Imaging dark matter at the smallest scales with $z\approx1$ lensed stars
J. M. Diego, Sung Kei Li, Alfred Amruth, Ashish K. Meena, Tom J. Broadhurst, Patrick L. Kelly, Alexei V. Filippenko, Liliya L. R. Williams, Adi Zitrin, William … 展开作者
J. M. Diego, Sung Kei Li, Alfred Amruth, Ashish K. Meena, Tom J. Broadhurst, Patrick L. Kelly, Alexei V. Filippenko, Liliya L. R. Williams, Adi Zitrin, William E. Harris, Marta Reina-Campos, Carlo Giocoli, Liang Dai, Mitchell F. Struble, Tommaso Treu, Yoshinobu Fudamoto, Daniel Gilman, Anton M. Koekemoer, Jeremy Lim, J. M. Palencia, Fengwu Sun, Rogier A. Windhorst
Observations of caustic-crossing galaxies at redshift $0.7<z<1$ show a wealth of transient events. Most of them are believed to be microlensing events of highly magnified stars. Earlier work predicted such events should be common near the critical curves (CCs) of galaxy clusters, but some are found relatively far away from these CCs. We consider the possibility that substructure on milliarcsecond scales (few parsecs in the lens plane) is boosting the microlensing signal. We study the combined magnification from the macrolens, millilenses, and microlenses (3M-lensing). After considering realistic populations of millilenses and microlenses, we conclude that the enhanced microlensing rate around millilenses is not sufficient to explain the high fraction of observed events in the far region. Instead we find a that the shape of the luminosity function (LF) of the lensed stars combined with the amount of substructure in the lens plane determines the number of mcirolensing events found near and far from the CC. By measuring $β$ (the exponent of the LF), and the number density of microlensing events at each location, one can create a pseudoimage of the underlying distribution of mass on small scales. We identify two regimes: (i) positive imaging regime where $β>2$ and the number density of events is greater around substructureand the number density of events is greater around substructures, and (ii) negative imaging regime where $β<2$. We study the particular case of seven microlensing events found by HST in the Dragon arc (at z=0.725). We find that a population of supergiant stars with a steep LF with $β=2.55$ fits the distribution of these events. We identify a small region of high density of microlensing events, and interpret it as evidence of a possible invisible substructure, for which we derive a mass of $\sim 1.3 \times 10^8\,\Msun$ (within its Einstein radius).
Retrospective Search for Strongly Lensed Supernovae in the DESI Legacy Imaging Surveys
University of California, Los Angeles（加州大学洛杉矶分校）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）；University of San Francisco（旧金山大学）；Gemini Observatory / NSF’s NOIRLab（吉米天文台/美国国家光学红外天文实验室）；Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo（东京大学宇宙物理数学研究所）；University of Hawaii（夏威夷大学）
本文开发了针对强引力透镜系统的瞬变源搜索流水线，应用于 DESI Legacy 巡天数据，发现七个新的透镜超新星候选体，其中一个极可能是 Ia 型，有助于宇宙学参数约束。
Cadenced optical imaging surveys in the next decade will be capable of detecting time-varying galaxy-scale strong gravitational lenses in large numbers, increasing the size of the statistically well-defined samples of multiply-imaged quasars by two orders of magnitude, and discovering the first strongly-lensed supernovae. We carry out a detailed calculation of the likely yields of several planned surveys, using realistic distributions for the lens and source properties and taking magnification bias and image configuration detectability into account. We find that upcoming wide-field synoptic su…
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…
Strong gravitational lenses are now being routinely discovered in wide-field surveys at (sub)millimeter wavelengths. We present Submillimeter Array (SMA) high-spatial resolution imaging and Gemini-South and Multiple Mirror Telescope optical spectroscopy of strong lens candidates discovered in the two widest extragalactic surveys conducted by the Herschel Space Observatory: the Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS) and the Herschel Multi-tiered Extragalactic Survey (HerMES). From a sample of 30 Herschel sources with S_500>100 mJy, 21 are strongly lensed (multiply imaged),…
We present new HST/WFC3 imaging data of RCSGA 032727-132609, a bright lensed galaxy at z=1.7 that is magnified and stretched by the lensing cluster RCS2 032727-132623. Using this new high-resolution imaging, we modify our previous lens model (which was based on ground-based data) to fully understand the lensing geometry, and use it to reconstruct the lensed galaxy in the source plane. This giant arc represents a unique opportunity to peer into 100-pc scale structures in a high-redshift galaxy. This new source reconstruction will be crucial for a future analysis of the spatially-resolved rest-U…
Supernovae that are strongly gravitationally lensed (gLSNe) by galaxies are powerful probes of astrophysics and cosmology that will be discovered systematically by next-generation wide-field, high-cadence imaging surveys such as the Zwicky Transient Facility (ZTF) and the Large Synoptic Survey Telescope (LSST). Here we use pixel-level simulations that include dust, observing strategy, and multiple supernova subtypes to forecast the rates and properties of gLSNe that ZTF and LSST will find. Applying the resolution-insensitive discovery strategy of Goldstein et al. (2018), we forecast that ZTF (…
We report on high-resolution JVLA and Chandra observations of the HST Frontier Cluster MACS J0717.5+3745. MACS J0717.5+3745 offers the largest contiguous magnified area of any known cluster, making it a promising target to search for lensed radio and X-ray sources. With the high-resolution 1.0-6.5 GHz JVLA imaging in A and B configuration, we detect a total of 51 compact radio sources within the area covered by the HST imaging. Within this sample we find 7 lensed sources with amplification factors larger than $2$. None of these sources are identified as multiply-lensed. Based on the radio lumi…
We present a novel pilot search for gravitational lenses in the mJIVE-20 survey, which observed $24\,903$ radio sources selected from FIRST with the VLBA at an angular resolution of 5 mas. We have taken the visibility data for an initial $3\,640$ sources that were detected by the mJIVE-20 observations and re-mapped them to make wide-field images, selecting fourteen sources that had multiple components separated by $\geq100$ mas, with a flux-ratio of $\leq15$:$1$ and a surface brightness consistent with gravitational lensing. Two of these candidates are re-discoveries of gravitational lenses fo…
We present physical properties of two submillimeter selected gravitationally lensed sources, identified in the Herschel Astrophysical Terahertz Large Area Survey. These submillimeter galaxies (SMGs) have flux densities > 100 mJy at 500 um, but are not visible in existing optical imaging. We fit light profiles to each component of the lensing systems in Spitzer IRAC 3.6 and 4.5 um data and successfully disentangle the foreground lens from the background source in each case, providing important constraints on the spectral energy distributions (SEDs) of the background SMG at rest-frame optical-ne…
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）
HOLISMOKES XXI: Detecting strongly lensed type Ia supernovae from time series of multi-band LSST-like imaging data -- Part II
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）；Aix Marseille Univ, CNRS, CNES, LAM（艾克斯-马赛大学）；Finnish Centre for Astronomy with ESO (FINCA), University of Turku（图尔库大学芬兰ESO天文中心）；University of Helsinki（赫尔辛基大学）；INAF - IASF Milano（意大利国家天体物理研究所米兰分院）；University Observatory, LMU Faculty of Physics（慕尼黑大学物理学院天文台）
We report on deep near-infrared observations obtained with the Wide Field Camera 3 (WFC3) onboard the Hubble Space Telescope (HST) of the first five confirmed gravitational lensing events discovered by the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS). We succeed in disentangling the background galaxy from the lens to gain separate photometry of the two components. The HST data allow us to significantly improve on previous constraints of the mass in stars of the lensed galaxy and to perform accurate lens modelling of these systems, as described in the accompanying paper by Dye e…
We present a comprehensive analysis of the rest-frame UV to near-IR spectral energy distributions and rest-frame optical spectra of four of the brightest gravitationally lensed galaxies in the literature: RCSGA 032727-132609 at z=1.70, MS1512-cB58 at z=2.73, SGAS J152745.1+065219 at z=2.76 and SGAS J122651.3+215220 at z=2.92. This includes new Spitzer imaging for RCSGA0327 as well as new spectra, near-IR imaging and Spitzer imaging for SGAS1527 and SGAS1226. Lensing magnifications of 3-4 magnitudes allow a detailed study of the stellar populations and physical conditions. We compare star forma…
We present a study using the Karl G. Jansky Very Large Array of 12CO J=1-0 emission in three strongly lensed submillimetre-selected galaxies (SMMJ16359, SMMJ14009 and SMMJ02399) at z=2.5-2.9. These galaxies span L(IR) = 10^11 - 10^13 Lsun, offering an opportunity to compare the interstellar medium of LIRGs and ULIRGs at high redshift. We estimate molecular gas masses in the range (2-40) x 10^9 Msun using a method that assumes canonical underlying brightness temperature ratios for star-forming and non-star-forming gas phases and a maximal star-formation efficiency. A more simplistic method usin…
Quiescent massive galaxies at z~2 are thought to be the progenitors of present-day massive ellipticals. Observations revealed them to be extraordinarily compact. The determination of stellar ages, star formation rates and dust properties via spectroscopic measurements has up to now only been feasible for the most luminous and massive specimens (~3x M*). Here we present a spectroscopic study of two near-infrared selected galaxies which are close to the characteristic stellar mass M* (~0.9x M* and ~1.3x M*) and whose observed brightness has been boosted by the gravitational lensing effect. We me…
We report the discovery of four very bright, strongly-lensed galaxies found via systematic searches for arcs in Sloan Digital Sky Survey Data Release 5 and 6. These were followed-up with spectroscopy and imaging data from the Astrophysical Research Consortium 3.5m telescope at Apache Point Observatory and found to have redshift $z>2.0$. With isophotal magnitudes $r = 19.2 - 20.4$ and $3\arcsec$-diameter magnitudes $r = 20.0 - 20.6$, these systems are some of the brightest and highest surface brightness lensed galaxies known in this redshift range. In addition to the magnitudes and redshifts, w…
In 2016, the first strongly lensed Type Ia supernova, iPTF16geu at redshift $z=0.409$ with four resolved images arranged symmetrically around the lens galaxy at $z=0.2163$, was discovered. Here, refined observations of iPTF16geu, including the time delay between images, are used to decrease uncertainties in the lens model, including the the slope of the projected surface density of the lens galaxy, $Σ\propto r^{1-η}$, and to constrain the universal expansion rate $H_0$. Imaging with HST provides an upper limit on the slope $η$, in slight tension with the steeper density profiles indicated by i…
We present a detailed analysis of the far-IR properties of the bright, lensed, z = 2.3, SMG, SMM J2135-0102, using new observations with Herschel, SCUBA-2 and the VLA. These data allow us to constrain the galaxy's SED and show that it has an intrinsic rest-frame 8-1000um luminosity, L(bol), of (2.3 +/- 0.2) x 10^12 L(sun) and a likely SFR of ~400 M(sun)/yr. The galaxy sits on the far-IR/radio correlation for far-IR-selected galaxies. At ~>70um, the SED can be described adequately by dust components with T(d) ~ 30 and 60K. Using SPIRE's Fourier Transform Spectrometer we report a detection of th…
We present observations of SPT-S J053816-5030.8, a gravitationally-lensed dusty star forming galaxy (DSFG) at z = 2.7817, first discovered at millimeter wavelengths by the South Pole Telescope. SPT 0538-50 is typical of the brightest sources found by wide-field millimeter-wavelength surveys, being lensed by an intervening galaxy at moderate redshift (in this instance, at z = 0.441). We present a wide array of multi-wavelength spectroscopic and photometric data on SPT 0538-50, including data from ALMA, Herschel PACS and SPIRE, Hubble, Spitzer, VLT, ATCA, APEX, and the SMA. We use high resolutio…
We examine the inner mass distribution of the relaxed galaxy cluster Abell 383 in deep 16-band HST/ACS+WFC3 imaging taken as part of the CLASH multi-cycle treasury program. Our program is designed to study the dark matter distribution in 25 massive clusters, and balances depth with a wide wavelength coverage to better identify lensed systems and generate precise photometric redshifts. This information together with the predictive strength of our strong-lensing analysis method identifies 13 new multiply-lensed images and candidates, so that a total of 27 multiple-images of 9 systems are used to…
We report the redshift of HATLAS J132427.0+284452 (hereafter HATLAS J132427), a gravitationally lensed starburst galaxy, the first determined 'blind' by the Herschel Space Observatory. This is achieved via the detection of [C II] consistent with z = 1.68 in a far-infrared spectrum taken with the SPIRE Fourier Transform Spectrometer. We demonstrate that the [C II] redshift is secure via detections of CO J = 2 - 1 and 3 - 2 using the Combined Array for Research in Millimeter-wave Astronomy and the Institut de Radioastronomie Millimetrique's Plateau de Bure Interferometer. The intrinsic propertie…
We quantify the performance of mass mapping techniques on mock imaging and gravitational lensing data of galaxy clusters. The optimum method depends upon the scientific goal. We assess measurements of clusters' radial density profiles, departures from sphericity, and their filamentary attachment to the cosmic web. We find that mass maps produced by direct (KS93) inversion of shear measurements are unbiased, and that their noise can be suppressed via filtering with MRLens. Forward-fitting techniques, such as Lenstool, suppress noise further, but at a cost of biased ellipticity in the cluster co…
We present multi-wavelength imaging and near-IR spectroscopy for ten gravitationally lensed galaxies at 0.9<z<2.5 selected from a new, large sample of strong lens systems in the Sloan Digital Sky Survey (SDSS) DR7. We derive stellar masses from the rest-frame UV to near-IR spectral energy distributions, star formation rates (SFR) from the dust-corrected Ha flux, and metallicities from the [N II]/Ha flux ratio. We combine the lensed galaxies with a sample of sixty star-forming galaxies from the literature in the same redshift range for which measurements of [N II]/Ha have been published. Due to…
