such as the sloan digital sky survey (sdss) have characterized the kinematics of [o ii... | the close agn reference survey (cars). locating the [o iii] wing component in luminous local type 1 agn |
cosmography is used in cosmological data processing in order to constrain the kinematics of the universe in a model-independent way. in this paper, we first investigate the effect of the ultraviolet (uv) and x-ray relation of a quasar on cosmological constraints. by fitting the quasar relation and cosmographic paramete... | high-redshift cosmography: application and comparison with different methods |
bright quasars, observed when the universe was less than one billion years old (z > 5.5), are known to host massive black holes (∼109 m⊙) and are thought to reside in the center of massive dark matter overdensities. in this picture, overdensities of galaxies are expected around high-redshift quasars. however, observ... | no overdensity of lyman-alpha emitting galaxies around a quasar at z ∼ 5.7 |
we present an atacama large millimeter/submillimeter array (alma) survey of co(4-3) line emitting galaxies in 17 quasar fields at z ~ 4 aimed at performing the first systematic search of dusty galaxies in high-z quasar environments. our blind search of galaxies around the quasars results in five co emitters with s/n ≥ ... | alma reveals a large overdensity and strong clustering of galaxies in quasar environments at z 4 |
which galaxies in the general population turn into active galactic nuclei (agns) is a keystone of galaxy formation and evolution. thanks to srg/erosita's contiguous 140 square degree pilot survey field, we constructed a large, complete, and unbiased soft x-ray flux-limited (fx > 6.5 × 10−15 erg s−1 cm−2) agn sample ... | the cosmic web of x-ray active galactic nuclei seen through the erosita final equatorial depth survey (efeds) |
gas surrounding high-redshift galaxies has been studied through observations of absorption line systems toward background quasars for decades. however, it has proven difficult to identify and characterize the galaxies associated with these absorbers due to the intrinsic faintness of the galaxies compared with the quasa... | [c ii] 158-μm emission from the host galaxies of damped lyman-alpha systems |
the first black hole seeds, formed when the universe was younger than ∼500 myr, are recognized to play an important role for the growth of early (z ∼ 7) supermassive black holes. while progresses have been made in understanding their formation and growth, their observational signatures remain largely unexplored. as a r... | first identification of direct collapse black hole candidates in the early universe in candels/goods-s |
we have applied a convolutional neural network (cnn) to classify and detect quasars in the sloan digital sky survey stripe 82 and also to predict the photometric redshifts of quasars. the network takes the variability of objects into account by converting light curves into images. the width of the images, noted w, corr... | deep learning approach for classifying, detecting and predicting photometric redshifts of quasars in the sloan digital sky survey stripe 82 |
the lyman-α (hereafter lyα) forest is a probe of large-scale matter density fluctuations at high redshift, z > 2.1. it consists of h i absorption spectra along individual lines-of-sight. if the line-of-sight density is large enough, 3d maps of h i absorption can be inferred by tomographic reconstruction. in this art... | a tomographic map of the large-scale matter distribution using the eboss—stripe 82 lyα forest |
we investigate the astrophysics of radio-emitting star-forming galaxies and active galactic nuclei (agns) and elucidate their statistical properties in the radio band, including luminosity functions, redshift distributions, and number counts at sub-mjy flux levels, which will be crucially probed by next-generation radi... | galaxy evolution in the radio band: the role of star-forming galaxies and active galactic nuclei |
we present the largest, publicly available sample of damped lyα systems (dlas) along the lines of sight of swift-discovered gamma-ray bursts (grbs) in order to investigate the environmental properties of long grb hosts in the z = 1.8-6 redshift range. compared with the most recent quasar dla sample (qso-dla), our analy... | unveiling the secrets of metallicity and massive star formation using dlas along gamma-ray bursts |
accurate and precise measurements of the hubble constant are critical for testing our current standard cosmological model and revealing possibly new physics. with hubble space telescope (hst) imaging, each strong gravitational lens system with measured time delays can allow one to determine the hubble constant with an ... | sharp - iii. first use of adaptive-optics imaging to constrain cosmology with gravitational lens time delays |
we have conducted a search for z ≃ 7 lyman-break galaxies over 8.2 deg2 of near-infrared imaging from the visible and infrared survey telescope for astronomy (vista) deep extragalactic observations (video) survey in the xmm-newton-large scale structure (xmm-lss) and the extended chandra deep field-south (ecdf-s) fields... | the bright end of the galaxy luminosity function at z ≃ 7 from the vista video survey |
we study the evolution of galaxies and the circumgalactic medium (cgm) through cosmic time by correlating ∼50,000 mg ii absorbers, tracers of cool gas (∼104 k), detected in the sloan digital sky survey quasar spectra with galaxies detected in the desi legacy imaging surveys. by doing so, we extract the properties of ga... | the coevolution of galaxies and the cool circumgalactic medium probed with the sdss and desi legacy imaging surveys |
we describe the polami (polarimetric monitoring of agn at millimetre wavelengths) programme for the monitoring of all four stokes parameters of a sample of bright radio-loud active galactic nuclei with the iram 30-m telescope at 3.5 and 1.3 mm. the programme started in 2006 october and accumulated, until 2014 august, 2... | polami: polarimetric monitoring of agn at millimetre wavelengths - i. the programme, calibration and calibrator data products |
we constrain the h i photoionization rate (γ _{h i}) at z ≲ 0.45 by comparing the flux probability distribution function and power spectrum of the lyα forest data along 82 quasi-stellar object (qso) sightlines obtained using cosmic origins spectrograph with models generated from smoothed particle hydrodynamic simulatio... | intergalactic lyman continuum photon budget in the past 5 billion years |
we present results from a survey of galaxies in the fields of six z ≥ 3 damped lyman α (lyα) systems (dlas) using the multi unit spectroscopic explorer (muse) at the very large telescope (vlt). we report a high detection rate of up to {≈ } 80{{ per cent}} of galaxies within 1000 km s-1 from dlas and with impact paramet... | linking gas and galaxies at high redshift: muse surveys the environments of six damped lyα systems at z ≈ 3 |
we assemble a catalogue of 488 spectroscopically confirmed very high (z ≥ 5.00) redshift quasars (vhzq) and report their near- (zyjhks/k) and mid- (wise w1234) infrared properties. 97 per cent of the vhzq sample is detected in one or more near-infrared (nir) band, with lack of coverage rather than lack of depth being t... | the near and mid-infrared photometric properties of known redshift z ≥ 5 quasars |
we evaluate the impact of imaging systematics on the clustering of luminous red galaxies (lrg), emission-line galaxies (elg), and quasars (qso) targeted for the upcoming dark energy spectroscopic instrument (desi) survey. using data release 7 of the decam legacy survey, we study the effects of astrophysical foregrounds... | imaging systematics and clustering of desi main targets |
in the present paper, we treat the problem of the existence of quark stars (qss) for selected homogeneous and unpaired charge-neutral 3-flavor interacting quark matter with o (ms4) corrections equations of state (eos). using the eos combined with the tolmann-oppenheimer-volkoff (tov) structure equations, the properties... | anisotropic quark stars in r2 gravity |
recent searches for the hosts of z ~ 4 damped ly α absorbers (dlas) have detected bright galaxies at distances of tens of kpc from the dla. using the fire-2 cosmological zoom simulations, we argue that these relatively large distances are due to a predominantly cool and neutral inner circumgalactic medium (cgm) surroun... | neutral cgm as damped ly α absorbers at high redshift |
we evaluate the cosmological coalescence and detection rates for massive black hole (mbh) binaries targeted by the gravitational wave observatory laser interferometer space antenna (lisa). our calculation starts with a population of gravitationally unbound mbh pairs, drawn from the tng50-3 cosmological simulation, and ... | massive black hole binaries from the tng50-3 simulation. i. coalescence and lisa detection rates |
we investigate the star-forming main sequence of the host galaxies of a large, well-defined sample of 453 redshift ~0.3 quasars with previously available star formation rates by deriving stellar masses from modeling their broadband (grizy) spectral energy distribution. we perform two-dimensional, simultaneous, multi-fi... | the star-forming main sequence of the host galaxies of low-redshift quasars |
the science operations of the spacecraft and remote sensing instruments for the martian moon exploration (mmx) mission are discussed by the mission operation working team. in this paper, we describe the phobos observations during the first 1.5 years of the spacecraft's stay around mars, and the deimos observations befo... | science operation plan of phobos and deimos from the mmx spacecraft |
large o vi columns are observed around star-forming low-redshift ∼ {l}*galaxies, with a dependence on impact parameter indicating that most {{{o}}}5+ particles reside beyond half the halo virial radius (≳ 100 {kpc}). in order to constrain the nature of the gas traced by {{o}} {{vi}}, we analyze additional observables o... | does circumgalactic o vi trace low-pressure gas beyond the accretion shock? clues from h i and low-ion absorption, line kinematics, and dust extinction |
we report on the spectroscopic confirmation of a large-scale structure around the luminous z = 6.31 quasi-stellar object (qso) sdss j1030+0524, powered by a one billion solar mass black hole. the structure is populated by at least six members, namely, four lyman-break galaxies (lbgs), and two lyman alpha emitters (laes... | web of the giant: spectroscopic confirmation of a large-scale structure around the z = 6.31 quasar sdss j1030+0524 |
the most luminous quasars at z > 6 are suspected to be both highly clustered and to reside in the most massive dark matter halos in the early universe, making them prime targets to search for galaxy overdensities and/or protoclusters. we search for lyman-break dropout-selected galaxies using hst wfc3/acs broadband i... | a mixture of lbg overdensities in the fields of three 6 < z < 7 quasars: implications for the robustness of photometric selection |
we investigate whether the dust content of the circum-galactic medium (cgm) depends on the location of the quasar sightline with respect to the galaxy major-axis using 13 galaxy-mg ii absorber pairs (9-81 kpc distance) from the muse gas flow and wind (megaflow) survey at 0.4 < z < 1.4. the dust content of the cgm... | muse gas flow and wind v. the dust/metallicity-anisotropy of the circum-galactic medium |
the amplitude of the ionizing background that pervades the intergalactic medium (igm) at the end of the epoch of reionization provides a valuable constraint on the emissivity of the sources that reionized the universe. while measurements of the ionizing background at lower redshifts rely on a simulation-calibrated mapp... | a new method to measure the post-reionization ionizing background from the joint distribution of lyα and lyβ forest transmission |
the recent discovery of supermassive black holes (smbhs) in high mass ultra-compact dwarf galaxies (ucds) suggests that at least some ucds are the nuclear star clusters of stripped galaxies. in this paper we present a new method to estimate how many ucds host an smbh and thus are stripped galaxy nuclei. we revisit the ... | the impact of stripped nuclei on the supermassive black hole number density in the local universe |
similarly to the cosmic star formation history, the black hole accretion rate density of the universe peaked at 1 < z < 3. this cosmic epoch is hence best suited for investigating the effects of radiative feedback from active galactic nucleus (agn). observational efforts are under way to quantify the impact of th... | alma observations of cold molecular gas in agn hosts at z ∼ 1.5 - evidence of agn feedback? |
we present x-ray and multiwavelength analyses of 32 weak emission-line quasars (wlqs) selected in a consistent and unbiased manner. new chandra 3.1-4.8 ks observations were obtained for 14 of these wlqs with c iv rest-frame equivalent widths (rews) of 5-15 å, and these serve as an x-ray observational "bridge" between p... | connecting the x-ray properties of weak-line and typical quasars: testing for a geometrically thick accretion disk |
in this paper we analyze the kinematics, chemistry, and physical properties of a sample of the most metal-poor damped lyα systems (dlas), to uncover their links to modern-day galaxies. we present evidence that the dla population as a whole exhibits a "knee" in the relative abundances of the α-capture and fe-peak elemen... | the most metal-poor damped lyα systems: an insight into dwarf galaxies at high-redshift |
we present the first results of a survey for high-redshift, z ≥ 6, quasars using izy multicolour photometric observations from the dark energy survey (des). here we report the discovery and spectroscopic confirmation of the zab, yab = 20.2, 20.2 (m1450 = -26.5) quasar des j0454-4448 with a redshift of z = 6.09±0.02 bas... | des j0454-4448: discovery of the first luminous z ≥ 6 quasar from the dark energy survey |
we conduct a pilot investigation to determine the optimal combination of color and variability information to identify quasars in current and future multi-epoch optical surveys. we use a bayesian quasar selection algorithm to identify 35,820 type 1 quasar candidates in a 239 {{deg}}2 field of the sloan digital sky surv... | quasar classification using color and variability |
we present the cross-correlation between 151 luminous quasars (muv < -26) and 179 protocluster candidates at z ∼ 3.8, extracted from the wide imaging survey (∼121 deg2) performed as part of the hyper suprime-cam subaru strategic program (hsc-ssp). we find that only two out of 151 quasars reside in regions that are m... | luminous quasars do not live in the most overdense regions of galaxies at z ∼ 4 |
we present a catalogue of alma flux density measurements of 754 calibrators observed between 2012 august and 2017 september, for a total of 16263 observations in different bands and epochs. the flux densities were measured by reprocessing the alma images generated in the framework of the almacal project, with a new cod... | almacal iv: a catalogue of alma calibrator continuum observations |
the reionization of the second electron of helium shapes the physical state of intergalactic gas at redshifts between 2 ≲ z ≲ 5. because performing full in situ radiative transfer in hydrodynamic simulations is computationally expensive for large volumes, the physics of he ii reionization is often approximated by a uni... | inhomogeneous he ii reionization in hydrodynamic simulations |
we study the long-term evolution of the global structure of axisymmetric accretion flows onto a black hole (bh) at rates substantially higher than the eddington value ( ${\dot{m}}_{\mathrm{edd}}$ ), performing 2d hydrodynamical simulations with and without radiative diffusion. in the high-accretion optically thick limi... | long-term evolution of supercritical black hole accretion with outflows: a subgrid feedback model for cosmological simulations |
we studied the broad-band x-ray spectra of swift/burst alert telescope selected low-accreting active galactic nuclei (agns) using the observations from xmm-newton, swift, and nustar in the energy range of 0.5-150 kev. our sample consists of 30 agns with eddington ratio, λedd < 10-3. we extracted several coronal para... | coronal properties of low-accreting agns using swift, xmm-newton, and nustar observations |
radio-loud compact radio sources (crss) are characterised by morphological compactness of the jet structure centred on the active nucleus of the galaxy. most of the local elliptical galaxies are found to host a crs with nuclear luminosities lower than those of typical quasars, ≲1042ergs-1 . recently, low-luminosity crs... | the nature of compact radio sources: the case of fr 0 radio galaxies |
the formation of the large-scale structure, the evolution and distribution of galaxies, quasars, and dark matter on cosmological scales, requires numerical simulations. differentiable simulations provide gradients of the cosmological parameters, that can accelerate the extraction of physical information from statistica... | pmwd: a differentiable cosmological particle-mesh $n$-body library |
baikal-gvd has recently published its first measurement of the diffuse astrophysical neutrino flux, performed using high-energy cascade-like events. we further explore the baikal-gvd cascade data set collected in 2018-2022, with the aim to identify possible associations between the baikal-gvd neutrinos and known astrop... | search for directional associations between baikal gigaton volume detector neutrino-induced cascades and high-energy astrophysical sources |
the range of currently proposed active galactic nucleus (agn) far-infrared templates results in uncertainties in retrieving host galaxy information from infrared observations and also undermines constraints on the outer part of the agn torus. we discuss how to test and reconcile these templates. physically, the fractio... | the intrinsic far-infrared continua of type-1 quasars |
recent observations indicate a $4.9\sigma$ tension between the cmb and quasar dipoles. this tension challenges the cosmological principle. we propose that if we live in a gigaparsec scale void, the cmb and quasar dipolar tension can be reconciled. this is because we are unlikely to live at the center of the void. and a... | reconciling cosmic dipolar tensions with a gigaparsec void |
in this paper, we investigate the cosmic anisotropy from the sn-q sample, consisting of the pantheon sample and quasars, by employing the hemisphere comparison (hc) method and the dipole fitting (df) method. compared to the pantheon sample, the new sample has a larger redshift range, a more homogeneous distribution, an... | testing cosmic anisotropy with pantheon sample and quasars at high redshifts |
the universe is largely transparent to γ -rays in the gev energy range, making these high-energy photons valuable for exploring energetic processes in the cosmos. after 7 years of operation, the fermi gamma-ray space telescope has produced a wealth of information about the high-energy sky. this review focuses on extrag... | the extragalactic gamma-ray sky in the fermi era |
photometric redshifts play an important role as a measure of distance for various cosmological topics. spectroscopic redshifts are only available for a very limited number of objects but can be used for creating statistical models. a broad variety of photometric catalogues provide uncertain low resolution spectral info... | uncertain photometric redshifts |
mrk 590 was originally classified as a seyfert 1 galaxy, but then it underwent dramatic changes: the nuclear luminosity dropped by over two orders of magnitude and the broad emission lines all but disappeared from the optical spectrum. here we present follow-up observations to the original discovery and characterizatio... | the changing-look quasar mrk 590 is awakening |
in this article, we elaborate further on the λ cdm "tension", suggested recently by the authors lusso et al. (astron astrophys 628:l4, 2019) and risaliti and lusso (nat astron 3(3):272, 2019). we combine supernovae type ia (snia) with quasars (qso) and gamma ray bursts (grb) data in order to reconstruct in a model inde... | does λ cdm really be in tension with the hubble diagram data? |
the hubble space telescope/cosmic origins spectrograph (cos) has opened a new discovery space for studying quasar absorption outflows and their contribution to active galactic nucleus (agn) feedback. specifically, cos provides high-quality far-ultraviolet (fuv) spectra covering the diagnostic-rich 500-1050 å rest frame... | hst/cos observations of quasar outflows in the 500-1050 å rest frame. i. the most energetic outflows in the universe and other discoveries |
dense gas in the centre of galaxies feeds massive black holes, but can also become a source of obscuration and limit our ability to find faint active galactic nuclei (agn). we use a high-resolution cosmological radiative hydrodynamics simulation to connect the properties of the gas in the central region (a few tens of ... | black hole obscuration and duty-cycles mediated by agn feedback in high-redshift galaxies |
winds outflowing from active galactic nuclei (agns) may carry significant amounts of mass and energy out to their host galaxies. in this paper we report the detection of a sub-relativistic outflow observed in the narrow line seyfert 1 galaxy iras 17020+4544 as a series of absorption lines corresponding to at least five... | x-ray high-resolution spectroscopy reveals feedback in a seyfert galaxy from an ultra-fast wind with complex ionization and velocity structure |
almost every helium atom in the universe was created just a few minutes after the big bang through a process commonly referred to as big bang nucleosynthesis1,2. the amount of helium that was made during big bang nucleosynthesis is determined by combining particle physics and cosmology3. the current leading measures of... | measurement of the primordial helium abundance from the intergalactic medium |
in this paper, we carry out an assessment of cosmic distance duality relation (cddr) based on the latest observations of hii galaxies acting as standard candles and ultra-compact structure in radio quasars acting as standard rulers. particularly, two machine learning reconstruction methods [gaussian process (gp) and ar... | revisiting the cosmic distance duality relation with machine learning reconstruction methods: the combination of hii galaxies and ultra-compact radio quasars |
we present observations of ionized gas outflows in 11 z = 1.39-2.59 radio-loud quasar host galaxies. data were taken with the integral field spectrograph osiris and the adaptive optics system at the w.m. keck observatory targeting nebular emission lines (hβ, [o iii], hα, [n ii], and [s ii]) redshifted into the near-inf... | a spatially resolved survey of distant quasar host galaxies. i. dynamics of galactic outflows |
we report atacama large millimeter/submillimeter array (alma) observations of the dust continuum and [c ii] emission of the host galaxy of j0439+1634, a gravitationally lensed quasar at z = 6.5. gravitational lensing boosts the source-plane resolution to ~0"15 (~0.8 kpc). the lensing model derived from the alma data is... | alma observations of the sub-kpc structure of the host galaxy of a z = 6.5 lensed quasar: a rotationally supported hyper-starburst system at the epoch of reionization |
we measure the location and evolutionary vectors of 69 herschel-detected broad-line active galactic nuclei (blagns) in the {{m}bh}-{{m}*} plane. blagns are selected from the cosmos and cdf-s fields, and span the redshift range 0.2≤slant z\lt 2.1. black hole masses are calculated using archival spectroscopy and single-e... | evolution in the black hole—galaxy scaling relations and the duty cycle of nuclear activity in star-forming galaxies |
the brightest southern quasar above redshift z = 1, he 0515-4414, with its strong intervening metal absorption line system at zabs = 1.1508, provides a unique opportunity to precisely measure or limit relative variations in the fine-structure constant (δα/α). a variation of just ∼3 parts per million (ppm) would produce... | high-precision limit on variation in the fine-structure constant from a single quasar absorption system |
we present new muse observations of a galaxy group probed by a background quasar. the quasar sightline passes between multiple z = 0.28 galaxies, whilst showing at the same redshift low-ionized metal line species, including ca ii, mg i, mg ii and fe ii. based on the galaxy redshifts measured from the muse data, we esti... | probing the intra-group medium of a z = 0.28 galaxy group |
we present a tentative detection of the large-scale structure of ly α emission in the universe at redshifts z = 2-3.5 by measuring the cross-correlation of ly α surface brightness with quasars in sloan digital sky survey/baryon oscillation spectroscopic survey. we use a million spectra targeting luminous red galaxies a... | large-scale clustering of lyman α emission intensity from sdss/boss |
hot dust-obscured galaxies (hot dogs), selected from wide-field infrared survey explorer’s all-sky infrared survey, host some of the most powerful active galactic nuclei known and may represent an important stage in the evolution of galaxies. most known hot dogs are located at z> 1.5, due in part to a strong bias ag... | nustar observations of wise j1036+0449, a galaxy at z~1 obscured by hot dust |
we study the correlation between the [o iii] λ5007 and x-ray luminosities of local active galactic nuclei (agns), using a complete, hard x-ray (>10 kev) selected sample in the swift/bat 9-month catalog. from our optical spectroscopic observations at the south african astronomical observatory and the literature, a ca... | [o iii] λ5007 and x-ray properties of a complete sample of hard x-ray selected agns in the local universe |
we investigate systematically the x-ray emission from type 1 quasars using a sample of 1825 sloan digital sky survey non-broad absorption line (non-bal) quasars with chandra archival observations. a significant correlation is found between the x-ray-to-optical power-law slope parameter (αox) and the 2500 å monochromati... | on the fraction of x-ray-weak quasars from the sloan digital sky survey |
this letter reports the discovery of spatially extended line-emitting nebula, reaching to ≈100 physical kpc (pkpc) from a damped {ly}α absorber (dla) at z dla = 0.313 along the sightline toward quasi-stellar object (qso) pks 1127-145 (z qso = 1.188). this dla was known to be associated with a galaxy group of dynamical ... | a giant intragroup nebula hosting a damped {ly}\\alphaabsorber at z = 0.313 |
we present data on the gas-phase abundances for 9 different elements in the interstellar medium of the small magellanic cloud (smc), based on the strengths of ultraviolet absorption features over relevant velocities in the spectra of 18 stars within the smc. from this information and the total abundances defined by the... | interstellar gas-phase element depletions in the small magellanic cloud: a guide to correcting for dust in qso absorption line systems |
the angular size of the broad line region (blr) of the nearby active galactic nucleus ngc 3783 has been spatially resolved by recent observations with vlti/gravity. a reverberation mapping (rm) campaign has also recently obtained high quality light curves and measured the linear size of the blr in a way that is complem... | a geometric distance to the supermassive black hole of ngc 3783 |
we test the anisotropy in the finslerian cosmological model with the x-ray and ultraviolet (uv) fluxes of quasars. the 2015 and 2020 compilations of quasars are used in the cosmological constraints. we find that the dipole direction given by the 2015 quasar compilation is not far away from the one provided by the panth... | constraining the anisotropy of the universe with the x-ray and uv fluxes of quasars |
we present space-vlbi radioastron observations at 1.6 ghz and 4.8 ghz of the flat spectrum radio quasar 3c 273, with detections on baselines up to 4.5 and 3.3 earth diameters, respectively. achieving the best angular resolution at 1.6 ghz to date, we have imaged limb-brightening in the jet, not previously detected in t... | radioastron reveals a spine-sheath jet structure in 3c 273 |
based on results by recent surveys, the number of bright quasars at redshifts z > 3 is being constantly revised upward. the current consensus is that at bright magnitudes (m1450 ≤ -27) the number densities of such sources could have been underestimated by a factor of 30%-40%. in the framework of the qubrics survey, ... | the luminosity function of bright qsos at z ∼ 4 and implications for the cosmic ionizing background |
on 2019/07/30.86853 ut, icecube detected a high-energy astrophysical neutrino candidate. the flat spectrum radio quasar pks 1502+106 is located within the 50 per cent uncertainty region of the event. our analysis of 15 ghz very long baseline array (vlba) and astrometric 8 ghz vlba data, in a time span prior and after t... | a ring accelerator? unusual jet dynamics in the icecube candidate pks 1502+106 |
as part of our program to identify host galaxies of known z = 2-3 mg ii absorbers with the keck cosmic web imager (kcwi), we discovered a compact group giving rise to a z = 2.431 dla with ultrastrong mg ii absorption in quasar field j234628+124859. the group consists of four star-forming galaxies within 8-28 kpc and v ... | a complex multiphase dla associated with a compact group at z = 2.431 traces accretion, outflows, and tidal streams |
we present a new catalogue of damped lyman-α absorbers from sdss dr16q, as well as new estimates of their statistical properties. our estimates are computed with the gaussian process models presented in garnett et al., ho, bird & garnett with an improved model for marginalizing uncertainty in the mean optical depth... | damped lyman-α absorbers from sloan digital sky survey dr16q with gaussian processes |
central supermassive black holes of active galactic nuclei host hot plasma with a temperature of 109 k, namely coronae. like the sun, black hole coronae are theoretically believed to be heated by their magnetic activity, which have not been observed yet. here we report the detection of coronal radio synchrotron emissio... | detection of coronal magnetic activity in nearby active supermassive black holes |
we analyze multi-unit spectroscopic explorer observations of nine low-redshift (z < 0.1) palomar-green quasar host galaxies to investigate the spatial distribution and kinematics of the warm, ionized interstellar medium, with the goal of searching for and constraining the efficiency of active galactic nucleus (agn) ... | ionized outflows in nearby quasars are poorly coupled to their host galaxies |
gravity+ is the upgrade for gravity and the very large telescope interferometer (vlti) with wide-separation fringe tracking, new adaptive optics, and laser guide stars on all four 8 m unit telescopes (uts) to enable ever-fainter, all-sky, high-contrast, milliarcsecond interferometry. here we present the design and firs... | first light for gravity wide. large separation fringe tracking for the very large telescope interferometer |
we report on the observations of the quasar nrao 530 with the event horizon telescope (eht) on 2017 april 5-7, when nrao 530 was used as a calibrator for the eht observations of sagittarius a*. at z = 0.902, this is the most distant object imaged by the eht so far. we reconstruct the first images of the source at 230 g... | the event horizon telescope image of the quasar nrao 530 |
we present data releases 4 and 5 of the quasar catalog from the quasar survey by the large sky area multi-object fiber spectroscopic telescope (lamost), which includes quasars observed between 2015 september and 2017 june. there are a total of 19,253 quasars identified by visual inspections of the spectra. among them, ... | the large sky area multi-object fiber spectroscopic telescope (lamost) quasar survey: the fourth and fifth data releases |
gravitational-waves (gws) data have widely been used for testing preferred modified gravity theories. in this paper, we investigate the possibility of testing them in the strong gravity regime by looking at the properties of compact objects in dense matter physics. in this direction modified gravity theories such as f(... | constraints on the maximum mass of quark star and the gw 190814 event |
observed at z = 4.601 and with lbol = 3.5 × 1014 l⊙ , w2246-0526 is the most luminous galaxy known in the universe and hosts a deeply buried active galactic nucleus (agn)/supermassive black hole (smbh). discovered using the wide-field infrared survey explorer, w2246-0526 is classified as a hot dust-obscured galaxy, bas... | the strikingly uniform, highly turbulent interstellar medium of the most luminous galaxy in the universe |
aims: the standard active galactic nuclei (agn)-galaxy co-evolutionary scenario predicts a phase of deeply "buried" supermassive black hole growth coexisting with a starburst (sb) before feedback phenomena deplete the cold molecular gas reservoir of the galaxy and an optically luminous quasar (qso) is revealed (called ... | molecular gas content in obscured agn at z > 1 |
we present alma observations of the co(6-5) and [cii] emission lines and the sub-millimeter continuum of the z ∼ 6 quasi-stellar object (qso) sdss j231038.88+185519.7. compared to previous studies, we have analyzed a synthetic beam that is ten times smaller in angular size, we have achieved ten times better sensitivity... | the dense molecular gas in the z ∼ 6 qso sdss j231038.88+185519.7 resolved by alma |
theoretical models for the expected merger rates of intermediate-mass black holes (imbhs) are vital for planned gravitational-wave detection experiments such as the laser interferometer space antenna (lisa). using collisionless n-body simulations of dwarf galaxy (dg) mergers, we examine how the orbital decay of imbhs a... | formation of lisa black hole binaries in merging dwarf galaxies: the imprint of dark matter |
we present new multi unit spectroscopic explorer observations of quasar field q2131-1207 with a log n(h i} = 19.50 ± 0.15 sub-damped lyman α at zabs = 0.42980. we detect four galaxies at a redshift consistent with that of the absorber where only one was known before this study. two of these are star-forming galaxies, w... | nature of the absorbing gas associated with a galaxy group at z∼0.4 |
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