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Dark-ages Reionization and Galaxy Formation Simulation - XIV. Gas accretion, cooling and star formation in dwarf galaxies at high redshiftFeb 12 2018We study dwarf galaxy formation at high redshift ($z\ge5$) using a suite of high-resolution, cosmological hydrodynamic simulations and a semi-analytic model (SAM). We focus on gas accretion, cooling and star formation in this work by isolating the relevant ... More
Increasing the Lensing Figure of Merit through Higher Order Convergence MomentsFeb 08 2018The unprecedented quality, the increased dataset, and the wide area of ongoing and near future weak lensing surveys allows to move beyond the standard two points statistics thus making worthwhile to investigate higher order probes. As an interesting step ... More
Multivariate Study of the Star Formation Rate in Galaxies: Bimodality RevisitedFeb 08 2018Subjective classification of galaxies can mislead us in the quest of the origin regarding formation and evolution of galaxies. Multivariate analyses are the best tools used for such kind of purpose to better understand the differences between various ... More
A dark energy scenario consistent with GW170817 in theories beyond HorndeskiFeb 08 2018The Gleyzes-Langlois-Piazza-Vernizzi (GLPV) theories up to quartic order are the general scheme of scalar-tensor theories allowing the possibility for realizing the tensor propagation speed $c_t$ equivalent to 1 on the isotropic cosmological background. ... More
On Non-slow Roll Inflationary RegimesFeb 07 2018We summarize our work on constant roll inflationary models. It was understood recently that constant roll inflation, in a regime beyond the slow roll approximation, can give models that are in agreement with the observational constraints. We describe ... More
A Universal Entropy Profile for the Hot Atmospheres of Galaxies and Clusters within $R_{2500}$Feb 07 2018We present atmospheric gas entropy profiles for 40 early type galaxies and 110 clusters spanning several decades of halo mass, atmospheric gas mass, radio jet power, and galaxy type. We show that within $\sim 0.1R_{2500}$ the entropy profiles of low-mass ... More
The Planes of Satellite Galaxies Problem, Suggested Solutions, and Open QuestionsFeb 07 2018Satellite galaxies of the Milky Way and of the Andromeda galaxy have been found to preferentially align in significantly flattened planes of satellite galaxies, and available velocity measurements are indicative of a preference of satellites in those ... More
Self-consistent redshift estimation using correlation functions without a spectroscopic reference sampleFeb 07 2018We present a new method to estimate redshift distributions and galaxy-dark matter bias model parameters (gdmbm) using correlation functions in a fully data driven manner. Unlike other machine learning, template methods, or correlation redshift methods, ... More
Signatures of Cosmic Reionization on the 21cm 2- and 3-point Correlation Function I: Quadratic Bias ModelingFeb 07 2018Constraints on reionization models from future 21cm observations will rely on the statistical characterization of the spatial fluctuations in the observed 21cm brightness temperature. Three-point correlation functions (3PCF) of this 21cm signal probe ... More
Structure formation in $f(T)$ gravity and a solution for $H_0$ tensionFeb 07 2018We investigate the evolution of scalar perturbations in $f(T)$ teleparallel gravity and its effects on the cosmic microwave background (CMB) anisotropy. The $f(T)$ gravity generalizes the teleparallel gravity which is formulated on the Weitzenb\"ock spacetime, ... More
Model Selection Using Cosmic Chronometers with Gaussian ProcessesFeb 06 2018The use of Gaussian Processes with a measurement of the cosmic expansion rate based solely on the observation of cosmic chronometers provides a completely cosmology-independent reconstruction of the Hubble constant H(z) suitable for testing different ... More
Building a linear equation of state for trapped gravitons from finite size effects and the Schwarzschild black hole caseFeb 06 2018In this paper we continue the investigations present in \cite{1} and \cite{2} concerning the spectrum of trapped gravitons in a spherical box, and in particular inside a Schwarzschild black hole (BH). We explore the possibility that, due to finite size ... More
Physical and numerical stability and instability of AGN bubbles in a hot intracluster mediumFeb 06 2018While feedback from Active Galactic Nuclei (AGN) is an important heating source in the centre of galaxy clusters, it is still unclear how the feedback energy is injected into the intracluster medium (ICM) and what role different numerical approaches play. ... More
A general framework to test gravity using galaxy clusters I: Modelling the dynamical mass of haloes in $ f(R) $ gravityFeb 06 2018We propose a new framework for testing gravity using cluster observations, which aims to provide an unbiased constraint on modified gravity models from Sunyaev Zel'dovich (SZ) and X-ray cluster counts and the cluster gas fraction, among other possible ... More
Constraints on energy-momentum squared gravity from neutron stars and its cosmological implicationsFeb 06 2018Deviations from the predictions of general relativity due to energy-momentum squared gravity (EMSG) are expected to become pronounced in the high density cores of neutron stars. We derive the hydrostatic equilibrium equations in EMSG and solve them numerically ... More
AGN feedback and the origin and fate of the hot gas in early-type galaxiesFeb 06 2018A recent determination of the relationships between the X-ray luminosity of the ISM (Lx) and the stellar and total mass, for a sample of nearby early-type galaxies (ETGs), is used to investigate the origin of the hot gas, via a comparison with the results ... More
Are gravitational wave ringdown echoes always equal-interval ?Feb 06 2018Feb 07 2018Gravitational wave (GW) ringdown waveforms may contain "echoes" that encode new physics in the strong gravity regime. It is commonly assumed that the new physics gives rise to the GW echoes whose intervals are constant. We point out that this assumption ... More
Testing modified gravity with globular clusters: the case of NGC 2419Feb 06 2018The dynamics of globular clusters has been studied in great detail in the context of general relativity as well as with modifications of gravity that strongly depart from the standard paradigm such as MOND. However, at present there are no studies that ... More
Analytical Noise Bias Correction for Weak Lensing Shear Analysis with ERAFeb 06 2018Highly precise weak lensing shear measurement is required for statistical weak gravitational lensing analysis such as cosmic shear measurement to achieve severe constraint on the cosmological parameters. For this purpose, the accurate shape measurement ... More
The Inhomogeneous Reionization Times of Present-day GalaxiesFeb 05 2018Today's galaxies experienced cosmic reionization at different times in different locations. For the first time, reionization ($50\%$ ionized) redshifts, $z_R$, at the location of their progenitors are derived from new, fully-coupled radiation-hydrodynamics ... More
Measuring the value of the Hubble constant "à la Refsdal"Feb 05 2018Realizing Refsdal's original idea from 1964, we present estimates of the Hubble constant that are complementary to and potentially competitive with those of other cosmological probes. We use the observed positions of 89 multiple images, with extensive ... More
Towards Precision Constraints on Gravity with the Effective Field Theory of Large-Scale StructureFeb 05 2018We compare analytical computations with numerical simulations for dark-matter clustering, in general relativity and in the normal branch of DGP gravity (nDGP). Our analytical frameword is the Effective Field Theory of Large-Scale Structure (EFTofLSS), ... More
ATLAS Probe: Breakthrough Science of Galaxy Evolution, Cosmology, Milky Way, and the Solar SystemFeb 05 2018ATLAS (Astrophysics Telescope for Large Area Spectroscopy) Probe is a concept for a NASA probe-class space mission, the spectroscopic follow-up to WFIRST, multiplexing its scientific return by obtaining deep 1 to 4 micron slit spectroscopy for ~90% of ... More
Non-conservative unimodular type gravityFeb 05 2018In unimodular gravity the cosmological constant $\Lambda$ appears naturally as an integration constant when deriving the field equations of the theory and using the conservation of the matter components. Therefore, the unimodular approach seems to naturally ... More
Analytic Study of Cosmological Perturbations in a Unified Model of Dark Matter and Dark Energy with a Sharp TransitionFeb 05 2018We study cosmological perturbations in a model of unified dark matter and dark energy with a sharp transition in the late-time universe. The dark sector is described by a dark fluid which evolves from an early stage at redshifts $z > z_C$ when it behaves ... More
Non-Gaussian information from weak lensing data via deep learningFeb 04 2018Feb 06 2018Weak lensing maps contain information beyond two-point statistics on small scales. Much recent work has tried to extract this information through a range of different observables or via nonlinear transformations of the lensing field. Here we train and ... More
Where is Population II?Feb 04 2018The use of roman numerals for stellar populations represents a classification approach to galaxy formation which is now well behind us. Nevertheless, the concept of a pristine generation of stars, followed by a protogalactic era, and finally the mainstream ... More
The S-PASS view of polarized Galactic Synchrotron at 2.3 GHz as a contaminant to CMB observationsFeb 04 2018We analyze the Southern Sky emission in linear polarization at 2.3 GHz as observed by the S-band Polarization All Sky Survey S-PASS. Our purpose is to study the properties of the diffuse Galactic polarized synchrotron as a contaminant to CMB B-mode observations. ... More
Spatial Distribution of Gamma-Ray Burst SourcesFeb 03 2018The spatial distribution of sources of gamma-ray bursts (GRB) with known red shifts is analyzed by the conditional density and pairwise distance methods. The sample of GRB is based on data from the Swift mission and contains fluxes, coordinates, and red ... More
Maximally Rotating Supermassive Stars at the Onset of Collapse: The Perturbative Effects of Gas Pressure, Magnetic Fields, Dark Matter and Dark EnergyFeb 02 2018The discovery of quasars at increasingly large cosmological redshifts may favor "direct collapse" as the most promising evolutionary route to the formation of supermassive black holes. In this scenario, supermassive black holes form when their progenitors ... More
Observational constraints on the physical nature of submillimetre source multiplicity: chance projections are commonFeb 01 2018Interferometric observations have demonstrated that a significant fraction of single-dish submillimetre (submm) sources are blends of multiple submm galaxies (SMGs), but the nature of this multiplicity, i.e. whether the galaxies are physically associated ... More
Higgscitement: Cosmological Dynamics of Fine TuningFeb 01 2018The Higgs potential appears to be fine-tuned, hence very sensitive to values of other scalar fields that couple to the Higgs. We show that this feature can lead to a new epoch in the early universe featuring violent dynamics coupling the Higgs to a scalar ... More
A whirling plane of satellite galaxies around Centaurus A challenges cold dark matter cosmologyJan 31 2018The Milky Way and Andromeda galaxy are each surrounded by a thin plane of satellite galaxies that may be corotating. Cosmological simulations predict that most satellite galaxy systems are close to isotropic with random motions, so those two well-studied ... More
The MASSIVE Survey - X. Stellar Velocity Features and Misalignment between Kinematic and Photometric Axes in Massive Early-Type GalaxiesJan 31 2018We use spatially resolved two-dimensional stellar velocity maps over a $107''\times 107''$ field of view to investigate the kinematic features of 90 early-type galaxies above stellar mass $10^{11.5}M_\odot$ in the MASSIVE survey. We measure the misalignment ... More
Can the cosmological dark sector be modeled by a single scalar field?Jan 31 2018In a previous paper it was shown that a minimally coupled scalar field of mass $M \sim H_0$ can describe both components of the dark sector in a unified way. In the solution found, the dark energy component decays linearly with the Hubble parameter, with ... More
The Reconstruction of $f(φ)R$ and Mimetic Gravity from Viable Slow-roll InflationJan 31 2018In this work, we extend the bottom-up reconstruction framework of $F(R)$ gravity to other modified gravities, and in particular for $f(\phi)R$ and mimetic $F(R)$ gravities. We investigate which are the important conditions in order for the method to work, ... More
Particle content, radio-galaxy morphology and jet power: all radio-loud AGN are not equalJan 30 2018Ongoing and future radio surveys aim to trace the evolution of black hole growth and feedback from active galactic nuclei (AGN) throughout cosmic time; however, there remain major uncertainties in translating radio luminosity functions into a reliable ... More
The history of star formation from the cosmic infrared background anisotropiesJan 30 2018We present a linear clustering model of cosmic infrared background (CIB) anisotropies at large scales that is used to measure the cosmic star formation rate density up to redshift 6, the effective bias of the CIB and the mass of dark-matter halos hosting ... More
First Limit on the Direct Detection of Lightly Ionizing Particles for Electric Charge as Low as $e$/1000 with the \textsc{Majorana Demonstrator}Jan 30 2018Feb 01 2018The \textsc{Majorana Demonstrator} is an ultra low-background experiment searching for neutrinoless double-beta decay in $^{76}$Ge. The heavily shielded array of germanium detectors, placed nearly a mile underground at the Sanford Underground Research ... More
Direct dark matter search by annual modulation with 2.7 years of XMASS-I dataJan 30 2018An annual modulation signal due to the Earth's rotation around the Sun would be one of the strongest indications of the direct detection of dark matter. In 2016, we reported a search for dark matter by looking for an annual modulation with the single-phase ... More
Dependence of the Substructure Abundance on the Orientation Coherence of the Halo Tidal FieldJan 30 2018A numerical evidence for the dependence of the substructure abundance of cluster halos on the orientation coherence of the surrounding tidal fields is presented. Applying the adapted minimal spanning tree (MST) algorithm to the cluster halos with $M\ge ... More
Polarized anisotropic spectral distortions of the CMB: Galactic and extragalactic constraints on photon-axion conversionJan 29 2018We revisit the cosmological constraints on resonant and non-resonant conversion of photons to axions in the cosmological magnetic fields. We find that the constraints on photon-axion coupling and primordial magnetic fields are much weaker than previously ... More
Primordial Black Holes from Inflation and non-GaussianityJan 29 2018Primordial black holes may owe their origin to the small-scale enhancement of the comoving curvature perturbation generated during inflation. Their mass fraction at formation is markedly sensitive to possible non-Gaussianities in such large, but rare ... More
Identification of multiple hard X-ray sources in solar flares: A Bayesian analysis of the February 20 2002 eventJan 27 2018Hard X-ray emission in solar flares is typically characterized by a number of discrete sources, each with its own spectral, temporal, and spatial variability. Establishing the relationship amongst these sources is critical to determine the role of each ... More
Testing modified gravity using a marked correlation functionJan 26 2018Jan 30 2018In theories of modified gravity with the chameleon screening mechanism, the strength of the fifth force depends on environment. This induces an environment dependence of structure formation, which differs from $\Lambda$CDM. We show that these differences ... More
Improving Weak Lensing Mass Map Reconstructions using Gaussian and Sparsity Priors: Application to DES SVJan 26 2018Mapping the underlying density field, including non-visible dark matter, using weak gravitational lensing measurements is now a standard tool in cosmology. Due to its importance to the science results of current and upcoming surveys, the quality of the ... More
Marked clustering statistics in $f(R)$ gravity cosmologiesJan 26 2018We analyse the two-point and marked correlation functions of haloes and galaxies in three variants of the chameleon $f(R)$ gravity model using N-body simulations, and compare to a fiducial $\Lambda$CDM model based on general relativity (GR). Using a halo ... More
Galaxy Formation Efficiency and the Multiverse Explanation of the Cosmological Constant with EAGLE SimulationsJan 26 2018Models of the very early universe, including inflationary models, are argued to produce varying universe domains with different values of fundamental constants and cosmic parameters. Using the cosmological hydrodynamical simulation code from the \eagle ... More
The impact of baryons on the matter power spectrum from the Horizon-AGN cosmological hydrodynamical simulationJan 25 2018Accurate cosmology from upcoming weak lensing surveys relies on knowledge of the total matter power spectrum at percent level at scales $k < 10$ $h$/Mpc, for which modelling the impact of baryonic physics is crucial. We compare measurements of the total ... More
Power Corrections to the Universal Heavy WIMP-Nucleon Cross SectionJan 25 2018WIMP-nucleon scattering is analyzed at order $1/M$ in Heavy WIMP Effective Theory. The $1/M$ power corrections, where $M\gg m_W$ is the WIMP mass, distinguish between different underlying UV models with the same universal limit and their impact on direct ... More
Extracting Particle Physics Information from Direct Detection of Dark Matter with Minimal AssumptionsJan 25 2018In the absence of direct accelerator data to constrain particle models, and given existing astrophysical uncertainties associated with the phase space distribution of WIMP dark matter in our galactic halo, extracting information on fundamental particle ... More
Density perturbations for running vacuum: a successful approach to structure formation and to the $σ_8$-tensionJan 25 2018Recent studies suggest that dynamical dark energy (DDE) provides a better fit to the rising affluence of modern cosmological observations than the concordance model ($\Lambda$CDM) with a rigid cosmological constant, $\Lambda$. Such is the case with the ... More
Dynamical System Analysis of a Five-Dimensional Cosmological ModelJan 25 2018A five-dimensional cosmological model including a single perfect fluid is studied in the framework of dynamical system analysis. All the critical points of the system with their stability properties are listed and some representative phase diagrams are ... More
Spotting high-z molecular absorbers using neutral carbon: Results from a complete spectroscopic survey with the VLTJan 25 2018Jan 26 2018While molecular quasar absorption systems provide unique probes of the physical and chemical properties of the gas as well as original constraints on fundamental physics and cosmology, their detection remains challenging. Here we present the results from ... More
Linear potentials in galaxy halos by Asymmetric WormholesJan 25 2018In this letter we study the spherically symmetric space-time for a diffusive two measures theory. It is demonstrated that by imposing an asymmetric wormhole geometry, one gets a metric coefficient which for galactic distances has a linear term and from ... More
First release of high-redshift superluminous supernovae from the Subaru HIgh-Z sUpernova CAmpaign (SHIZUCA). II. Spectroscopic propertiesJan 24 2018We present Keck spectroscopic confirmation of three superluminous supernovae (SLSNe) at z = 1.851, 1.965 and 2.399 detected as part of the Subaru HIgh-Z sUpernova CAmpaign (SHIZUCA). The host galaxies have multi-band photometric redshifts consistent with ... More
First release of high-redshift superluminous supernovae from the Subaru HIgh-Z sUpernova CAmpaign (SHIZUCA). I. Photometric propertiesJan 24 2018We report our first discoveries of high-redshift supernovae from the Subaru HIgh-Z sUpernova CAmpaign (SHIZUCA), a transient survey using Subaru/Hyper Suprime-Cam. We report the discovery of three supernovae at spectroscopically-confirmed redshifts of ... More
AX-GADGET: a new code for cosmological simulations of Fuzzy Dark Matter and Axion modelsJan 24 2018We present a new module of the parallel N-Body code P-GADGET3 for cosmological simulations of light bosonic non-thermal dark matter, often referred as Fuzzy Dark Matter (FDM). The dynamics of the FDM features a highly non-linear Quantum Potential (QP) ... More
Current and future constraints on extended Bekenstein-type models for a varying fine-structure constantJan 24 2018There is a growing interest in astrophysical tests of the stability of dimensionless fundamental couplings, such as the fine-structure constant $\alpha$, as an optimal probe of new physics. The imminent arrival of the ESPRESSO spectrograph will soon enable ... More
Modelling redshift-space distortion in the post-reionization ${\rm HI}$ 21-cm power spectrumJan 24 2018The post-reionization ${\rm HI}$ 21-cm signal is an excellent candidate for precision cosmology, this however requires accurate modelling of the expected signal. Sarkar et al. (2016) have simulated the real space ${\rm HI}$ 21-cm signal, and have modelled ... More
Early growth of high redshift black holesJan 23 2018Understanding the growth of high redshift massive black holes (MBHs) is a problem of great astrophysical interest. The most luminous quasars at $z>6$ are frequently observed but they represent only the tip of the iceberg as the majority of the low luminosity ... More
Predicting Quasar Continua Near Lyman-$α$ with Principal Component AnalysisJan 23 2018Measuring the proximity effect and the damping wing of intergalactic neutral hydrogen in quasar spectra during the epoch of reionization requires an estimate of the intrinsic continuum at rest-frame wavelengths $\lambda_{\rm rest}\sim1200$-$1260$ {\AA}. ... More
Large-scale messengers from arbitrary spin fieldsJan 22 2018We show that nonperturbative production of arbitrary spin fields from vacuum will accompany the generation of non-vanishing macroscopic energy-momentum tensor correlators. This argument is based on the general causal field formalism, which gives a manifestly ... More
Dynamical constraints on the dark matter distribution of the Sculptor dwarf spheroidal from stellar proper motionsJan 22 2018We compare the transverse velocity dispersions recently measured within the Sculptor dwarf spheroidal galaxy to the predictions of previously published dynamical models. These provide good fits to the observed number count and velocity dispersion profiles ... More
Machine Learning-based Brokers for Real-time Classification of the LSST Alert StreamJan 22 2018The unprecedented volume and rate of transient events that will be discovered by the Large Synoptic Survey Telescope (LSST) demands that the astronomical community update its followup paradigm. Alert-brokers -- automated software system to sift through, ... More
ALMA observations of lensed Herschel sources : Testing the dark-matter halo paradigmJan 22 2018With the advent of wide-area submillimeter surveys, a large number of high-redshift gravitationally lensed dusty star-forming galaxies (DSFGs) has been revealed. Due to the simplicity of the selection criteria for candidate lensed sources in such surveys, ... More
The Second Nucleus of NGC 7727: Direct Evidence for the Formation and Evolution of an Ultracompact Dwarf GalaxyJan 22 2018We present new observations of the late-stage merger galaxy NGC 7727, including HST/WFPC2 images and long-slit spectra obtained with the Clay telescope. NGC 7727 is relatively luminous ($M_V = -21.7$) and features two unequal tidal tails, various bluish ... More
Cospatial Star Formation and Supermassive Black Hole Growth in $z \sim 3$ Galaxies: Evidence for In-situ Co-evolutionJan 22 2018We present a sub-kpc localization of the sites of supermassive black hole (SMBH) growth in three active galactic nuclei (AGN) at $z \sim 3$ in relation to the regions of intense star formation in their hosts. These AGNs are selected from Karl G. Jansky ... More
Gravitational wave speed: Implications for models without a mass scaleJan 20 2018The recent report that the gravitational wave speed equals the light speed puts strong constraints on the anisotropic stress parameter of many modified gravity models, a quantity that is directly observable through large-scale structure. We show here ... More
Role of primordial black holes in the direct collapse scenario of supermassive black hole formation at high redshiftsJan 20 2018In this paper, we explore the possibility of accreting primordial black holes as the source of heating for the collapsing gas in the context of the direct collapse black hole scenario for the formation of super-massive black holes (SMBHs) at high redshifts, ... More
Workshop 8: SupernovaeJan 20 2018Jan 24 2018This contribution presents the results of workshop 8 (supernovae) held during the IAU Symposium 339 "Southern Horizons in Time-Domain Astronomy" at Stellenbosch University, South Africa. Workshop 8 covered a cornucopia of topics with each one having a ... More
Probing galaxy assembly bias with LRG weak lensing observationsJan 19 2018In Montero-Dorta et al. 2017, we show that luminous red galaxies (LRGs) from the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) at $z\sim0.55$ can be divided into two groups based on their star formation histories. So-called fast-growing LRGs ... More
Elemental gas-phase abundances of intermediate redshift type Ia supernova star-forming host galaxiesJan 19 2018Feb 01 2018The maximum luminosity of type Ia supernovae (SNe Ia) depends on the oxygen abundance of the regions of the host galaxies where they explode. This metallicity dependence reduces the dispersion in the Hubble diagram (HD) when included with the traditional ... More
Mean Occupation Function of High Redshift Quasars from the Planck Cluster CatalogJan 19 2018We characterise the distribution of quasars within dark matter halos using a direct measurement technique for the first time at redshifts as high as $z \sim 1$. Using the Planck Sunyaev-Zeldovich (SZ) catalogue for galaxy groups and the Sloan Digital ... More
The Megamaser Cosmology Project. X. High Resolution Maps and Mass Constraint for SMBHsJan 19 2018We present high resolution (sub-mas) VLBI maps of nuclear H2O megamasers for seven galaxies. In UGC6093, the well-aligned systemic masers and high-velocity masers originate in an edge-on, flat disk and we determine the mass of the central SMBH to be M_SMBH ... More
Aligned metal absorbers and the ultraviolet background at the end of reionizationJan 18 2018We use observations of spatially-aligned C II, C IV, Si II, Si IV, and O I absorbers to probe the slope and intensity of the ultraviolet background (UVB) at $z \sim 6$. We accomplish this by comparing observations with predictions from a cosmological ... More
Indication of anisotropy in arrival directions of ultra-high-energy cosmic rays through comparison to the flux pattern of extragalactic gamma-ray sourcesJan 18 2018Feb 06 2018A new analysis of the dataset from the Pierre Auger Observatory provides evidence for anisotropy in the arrival directions of ultra-high-energy cosmic rays on an intermediate angular scale, which is indicative of excess arrivals from strong, nearby sources. ... More
Robust Foregrounds Removal for 21-cm ExperimentsJan 18 2018Direct detection of the Epoch of Reionization via the redshifted 21-cm line will have unprecedented implications on the study of structure formation in the early Universe. To fulfill this promise current and future 21-cm experiments will need to detect ... More
A Precise Distance to the Host Galaxy of the Binary Neutron Star Merger GW170817 Using Surface Brightness FluctuationsJan 18 2018The joint detection of gravitational waves and electromagnetic radiation from the binary neutron star (BNS) merger GW170817 has provided unprecedented insight into a wide range of physical processes: heavy element synthesis via the $r$-process; the production ... More
Collisions in Primordial Star Clusters: Formation Pathway for intermediate mass black holesJan 18 2018Jan 20 2018Collisions were suggested to potentially play a role in the formation of massive stars in present day clusters, and have likely been relevant during the formation of massive stars and intermediate mass black holes within the first star clusters. In the ... More
Formation of massive seed black holes via collisions and accretionJan 17 2018Models aiming to explain the formation of massive black hole seeds, and in particular the direct collapse scenario, face substantial difficulties. These are rooted in rather ad hoc and fine-tuned initial conditions, such as the simultaneous requirements ... More
Cosmological constraints from low-redshift dataJan 17 2018In this paper we summarise the constraints that low-redshift data -such as supernovae Ia, baryon acoustic oscillations and cosmic chronometers- are able to set on the concordance model and its extensions, as well as on inhomogeneous but isotropic models. ... More
Detection of the rapid variability in the Q2237+0305 quasarJan 17 2018Rapid intrinsic variability has been detected for the first time in the Einstein Cross QSO 2237+0305, a radio quiet flat spectrum quasar at z=1.7 that is quadruply lensed by a foreground galaxy at z=0.04. The observed short-period event at the time scale ... More
Electromagnetic redshift in anisotropic cosmologiesJan 16 2018Redshift of light is calculated for an anisotropic cosmological spacetime. Two different approaches are considered. In the first one, electromagnetic waves are modeled using the geometrical optics approximation. This approach considers light rays following ... More
Optimal and fast E/B separation with a dual messenger fieldJan 16 2018Feb 08 2018We adapt our recently proposed dual messenger algorithm for spin field reconstruction and showcase its efficiency and effectiveness in Wiener filtering polarized cosmic microwave background (CMB) maps. Unlike conventional preconditioned conjugate gradient ... More
Reconstructing warm inflationJan 16 2018Jan 22 2018The reconstruction of a warm inflationary universe model from the scalar spectral index $n_S(N)$ and the tensor to scalar ratio $r(N)$ as a function of the number of e-folds $N$ is studied. Under a general formalism we find the effective potential and ... More
FSD: Frequency Space Differential measurement of CMB spectral distortionsJan 16 2018Although the Cosmic Microwave Background agrees with a perfect blackbody spectrum within the current experimental limits, it is expected to exhibit certain spectral distortions with known spectral properties. We propose a new method, Frequency Space Differential ... More
Initial conditions for Inflation in an FRW UniverseJan 15 2018We examine the class of initial conditions which give rise to inflation. Our analysis is carried out for several popular models including: Higgs inflation, Starobinsky inflation, chaotic inflation, axion monodromy inflation and non-canonical inflation. ... More
Neutrino masses and their ordering: Global Data, Priors and ModelsJan 15 2018We present a Bayesian analysis of the combination of current neutrino oscillation, neutrinoless double beta decay and CMB observations. Our major goal is to carefully investigate the possibility to single out one neutrino mass ordering, Normal Ordering ... More
Planck intermediate results. LIV. Polarized dust foregroundsJan 15 2018The study of polarized dust emission has become entwined with the analysis of the cosmic microwave background (CMB) polarization. We use new Planck maps to characterize Galactic dust emission as a foreground to the CMB polarization. We present Planck ... More
The dependence of galaxy clustering on stellar mass, star-formation rate and redshift at z = 0.8-2.2, with HiZELSJan 15 2018The deep, near-infrared narrow-band survey HiZELS has yielded robust samples of H-alpha emitting star-forming galaxies within narrow redshift slices at z = 0.8, 1.47 and 2.23. In this paper, we distinguish the stellar mass and star-formation rate (SFR) ... More
Cosmic web dependence of galaxy clustering and quenching in SDSSJan 15 2018Galaxies exhibit different clustering and quenching properties in clusters, filaments, and the field, but it is still uncertain whether such differences are imprints of the tidal environment on galaxy formation, or if they reflect the variation of the ... More
Primordial deuterium abundance at z=2.504 towards Q1009+2956Jan 15 2018The z_abs = 2.504 Lyman Limit absorption system (LLS) towards Q1009+2956 has previously been used to estimate the primordial deuterium abundance. Since the initial measurement by Burles & Tytler, this quasar has been observed extensively with the Keck ... More
Constraining the range of Yukawa gravity interaction from S2 star orbits III: improvement expectations for graviton mass boundsJan 15 2018Jan 16 2018Recently, the LIGO-Virgo collaboration discovered gravitational waves and in their first publication on the subject the authors also presented a graviton mass constraint as $m_g < 1.2 \times 10^{-22}$ eV (Abbott et al., 2016). In the paper we analyze ... More
Observational bounds on extended theories of gravity from energy conditionsJan 14 2018The attempt to describe the recent accelerated expansion of the universe includes different propositions for dark energy models and modified gravity theories. Establish their features in order to discriminate and even rule out part of these models using ... More
Optical identifications of high-redshift galaxy clusters from Planck Sunyaev-Zeldovich surveyJan 13 2018We present the results of optical identifications and spectroscopic redshifts measurements for galaxy clusters from 2-nd Planck catalogue of Sunyaev-Zeldovich sources (PSZ2), located at high redshifts, $z\approx0.7-0.9$. We used the data of optical observations ... More
BAO from angular clustering: optimization and mitigation of theoretical systematicsJan 13 2018We study the theoretical systematics and optimize the methodology in Baryon Acoustic Oscillations (BAO) detections using the angular correlation function with tomographic bins. We calibrate and optimize the pipeline for the Dark Energy Survey Year 1 dataset ... More
Testing (modified) gravity with 3D and tomographic cosmic shearJan 12 2018Cosmic shear, the weak gravitational lensing caused by the large-scale structure, is one of the primary probes to test gravity with current and future surveys. There are two main techniques to analyse a cosmic shear survey; a tomographic method, where ... More
Optical Follow-up of Planck Cluster Candidates with Small InstrumentsJan 12 2018We report on the search for optical counterparts of Planck Sunyaev-Zel'dovich (SZ) cluster candidates using a 0.6 meter non-professional telescope. Among the observed sources, an unconfirmed candidate, PSZ2 G156.24+22.32, is found to be associated with ... More
Connecting optical and X-ray tracers of galaxy cluster relaxationJan 11 2018Substantial effort has been devoted in determining the ideal proxy for quantifying the morphology of the hot intracluster medium in clusters of galaxies. These proxies, based on X-ray emission, typically require expensive, high-quality X-ray observations ... More