We explore the weak lensing effect by line-of-sight halos and sub-halos with a mass of M < 10^7 solar mass in QSO-galaxy strong lens systems with quadruple images in a concordant LCDM universe. Using a polynomially fitted non-linear power spectrum P(k) obtained from N-body simulations that can resolve halos with a mass of M ~ 10^5 solar mass, or structures with a comoving wavenumber of k ~ 3*10^2 h/Mpc, we find that the ratio of magnification perturbation due to intervening halos to that of a primary lens is typically ~10 per cent and the predicted values agree well with the estimated values for 6 observed QSO-galaxy lens systems with quadruple images in the mid-infrared band without considering the effects of substructures inside a primary lens. We also find that the estimated amplitudes of convergence perturbation for the 6 lenses increase with the source redshift as predicted by theoretical models. Using an extrapolated matter power spectrum, we demonstrate that small halos or sub-halos in the line-of-sight with a mass of M=10^3-10^7 solar mass, or structures with a comoving wavenumber of k=3*10^2-10^4 h/Mpc can significantly affect the magnification ratios of the lensed images. Flux ratio anomalies in QSO-galaxy strong lens systems offer us a unique probe into clustering property of mini-halos with a mass of M < 10^6 solar mass.
The Southern Hemisphere has just recently begun to be charted by wide-field surveys, with a sufficient depth and image quality to enable the discovery of strongly lensed quasars. The quadruply imaged quasar WG0214-2105 (r.a.=02:14:16.37, dec.=-21:05:35.3) is a previously unknown lens, with `blue' mid-IR colors and high UV deficit, found in the intersection of three survey footprints: the Dark Energy Survey public DR1 (DES, Abbott et al. 2018), The VST-ATLAS (Shanks et al. 2015) and Pan-STARRS (Chambers et al. 2016). Its discovery relied on high spatial resolution from the Gaia mission (Lindegr…
We report the discovery of the quadruply lensed quasar J1433+6007, mined in the SDSS DR12 photometric catalogues using a novel outlier-selection technique, without prior spectroscopic or UV excess information. Discovery data obtained at the Nordic Optical telescope (NOT, La Palma) show nearly identical quasar spectra at $z_s=2.74$ and four quasar images in a fold configuration, one of which sits on a blue arc. The deflector redshift is $z_{l}=0.407,$ from Keck-ESI spectra. We describe the selection procedure, discovery and follow-up, image positions and $BVRi$ magnitudes, and first results and…
We develop a robust method to model quadruply lensed quasars, relying heavily on the work of Witt (1996), who showed that for elliptical potentials, the four image positions, the source, and the lensing galaxy lie on a right hyperbola. For the singular isothermal elliptical potential, there exists a complementary ellipse centered on the source which also maps through the four images, with the same axis ratio as the potential but perpendicular to it. We first solve for Witt's hyperbola, reducing the allowable space of models to three dimensions. We then obtain the best fitting complementary ell…
We present a microlensing analysis of 61 Chandra observations of 14 quadruply lensed quasars. X-ray flux measurements of the individual quasar images give a clean determination of the microlensing effects in the lensing galaxy and thus offer a direct assessment of the local fraction of stellar matter making up the total integrated mass along the lines of sight through the lensing galaxy. A Bayesian analysis of the ensemble of lensing galaxies gives a most likely local stellar fraction of 7%, with the other 93% in a smooth, dark matter component, at an average impact parameter R_c of 6.6 kpc fr…
We use archival data of NASA's Chandra X-ray telescope to compile an X-ray light curve of all four images of the quadruply lensed quasar Q2237+0305 (z=1.695) from January 2006 to January 2007. We fit simulated point spread functions to the four individual quasar images using Cash's C-statistic to account for the Poisson nature of the X-ray signal. The quasar images display strong flux variations up to a factor of ~4 within one month. We can disentangle the intrinsic quasar variability from flux variations due to gravitational microlensing by looking at the flux ratios of the individual quasar …
HST imaging, pipeline modeling, and time-delay predictions of 2 triply-imaged and 15 quadruply-imaged lensed quasars
University of California, Los Angeles（加州大学洛杉矶分校）；STFC Hartree Centre（STFC哈特里中心）；Universidad Andres Bello（安德烈斯贝略大学）；Stony Brook University（石溪大学）；University of Chicago（芝加哥大学）；University of San Francisco（旧金山大学）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）；University of Cambridge（剑桥大学）；Kavli Institute for Cosmology, University of Cambridge（剑桥大学卡弗里宇宙学研究所）；Staples High School（斯塔普尔斯高中）；Universidad de Valparaíso（瓦尔帕莱索大学）
Gravitationally lensed QSOs (GLQs) at redshift z = 1-2 play a key role in understanding the cosmic evolution of the innermost parts of active galaxies (black holes, accretion disks, coronas and internal jets), as well as the structure of galaxies at intermediate redshifts. With respect to studies of normal QSOs, GLQ programmes have several advantages. For example, a monitoring of GLQs may lead to unambiguous detections of intrinsic and extrinsic variations. Both kinds of variations can be used to discuss central engines in distant QSOs, and mass distributions and compositions of lensing galaxi…
We investigate the flux ratio anomalies between macro-model predictions and the observed brightness of the supernova iPTF16geu, as published in a recent paper by More et al., 2017. This group suggested that these discrepancies are, qualitatively, likely due to microlensing. We analyze the plausibility of attributing this discrepancy to microlensing, and find that the discrepancy is too large to be due to microlensing alone. This is true whether one assumes knowledge of the luminosity of the supernova or allows the luminosity to be a free parameter. Varying the dark/stellar ratio likewise doesn…
JWST lensed quasar dark matter survey V: Hints of self-interacting dark matter from 29 quadruply imaged quasars
University of Chicago（芝加哥大学）；Kavli Institute for Cosmological Physics, University of Chicago（芝加哥大学卡弗里宇宙学物理研究所）；University of California, Merced（加州大学默塞德分校）；Perimeter Institute for Theoretical Physics（理论物理前沿研究所）；Carnegie Observatories（卡内基观测站）；University of California, Los Angeles（加州大学洛杉矶分校）；University of California, Irvine（加州大学尔湾分校）；Universidad Andres Bello（安德烈斯贝略大学）；Millennium Institute of Astrophysics, Chile（智利天体物理千年研究所）；California Polytechnic State University（加州州立理工大学）
aims: We present VRi photometric observations of the quadruply imaged quasar HE 0435-1223, carried out with the Danish 1.54m telescope at the La Silla Observatory. Our aim was to monitor and study the magnitudes and colors of each lensed component as a function of time. methods: We monitored the object during two seasons (2008 and 2009) in the VRi spectral bands, and reduced the data with two independent techniques: difference imaging and PSF (Point Spread Function) fitting.results: Between these two seasons, our results show an evident decrease in flux by ~0.2-0.4 magnitudes of the four lense…
It has been recently shown that quadruply lensed gravitational-wave (GW) events due to coalescing binaries can be localized to one or just a few galaxies, even in the absence of an electromagnetic counterpart. We discuss how this can be used to extract information on modified GW propagation, which is a crucial signature of modifications of gravity at cosmological scales. We show that, using quadruply lensed systems, it is possible to constrain the parameter $Ξ_0$ that characterizes modified GW propagation, without the need of imposing a prior on $H_0$. A LIGO/Virgo/Kagra network at target sens…
We present new measurements of the time delays of WFI2033-4723. The data sets used in this work include 14 years of data taken at the 1.2m Leonhard Euler Swiss telescope, 13 years of data from the SMARTS 1.3m telescope at Las Campanas Observatory and a single year of high-cadence and high-precision monitoring at the MPIA 2.2m telescope. The time delays measured from these different data sets, all taken in the R-band, are in good agreement with each other and with previous measurements from the literature. Combining all the time-delay estimates from our data sets results in Dt_AB = 36.2-0.8+0.7…
TDCOSMO XXVIII. The Hubble constant from the quadruply lensed quasar J1537$-$3010 with precise time delays
University of Geneva（日内瓦大学）；Technical University of Munich（慕尼黑工业大学）；Max-Planck-Institut für Astrophysik（马克斯·普朗克天体物理学研究所）；Laboratoire Univers et Particules de Montpellier (LUPM), CNRS & Université Montpellier（蒙彼利埃宇宙与粒子实验室（LUPM），法国国家科学研究中心与蒙彼利埃大学）；STAR Institute, University of Liège（列日大学STAR研究所）；Armagh Observatory and Planetarium（阿马天文台和天文馆）；Fermi National Accelerator Laboratory（费米国家加速器实验室）
We report the discovery of a z_{phot}=6.18^{+0.05}_{-0.07} (95% confidence level) dwarf galaxy, lensed into four images by the galaxy cluster MACS J0329.6-0211 (z_{l}=0.45). The galaxy is observed as a high-redshift dropout in HST/ACS/WFC3 CLASH and Spitzer/IRAC imaging. Its redshift is securely determined due to a clear detection of the Lyman-break in the 18-band photometry, making this galaxy one of the highest-redshift multiply-lensed objects known to date with an observed magnitude of F125W=24.00\pm0.04 AB mag for its highest-magnified image. We also present the first strong-lensing analys…
Aims: In this work, we aim to provide a reliable list of gravitational lens (GL) candidates based on a search performed over the entire Gaia Data Release 2 (Gaia DR2). We also show that the sole astrometric and photometric informations coming from the Gaia satellite yield sufficient insights for supervised learning methods to automatically identify GL candidates with an efficiency that is comparable to methods based on image processing. Methods: We simulated 106,623,188 lens systems composed of more than two images, based on a regular grid of parameters characterizing a non-singular isothermal…
We report the result of our search for the 380 GHz H2O line emissions from the quadruply lensed QSO MG J0104+0534 at z = 2.639 with the Atacama Large Millimeter/submillimeter Array (ALMA). Our observation shows a tentative detection of the 380 GHz line from the lensed QSO, and line spectrum shows a broad spectral distribution that has a velocity width of ~290 km/s and a peak flux of ~0.8 mJy. The integrated-intensity map of the H2O line show lensed emissions at the A1 and A2 component of the QSO, with the A2 component slightly resolved. The integrated line flux ratio between the A1 and A2 comp…
Sub-parsec binary massive black holes (BBHs) are long anticipated to exist in many QSOs but remain observationally elusive. In this paper, we propose a novel method to probe sub-parsec BBHs through microlensing of lensed QSOs. If a QSO hosts a sub-parsec BBH in its center, it is expected that the BBH is surrounded by a circum-binary disk, each component of the BBH is surrounded by a small accretion disk, and a gap is opened by the secondary component in between the circum-binary disk and the two small disks. Assuming such a BBH structure, we generate mock microlensing light curves for some QSO…
We report the serendipitous discovery of the first gravitationally lensed quasar candidate from Pan-STARRS. The grizy images reveal four point-like images with magnitudes between 14.9 mag and 18.1 mag. The colors of the point sources are similar, and they are more consistent with quasars than with stars or galaxies. The lensing galaxy is detected in the izy bands, with an inferred photometric redshift of ~0.6, lower than that of the point sources. We successfully model the system with a singular isothermal ellipsoid with shear, using the relative positions of the five objects as constraints. W…
Absorption-line spectroscopy of multiply-lensed QSOs near a known foreground galaxy provides a unique opportunity to go beyond the traditional one-dimensional application of QSO probes and establish a crude three-dimensional (3D) map of halo gas around the galaxy that records the line-of-sight velocity field at different locations in the gaseous halo. Two intermediate-redshift galaxies are targeted in the field around the quadruply-lensed QSO HE0435-1223 at redshift z=1.689, and absorption spectroscopy along each of the lensed QSOs is carried out in the vicinities of these galaxies. One galaxy…
We report the serendipitous discovery of a quadruply lensed source at $z_{\rm s}=3.76$, HSC~J115252+004733, from the Hyper Suprime-Cam (HSC) Survey. The source is lensed by an early-type galaxy at $z_{\rm l}=0.466$ and a satellite galaxy. Here, we investigate the properties of the source by studying its size and luminosity from the imaging and the luminosity and velocity width of the Ly-$α$ line from the spectrum. Our analyses suggest that the source is most probably a low-luminosity active galactic nucleus (LLAGN) but the possibility of it being a compact bright galaxy (e.g., a Lyman-$α$ emit…
We explore the weak lensing effects by ministructures in the line-of-sight in a quadruply lensed quasar MG0414+0534 that shows an anomaly in the flux-ratios. We find that the observed flux-ratio anomaly can be explained by a presence of either a minifilament or a minivoid in the line-of-sight with a surface mass density of the order of 10^(8-9) h^(-1) solar mass /arcsec^2 without taking into account any subhalos in the lensing galaxy. The astrometric perturbation by a possible minifilament/minivoid is <~ 0.001 arcsec and the amplitudes of convergence perturbations due to these perturbers are ~…
With the increase in the number of observed gravitational wave (GW) signals, detecting strongly lensed GWs by galaxies has become a real possibility. Lens galaxies also contain microlenses (e.g., stars and black holes), introducing further frequency-dependent modulations in the strongly lensed GW signal within the LIGO frequency range. The multiple lensed signals in a given lens system have different underlying macro-magnifications ($|μ|$) and are located in varied microlens densities ($Σ_\bullet$), leading to different levels of microlensing distortions. This work quantifies the fraction of s…
We present new mid-IR observations of the quadruply lensed quasar Q2237+0305 taken with CanariCam on the Gran Telescopio Canarias. Mid-IR emission by hot dust, unlike the optical and near-IR emission from the accretion disk, is unaffected by the interstellar medium (extinction/scattering) or stellar microlensing. We compare these "true" ratios to the (stellar) microlensed flux ratios observed in the optical/near-IR to constrain the structure of the quasar accretion disk. We find a half-light radius of $R_{1/2}=3.4_{-2.1}^{+5.3}\sqrt{\langle M \rangle/0.3\,\rm{M_{\odot}}}$ light-days at $λ_{res…
We report near simultaneous imaging using LMIRCam on the LBTI of the quadruply imaged lensed quasar HS 0810+2554 at wavelengths of 2.16, 3.7 and $4.78~μ$m with a Full Width Half Max (FWHM) spatial resolution of $0^{\prime\prime}\!\!.13$, $0^{\prime\prime}\!\!.12$ and $0^{\prime\prime}\!\!.15$ respectively, comparable to HST optical imaging. In the $\rm{z} = 1.5$ rest frame of the quasar, the observed wavelengths correspond to 0.86, 1.48, and $1.91~μ$m respectively. The two brightest images in the quad, A and B, are clearly resolved from each other with a separation of $0.187^{\prime\prime}$. T…
The Chandra observations of several gravitationally lensed quasars show evidence for flux and spectral variability of the X-ray emission that is uncorrelated between images and is thought to result from the microlensing by stars in the lensing galaxy. We report here on the most detailed modeling of such systems to date, including simulations of the emission of the Fe K-alpha fluorescent radiation from the accretion disk with a general relativistic ray tracing code, the use of realistic microlensing magnification maps derived from inverse ray shooting calculations, and the simulation of the lin…
Here we give a brief overview of some investigations of the gravitational microlensing influence on broad absorption spectral lines of lensed QSOs. Especially, we consider the microlensing influence on the Fe K$α$ broad absorption lines using a model of an accretion disk covered by an absorption region. Gravitational microlensing is modeled by ray shooting method which enables us to obtain realistic microlensing patterns. We obtain that microlensing can affect both emission and absorption component of line that depends on dimensions on emission and absorption line regions. Here we give detaile…
We report on high angular resolution observations of the CO(7-6) line and millimeter continuum in the host galaxy of the gravitationally lensed (z~2.8) quasar RXJ0911.4+0551 using the Plateau de Bure Interferometer. Our CO observations resolve the molecular disk of the source. Using a lens model based on HST observations we fit source models to the observed visibilities. We estimate a molecular disk radius of 1$\pm$0.2 kpc and an inclination of 69$\pm$6°, the continuum is more compact and is only marginally resolved by our observations. The relatively low molecular gas mass, $Mgas=(2.3\pm 0.5)…
We present a weak gravitational lensing measurement of the external convergence along the line of sight to the quadruply lensed quasar HE$\,$0435$-$1223. Using deep r-band images from Subaru-Suprime-Cam we observe galaxies down to a 3$σ$ limiting magnitude of $\sim 26$ mags resulting in a source galaxy density of 14 galaxies / arcmin$^2$ after redshift-based cuts. Using an inpainting technique and Multi-Scale Entropy filtering algorithm, we find that the region in close proximity to the lens has an estimated external convergence of $κ=-0.012^{+0.020}_{-0.013}$ and is hence marginally under-den…
TDCOSMO: XX. WFI2033--4723, the First Quadruply-Imaged Quasar Modeled with JWST Imaging
Department of Physics and Astronomy, UCLA（加州大学洛杉矶分校物理与天文系）；Department of Physics and Astronomy, Stony Brook University（纽约州立大学石溪分校物理与天文系）；Department of Astronomy and Astrophysics, University of Chicago（芝加哥大学天文与天体物理系）；Kavli Institute for Cosmological Physics, University of Chicago（芝加哥大学卡弗里宇宙物理学研究所）；Center for Astronomy, Space Science and Astrophysics, Independent University, Bangladesh（孟加拉国独立大学天文学、空间科学与天体物理中心）；Research Center for the Early Universe, Graduate School of Science, The University of Tokyo（东京大学理学研究科早期宇宙研究中心）；IPAC, California Institute of Technology（加州理工学院红外处理分析中心）；Space Telescope Science Institute（太空望远镜科学研究所）
Context. Strong gravitationally lensed quasars are among the most interesting and useful observable extragalactic phenomena. Because their study constitutes a unique tool in various fields of astronomy, they are highly sought, not without difficulty. Indeed, even in this era of all-sky surveys, their recognition remains a great challenge, with barely a few hundred currently known systems. Aims. In this work we aim to detect new strongly lensed quasar candidates in the recently published Gaia Data Release 2 (DR2), which is the highest spatial resolution astrometric and photometric all-sky surve…
We report observations of CO(J=2-1) and CO(J=3-2) line emission towards the quadruply-lensed quasar RXS J1131-1231 at z = 0.654 obtained using the Plateau de Bure Interferometer (PdBI) and the Combined Array for Research in Millimeter-wave Astronomy (CARMA). Our lens modeling shows that the asymmetry in the double-horned CO(J = 2-1) line profile is mainly a result of differential lensing, where the magnification factor varies from ~3 to ~9 across different kinematic components. The intrinsically symmetric line profile and a smooth source-plane velocity gradient suggest that the host galaxy is …
This is the first version (v1) of the Gravitational LENses and DArk MAtter (GLENDAMA) database accessible at http://grupos.unican.es/glendama/database The new database contains more than 6000 ready-to-use (processed) astronomical frames corresponding to 15 objects that fall into three classes: (1) lensed QSO (8 objects), (2) binary QSO (3 objects), and (3) accretion-dominated radio-loud QSO (4 objects). Data are also divided into two categories: freely available and available upon request. The second category includes observations related to our yet unpublished analyses. Although this v1 of th…
Strong gravitational lensing provides a powerful test of Cold Dark Matter (CDM) as it enables the detection and mass measurement of low mass haloes even if they do not contain baryons. Compact lensed sources such as Active Galactic Nuclei (AGN) are particularly sensitive to perturbing subhalos, but their use as a test of CDM has been limited by the small number of systems which have significant radio emission which is extended enough avoid significant lensing by stars in the plane of the lens galaxy, and red enough to be minimally affected by differential dust extinction. Narrow-line emission …
We apply the iterative MCS deconvolution method (ISMCS) to near-IR HST archives data of seven gravitationally lensed quasars currently monitored by the COSMOGRAIL collaboration: HE 0047-1756, RX J1131-1231, SDSS J1138+0314, SDSS J1155+6346, SDSS J1226-0006, WFI J2026-4536 and HS 2209+1914. In doing so, we obtain relative positions for the lensed images and shape parameters for the light distribution of the lensing galaxy in each system. The lensed image positions are derived with 1-2 mas accuracy. To predict time delays and to test the ability of simple mass models to reproduce the observed co…
We report the $4 \, σ$ detection of a faint object with a flux of ~ 0.3 mJy, in the vicinity of the quadruply lensed QSO MG0414+0534 using the Atacama Large Millimeter/submillimeter array (ALMA) Band 7. The object is most probably a dusty dark dwarf galaxy, which has not been detected in either the optical, near-infrared (NIR) or radio (cm) bands. An anomaly in the flux ratio of the lensed images observed in Band 7 and the mid-infrared (MIR) band and the reddening of the QSO light color can be simultaneously explained if we consider the object as a lensing substructure with an ellipticity ~ 0.…
[abridged] We present VLT/FORS1 spectroscopic follow-up observations and HST/WFPC2 imaging of the system COSMOS 5921+0638, which exhibits quadruply lensed images and a perfect Einstein ring. We investigate the nature of COSMOS 5921+0638 by studying its photometric, spectroscopic and physical properties. We completed both an environmental analysis and detailed analytical and grid-based mass modeling of the system. We measured the redshifts of the lensing galaxy in COSMOS 5921+0638 (z_l=0.551+/-0.001) and 9 additional galaxies in the field (5 of them at z~0.35). The redshift of the lensed source…
The current gravitational-wave localization methods rely mainly on sources with electromagnetic counterparts. Unfortunately, a binary black hole does not emit light. Due to this, it is generally not possible to localize these objects precisely. However, strongly lensed gravitational waves, which are forecasted in this decade, could allow us to localize the binary by locating its lensed host galaxy. Identifying the correct host galaxy is challenging because there are hundreds to thousands of other lensed galaxies within the sky area spanned by the gravitational-wave observation. However, we can…
Quadruply lensed quasars are extremely rare objects, but incredibly powerful cosmological tools. Only few dozen are known in the whole sky. Here we present the spectroscopic confirmation of two new quadruplets WG0214-2105 and WG2100-4452 discovered by Agnello & Spiniello (2018) within the Dark Energy Survey (DES) public footprints. We have conducted spectroscopic follow-up of these systems with the Southern African Large Telescope as part of a program that aims at confirming the largest possible number of optically selected strong gravitational lensing systems in the Equatorial and Southern He…
We present an analysis of the ALMA long baseline science verification data of the gravitational lens system SDP.81. We fit the positions of the brightest clumps at redshift z=3.042 and a possible AGN component of the lensing galaxy at redshift z=0.2999 in the band 7 continuum image using a canonical lens model, a singular isothermal ellipsoid plus an external shear. Then, we measure the ratio of fluxes in some apertures at the source plane where the lensed images are inversely mapped. We find that the aperture flux ratios of band 7 continuum image are perturbed by 10-20 percent with a signific…
Prospect of Measuring the Cosmic Dipole by Associating Strongly Lensed Gravitational Waves with Galaxy Surveys
International Center for Theoretical Physics Asia-Pacific, University of Chinese Academy of Sciences（国际理论物理中心亚太，中国科学院大学）；Taiji Laboratory for Gravitational Wave Universe, University of Chinese Academy of Sciences（太极引力波宇宙实验室，中国科学院大学）
Impact on time delays due to milli-lensing by subhalos on lensed gravitational waves
Department of Physics, Dr. Vishwanath Karad MIT World Peace University（德拉·维斯瓦纳特·卡拉德麻省理工学院世界和平大学物理系）；Inter-University Centre for Astronomy and Astrophysics（大学间天文学和天体物理学中心）；Kavli IPMU (WPI), UTIAS, The University of Tokyo（卡弗里宇宙物理学与数学起源研究所（WPI），东京大学宇宙射线研究所）；Department of Physics, Indian Institute of Science Education and Research（印度科学教育与研究机构物理系）
We explore the halo-to-halo variation of dark matter substructure in galaxy-sized dark matter halos, focusing on its implications for strongly gravitational lensed systems. We find that the median value for projected substructure mass fractions within projected radii of 3% of the host halo virial radius is approximately fsub ~ 0.25%, but that the variance is large with a 95-percentile range of 0 <= fsub <= 1%. We quantify possible effects of substructure on quadruply-imaged lens systems using the cusp relation and the simple statistic, Rcusp. We estimate that the probability of obtaining the l…
The gravitational field of a galaxy can act as a lens and deflect the light emitted by a more distant object such as a quasar. Strong gravitational lensing causes multiple images of the same quasar to appear in the sky. Since the light in each gravitationally lensed image traverses a different path length from the quasar to the Earth, fluctuations in the source brightness are observed in the several images at different times. The time delay between these fluctuations can be used to constrain cosmological parameters and can be inferred from the time series of brightness data or light curves of …
