We measure the size-luminosity relation of photometrically-selected galaxies within the redshift range $z\sim6-9$, using galaxies lensed by six foreground Hubble Frontier Fields (HFF) clusters. The power afforded by strong gravitational lensing allows us to observe fainter and smaller galaxies than in blank fields. We select our sample of galaxies and obtain their properties, e.g., redshift, magnitude, from the photometrically-derived ASTRODEEP catalogues. The intrinsic size is measured with the Lenstruction software, and completeness maps are created as a function of size and luminosity via the GLACiAR2 software. We perform a Bayesian analysis to estimate the intrinsic and incompleteness-corrected size-luminosity distribution, with parameterization $r_e \propto L^β$. We find slopes of $β\sim0.48\pm0.08$ at $z\sim6-7$ and $β\sim0.68\pm0.14$ at $z\sim8.5$, adopting the Bradac lens model. The slope derived by lensed galaxies is steeper than that obtained in blank fields and is consistent with other independent determinations of the size-luminosity relation from the HFF dataset. We also investigate the systematic uncertainties correlated with the choice of lens models, finding that the slopes of size-luminosity relations derived from different models are consistent with each other, i.e. the modeling errors are not a significant source of uncertainty in the size-luminosity relation.
We report results of a search for CIII] $λλ$1907,1909 Å emission using Keck's MOSFIRE spectrograph in a sample of 7 $z_{phot}\sim7-8$ candidates ($H\sim27$) lensed by the Hubble Frontier Field cluster Abell 2744. Earlier work has suggested the promise of using the CIII] doublet for redshift confirmation of galaxies in the reionization era given $Lyα$ ($λ$1216 Å) is likely attenuated by the neutral intergalactic medium. The primary challenge of this approach is the feasibility of locating CIII] emission without advanced knowledge of the spectroscopic redshift. With an integration time of 5 hour…
We present an investigation on escape fractions of UV photons from a unique sample of lensed low-mass emission line selected galaxies at z < 3.5 found in the SHARDS Hubble Frontier Fields medium-band survey. We have used this deep imaging survey to locate 42 relatively low-mass galaxies, down to $log(M_{*}/M_{\odot}) = 7$, between redshifts 2.4 < z < 3.5 which are candidate line emitters. Using deep multi-band Hubble UVIS imaging we investigate the flux of escaping ionizing photons from these systems, obtaining 1$σ$ upper limits of $f^{rel}_{esc}$ ~7% for individual galaxies, and < 2% for stac…
For lensed galaxy SGAS J111020.0+645950.8 at redshift z=2.481, which is magnified by a factor of 28 +- 8, we analyze the morphology of star formation as traced by rest-frame ultraviolet emission, in both the highly-magnified source plane, and in simulations of how this galaxy would appear without lensing magnification. Were this galaxy not lensed but drawn from an HST deep field, we would conclude that almost all its star formation arises from an exponential disk (Sérsic index of 1.0 +- 0.4) with an effective radius of r_e = 2.7 +- 0.3 kpc measured from two-dimensional fitting to F606W using G…
We investigate the blue and optical rest-frame sizes (lambda~2300A-4000A) of three compact star-forming regions in a galaxy at z=4 strongly lensed (x30, x45, x100) by the Hubble Frontier Field galaxy cluster A2744 using GLASS-ERS JWST/NIRISS imaging at 1.15um, 1.50mu and 2.0mu with PSF < 0.1". In particular, the Balmer break is probed in detail for all multiply-imaged sources of the system. With ages of a few tens of Myr, stellar masses in the range (0.7-4.0) x 10^6 Msun and optical/ultraviolet effective radii spanning the interval 3 < R_eff < 20 pc, such objects are currently the highest reds…
Strong gravitational lensing provides a powerful means for studying faint galaxies in the distant universe. By magnifying the apparent brightness of background sources, massive clusters enable the detection of galaxies fainter than the usual sensitivity limit for blank fields. However, this gain in effective sensitivity comes at the cost of a reduced survey volume and, in this {\it Letter}, we demonstrate there is an associated increase in the cosmic variance uncertainty. As an example, we show that the cosmic variance uncertainty of the high redshift population viewed through the Hubble Space…
We present the results of combined deep Keck/NIRC2, HST/WFC3 near-infrared and Herschel far infrared observations of an extremely star forming dusty lensed galaxy identified from the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS J133542.9+300401). The galaxy is gravitationally lensed by a massive WISE identified galaxy cluster at $z\sim1$. The lensed galaxy is spectroscopically confirmed at $z=2.685$ from detection of $\rm {CO (1 \rightarrow 0)}$ by GBT and from detection of $\rm {CO (3 \rightarrow 2)}$ obtained with CARMA. We use the combined spectroscopic and imaging observatio…
Context: A census of faint and tiny star forming complexes at high redshift is key to improving our understanding of reionizing sources, galaxy growth and the formation of globular clusters. Aims: We present the MUSE Deep Lensed Field (MDLF) program. Methods: We describe Deep MUSE observations of 17.1 hours integration on a single pointing over the Hubble Frontier Field galaxy cluster MACS~J0416. Results: We confirm spectroscopic redshifts for all 136 multiple images of 48 source galaxies at 0.9<z<6.2. Within those galaxies, we securely identify 182 multiple images of 66 galaxy components that…
We derive a free-form mass distribution for the massive cluster AS1063 (z=0.348) using the completed optical imaging from the Hubble Frontier Fields programme. Based on a subset of 11 multiply lensed systems with spectroscopic redshift we produce a lens model that is accurate enough to unveil new multiply lensed systems, totalling over a 100 arclets, and to estimate their redshifts geometrically. Consistency is found between this precise model and that obtained using only the subset of lensed sources with spectroscopically measured redshifts. Although a relatively large elongation of the mass …
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 constrain the rest-UV size-luminosity relation for star-forming galaxies at z~4 and z~6, 7, and 8 identified behind clusters from the Hubble Frontier Fields (HFF) program. The size-luminosity relation is key to deriving accurate luminosity functions (LF) for faint galaxies. Making use of the latest lensing models and full data set for these clusters, lensing-corrected sizes and luminosities are derived for 68 z~4, 184 z~6, 93 z~7, and 53 z~8 galaxies. We show that size measurements can be reliably measured up to linear magnifications of 30x, where the lensing models are well calibrated. The…
We investigate sizes of $z\sim6-8$ dropout galaxies using the complete data of the Abell 2744 cluster and parallel fields in the Hubble Frontier Fields program. By directly fitting light profiles of observed galaxies with lensing-distorted Sérsic profiles on the image plane with the \texttt{glafic} software, we accurately measure intrinsic sizes of 31 $z\sim6-7$ and eight $z\sim8$ galaxies, including those as faint as $M_{\mathrm{UV}}\simeq-16.6$. We find that half-light radii $r_\mathrm{e}$ positively correlates with UV luminosity at each redshift, although the correlation is not very tight. …
At cosmological distances, gravitational lensing can provide a direct measurement of supermassive black hole (SMBH) masses irrespective of their luminosities. Here, we directly estimate the mass of a SMBH in the brightest cluster galaxy (BCG) of MACS J1149+2223.5 at $z=0.54$ through one of the multiply-lensed images of a background spiral galaxy at $z=1.49$ projected close to the BCG. In this particular image, an intrinsically compact region in one of the spiral arms is lensed into an arc that curves towards the BCG center. This arc has a radius of curvature of only $\sim$0."6, betraying the p…
The Grism Lens-Amplified Survey from Space (GLASS) is a Hubble Space Telescope (HST) Large Program, which will obtain 140 orbits of grism spectroscopy of the core and infall regions of 10 galaxy clusters, selected to be among the very best cosmic telescopes. Extensive HST imaging is available from many sources including the CLASH and Frontier Fields programs. We introduce the survey by analyzing spectra of faint multiply-imaged galaxies and $z\gtrsim6$ galaxy candidates obtained from the first seven orbits out of fourteen targeting the core of the Frontier Fields cluster MACS0717.5+3745. Using…
The Hubble Frontier Fields (HFF) are a selection of well-studied galaxy clusters used to probe dense environments and distant gravitationally lensed galaxies. We explore the 21cm neutral hydrogen (HI) content of galaxies in three of the HFF clusters, Abell 2744 ($z = 0.308$), Abell S1063 ($z = 0.346$) and Abell 370 ($z = 0.375$), to investigate the evolution of gas in galaxies within intermediate redshift clusters. Using Early Science MeerKAT observations, we perform spectral-line stacking with HI cubes and make a 3$σ$ stacked detection for blue galaxies in Abell S1063 ($M_\mathrm{HI} = 1.22^{…
We searched for z > 7 Lyman-break galaxies (LBGs) in the optical-to-mid-infrared Hubble Frontier Field and associated parallel field observations of the strong-lensing cluster MACS J0416-2403. We discovered 22 candidates, of which six lie at z > 9 and one lies at z > 10. Based on the Hubble and Spitzer photometry, all have secure photometric redshifts and a negligible probability of being at lower redshifts, according to their peak probability ratios, R. This substantial increase in the number of known high-redshift galaxies allows a solid determination of the luminosity function at z > 8. The…
We derive a free-form mass distribution for the unrelaxed cluster A370 (z=0.375), using the latest Hubble Frontier Fields images and GLASS spectroscopy. Starting from a reliable set of 10 multiply lensed systems we produce a free-form lens model that identifies ~ 80 multiple-images. Good consistency is found between models using independent subsamples of these lensed systems, with detailed agreement for the well resolved arcs. The mass distribution has two very similar concentrations centred on the two prominent Brightest Cluster Galaxies (or BCGs), with mass profiles that are accurately const…
We directly detect dust emission in an optically-detected, multiply-imaged galaxy lensed by the Frontier Fields cluster MACSJ0717.5+3745. We detect two images of the same galaxy at 1.1mm with the AzTEC camera on the Large Millimeter Telescope leaving no ambiguity in the counterpart identification. This galaxy, MACS071_Az9, is at z>4 and the strong lensing model (mu=7.5) allows us to calculate an intrinsic IR luminosity of 9.7e10 Lsun and an obscured star formation rate of 14.6 +/- 4.5 Msun/yr. The unobscured star formation rate from the UV is only 4.1 +/- 0.3 Msun/yr which means the total star…
The most distant galaxies known are at z~10-11, observed 400-500 Myr after the Big Bang. The few z~10-11 candidates discovered to date have been exceptionally small- barely resolved, if at all, by the Hubble Space Telescope. Here we present the discovery of SPT0615-JD, a fortuitous z~10 (z_phot=9.9+/-0.6) galaxy candidate stretched into an arc over ~2.5" by the effects of strong gravitational lensing. Discovered in the Reionization Lensing Cluster Survey (RELICS) Hubble Treasury program and companion S-RELICS Spitzer program, this candidate has a lensed H-band magnitude of 25.7+/-0.1 AB mag. W…
Thick disk evolution is studied using edge-on galaxies in two Hubble Space Telescope Frontier Field Parallels. The galaxies were separated into 72 clumpy types and 35 spiral types with bulges. Perpendicular light profiles in F435W, F606W and F814W (B, V and I) passbands were measured at 1 pixel intervals along the major axes and fitted to sech^2 functions convolved with the instrument line spread function (LSF). The LSF was determined from the average point spread function (PSF) of ~20 stars in each passband and field, convolved with a line of uniform brightness to simulate disk blurring. A sp…
This paper presents multiwavelength photometric catalogues of the last two Hubble Frontier Fields (HFF), the massive galaxy clusters Abell 370 and RXC J2248.7-4431. The photometry ranges from imaging performed on the Hubble Space Telescope (HST) to ground based Very Large Telescope (VLT) and Spitzer/IRAC, in collaboration with the ASTRODEEP team, and using the ASTRODEEP pipeline. While the main purpose of this paper is to release the catalogues, we also perform, as a proof of concept, a brief analysis of z > 6 objects selected using drop-out method, as well as spectroscopically confirmed sourc…
In this paper we present the results of our search for and study of $z \gtrsim 6$ galaxy candidates behind the third Frontier Fields (FF) cluster, MACSJ0717.5+3745, and its parallel field, combining data from Hubble and Spitzer. We select 39 candidates using the Lyman Break technique, for which the clear non-detection in optical make the extreme mid-$z$ interlopers hypothesis unlikely. We also take benefit from $z \gtrsim 6$ samples selected using previous Frontier Fields datasets of Abell 2744 and MACS0416 to improve the constraints on the properties of very high-redshift objects. We compute …
Hubble Frontier Fields (HFF) imaging of the most powerful lensing clusters provides access to the most magnified distant galaxies. The challenge is to construct lens models capable of describing these complex massive, merging clusters so that individual lensed systems can be reliably identified and their intrinsic properties accurately derived. We apply the free-form lensing method (WSLAP+) to A2744, providing a model independent map of the cluster mass, magnification, and geometric distance estimates to multiply-lensed sources. We solve simultaneously for a smooth cluster component on a pixel…
We present Hubble multi-wavelength photometric catalogs, including (up to) 17 filters with the Advanced Camera for Surveys and Wide Field Camera 3 from the ultra-violet to near-infrared for the Hubble Frontier Fields and associated parallels. We have constructed homogeneous photometric catalogs for all six clusters and their parallels. To further expand these data catalogs, we have added ultra-deep $K_{S}$-band imaging at 2.2~\micron\ from the Very Large Telescope HAWK-I and Keck-I MOSFIRE instruments. We also add post-cryogenic \spitzer\ imaging at 3.6~\micron\ and 4.5~\micron\ with the Infra…
LensExplorer is an IDL GUI code that can be used to visualize the lensing deflection field derived in the Hubble Frontier Fields clusters. The code can be used for both, research and educational purposes as it offers and intuitive and user friendly way to explore the solutions in the different clusters. LensExplorer can be used to predict the magnifications at different redshifts of background sources and for a given location. We present in this document a quick guide to get started with LensExplorer. The code and lens models for the cluster A2744 and MACSJ0416.1-2403 are publicly available fr…
We present an analysis of MUSE observations obtained on the massive Frontier Fields cluster Abell 2744. This new dataset covers the entire multiply-imaged region around the cluster core. We measure spectroscopic redshifts for HST-selected continuum sources together with line emitters blindly detected in the datacube. The combined catalog consists of 514 spectroscopic redshifts (with 414 new identifications), including 156 cluster members and 326 magnified background sources. We use this redshift information to perform a strong-lensing analysis of all multiple images previously found in the dee…
Galaxies with stellar masses <10^7 Msun and specific star formation rates sSFR>10^{-7} yr^{-1} were examined on images of the Hubble Space Telescope Frontier Field Parallels for Abell 2744 and MACS J0416.1-02403. They appear as unresolved "Little Blue Dots" (LBDs). They are less massive and have higher sSFR than "blueberries" studied by yang et al. (2017) and higher sSFR than "Blue Nuggets" studied by Tacchella et al.(2016). We divided the LBDs into 3 redshift bins and, for each, stacked the B435, V606, and I814 images convolved to the same stellar point spread function (PSF). Their radii were…
We report the discovery of ultra-diffuse galaxies (UDGs) in Abell 370 ($z=0.375$). We find 46 UDGs in Abell 370 from the images of the Hubble Frontier Fields (HFF). Most UDGs are low-luminosity red sequence galaxies, while a few of them are blue UDGs. We estimate the abundance of UDGs in Abell 370, $N(\rm UDG)=644\pm104$. Combining these results with those of Abell S1063 ($z=0.348$) and Abell 2744 ($z=0.308$) \citep{Lee17}, we derive a mean radial number density profile of UDGs in the three clusters. The number density profiles of UDGs and bright galaxies show a discrepancy in the central regi…
We investigate the intra-cluster light (ICL) in the 6 Hubble Frontier Field clusters at $0.3<z<0.6$. We employ a new method, which is free from any functional form of the ICL profile, and exploit the unprecedented depth of this Hubble Space Telescope imaging to map the ICL's diffuse light out to clustrocentric radii $R\sim300$kpc ($μ_{\rm ICL}\sim27$mag arcsec$^{-2}$). From these maps, we construct radial color and stellar mass profiles via SED fitting and find clear negative color gradients in all systems with increasing distance from the Brightest Cluster Galaxy (BCG). While this implies old…
Exploiting the power of gravitational lensing, the Hubble Frontier Fields (HFF) program aims at observing six massive galaxy clusters to explore the distant Universe far beyond the depth limits of blank field surveys. Using the complete Hubble Space Telescope observations of the first HFF cluster Abell 2744, we report the detection of 50 galaxy candidates at $z \sim 7$ and eight candidates at $z \sim 8$ in a total survey area of 0.96 arcmin$^{2}$ in the source plane. Three of these galaxies are multiply-imaged by the lensing cluster. Using an updated model of the mass distribution in the clust…
We present new measurements of the UV spectral slope $β$ for galaxies at $z=6-9$ in the Frontier Fields cluster MACSJ0416.1-2403 and its parallel field, to an unprecedented level of low stellar mass. We fit synthetic stellar population models to the observed spectral energy distribution and calculate $β$ by fitting a power law to the best-fit spectrum. With this method, we report the derivation of rest-frame UV colours of galaxies for the Frontier Fields program extending out to $z=9$, probing magnitudes as faint as $M\mathrm{_{UV}=-13.5}$ at $z=6$. We find no significant correlation between $…
We present UV luminosity functions of dropout galaxies at $z\sim6-10$ with the complete Hubble Frontier Fields data. We obtain a catalog of $\sim450$ dropout-galaxy candidates (350, 66, and 40 at $z\sim6-7$, 8, and 9, respectively), whose UV absolute magnitudes reach $\sim-14$ mag, $\sim2$ mag deeper than the Hubble Ultra Deep Field detection limits. We carefully evaluate number densities of the dropout galaxies by Monte-Carlo simulations, including all lensing effects such as magnification, distortion, and multiplication of images as well as detection completeness and contamination effects in…
We describe a general purpose method to reconstruct the intrinsic properties of sources lensed by the gravitational potential of foreground clusters of galaxies. The tool Lenstruction is implemented in the publicly available multi-purpose gravitational lensing software Lenstronomy, in order to provide an easy and fast solution to this common astrophysical problem. The tool is based on forward modeling the appearance of the source in the image plane, taking into account the distortion by lensing and the instrumental point spread function (PSF). For singly-imaged sources a global lens model in t…
We assemble a large comprehensive sample of 2534 z~2, 3, 4, 5, 6, 7, 8, and 9 galaxies lensed by the six clusters from the Hubble Frontier Fields (HFF) program. Making use of the availability of multiple independent magnification models for each of the HFF clusters and alternatively treating one of the models as the "truth," we show that the median magnification factors from the v4 parametric models are typically reliable to values of 30 to 50, and in one case to 100. Using the median magnification factor from the latest v4 models, we estimate the UV luminosities of the 2534 lensed z~2-9 galax…
Emission line galaxies provide a crucial tool for the study of galaxy formation and evolution, providing a means to trace a galaxy's star formation history or metal enrichment, and to identify galaxies at a range of stellar masses. In this paper we present a study of emission line galaxies in the SHARDS Frontier Fields medium-band survey. Through detailed flux calibrations we combine the first results of the SHARDS-FF survey with existing Hubble Frontier Field data to select 1,098 candidate emission line galaxies from the Hubble Frontier Filed clusters Abell 370 and MACS J1149.5+2223. Furtherm…
We present a multi-band analysis of the six Hubble Frontier Field clusters and their parallel fields, producing catalogs with measurements of source photometry and photometric redshifts. We release these catalogs to the public along with maps of intracluster light and models for the brightest galaxies in each field. This rich data set covers a wavelength range from 0.2 to 8 $μm$, utilizing data from the Hubble Space Telescope, Keck Observatories, Very Large Telescope array, and Spitzer Space Telescope. We validate our products by injecting into our fields and recovering a population of synthet…
We present new measurements of the very low-mass end of the galaxy stellar mass function (GSMF) at $z\sim6-7$ computed from a rest-frame ultraviolet selected sample of dropout galaxies. These galaxies lie behind the six Hubble Frontier Fields clusters and are all gravitationally magnified. Using deep Spitzer/IRAC and Hubble Space Telescope imaging, we derive stellar masses by fitting galaxy spectral energy distributions and explore the impact of different model assumptions and parameter degeneracies on the resulting GSMF. Our sample probes stellar masses down to $M_{\star}>10^{6}\,\text{M}_{\o…
One of the challenges in understanding the quenching processes for galaxies is connecting progenitor star-forming populations to their descendant quiescent populations over cosmic time. Here we attempt a novel approach to this challenge by assuming that the underlying stellar mass distribution of galaxies is not significantly altered during environmental quenching processes that solely affect the gas content of cluster galaxies, such as strangulation and ram-pressure stripping. Using the deep, high-resolution photometry of the Hubble Frontier Fields, we create resolved stellar mass maps for bo…
We construct $z\sim6-7$, 8, and 9 faint Lyman break galaxy samples (334, 61, and 37 galaxies, respectively) with accurate size measurements with the software $\texttt{glafic}$ from the complete Hubble Frontier Fields (FF) cluster and parallel fields data. These are the largest samples hitherto and reach down to the faint ends of recently obtained deep luminosity functions. At faint magnitudes, however, these samples are highly incomplete for galaxies with large sizes, implying that derivation of the luminosity function (LF) sensitively depends on the intrinsic size--luminosity (RL) relation. W…
One of the main challenges in using high redshift active galactic nuclei to study the correlations between the mass of the supermassive Black Hole (MBH) and the properties of their active host galaxies is instrumental resolution. Strong lensing magnification effectively increases instrumental resolution and thus helps to address this challenge. In this work, we study eight strongly lensed active galactic nuclei (AGN) with deep Hubble Space Telescope imaging, using the lens modelling code Lenstronomy to reconstruct the image of the source. Using the reconstructed brightness of the host galaxy, …
We use the largest sample of z~6 galaxies to date from the first four Hubble Frontier Fields clusters to set constraints on the shape of the z~6 luminosity functions (LFs) to fainter than Muv=-14 mag. We quantify, for the first time, the impact of magnification uncertainties on LF results and thus provide more realistic constraints than other recent work. Our simulations reveal that for the highly-magnified sources the systematic uncertainties can become extremely large fainter than -14 mag, reaching several orders of magnitude at 95% confidence at ~-12 mag. Our new forward-modeling formalism …
TDCOSMO. XXIII. Measurement of the Hubble constant from the doubly lensed quasar HE1104-1805
The University of Tokyo（东京大学）；Ecole Polytechnique Fédérale de Lausanne (EPFL)（洛桑联邦理工学院）；Universitat de Barcelona (IEEC-UB)（巴塞罗那大学）；Institució Catalana de Recerca i Estudis Avançats (ICREA)（加泰罗尼亚高级研究学院）；UC Davis（加州大学戴维斯分校）；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）；ETH Zurich（苏黎世联邦理工学院）；Liège Université（列日大学）；University of California, Los Angeles（加州大学洛杉矶分校）；Stony Brook University（石溪大学）；Fermi National Accelerator Laboratory（费米国家加速器实验室）
本文利用双镜像类星体HE1104-1805测量哈勃常数，通过结合多 telescope 数据测量时间延迟、恒星速度弥散、费马势差和收敛，采用幂律质量模型得出H_0=64.2±5.8xλ_int km s⁻¹ Mpc⁻¹。
We present an overview of the "KIFF" project, which provides ultra-deep Ks-band imaging of all six of the Hubble Frontier Fields clusters Abell 2744, MACS-0416, Abell S1063, Abell 370, MACS-0717 and MACS-1149. All of these fields have recently been observed with large allocations of Directors' Discretionary Time with the HST and Spitzer telescopes covering 0.4 < lambda < 1.6 microns and 3.6--4.5 microns, respectively. VLT/HAWK-I integrations of the first four fields reach 5-sigma limiting depths of Ks~26.0 (AB, point sources) and have excellent image quality (FWHM ~ 0."4). Shorter Keck/MOSFIRE…
In recent years, the rise in the number of Lyman Break Galaxies detected at high redshifts z >= 6 has opened up the possibility of understanding early galaxy formation physics in great detail. In particular, the faint-end slope (alpha) of the Ultra-violet luminosity function (UV LF) of these galaxies is a potential probe of feedback effects that suppress star formation in low mass haloes. In this work, we propose a proof-of-concept calculation for constraining the fluctuating UV background during reionization by constraining alpha in different volumes of the Universe. Because of patchy reioniz…
We present the rest-frame optical spectral energy distribution and stellar masses of six Herschel- selected gravitationally lensed dusty, star-forming galaxies (DSFGs) at 1 < z < 3. These galaxies were first identified with Herschel/SPIRE imaging data from the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) and the Herschel Multi-tiered Extragalactic Survey (HerMES). The targets were observed with Spitzer/IRAC at 3.6 and 4.5um. Due to the spatial resolution of the IRAC observations at the level of 2 arcseconds, the lensing features of a background DSFG in the near-infrared are ble…
The faint end of the UV luminosity function at $0.4 < z < 0.7$ from the Hubble Frontier Fields
School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University（北京师范大学前沿天文与天体物理研究所）；The Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学科维理天文与天体物理研究所）；National Astronomical Research Institute of Thailand (NARIT)（泰国国家天文研究所）；Department of Physics and Astronomy, University of California, Riverside（加州大学河滨分校物理与天文系）
通过哈勃前沿场观测扩展到F225W波段，研究了0.4 < z < 0.7红移范围内星系紫外光度函数的微弱端特性，确定了最佳拟合参数和微弱端斜率。
Time-delay cosmography in strongly lensed quasars offer an independent way of measuring the Hubble constant, $H_0$. However, it has been proposed that the combination of microlensing and source-size effects, also known as microlensing time delay can potentially increase the uncertainty in time-delay measurements as well as lead to a biased time delay. In this work, we first investigate how microlensing time delay changes with assumptions on the initial mass function (IMF) and find that the more massive microlenses produce the sharper distributions of microlensing time delays. We also find that…
We present the first observations of the Frontier Fields Cluster Abell S1063 taken with the newly commissioned Multi Unit Spectroscopic Explorer (MUSE) integral field spectrograph. Because of the relatively large field of view (1 arcmin^2), MUSE is ideal to simultaneously target multiple galaxies in blank and cluster fields over the full optical spectrum. We analysed the four hours of data obtained in the Science Verification phase on this cluster and measured redshifts for 53 galaxies. We confirm the redshift of five cluster galaxies, and determine the redshift of 29 other cluster members. Be…
We search for high-redshift dropout galaxies behind the Hubble Frontier Fields (HFF) galaxy cluster MACS J1149.5+2223, a powerful cosmic lens that has revealed a number of unique objects in its field. Using the deep images from the Hubble and Spitzer space telescopes, we find 11 galaxies at z>7 in the MACS J1149.5+2223 cluster field, and 11 in its parallel field. The high-redshift nature of the bright z~9.6 galaxy MACS1149-JD, previously reported by Zheng et al., is further supported by non-detection in the extremely deep optical images from the HFF campaign. With the new photometry, the best …
Cluster lensing has become an important tool in the search for high redshift galaxies through its ability to magnify sources. In order to determine the intrinsic properties of these galaxies, lensing mass models must be constructed to determine the magnification of the images. These models are traditionally two-dimensional, focusing on the mass within the cluster and either ignoring or approximating any contribution from line-of-sight galaxies. In this paper, we present the first full set of three-dimensional mass models of the six Hubble Frontier Fields and use them to test for systematic bia…
We present the results of a search for z=9-10 galaxies within the first 8 pointings of the Hubble Frontier Fields (HFF) (4 clusters plus 4 parallel fields) and 20 cluster fields from the CLASH survey. Combined with our previous analysis of the Hubble Ultra-Deep field (HUDF), we have now completed a search for z=9-10 galaxies over ~130 sq. arcmin, across 29 HST WFC3/IR pointings. As in our recent study of the first two HFF fields, we confine our primary search for high-redshift candidates in the HFF imaging to the uniformly deep (i.e. sigma_160>30 AB mag in 0.5-arcsec diameter apertures), relat…
ID11 is an actively star forming extremely compact galaxy and Ly alpha emitter at z=3.117 that is gravitationally magnified by a factor of ~17 by the cluster of galaxies Hubble Frontier Fields AS1063. Its observed properties resemble those of low luminosity HII galaxies or Giant HII regions like 30-Doradus in the LMC. Using the tight correlation correlation between the Balmer-line luminosities and the width of the emission lines (typically L(Hbeta)-sigma(Hbeta)) valid for HII galaxies and Giant HII regions to estimate its total luminosity, we are able to measure the lensing amplification of ID…
We provide the first observational constraints on the sizes of the faintest galaxies lensed by the Hubble Frontier Fields (HFF) clusters. Ionizing radiation from faint galaxies likely drives cosmic reionization, and the HFF initiative provides a key opportunity to find such galaxies. Yet, we cannot really assess their ionizing emissivity without a robust measurement of their sizes, since this is key to quantifying both their prevalence and the faint-end slope to the UV luminosity function. Here we provide the first such size constraints with 2 new techniques. The first utilizes the fact that t…
The Frontier Fields program is obtaining deep Hubble and Spitzer Space Telescope images of new "blank" fields and nearby fields gravitationally lensed by massive galaxy clusters. The Hubble images of the lensed fields are revealing nJy sources (AB mag > 31), the faintest galaxies yet observed. In this paper, we present high-redshift (z > 6) number count predictions for the full program and candidates in three of the first Hubble Frontier Fields images. The full program will transform our understanding of galaxy evolution in the first 600 million years (z > 9). Where previous programs yielded p…
We present the first results and design from the redshift z~9-10 Brightest of the Reionizing Galaxies {\it Hubble Space Telescope} survey BoRG[z9-10], aimed at searching for intrinsically luminous unlensed galaxies during the first 700 Myr after the Big Bang. BoRG[z9-10] is the continuation of a multi-year pure-parallel near-IR and optical imaging campaign with the Wide Field Camera 3. The ongoing survey uses five filters, optimized for detecting the most distant objects and offering continuous wavelength coverage from λ=0.35μm to λ=1.7μm. We analyze the initial ~130 arcmin$^2$ of area over 28…
We investigate the relation between the star formation rate (SFR) and the stellar mass (M), i.e. the Main Sequence (MS) relation of star-forming galaxies, at 1.3<=z<6 in the first four HST Frontier Fields, based on rest-frame UV observations. Gravitational lensing combined with deep HST observations allows us to extend the analysis of the MS down to stellar masses as low as logM/Msun~7.5 at z<~4 and logM/Msun~8 at higher redshifts, a factor of ~10 below most previous results. We perform an accurate simulation to take into account the effect of observational uncertainties on the MS and correct …
