References of "Sluse, Dominique"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailCOSMOGRAIL XIX: Time delays in 18 strongly lensed quasars from 15 years of optical monitoring
Millon, M.; Courbin, F.; Bonvin, V. et al

in Astronomy and Astrophysics (2020), 640

We present the results of 15 years of monitoring of lensed quasars conducted by the COSMOGRAIL program at the Leonhard Euler 1.2m Swiss Telescope. The decade-long light curves of 23 lensed QSOs are ... [more ▼]

We present the results of 15 years of monitoring of lensed quasars conducted by the COSMOGRAIL program at the Leonhard Euler 1.2m Swiss Telescope. The decade-long light curves of 23 lensed QSOs are presented for the first time. We complement our data set with other monitoring data available in the literature to measure the time delays in 18 systems, among which 9 reach a relative precision better than 15% for at least one time delay. To achieve this, we develop an automated version of the curve-shifting toolbox PyCS to ensure robust estimation of the time delay in the presence of microlensing while accounting for the errors due to imperfect representation of microlensing. We also reanalyze the previously published time delays of RX J1131$-$1231 and HE 0435$-$1223, adding respectively 6 and 2 new seasons of monitoring and confirming the previous time-delay measurements. When the time delay measurement is possible, we correct the light curves of the lensed images from their time delay and present the difference curves to highlight the microlensing signal contained in the data. This is to date the largest sample of decade-long lens monitoring data, useful to measure $H_0$, to measure the size of quasar accretion disks with microlensing, and to study quasar variability. [less ▲]

Detailed reference viewed: 24 (2 ULiège)
Full Text
Peer Reviewed
See detailCosmic dissonance: are new physics or systematics behind a short sound horizon?
Arendse, Nikki; Wojtak, Radosław J.; Agnello, Adriano et al

in Astronomy and Astrophysics (2020), 639

Context. Persistent tension between low-redshift observations and the cosmic microwave background radiation (CMB), in terms of two fundamental distance scales set by the sound horizon r[SUB]d[/SUB] and ... [more ▼]

Context. Persistent tension between low-redshift observations and the cosmic microwave background radiation (CMB), in terms of two fundamental distance scales set by the sound horizon r[SUB]d[/SUB] and the Hubble constant H[SUB]0[/SUB], suggests new physics beyond the Standard Model, departures from concordance cosmology, or residual systematics. <BR /> Aims: The role of different probe combinations must be assessed, as well as of different physical models that can alter the expansion history of the Universe and the inferred cosmological parameters. <BR /> Methods: We examined recently updated distance calibrations from Cepheids, gravitational lensing time-delay observations, and the tip of the red giant branch. Calibrating the baryon acoustic oscillations and type Ia supernovae with combinations of the distance indicators, we obtained a joint and self-consistent measurement of H[SUB]0[/SUB] and r[SUB]d[/SUB] at low redshift, independent of cosmological models and CMB inference. In an attempt to alleviate the tension between late-time and CMB-based measurements, we considered four extensions of the standard ΛCDM model. <BR /> Results: The sound horizon from our different measurements is r[SUB]d[/SUB] = (137 ± 3[SUP]stat.[/SUP] ± 2[SUP]syst.[/SUP]) Mpc based on absolute distance calibration from gravitational lensing and the cosmic distance ladder. Depending on the adopted distance indicators, the combined tension in H[SUB]0[/SUB] and r[SUB]d[/SUB] ranges between 2.3 and 5.1 σ, and it is independent of changes to the low-redshift expansion history. We find that modifications of ΛCDM that change the physics after recombination fail to provide a solution to the problem, for the reason that they only resolve the tension in H[SUB]0[/SUB], while the tension in r[SUB]d[/SUB] remains unchanged. Pre-recombination extensions (with early dark energy or the effective number of neutrinos N[SUB]eff[/SUB] = 3.24 ± 0.16) are allowed by the data, unless the calibration from Cepheids is included. <BR /> Conclusions: Results from time-delay lenses are consistent with those from distance-ladder calibrations and point to a discrepancy between absolute distance scales measured from the CMB (assuming the standard cosmological model) and late-time observations. New proposals to resolve this tension should be examined with respect to reconciling not only the Hubble constant but also the sound horizon derived from the CMB and other cosmological probes. [less ▲]

Detailed reference viewed: 30 (3 ULiège)
Full Text
Peer Reviewed
See detailTDCOSMO. I. An exploration of systematic uncertainties in the inference of H[SUB]0[/SUB] from time-delay cosmography
Millon, M.; Galan, A.; Courbin, F. et al

in Astronomy and Astrophysics (2020), 639

Time-delay cosmography of lensed quasars has achieved 2.4% precision on the measurement of the Hubble constant, H[SUB]0[/SUB]. As part of an ongoing effort to uncover and control systematic uncertainties ... [more ▼]

Time-delay cosmography of lensed quasars has achieved 2.4% precision on the measurement of the Hubble constant, H[SUB]0[/SUB]. As part of an ongoing effort to uncover and control systematic uncertainties, we investigate three potential sources: 1- stellar kinematics, 2- line-of- sight effects, and 3- the deflector mass model. To meet this goal in a quantitative way, we reproduced the H0LiCOW/SHARP/STRIDES (hereafter TDCOSMO) procedures on a set of real and simulated data, and we find the following. First, stellar kinematics cannot be a dominant source of error or bias since we find that a systematic change of 10% of measured velocity dispersion leads to only a 0.7% shift on H[SUB]0[/SUB] from the seven lenses analyzed by TDCOSMO. Second, we find no bias to arise from incorrect estimation of the line-of-sight effects. Third, we show that elliptical composite (stars + dark matter halo), power-law, and cored power-law mass profiles have the flexibility to yield a broad range in H[SUB]0[/SUB] values. However, the TDCOSMO procedures that model the data with both composite and power-law mass profiles are informative. If the models agree, as we observe in real systems owing to the "bulge- halo" conspiracy, H[SUB]0[/SUB] is recovered precisely and accurately by both models. If the two models disagree, as in the case of some pathological models illustrated here, the TDCOSMO procedure either discriminates between them through the goodness of fit, or it accounts for the discrepancy in the final error bars provided by the analysis. This conclusion is consistent with a reanalysis of six of the TDCOSMO (real) lenses: the composite model yields H[SUB]0[/SUB] = 74.0[SUB]-1.8[/SUB][SUP]+1.7[/SUP] km s[SUP]-1[/SUP] Mpc[SUP]-1[/SUP], while the power-law model yields 74.2[SUB]-1.6[/SUB][SUP]+1.6[/SUP] km s[SUP]-1[/SUP] Mpc[SUP]-1[/SUP]. In conclusion, we find no evidence of bias or errors larger than the current statistical uncertainties reported by TDCOSMO. [less ▲]

Detailed reference viewed: 26 (1 ULiège)
Full Text
Peer Reviewed
See detailH0LiCOW - XI. A weak lensing measurement of the external convergence in the field of the lensed quasar B1608+656 using HST and Subaru deep imaging
Tihhonova, O.; Courbin, F.; Harvey, D. et al

in Monthly Notices of the Royal Astronomical Society (2020), 498

We investigate the environment and line of sight (LoS) of the H0LiCOW (H[SUB]0[/SUB] Lenses in COSMOGRAIL's Wellspring) lens B1608+656 using Subaru Suprime-Cam and the Hubble Space Telescope (HST) to ... [more ▼]

We investigate the environment and line of sight (LoS) of the H0LiCOW (H[SUB]0[/SUB] Lenses in COSMOGRAIL's Wellspring) lens B1608+656 using Subaru Suprime-Cam and the Hubble Space Telescope (HST) to perform a weak lensing analysis. We compare three different methods to reconstruct the mass map of the field, i.e. the standard Kaiser-Squires inversion coupled with inpainting and Gaussian or wavelet filtering, and ${\rm {\small {glimpse}}}$ , a method based on sparse regularization of the shear field. We find no substantial difference between the 2D mass reconstructions, but we find that the ground-based data are less sensitive to small-scale structures than the space-based observations. Marginalizing over the results obtained with all the reconstruction techniques applied to the two available HST filters F606W and F814W, we estimate the external convergence, κ[SUB]ext[/SUB], at the position of B1608+656 is $\kappa _{\mathrm{ext}}= 0.11^{+0.06}_{-0.04}$ , where the error bars correspond, respectively, to the 16th and 84th quartiles. This result is compatible with previous estimates using the number counts technique, suggesting that B1608+656 resides in an overdense LoS, but with a completely different technique. Using our mass reconstructions, we also compare the convergence at the position of several groups of galaxies in the field of B1608+656 with the mass measurements using various analytical mass profiles, and find that the weak lensing results favour truncated halo models. [less ▲]

Detailed reference viewed: 24 (1 ULiège)
Full Text
See detailVizieR Online Data Catalog: R-band light curves of 23 lensed QSOs (Millon+, 2020)
Millon, M.; Courbin, F.; Bonvin, V. et al

Textual, factual or bibliographical database (2020)

Data associated with paper Millon et al. 2020, A&A 639, A101. R-band cosmograil light curves of lensed quasars taken at the Euler 1.2m Swiss telescope with the EulerCAM and EulerC2 instrument. Additional ... [more ▼]

Data associated with paper Millon et al. 2020, A&A 639, A101. R-band cosmograil light curves of lensed quasars taken at the Euler 1.2m Swiss telescope with the EulerCAM and EulerC2 instrument. Additional data taken at the SMARTS 1.3m telescope with the ANDICAM optical/ infrared camera are also included for SDSS J0924+0219 (MacLeod et al., 2015ApJ...806..258M, Cat. J/ApJ/806/258). <P />For HE 0435-1223 and RX J1131-1231, data taken at the 1.5m telescope at the Maidanak Observatory, the Mercator Belgian telescope and at the SMARTS 1.3 m telescope are included (Courbin et al. 2011A&A...536A..53C, Cat, J/A+A/536/A53, Tewes et al. 2013A&A...553A.120T, 2013A&A...556A..22T, Cat. J/A+A/556/A22). For SDSS J1515+1511, we had the data from Shalyapin & Goicoechea (2017ApJ...836...14S) from the Liverpool Telescope. <P />(5 data files). [less ▲]

Detailed reference viewed: 22 (1 ULiège)
Full Text
Peer Reviewed
See detailVLA and ALMA observations of the lensed radio-quiet quasar SDSS J0924+0219: a molecular structure in a 3 μJy radio source
Badole, Shruti; Jackson, Neal; Hartley, Philippa et al

in Monthly Notices of the Royal Astronomical Society (2020), 496

We present Karl G. Jansky Very Large Array (VLA) and Atacama Large Millimetre Array (ALMA) observations of SDSS J0924+0219, a z = 1.524 radio-quiet lensed quasar with an intrinsic radio flux density of ... [more ▼]

We present Karl G. Jansky Very Large Array (VLA) and Atacama Large Millimetre Array (ALMA) observations of SDSS J0924+0219, a z = 1.524 radio-quiet lensed quasar with an intrinsic radio flux density of about 3 $\, \mu$ Jy. The four lensed images are clearly detected in the radio continuum and the CO(5-4) line, whose centroid is at z = 1.5254 ± 0.0001, with a marginal detection in the submillimetre continuum. The molecular gas displays ordered motion, in a structure approximately 1-2.5 kpc in physical extent, with typical velocities of 50-100 km s[SUP]-1[/SUP]. Our results are consistent with the radio emission being emitted from the same region, but not with a point source of radio emission. SDSS J0924+0219 shows an extreme anomaly in the flux ratios of the two merging images in the optical continuum and broad emission lines, suggesting the influence of microlensing by stars in the lensing galaxy. We find the flux ratio in the radio, submillimetre continuum and CO lines to be slightly greater than 1 but much less than that in the optical, which can be reproduced with a smooth galaxy mass model and an extended source. Our results, supported by a microlensing simulation, suggest that the most likely explanation for the optical flux anomaly is indeed microlensing. [less ▲]

Detailed reference viewed: 30 (2 ULiège)
Full Text
See detailVizieR Online Data Catalog: Redshift catalog of HE 0435-1223 field-of-view (Sluse+, 2017)
Sluse, Dominique ULiege; Sonnenfeld, A.; Rumbaugh, N. et al

Textual, factual or bibliographical database (2020)

Our data set combines multi-object spectroscopy obtained at Gemini- South, Keck, and ESO-Paranal observatories. <P />The catalogue contains 534 unique objects, including 368 redshifts exclusively reported ... [more ▼]

Our data set combines multi-object spectroscopy obtained at Gemini- South, Keck, and ESO-Paranal observatories. <P />The catalogue contains 534 unique objects, including 368 redshifts exclusively reported by MOM15 (Momcheva et al., 2015, Cat. J/ApJS/219/29). Our new measurement expands to 169 the number of targeted objects separated by less than 3 arcmin from the lens. <P />(6 data files). [less ▲]

Detailed reference viewed: 19 (1 ULiège)
Full Text
Peer Reviewed
See detailSTRIDES: a 3.9 per cent measurement of the Hubble constant from the strong lens system DES J0408-5354
Shajib, A. J.; Birrer, S.; Treu, T. et al

in Monthly Notices of the Royal Astronomical Society (2020), 494

We present a blind time-delay cosmographic analysis for the lens system DES J0408-5354. This system is extraordinary for the presence of two sets of multiple images at different redshifts, which provide ... [more ▼]

We present a blind time-delay cosmographic analysis for the lens system DES J0408-5354. This system is extraordinary for the presence of two sets of multiple images at different redshifts, which provide the opportunity to obtain more information at the cost of increased modelling complexity with respect to previously analysed systems. We perform detailed modelling of the mass distribution for this lens system using three band Hubble Space Telescope imaging. We combine the measured time delays, line-of-sight central velocity dispersion of the deflector, and statistically constrained external convergence with our lens models to estimate two cosmological distances. We measure the 'effective' time- delay distance corresponding to the redshifts of the deflector and the lensed quasar $D_{\Delta t}^{\rm eff}=$ $3382_{-115}^{+146}$ Mpc and the angular diameter distance to the deflector D[SUB]d[/SUB] = $1711_{-280}^{+376}$ Mpc, with covariance between the two distances. From these constraints on the cosmological distances, we infer the Hubble constant H[SUB]0[/SUB]= $74.2_{-3.0}^{+2.7}$ km s[SUP]-1 [/SUP]Mpc[SUP]-[/SUP][SUP]1[/SUP] assuming a flat ΛCDM cosmology and a uniform prior for Ω[SUB]m[/SUB] as $\Omega _{\rm m} \sim \mathcal {U}(0.05, 0.5)$ . This measurement gives the most precise constraint on H[SUB]0[/SUB] to date from a single lens. Our measurement is consistent with that obtained from the previous sample of six lenses analysed by the H[SUB]0[/SUB] Lenses in COSMOGRAIL's Wellspring (H0LiCOW) collaboration. It is also consistent with measurements of H[SUB]0[/SUB] based on the local distance ladder, reinforcing the tension with the inference from early Universe probes, for example, with 2.2σ discrepancy from the cosmic microwave background measurement. [less ▲]

Detailed reference viewed: 21 (1 ULiège)
Full Text
Peer Reviewed
See detailDouble dark matter vision: twice the number of compact-source lenses with narrow-line lensing and the WFC3 grism
Nierenberg, A. M.; Gilman, D.; Treu, T. et al

in Monthly Notices of the Royal Astronomical Society (2020), 492

The magnifications of compact-source lenses are extremely sensitive to the presence of low-mass dark matter haloes along the entire sightline from the source to the observer. Traditionally, the study of ... [more ▼]

The magnifications of compact-source lenses are extremely sensitive to the presence of low-mass dark matter haloes along the entire sightline from the source to the observer. Traditionally, the study of dark matter structure in compact-source strong gravitational lenses has been limited to radio-loud systems, as the radio emission is extended and thus unaffected by microlensing which can mimic the signal of dark matter structure. An alternate approach is to measure quasar nuclear-narrow- line emission, which is free from microlensing and present in virtually all quasar lenses. In this paper, we double the number of systems which can be used for gravitational lensing analyses by presenting measurements of narrow-line emission from a sample of eight quadruply imaged quasar lens systems, WGD J0405-3308, HS 0810+2554, RX J0911+0551, SDSS J1330+1810, PS J1606-2333, WFI 2026-4536, WFI 2033-4723, and WGD J2038-4008. We describe our updated grism spectral modelling pipeline, which we use to measure narrow-line fluxes with uncertainties of 2-10 per cent, presented here. We fit the lensed image positions with smooth mass models and demonstrate that these models fail to produce the observed distribution of image fluxes over the entire sample of lenses. Furthermore, typical deviations are larger than those expected from macromodel uncertainties. This discrepancy indicates the presence of perturbations caused by small-scale dark matter structure. The interpretation of this result in terms of dark matter models is presented in a companion paper. [less ▲]

Detailed reference viewed: 40 (2 ULiège)
Full Text
See detailH_0 using strongly lensed quasars: Recent results from H0LICOW
Sluse, Dominique ULiege

Scientific conference (2020, February 18)

Detailed reference viewed: 25 (1 ULiège)
Full Text
Peer Reviewed
See detailSpatially separated continuum sources revealed by microlensing in the gravitationally lensed broad absorption line quasar SDSS J081830.46+060138.0⋆
Hutsemekers, Damien ULiege; Sluse, Dominique ULiege; Kumar, P.

in Astronomy and Astrophysics (2020), 633

Gravitational microlensing is a powerful tool for probing the inner structure of distant quasars. In this context, we have obtained spectropolarimetric observations of the two images of the broad ... [more ▼]

Gravitational microlensing is a powerful tool for probing the inner structure of distant quasars. In this context, we have obtained spectropolarimetric observations of the two images of the broad absorption line (BAL) quasar SDSS J081830.46+060138.0 (J0818+0601) at redshift z ≃ 2.35. We first show that J0818+0601 is actually gravitationally lensed, and not a binary quasar. A strong absorption system detected at z = 1.0065 ± 0.0002 is possibly due to the lensing galaxy. Microlensing is observed in one image and it magnifies the emission lines, the continuum, and the BALs differently. By disentangling the part of the spectrum that is microlensed from the part that is not microlensed, we unveil two sources of continuum that must be spatially separated: a compact one, which is microlensed, and an extended one, which is not microlensed and contributes to two thirds of the total continuum emission. J0818+0601 is the second BAL quasar in which an extended source of rest-frame ultraviolet continuum is found. We also find that the images are differently polarized, suggesting that the two continua might be differently polarized. Our analysis provides constraints on the BAL flow. In particular, we find that the outflow is seen with a nonzero onset velocity, and stratified according to ionization. <P />The reduced spectra are only available at the CDS via anonymous ftp to <A href="http://cdsarc.u-strasbg.fr/">http://cdsarc.u-strasbg.fr</A> (ftp://130.79.128.5) or via <A href="http://cdsarc.u-strasbg.fr/viz- bin/cat/J/A+A/633/A101">http://cdsarc.u-strasbg.fr/viz- bin/cat/J/A+A/633/A101</A> <P />Based on observations made with ESO Very Large Telescope at the Paranal Observatory under program ID 100.B-0590. [less ▲]

Detailed reference viewed: 33 (4 ULiège)
Full Text
Peer Reviewed
See detailA SHARP view of H0LiCOW: H[SUB]0[/SUB] from three time-delay gravitational lens systems with adaptive optics imaging
Chen, Geoff C.-F.; Fassnacht, Christopher D.; Suyu, Sherry H. et al

in Monthly Notices of the Royal Astronomical Society (2019), 490

We present the measurement of the Hubble constant, H[SUB]0[/SUB], with three strong gravitational lens systems. We describe a blind analysis of both PG 1115+080 and HE 0435-1223 as well as an extension of ... [more ▼]

We present the measurement of the Hubble constant, H[SUB]0[/SUB], with three strong gravitational lens systems. We describe a blind analysis of both PG 1115+080 and HE 0435-1223 as well as an extension of our previous analysis of RXJ 1131-1231. For each lens, we combine new adaptive optics (AO) imaging from the Keck Telescope, obtained as part of the SHARP (Strong-lensing High Angular Resolution Programme) AO effort, with Hubble Space Telescope (HST) imaging, velocity dispersion measurements, and a description of the line-of-sight mass distribution to build an accurate and precise lens mass model. This mass model is then combined with the COSMOGRAIL-measured time delays in these systems to determine H[SUB]0[/SUB]. We do both an AO-only and an AO + HST analysis of the systems and find that AO and HST results are consistent. After unblinding, the AO-only analysis gives H[SUB]0[/SUB]=82.8^{+9.4}_{-8.3} km s^{-1} Mpc^{-1} for PG 1115+080, H[SUB]0[/SUB]=70.1^{+5.3}_{-4.5} km s^{-1} Mpc^{-1} for HE 0435-1223, and H[SUB]0[/SUB]=77.0^{+4.0}_{-4.6} km s^{-1} Mpc^{-1} for RXJ 1131-1231. The joint AO-only result for the three lenses is H[SUB]0[/SUB]=75.6^{+3.2}_{-3.3} km s^{-1} Mpc^{-1}. The joint result of the AO + HST analysis for the three lenses is H[SUB]0[/SUB]=76.8^{+2.6}_{-2.6} km s^{-1} Mpc^{-1}. All of these results assume a flat Λ cold dark matter cosmology with a uniform prior on Ω[SUB]m[/SUB] in [0.05, 0.5] and H[SUB]0[/SUB] in [0, 150] km s^{-1} Mpc^{-1}. This work is a collaboration of the SHARP and H0LiCOW teams, and shows that AO data can be used as the high-resolution imaging component in lens-based measurements of H[SUB]0[/SUB]. The full time- delay cosmography results from a total of six strongly lensed systems are presented in a companion paper. <P /> [less ▲]

Detailed reference viewed: 37 (2 ULiège)
Full Text
See detailVizieR Online Data Catalog: SDSS J081830.46+060138.0 spectropolarimetry (Hutsemekers+, 2020)
Hutsemekers, Damien ULiege; Sluse, Dominique ULiege; Kumar, P.

Textual, factual or bibliographical database (2019)

This Table contains the spectropolarimetric data obtained for images A and B of the gravitationally lensed quasar SDSS J081830.46+060138 on December 24 and 25, 2017, with FORS2 at the ESO VLT. <P />(1 ... [more ▼]

This Table contains the spectropolarimetric data obtained for images A and B of the gravitationally lensed quasar SDSS J081830.46+060138 on December 24 and 25, 2017, with FORS2 at the ESO VLT. <P />(1 data file). [less ▲]

Detailed reference viewed: 22 (2 ULiège)
Full Text
Peer Reviewed
See detailH0LiCOW - X. Spectroscopic/imaging survey and galaxy-group identification around the strong gravitational lens system WFI 2033-4723
Sluse, Dominique ULiege; Rusu, C. E.; Fassnacht, C. D. et al

in Monthly Notices of the Royal Astronomical Society (2019), 490

Galaxies and galaxy groups located along the line of sight towards gravitationally lensed quasars produce high-order perturbations of the gravitational potential at the lens position. When these ... [more ▼]

Galaxies and galaxy groups located along the line of sight towards gravitationally lensed quasars produce high-order perturbations of the gravitational potential at the lens position. When these perturbation are too large, they can induce a systematic error on H[SUB]0[/SUB] of a few per cent if the lens system is used for cosmological inference and the perturbers are not explicitly accounted for in the lens model. In this work, we present a detailed characterization of the environment of the lens system WFI 2033-4723 (z_src = 1.662, z_lens= 0.6575), one of the core targets of the H0LiCOW project for which we present cosmological inferences in a companion paper. We use the Gemini and ESO- Very Large telescopes to measure the spectroscopic redshifts of the brightest galaxies towards the lens, and use the ESO-MUSE integral field spectrograph to measure the velocity-dispersion of the lens (σ _{los}= 250^{+15}_{-21} km s[SUP]-1[/SUP]) and of several nearby galaxies. In addition, we measure photometric redshifts and stellar masses of all galaxies down to i < 23 mag, mainly based on Dark Energy Survey imaging (DR1). Our new catalogue, complemented with literature data, more than doubles the number of known galaxy spectroscopic redshifts in the direct vicinity of the lens, expanding to 116 (64) the number of spectroscopic redshifts for galaxies separated by less than 3 arcmin (2 arcmin ) from the lens. Using the flexion-shift as a measure of the amplitude of the gravitational perturbation, we identify two galaxy groups and three galaxies that require specific attention in the lens models. The ESO MUSE data enable us to measure the velocity-dispersions of three of these galaxies. These results are essential for the cosmological inference analysis presented in Rusu et al. [less ▲]

Detailed reference viewed: 48 (3 ULiège)
Full Text
Peer Reviewed
See detailStrong lensing studies with the 3.6-m Devasthal Optical Telescope: opportunities and challenges
Sluse, Dominique ULiege

in Bulletin de la Societe Royale des Sciences de Liege (2019, October 01), 88

Strongly-lensed quasars and active galactic nuclei (AGN), namely active galaxies that appear multiply imaged due to a foreground lensing galaxy, are exceptional astrophysical tools that may be used to ... [more ▼]

Strongly-lensed quasars and active galactic nuclei (AGN), namely active galaxies that appear multiply imaged due to a foreground lensing galaxy, are exceptional astrophysical tools that may be used to probe the expansion rate of the Universe, study the evolution of galaxies and of their dark matter content over cosmic time, and zoom in into the structure of AGNs. We are entering a new era in observational astrophysics, no longer limited by the number of accessible targets, but by our ability to carry out follow-up observations. We list several science cases where the DOT and other Belgo-Indian telescopes may provide crucial high-quality data: (1) Photometric monitoring of strong lenses for cosmography (2) Confirmation of new strongly-lensed candidates in the era of big surveys (3) Advanced study of the structure of AGN using the technique of gravitational microlensing. For each of these topics, we provide a brief scientific overview of the technique and scientific question, and quantify the observational requirements for successful programs. <P /> [less ▲]

Detailed reference viewed: 37 (2 ULiège)
Full Text
Peer Reviewed
See detailH0LiCOW XII. Lens mass model of WFI2033 - 4723 and blind measurement of its time-delay distance and H[SUB]0[/SUB]
Rusu, Cristian E.; Wong, Kenneth C.; Bonvin, Vivien et al

in Monthly Notices of the Royal Astronomical Society (2019), 498

We present the lens mass model of the quadruply-imaged gravitationally lensed quasar WFI2033-4723, and perform a blind cosmographical analysis based on this system. Our analysis combines (1) time-delay ... [more ▼]

We present the lens mass model of the quadruply-imaged gravitationally lensed quasar WFI2033-4723, and perform a blind cosmographical analysis based on this system. Our analysis combines (1) time-delay measurements from 14 yr of data obtained by the COSmological MOnitoring of GRAvItational Lenses (COSMOGRAIL) collaboration, (2) high-resolution Hubble Space Telescope imaging, (3) a measurement of the velocity dispersion of the lens galaxy based on ESO-MUSE data, and (4) multi- band, wide-field imaging and spectroscopy characterizing the lens environment. We account for all known sources of systematics, including the influence of nearby perturbers and complex line-of-sight structure, as well as the parametrization of the light and mass profiles of the lensing galaxy. After unblinding, we determine the effective time-delay distance to be $4784_{-248}^{+399}~\mathrm{Mpc}$ , an average precision of $6.6{{\ \rm per\ cent}}$ . This translates to a Hubble constant $H_{0} = 71.6_{-4.9}^{+3.8}~\mathrm{km~s^{-1}~Mpc^{-1}}$ , assuming a flat ΛCDM cosmology with a uniform prior on Ω[SUB]m[/SUB] in the range [0.05, 0.5]. This work is part of the H[SUB]0[/SUB] Lenses in COSMOGRAIL's Wellspring (H0LiCOW) collaboration, and the full time-delay cosmography results from a total of six strongly lensed systems are presented in a companion paper (H0LiCOW XIII). [less ▲]

Detailed reference viewed: 25 (2 ULiège)
Full Text
Peer Reviewed
See detailH0LiCOW - XIII. A 2.4 per cent measurement of H[SUB]0[/SUB] from lensed quasars: 5.3σ tension between early- and late-Universe probes
Wong, Kenneth C.; Suyu, Sherry H.; Chen, Geoff C.-F. et al

in Monthly Notices of the Royal Astronomical Society (2019), 498

We present a measurement of the Hubble constant (H[SUB]0[/SUB]) and other cosmological parameters from a joint analysis of six gravitationally lensed quasars with measured time delays. All lenses except ... [more ▼]

We present a measurement of the Hubble constant (H[SUB]0[/SUB]) and other cosmological parameters from a joint analysis of six gravitationally lensed quasars with measured time delays. All lenses except the first are analysed blindly with respect to the cosmological parameters. In a flat Λ cold dark matter (ΛCDM) cosmology, we find $H_{0} = 73.3_{-1.8}^{+1.7}~\mathrm{km~s^{-1}~Mpc^{-1}}$ , a $2.4{{\ \rm per\ cent}}$ precision measurement, in agreement with local measurements of H[SUB]0[/SUB] from type Ia supernovae calibrated by the distance ladder, but in 3.1σ tension with Planck observations of the cosmic microwave background (CMB). This method is completely independent of both the supernovae and CMB analyses. A combination of time-delay cosmography and the distance ladder results is in 5.3σ tension with Planck CMB determinations of H[SUB]0[/SUB] in flat ΛCDM. We compute Bayes factors to verify that all lenses give statistically consistent results, showing that we are not underestimating our uncertainties and are able to control our systematics. We explore extensions to flat ΛCDM using constraints from time-delay cosmography alone, as well as combinations with other cosmological probes, including CMB observations from Planck, baryon acoustic oscillations, and type Ia supernovae. Time- delay cosmography improves the precision of the other probes, demonstrating the strong complementarity. Allowing for spatial curvature does not resolve the tension with Planck. Using the distance constraints from time-delay cosmography to anchor the type Ia supernova distance scale, we reduce the sensitivity of our H[SUB]0[/SUB] inference to cosmological model assumptions. For six different cosmological models, our combined inference on H[SUB]0[/SUB] ranges from ∼73 to 78 km s[SUP]-1[/SUP] Mpc[SUP]-1[/SUP], which is consistent with the local distance ladder constraints. [less ▲]

Detailed reference viewed: 27 (1 ULiège)
Full Text
Peer Reviewed
See detailCOSMOGRAIL. XVIII. time delays of the quadruply lensed quasar WFI2033-4723
Bonvin, V.; Millon, M.; Chan, J. H.-H. et al

in Astronomy and Astrophysics (2019), 629

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 1.2 m Leonhard Euler Swiss telescope, 13 years of data from the SMARTS ... [more ▼]

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 1.2 m Leonhard Euler Swiss telescope, 13 years of data from the SMARTS 1.3 m telescope at Las Campanas Observatory and a single year of high-cadence and high-precision monitoring at the MPIA 2.2 m 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 ∆t[SUB]AB[/SUB] = 36.2[SUP]+0.7[/SUP][SUB]-0.8[/SUB] days (2.1% precision), ∆t[SUB]AC[/SUB] = -23.3[SUP]+1.2[/SUP][SUB]-1.4[/SUB] days (5.6%) and ∆t[SUB]BC[/SUB] = -59.4[SUP]+1.3[/SUP][SUB]-1.3[/SUB] days (2.2%). In addition, the close image pair A1-A2 of the lensed quasars can be resolved in the MPIA 2.2 m data. We measure a time delay consistent with zero in this pair of images. We also explore the prior distributions of microlensing time-delay potentially affecting the cosmological time- delay measurements of WFI2033-4723. Our time-delay measurements are not precise enough to conclude that microlensing time delay is present or absent from the data. This work is part of a H0LiCOW series focusing on measuring the Hubble constant from WFI2033-4723. Full light curves of the four data sets are only available at the CDS via anonymous ftp to <A href="http://cdsarc.u-strasbg.fr/">http://cdsarc.u-strasbg.fr</A> (ftp://130.79.128.5) or via <A href="http://cdsarc.u-strasbg.fr/viz- bin/cat/J/A+A/629/A97">http://cdsarc.u-strasbg.fr/viz- bin/cat/J/A+A/629/A97</A> [less ▲]

Detailed reference viewed: 26 (1 ULiège)
Full Text
Peer Reviewed
See detailConstraining the geometry and kinematics of the quasar broad emission line region using gravitational microlensing. II. Comparing models with observations in the lensed quasar HE0435-1223
Hutsemekers, Damien ULiege; Braibant, L.; Sluse, Dominique ULiege et al

in Astronomy and Astrophysics (2019), 629

The quadruply lensed quasar HE0435-1223 shows a clear microlensing effect that affects differently the blue and red wings of the Hα line profile in its image D. To interpret these observations, and ... [more ▼]

The quadruply lensed quasar HE0435-1223 shows a clear microlensing effect that affects differently the blue and red wings of the Hα line profile in its image D. To interpret these observations, and constrain the broad emission line region (BLR) properties, the effect of gravitational microlensing on quasar broad emission line profiles and their underlying continuum has been simulated considering representative BLR models and microlensing magnification maps. The amplification and distortion of the Hα line profile, characterized by a set of four indices, can be reproduced by the simulations. Although the constraints on the BLR models set by the observed single-epoch microlensing signal are not very robust, we found that flattened geometries (Keplerian disk and equatorial wind) can more easily reproduce the observed line profile deformations than a biconical polar wind. With an additional independent constraint on the size of the continuum source, the Keplerian disk model of the Hα BLR is slightly favored. [less ▲]

Detailed reference viewed: 22 (1 ULiège)
Full Text
See detailVizieR Online Data Catalog: Quadruply lensed quasar WFI2033-4723 light curves (Bonvin+, 2019)
Bonvin, V.; Millon, M.; Chan, J. H. H. et al

Textual, factual or bibliographical database (2019)

R-band light curves of the quadruply lensed quasar WFI2033-4723. The observing logs are available on Table 1 of the paper. C2 data, taken between Oct 2004 and Sep 2010, bi-weekly cadence ECAM data, taken ... [more ▼]

R-band light curves of the quadruply lensed quasar WFI2033-4723. The observing logs are available on Table 1 of the paper. C2 data, taken between Oct 2004 and Sep 2010, bi-weekly cadence ECAM data, taken between Oct 2010 and May 2018, bi-weekly cadence SMARTS data, taken between Apr 2004 and Nov 2016, bi-weekly cadence WFI data, taken between Mar 2017 and Dec 2017, daily cadence <P />(5 data files). <P /> [less ▲]

Detailed reference viewed: 34 (1 ULiège)