Latest in astro-ph.im

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Robust model comparison tests of DAMA/LIBRA annual modulationJun 13 2019We evaluate the statistical significance of the DAMA/LIBRA claims for annual modulation using three independent model comparison techniques, viz frequentist, information theory, and Bayesian analysis. We fit the data from the DAMA/LIBRA experiment to ... More
Thin glass shells for active optics for future space telescopesJun 13 2019We present a method for the manufacturing of thin shells of glass, which appears promising for the development of active optics for future space telescopes. The method exploits the synergy of different mature technologies, while leveraging the commercial ... More
Developing a mass-production model of large-area Si(Li) detectors with high operating temperaturesJun 13 2019This study presents a fabrication process for lithium-drifted silicon (Si(Li)) detectors that, compared to previous methods, allows for mass production at a higher yield, while providing a large sensitive area and low leakage currents at relatively high ... More
Nuclear Mass Measurements With Radioactive Ion BeamsJun 13 2019Nuclear masses are the most fundamental of all nuclear properties, yet they can provide a wealth of knowledge, including information on astrophysical sites, constraints on existing theory, and fundamental symmetries. In nearly all applications, it is ... More
Reconstruction of air-shower measurements with AERA in the presence of pulsed radio-frequency interferenceJun 12 2019The Auger Engineering Radio Array (AERA) is situated in the Argentinian Pampa Amarilla, a location far away from large human settlements. Nevertheless, a strong background of pulsed radio-frequency interference (RFI) exists on site, which not only makes ... More
A Thousand Earths: A Very Large Aperture, Ultralight Space Telescope Array for Atmospheric Biosignature SurveysJun 12 2019An outstanding, multi-disciplinary goal of modern science is the study of the diversity of potentially Earth-like planets and the search for life in them. This goal requires a bold new generation of space telescopes, but even the most ambitious designs ... More
Estimation and correction of the instrumental perturbations of Vainu Bappu Telescope Echelle spectrograph using a model-based approachJun 12 2019The Echelle spectrograph operating at Vainu Bappu Telescope (VBT), India, is a general purpose instrument used for many high-resolution spectroscopic observations. A concerted effort is being made to expand the scientific capability of the instrument ... More
The GIST Pipeline: A Multi-Purpose Tool for the Analysis and Visualisation of (Integral-field) Spectroscopic DataJun 11 2019We present a convenient, all-in-one framework for the scientific analysis of fully reduced, (integral-field) spectroscopic data. The GIST pipeline (Galaxy IFU Spectroscopy Tool) is entirely written in Python3 and conducts all steps from the preparation ... More
Measuring clock jumps using pulsar timingJun 11 2019In this paper, we investigate the statistical signal-processing algorithm to measure the instant local clock jump from the timing data of multiple pulsars. Our algorithm is based on the framework of Bayesian statistics. In order to make the Bayesian algorithm ... More
k-Means Aperture Optimization Applied to Kepler K2 Time Series Photometry of TitanJun 10 2019Motivated by the Kepler K2 time series of Titan, we present an aperture optimization technique for extracting photometry of saturated moving targets with high temporally- and spatially-varying backgrounds. Our approach uses $k$-means clustering to identify ... More
CAFE2: an upgrade to the CAFE high-resolution spectrograph. Commissioning results and new public pipelineJun 10 2019The Calar Alto Fiber-fed \'Echelle spectrograph (CAFE) is a high-resolution spectrographs with high-precision radial velocity capabilities mounted in the 2.2m telescope of Calar Alto Observatory. It suffered from strong degradation after 4 years of operations ... More
Gain Stabilization for Radio Intensity Mapping using a Continuous-Wave Reference SignalJun 10 2019Stabilizing the gain of a radio astronomy receiver is of great importance for sensitive radio intensity mapping. In this paper we discuss a stabilization method using a continuous-wave reference signal injected into the signal chain and tracked in a single ... More
RadioGAN - Translations between different radio surveys with generative adversarial networksJun 10 2019Radio surveys are widely used to study active galactic nuclei. Radio interferometric observations typically trade-off surface brightness sensitivity for angular resolution. Hence, observations using a wide range of baseline lengths are required to recover ... More
Detector Characterization of a Near-Infrared Discrete Avalanche Photodiode 5x5 Array for Astrophysical ObservationsJun 10 2019We present detector characterization of a state-of-the-art near-infrared (950nm - 1650 nm) Discrete Avalanche Photodiode detector (NIRDAPD) 5x5 array. We designed an experimental setup to characterize the NIRDAPD dark count rate, photon detection efficiency ... More
The ssos Pipeline: Identification of Solar System Objects in Astronomical ImagesJun 09 2019Observatories and satellites around the globe produce tremendous amounts of imaging data to study many different astrophysical phenomena. The serendipitous observations of Solar System objects are a fortunate by-product which have often been neglected ... More
A Probabilistic Approach to Kepler Completeness and Reliability for Exoplanet Occurrence RatesJun 09 2019Exoplanet catalogs produced by surveys suffer from a lack of completeness (not every planet is detected) and less than perfect reliability (not every planet in the catalog is a true planet). Occurrence rate studies of the exoplanet population structure ... More
Identifying optical turbulence profiles for realistic tomographic error in adaptive opticsJun 08 2019For extremely large telescopes, adaptive optics will be required to correct the Earth's turbulent atmosphere. The performance of tomographic adaptive optics is strongly dependent on the vertical distribution (profile) of this turbulence. An important ... More
Learning Radiative Transfer Models for Climate Change Applications in Imaging SpectroscopyJun 08 2019According to a recent investigation, an estimated 33-50% of the world's coral reefs have undergone degradation, believed to be as a result of climate change. A strong driver of climate change and the subsequent environmental impact are greenhouse gases ... More
Learning Transient Universe in Near-Ultraviolet By Wide-angle CamerasJun 08 2019We perform a detailed analysis and simulations on the transient detection capability in the near-ultraviolet (NUV) band by focusing on some major local transient events. These events include the tidal disruption event due to a supermassive blackhole, ... More
Stochastic Speckle Discrimination with Time-Tagged Photon Lists: Digging Below the Speckle Noise FloorJun 07 2019We present an algorithm that uses the distribution of photon arrival times to distinguish speckles from incoherent sources, like planets and disks, in high contrast images. Using simulated data, we show that our approach can overcome the noise limit from ... More
Polarisation and Brightness Temperature Observations of Venus with the GMRTJun 07 2019Venus was observed at frequencies of 1297.67 MHz (23 cm), 607.67 MHz (49 cm) and 233.67 MHz (1.28 m) with the Giant Metrewave Radio Telescope (GMRT) during the period of 25th July and 6th September 2015 when it was close to its inferior conjunction. Values ... More
The minimum of the time-delay wavefront error in Adaptive OpticsJun 07 2019An analytical expression is given for the minimum of the mean square of the time-delay induced wavefront error (also known as the servo-lag error) in Adaptive Optics systems. The analysis is based on the von K\'arm\'an model for the spectral density of ... More
An adaptive scheduling tool to optimize measurements to reach a scientific objective: methodology and application to the measurements of stellar orbits in the Galactic CenterJun 07 2019In various fields of physics and astronomy, access to experimental facilities or to telescopes is becoming more and more competitive and limited. It becomes therefore important to optimize the type of measurements and their scheduling to reach a given ... More
Standardized spectral and radiometric calibration of consumer camerasJun 07 2019Consumer cameras, particularly onboard smartphones and UAVs, are now commonly used as scientific instruments. However, their data processing pipelines are not optimized for quantitative radiometry and their calibration is more complex than that of scientific ... More
Radio Galaxy Zoo: Unsupervised Clustering of Convolutionally Auto-encoded Radio-astronomical ImagesJun 07 2019This paper demonstrates a novel and efficient unsupervised clustering method with the combination of a Self-Organising Map (SOM) and a convolutional autoencoder. The rapidly increasing volume of radio-astronomical data has increased demand for machine ... More
Constraining Exoplanet Metallicities and Aerosols with ARIEL: An Independent Study by the Contribution to ARIEL Spectroscopy of Exoplanets (CASE) TeamJun 06 2019Launching in 2028, ESA's Atmospheric Remote-sensing Exoplanet Large-survey (ARIEL) survey of $\sim$1000 transiting exoplanets will build on the legacies of Kepler and TESS and complement JWST by placing its high precision exoplanet observations into a ... More
Searching for fast extragalactic X-ray transients in Chandra surveysJun 06 2019Recent works have discovered two fast ($\approx 10$ ks) extragalactic X-ray transients in the Chandra Deep Field-South (CDF-S XT1 and XT2). These findings suggest that a large population of similar extragalactic transients might exist in archival X-ray ... More
Inferring black hole spins and probing accretion/ejection flows in AGNs with the Athena X-ray Integral Field UnitJun 06 2019Active Galactic Nuclei (AGN) display complex X-ray spectra which exhibit a variety of emission and absorption features, that are commonly interpreted as a combination of i) a relativistically smeared reflection component, resulting from the irradiation ... More
An analysis of binary microlensing event OGLE-2015-BLG-0060Jun 06 2019We present the analysis of stellar binary microlensing event OGLE-2015-BLG-0060 based on observations obtained from 13 different telescopes. Intensive coverage of the anomalous parts of the light curve was achieved by automated follow-up observations ... More
Calibration of Argus and the 4mm Receiver on the GBTJun 05 2019The calibration procedures for data collected for Argus and the 4mm Receiver instruments on the GBT are presented. The measured beam size, aperture efficiency, and main-beam efficiency are derived for the range of observing frequencies (66--116 GHz) within ... More
A Pathfinder for Imaging Extrasolar Earths from the GroundJun 05 2019The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) project is an instrument on the Subaru telescope that is pushing the frontiers of what is possible with ground-based high-contrast imaging of extrasolar planets. The system features key breakthroughs ... More
Exploring low-energy neutrino physics with the Coherent Neutrino Nucleus Interaction Experiment (CONNIE)Jun 05 2019The Coherent Neutrino-Nucleus Interaction Experiment (CONNIE) uses low-noise fully depleted charge-coupled devices (CCDs) with the goal of measuring low-energy recoils from coherent elastic scattering (CE$\nu$NS) of reactor antineutrinos with silicon ... More
Cold Debris Disks as Strategic Targets for the 2020sJun 05 2019Cold debris disks (T$<$200 K) are analogues to the dust in the Solar System's Kuiper belt--dust generated from the evaporation and collision of minor bodies perturbed by planets, our Sun, and the local interstellar medium. Scattered light from debris ... More
Resolving starlight: a quantum perspectiveJun 05 2019The wave-particle duality of light introduces two fundamental problems to imaging, namely, the diffraction limit and the photon shot noise. Quantum information theory can tackle them both in one holistic formalism: model the light as a quantum object, ... More
Brighter-fatter effect in near-infrared detectors -- II. Auto-correlation analysis of H4RG-10 flatsJun 05 2019The Wide Field Infrared Survey Telescope (WFIRST) will investigate the origins of cosmic acceleration using weak gravitational lensing at near infrared wavelengths. Lensing analyses place strict constraints on the precision of size and ellipticity measurements ... More
Brighter-fatter effect in near-infrared detectors -- I. Theory of flat auto-correlationsJun 05 2019Weak gravitational lensing studies aim to measure small distortions in the shapes of distant galaxies, and thus place very tight demands on the understanding of detector-induced systematic effects in astronomical images. The Wide-Field Infrared Survey ... More
An experiment to search for dark matter interactions using sodium iodide detectorsJun 05 2019Observations of galaxies and primordial radiation suggest that the Universe is made mostly of non-luminous dark matter. Several types of new fundamental particles have been proposed as candidates for dark matter such as weakly interacting massive particles ... More
Confusion noise due to clustered extragalactic point sources. Application of logarithmic cumulants for parameter estimationJun 04 2019The calculation of the characteristic function of the signal fluctuations due to clustered astrophysical sources is performed in this paper. For the typical case of power-law differential number counts and two-point angular correlation function, we present ... More
NuRadioMC: Simulating the radio emission of neutrinos from interaction to detectorJun 04 2019NuRadioMC is a Monte Carlo framework designed to simulate ultra-high energy neutrino detectors that rely on the radio detection method. This method exploits the radio emission generated in the electromagnetic component of a particle shower following a ... More
BlueMUSE: Project Overview and Science CasesJun 04 2019We present the concept of BlueMUSE, a blue-optimised, medium spectral resolution, panoramic integral field spectrograph based on the MUSE concept and proposed for the Very Large Telescope. With an optimised transmission down to 350 nm, a larger FoV (1.4 ... More
Detailed study of the ELAIS N1 field with the uGMRT - I. Characterizing the 325 MHz foreground for redshifted 21 cm observationsJun 04 2019In this first paper of the series, we present initial results of newly upgraded Giant Meterwave Radio Telescope (uGMRT) observation of European Large-Area ISO Survey-North 1 (ELAIS-N1) at 325 MHz with 32 MHz bandwidth. Precise measurement of fluctuations ... More
The Measured Impact of Chromatic Atmospheric Effects on Barycentric Corrections: Results from the EXtreme PREcision SpectrographJun 04 2019One source of error in high-precision radial velocity measurements of exoplanet host stars is chromatic change in Earth's atmospheric transmission during observations. Mitigation of this error requires that the photon-weighted barycentric correction be ... More
KiDS-SQuaD II: Machine learning selection of bright extragalactic objects to search for new gravitationally lensed quasarsJun 04 2019The KiDS Strongly lensed QUAsar Detection project (KiDS-SQuaD) aims at finding as many previously undiscovered gravitational lensed quasars as possible in the Kilo Degree Survey. This is the second paper of this series where we present a new, automatic ... More
KiDS-SQuaD II: Machine learning selection of bright extragalactic objects to search for new gravitationally lensed quasarsJun 04 2019Jun 07 2019The KiDS Strongly lensed QUAsar Detection project (KiDS-SQuaD) aims at finding as many previously undiscovered gravitational lensed quasars as possible in the Kilo Degree Survey. This is the second paper of this series where we present a new, automatic ... More
Spherical ansatz for parameter-space metricsJun 04 2019A fundamental quantity in signal analysis is the metric $g_{ab}$ on parameter space, which quantifies the fractional "mismatch" $m$ between two (time- or frequency-domain) waveforms. When searching for weak gravitational-wave or electromagnetic signals ... More
Local monitoring of atmospheric transparency from the NASA MERRA-2 global assimilation systemJun 04 2019Ground-based astronomy has to correct astronomical observations from the impact of the atmospheric transparency and its variability. The current objective of several observatories is to achieve a sub-percent level monitoring of atmospheric transmission. ... More
A semiconductor-based neutron detection system for planetary explorationJun 04 2019We explore the use of microstructured semiconductor neutron detectors (MSNDs) to map the ratio between thermal neutrons and higher energy neutrons. The system consists of alternating layers of modular neutron detectors (MNDs), each comprising arrays of ... More
Absolving the SSINS of Precision Interferometric Radio Data: A New Technique for Mitigating Ultra-faint Radio Frequency InterferenceJun 03 2019We introduce a new method for mitigating ultra-faint radio frequency interference (RFI), which we call Sky-Subtracted Incoherent Noise Spectra (SSINS). SSINS is designed to identify and remove RFI below the single baseline thermal noise. We demonstrate ... More
hankel: A Python library for performing simple and accurate Hankel transformationsJun 03 2019This paper presents \textsc{hankel}, a pure-python code for solving Hankel-type integrals and transforms. Such transforms are common in the physical sciences, especially appearing as the radial solution to angularly symmetric Fourier Transforms in arbitrary ... More
A Curated Image Parameter Dataset from Solar Dynamics Observatory MissionJun 03 2019We provide a large image parameter dataset extracted from the Solar Dynamics Observatory (SDO) mission's AIA instrument, for the period of January 2011 through the current date, with the cadence of six minutes, for nine wavelength channels. The volume ... More
Wotan: Comprehensive time-series de-trending in PythonJun 03 2019The detection of transiting exoplanets in time-series photometry requires the removal or modeling of instrumental and stellar noise. While instrumental systematics can be reduced using methods such as pixel level decorrelation, removing stellar trends ... More
Wotan: Comprehensive time-series de-trending in PythonJun 03 2019Jun 13 2019The detection of transiting exoplanets in time-series photometry requires the removal or modeling of instrumental and stellar noise. While instrumental systematics can be reduced using methods such as pixel level decorrelation, removing stellar trends ... More
In-flight photometry extraction of PLATO targets: Optimal apertures for detecting extrasolar planetsJun 03 2019The ESA PLATO space mission is devoted to unveiling and characterizing new extrasolar planets and their host stars. This mission will encompass a very large field of view, granting it the potential to survey up to one million stars depending on the final ... More
Wide-band Rotation Measure SynthesisJun 03 2019Rotation measure synthesis allows the estimation of Faraday dispersion via a Fourier transform and is the primary tool to probe cosmic magnetic fields. We show this can be considered mathematically equivalent to the one dimensional interferometric intensity ... More
A photomultiplier tube test stand and on-site measurements to characterise the performance of Photonis XP3062 photomultiplier tubes at increased background light conditions and lower gainJun 03 2019Photomultiplier tubes (PMTs) are widely used in astroparticle physics experiments to detect light flashes (e.g. fluorescence or Cherenkov light) from extensive air showers (EASs) initiated by statistically rare very high energy cosmic particles when travelling ... More
Evolution of Novel Activation Functions in Neural Network Training with Applications to Classification of ExoplanetsJun 01 2019We present analytical exploration of novel activation functions as consequence of integration of several ideas leading to implementation and subsequent use in habitability classification of exoplanets. Neural networks, although a powerful engine in supervised ... More
Radiation hardness of a p-channel notch CCD developed for the X-ray CCD camera onboard the XRISM satelliteJun 01 2019We report the radiation hardness of a p-channel CCD developed for the X-ray CCD camera onboard the XRISM satellite. This CCD has basically the same characteristics as the one used in the previous Hitomi satellite, but newly employs a notch structure of ... More
Detection Prospects of Core-Collapse Supernovae with Supernova-Optimized Third-Generation Gravitational-wave DetectorsMay 31 2019We optimize the third-generation gravitational-wave detector to maximize the range to detect core-collapse supernovae. Based on three-dimensional simulations for core-collapse and the corresponding gravitational-wave waveform emitted, the corresponding ... More
Large-area Si(Li) detectors for X-ray spectrometry and particle tracking in the GAPS experimentMay 31 2019The first lithium-drifted silicon (Si(Li)) detectors to satisfy the unique geometric, performance, and cost requirements of the GAPS (General Antiparticle Spectrometer) experiment have been produced by Shimadzu Corporation. The GAPS Si(Li) detectors will ... More
X-ray imaging polarimetry with a 2.5-$\mathrmμ$m pixel CMOS sensor for visible light at room temperatureMay 31 2019X-ray polarimetry in astronomy has not been exploited well, despite its importance. The recent innovation of instruments is changing this situation. We focus on a complementary MOS (CMOS) pixel detector with small pixel size and employ it as an x-ray ... More
A New Approach to Free-Form Cluster Lens Modeling Inspired by the JPEG Image Compression MethodMay 31 2019I propose a new approach to free-form cluster lens modeling that is inspired by the JPEG image compression method. This approach is motivated specifically by the need for accurate modeling of high-magnification regions in galaxy clusters. Existing modeling ... More
GROWTH on S190510g: DECam Observation Planning and Follow-Up of a Distant Binary Neutron Star Merger CandidateMay 31 2019The first two months of the third Advanced LIGO and Virgo observing run (2019 April-May) showed that distant gravitational wave (GW) events can now be readily detected, with three neutron star (NS) mergers more than 100 Mpc away reported in a span of ... More
Fast Solar Image Classification Using Deep Learning and its Importance for Automation in Solar PhysicsMay 31 2019The volume of data being collected in solar physics has exponentially increased over the past decade and with the introduction of the $\textit{Daniel K. Inouye Solar Telescope}$ (DKIST) we will be entering the age of petabyte solar data. Automated feature ... More
Demonstration of the broadband half-wave plate using the nine-layer sapphire for the CMB polarization experimentMay 31 2019Jun 03 2019We report the development of the achromatic half-wave plate (AHWP) at millimeter wave for cosmic microwave background polarization experiments. We fabricate an AHWP consisting of nine a-cut sapphire plates based on the Pancharatnam recipe to cover a wide ... More
Follow-up procedure for gravitational wave searches from isolated neutron stars using the time-domain $\mathcal{F}$-statistic methodMay 31 2019Among promising sources of gravitational waves are long-lived nearly periodic signals produced by rotating, asymmetric neutron stars. Depending on the astrophysical scenario, the sources of asymmetry may have thermal, viscous, elastic and/or magnetic ... More
Photodesorption of water ice from dust grains and thermal desorption of cometary ices studied by the INSIDE experimentMay 31 2019A new experimental set-up INterStellar Ice-Dust Experiment (INSIDE), was designed for studying cosmic grain analogues represented by ice-coated carbon- and silicate-based dust grains. In the new instrument, we can simulate physical and chemical conditions ... More
Neural network-based anomaly detection for high-resolution X-ray spectroscopyMay 31 2019We propose an anomaly detection technique for high-resolution X-ray spectroscopy. The method is based on the neural network architecture variational autoencoder, and requires only {\it normal} samples for training. We implement the network using Python ... More
Measurement of Charge Cloud Size in X-ray SOI Pixel SensorsMay 31 2019We report on a measurement of the size of charge clouds produced by X-ray photons in X-ray SOI (Silicon-On-Insulator) pixel sensor named XRPIX. We carry out a beam scanning experiment of XRPIX using a monochromatic X-ray beam at 5.0 keV collimated to ... More
A Do-it-yourself Spectrograph Kit for Educational Outreach in Optics and PhotonicsMay 30 2019We designed and built a do-it-yourself spectrograph assembly to demonstrate the concept of spectroscopy, an indispensable tool for exploring the cosmos. This spectrograph is designed for optical band (400-750 nm). It uses a transmission grating to disperse ... More
Towards a multi-input astrophotonic AWG spectrographMay 30 2019Astrophotonics is the new frontier technology to develop diffraction-limited, miniaturized, and cost-effective instruments for the next generation of large telescopes. For various astronomical studies such as probing the early universe, observing in near ... More
Astrophotonic SpectrographsMay 30 2019Astrophotonics is the application of photonic technologies to channel, manipulate, and disperse light from one or more telescopes to achieve scientific objectives in astronomy in an efficient and cost-effective way. Utilizing photonic advantage for astronomical ... More
An efficient method for solving highly oscillatory ordinary differential equations with applications to physical systemsMay 30 2019We present a novel numerical routine (oscode) with a C++ and Python interface for the efficient solution of one-dimensional, second-order, ordinary differential equations with rapidly oscillating solutions. The method is based on a Runge-Kutta-like stepping ... More
A Beginner's Guide to Working with Astronomical DataMay 30 2019This elementary review covers the basics of working with astronomical data, notably with images, spectra and higher-level (catalog) data. The basic concepts and tools are presented using both application software (DS9 and TOPCAT) and Python. The level ... More
The 3.6 meter Devasthal Optical Telescope: From inception to realisationMay 30 2019Jun 02 2019India's largest size 3.6 meter Devashal optical telescope (DOT) was commissioned in the year 2016, though the idea of building it germinated way back in the year 1976. This article provides research accounts as well as glimpses of its nearly four decades ... More
Study of cosmogenic radionuclides in the COSINE-100 NaI(Tl) detectorsMay 30 2019COSINE-100 is a direct detection dark matter search experiment that uses a 106 kg array of eight NaI(Tl) crystals that are kept underground at the Yangyang Underground Laboratory to avoid cosmogenic activation of radioisotopes by cosmic rays. Even though ... More
The Global Magneto-Ionic Medium Survey: Polarimetry of the Southern Sky from 300 to 480 MHzMay 29 2019Much data on the Galactic polarized radio emission has been gathered in the last five decades. All-sky surveys have been made, but only in narrow, widely spaced frequency bands, and the data are inadequate for the characterization of Faraday rotation, ... More
Glancing Through Massive Binary Radio Lenses: Hardware-Aware Interferometry With 1-Bit SensorsMay 29 2019Energy consumption and hardware cost of signal digitization together with the management of the resulting data volume form serious issues for high-rate measurement systems with multiple sensors. Switching to binary sensing front-ends results in resource-efficient ... More
Measurement of the Crab Nebula at the Highest Energies with HAWCMay 29 2019We present TeV gamma-ray observations of the Crab Nebula, the standard reference source in ground-based gamma-ray astronomy, using data from the High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory. In this analysis we use two independent energy-estimation ... More
Second Data Release of the Hyper Suprime-Cam Subaru Strategic ProgramMay 29 2019This paper presents the second data release of the Hyper Suprime-Cam Subaru Strategic Program, a wide-field optical imaging survey on the 8.2 meter Subaru Telescope. The release includes data from 174 nights of observation through January 2018. The Wide ... More
Scientific potential of the Indo-Belgian 3.6-m DOT in the field of Galactic AstronomyMay 28 2019India and Belgium have jointly established two 4 meter class optical telescopes at Devasthal located in Nainital, India. After successful installation of the 3.6-m modern new technology Devasthal Optical Telescope (DOT) in 2015, it was technically activated ... More
Anomaly Detection in the Open Supernova CatalogMay 27 2019In the upcoming decade large astronomical surveys will discover millions of transients raising unprecedented data challenges in the process. Only the use of the machine learning algorithms can process such large data volumes. Most of the discovered transients ... More
Precise photometric transit follow-up observations of five close-in exoplanets : update on their physical propertiesMay 27 2019We report the results of the high precision photometric follow-up observations of five transiting hot jupiters - WASP-33b, WASP-50b, WASP-12b, HATS-18b and HAT-P-36b. The observations are made from the 2m Himalayan Chandra Telescope at Indian Astronomical ... More
Reconstructing the cosmic-ray energy from the radio signal measured in one single stationMay 27 2019Short radio pulses can be measured from showers of both high-energy cosmic rays and neutrinos. While commonly several antenna stations are needed to reconstruct the energy of an air shower, we describe a novel method that relies on the radio signal measured ... More
Space VLBI: from first ideas to operational missionsMay 27 2019The operational period of the first generation of dedicated Space VLBI (SVLBI) missions commenced in 1997 with the launch of the Japan-led mission VSOP/HALCA and is coming to closure in 2019 with the completion of in-flight operations of the Russia-led ... More
Atmospheric circulation of Venus measured with visible imaging-spectroscopy at the THEMIS observatoryMay 27 2019Jun 13 2019Measuring Venus' atmospheric circulation at different altitudes is important for understanding its complex dynamics, in particular the mechanisms driving the super-rotation. Observationally, Doppler imaging spectroscopy is in principle be the most reliable ... More
Atmospheric circulation of Venus measured with visible imaging-spectroscopy at the THEMIS observatoryMay 27 2019Measuring Venus' atmospheric circulation at different altitudes is important for understanding its complex dynamics, in particular the mechanisms driving the super-rotation. Observationally, Doppler imaging spectroscopy is in principle be the most reliable ... More
Subpixel Response of SOI Pixel Sensor for X-ray Astronomy with Pinned Depleted Diode: First Result from Mesh ExperimentMay 26 2019We have been developing a monolithic active pixel sensor, ``XRPIX``, for the Japan led future X-ray astronomy mission ``FORCE`` observing the X-ray sky in the energy band of 1-80 keV with angular resolution of better than 15``. XRPIX is an upper part ... More
Sensitivity of top-of-the-mountain fluorescence telescope system for astrophysical neutrino flux above 10 PeVMay 25 2019Tau neutrinos with energies in the PeV-EeV range produce up-going extensive air showers (UEAS) if they interact underground close enough to the surface of the Earth. This work studies detectability of the UEAS with a system of fluorescence telescopes ... More
Toward precision radial velocity measurements using Echelle spectrograph at Vainu Bappu TelescopeMay 25 2019The Echelle spectrograph operating at Vainu Bappu Telescope (VBT) is a general purpose instrument designed for high resolution spectroscopy. It is being considered for precision Doppler measurements without altering the existing design and basic usage. ... More
Dedalus: A Flexible Framework for Numerical Simulations with Spectral MethodsMay 24 2019Numerical solutions of partial differential equations enable a broad range of scientific research. The Dedalus Project is a flexible, open-source, parallelized computational framework for solving general partial differential equations using spectral methods. ... More
Large-Scale Statistical Survey of Magnetopause ReconnectionMay 24 2019The Magnetospheric Multiscale Mission (MMS) seeks to study the micro-physics of reconnection, which occurs at the magnetopause boundary layer between the magnetosphere of Earth and the interplanetary magnetic field originating from the sun. Identifying ... More
Polarization Modeling and Predictions for DKIST Part 5: Impacts of enhanced mirror and dichroic coatings on system polarization calibrationMay 24 2019The DKIST is designed to deliver accurate spectropolarimetric calibrations across a wide wavelength range and large field of view for solar observations. Instruments deliver spectral resolving powers up to 300,000 in multiple cameras of several instrument. ... More
A novel method for component separation of extended sources in X-ray astronomyMay 24 2019In high-energy astronomy, spectro-imaging instruments such as X-ray detectors allow investigation of the spatial and spectral properties of extended sources including galaxy clusters, galaxies, diffuse interstellar medium, supernova remnants and pulsar ... More
Perception Evaluation -- A new solar image quality metric based on the multi-fractal property of texture featuresMay 24 2019Next-generation ground-based solar observations require good image quality metrics for post-facto processing techniques. Based on the assumption that texture features in solar images are multi-fractal which can be extracted by a trained deep neural network ... More
The Kepler Smear Campaign: Light curves for 102 Very Bright StarsMay 23 2019We present the first data release of the Kepler Smear Campaign, using collateral 'smear' data obtained in the Kepler four-year mission to reconstruct light curves of 102 stars too bright to have been otherwise targeted. We describe the pipeline developed ... More
Gaussbock: Fast parallel-iterative cosmological parameter estimation with Bayesian nonparametricsMay 23 2019We present and apply Gaussbock, a new embarrassingly parallel iterative algorithm for cosmological parameter estimation designed for an era of cheap parallel computing resources. Gaussbock uses Bayesian nonparametrics and truncated importance sampling ... More
Improving the muon track reconstruction of IceCube and IceCube-Gen2May 23 2019IceCube is a cubic-kilometer Cherenkov telescope operating at the South Pole. Its goal is to detect astrophysical neutrinos and identify their sources. High-energy muon neutrinos are identified through the secondary muons produced via charge current interactions ... More
Projected Pupil Plane Pattern (PPPP) with artificial Neural NetworksMay 23 2019Focus anisoplanatism is a significant measurement error when using one single laser guide star (LGS) in an Adaptive Optics (AO) system, especially for the next generation of extremely large telescopes. An alternative LGS configuration, called Projected ... More
CASI: A Convolutional Neural Network Approach for Shell IdentificationMay 22 2019We utilize techniques from deep learning to identify signatures of stellar feedback in simulated molecular clouds. Specifically, we implement a deep neural network with an architecture similar to U-Net and apply it to the problem of identifying wind-driven ... More
CASI: A Convolutional Neural Network Approach for Shell IdentificationMay 22 2019Jun 12 2019We utilize techniques from deep learning to identify signatures of stellar feedback in simulated molecular clouds. Specifically, we implement a deep neural network with an architecture similar to U-Net and apply it to the problem of identifying wind-driven ... More