Direct imaging of sub-Jupiter mass exoplanets with James Webb Space Telescope coronagraphy

ABSTRACT The James Webb Space Telescope (JWST), currently scheduled to launch in 2021, will dramatically advance our understanding of exoplanetary systems with its ability to directly image and characterize planetary-mass companions at wide separations through coronagraphy. Using state-of-the-art simulations of JWST performance, in combination with the latest evolutionary models, we present the most sophisticated simulated mass sensitivity limits of JWST coronagraphy to date. In particular, we focus our efforts towards observations of members within the nearby young moving groups β Pictoris and TW Hya. These limits indicate that whilst JWST will provide little improvement towards imaging exoplanets at short separations, at wide separations the increase in sensitivity is dramatic. We predict JWST will be capable of imaging sub-Jupiter mass objects beyond ∼30 au, sub-Saturn mass objects beyond ∼50 au, and that beyond ∼100 au, JWST will be capable of directly imaging companions as small as 0.1 MJ − at least an order of magnitude improvement over the leading ground-based instruments. Probing this unexplored parameter space will be of immediate value to modelling efforts focused on planetary formation and population synthesis. JWST will also serve as an excellent complement to ground-based observatories through its unique ability to characterize previously detected companions across the near- to mid-infrared for the first time.

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Properties of reionization-era galaxies from JWST luminosity functions and 21-cm interferometry

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz3278 ◽

2019 ◽

Vol 491 (3) ◽

pp. 3891-3899 ◽

Cited By ~ 2

Author(s):

Jaehong Park ◽

Nicolas Gillet ◽

Andrei Mesinger ◽

Bradley Greig

Keyword(s):

Star Formation Rate ◽

Hubble Space Telescope ◽

Formation Rate ◽

Power Spectra ◽

Mass Relation ◽

Space Telescope ◽

James Webb Space Telescope ◽

Luminosity Functions ◽

Order Of Magnitude ◽

Magnitude Improvement

ABSTRACT Upcoming observations will probe the first billion years of our Universe in unprecedented detail. Foremost among these are 21-cm interferometry with the Hydrogen Epoch of Reionization Arrays (HERA) and the Square Kilometre Array (SKA), and high-z galaxy observations with the James Webb Space Telescope (JWST). Here, we quantify how observations from these instruments can be used to constrain the astrophysics of high-z galaxies. We generate several mock JWST luminosity functions (LFs) and SKA1 21-cm power spectra, which are consistent with current observations, but assume different properties for the unseen, ultrafaint galaxies driving the epoch of reionization (EoR). Using only JWST data, we predict up to a factor of 2–3 improvement (compared with Hubble Space Telescope, HST) in the fractional uncertainty of the star formation rate to halo mass relation and the turnover magnitude. Most parameters regulating the ultraviolet (UV) galaxy properties can be constrained at the level of ∼10 per cent or better, if either (i) we are able to better characterize systematic lensing uncertainties than currently possible; or (ii) the intrinsic LFs peak at magnitudes brighter than MUV ≲ −13. Otherwise, improvement over HST-based inference is modest. When combining with upcoming 21-cm observations, we are able to significantly mitigate degeneracies, and constrain all of our astrophysical parameters, even for our most pessimistic assumptions about upcoming JWST LFs. The 21-cm observations also result in an order of magnitude improvement in constraints on the EoR history.

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Eta Carinae: A Tale of Two Periastron Passages

The Astrophysical Journal ◽

10.3847/1538-4357/ac22a6 ◽

2021 ◽

Vol 923 (1) ◽

pp. 102

Author(s):

Theodore R. Gull ◽

Felipe Navarete ◽

Michael F. Corcoran ◽

Augusto Damineli ◽

David Espinoza ◽

...

Keyword(s):

Transient Absorption ◽

Hubble Space Telescope ◽

Wavelength Dependence ◽

Primary Star ◽

Space Telescope ◽

Eta Carinae ◽

Secondary Star ◽

Order Of Magnitude ◽

Far Ultraviolet ◽

First Time

Abstract Since 2002, the far-ultraviolet (FUV) flux (1150–1680 Å) of Eta Carinae, monitored by the Hubble Space Telescope/Space Telescope Imaging Spectrograph, has increased by an order of magnitude. This increase is attributed to partial dissipation of a line-of-sight (LOS) occulter that blocks the central core of the system. Across the 2020 February periastron passage, changes in the FUV emission show a stronger wavelength dependence than occurred across the 2003 July periastron passage. Across both periastron passages, most of the FUV spectrum dropped in flux then recovered a few months later. The 2020 periastron passage included enhancements of FUV flux in narrow spectral intervals near periastron followed by a transient absorption and recovery to pre-periastron flux levels. The drop in flux is due to increased absorption by singly ionized species as the secondary star plunges deep into the wind of the primary star, which blocks the companion’s ionizing radiation. The enhanced FUV emission is caused by the companion’s wind-blown cavity briefly opening a window to deeper layers of the primary star. This is the first time transient brightening has been seen in the FUV comparable to transients previously seen at longer wavelengths. Changes in resonance line-velocity profiles hint that the dissipating occulter is associated with material in LOS moving at −100 to −300 km s−1, similar in velocity of structures previously associated with the 1890s lesser eruption.

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Free-form grale lens inversion of galaxy clusters with up to 1000 multiple images

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa962 ◽

2020 ◽

Vol 494 (3) ◽

pp. 3998-4014 ◽

Cited By ~ 1

Author(s):

Agniva Ghosh ◽

Liliya L R Williams ◽

Jori Liesenborgs

Keyword(s):

Galaxy Clusters ◽

Hubble Space Telescope ◽

Free Form ◽

Inversion Method ◽

Space Telescope ◽

Multiple Images ◽

Mass Distributions ◽

James Webb Space Telescope ◽

Order Of Magnitude ◽

Galaxy Population

ABSTRACT In the near future, ultra deep observations of galaxy clusters with Hubble Space Telescope or James Webb Space Telescope will uncover 300–1000 lensed multiple images, increasing the current count per cluster by up to an order of magnitude. This will further refine our view of clusters, leading to a more accurate and precise mapping of the total and dark matter distribution in clusters, and enabling a better understanding of background galaxy population and their luminosity functions. However, to effectively use that many images as input to lens inversion will require a re-evaluation of, and possibly upgrades to the existing methods. In this paper, we scrutinize the performance of the free-form lens inversion method grale in the regime of 150–1000 input images, using synthetic massive galaxy clusters. Our results show that with an increasing number of input images, grale produces improved reconstructed mass distributions, with the fraction of the lens plane recovered at better than $10{{\ \rm per\ cent}}$ accuracy increasing from $40\!-\!50{{\ \rm per\ cent}}$ for ∼150 images to $65{{\ \rm per\ cent}}$ for ∼1000 images. The reconstructed time delays imply a more precise measurement of H0, with $\lesssim 1{{\ \rm per\ cent}}$ bias. While the fidelity of the reconstruction improves with the increasing number of multiple images used as model constraints, ∼150 to ∼1000, the lens plane rms deteriorates from ∼0.11 to ∼0.28 arcsec. Since lens plane rms is not necessarily the best indicator of the quality of the mass reconstructions, looking for an alternative indicator is warranted.

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Passively parallel regularized stokeslets

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2019.0528 ◽

2020 ◽

Vol 378 (2179) ◽

pp. 20190528

Author(s):

Meurig T. Gallagher ◽

David J. Smith

Keyword(s):

Gpu Computing ◽

State Of The Art ◽

Computer Code ◽

Flagellar Motility ◽

The Past ◽

Recent Modification ◽

Flow Phenomena ◽

Order Of Magnitude ◽

Computational Research ◽

Magnitude Improvement

Stokes flow, discussed by G.G. Stokes in 1851, describes many microscopic biological flow phenomena, including cilia-driven transport and flagellar motility; the need to quantify and understand these flows has motivated decades of mathematical and computational research. Regularized stokeslet methods, which have been used and refined over the past 20 years, offer significant advantages in simplicity of implementation, with a recent modification based on nearest-neighbour interpolation providing significant improvements in efficiency and accuracy. Moreover this method can be implemented with the majority of the computation taking place through built-in linear algebra, entailing that state-of-the-art hardware and software developments in the latter, in particular multicore and GPU computing, can be exploited through minimal modifications (‘passive parallelism’) to existing Matlab computer code. Hence, and with widely available GPU hardware, significant improvements in the efficiency of the regularized stokeslet method can be obtained. The approach is demonstrated through computational experiments on three model biological flows: undulatory propulsion of multiple Caenorhabditis elegans , simulation of progression and transport by multiple sperm in a geometrically confined region, and left–right symmetry breaking particle transport in the ventral node of the mouse embryo. In general an order-of-magnitude improvement in efficiency is observed. This development further widens the complexity of biological flow systems that are accessible without the need for extensive code development or specialist facilities. This article is part of the theme issue ‘Stokes at 200 (part 2)’.

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Oxygen evolution on well-characterized mass-selected Ru and RuO2nanoparticles

Chemical Science ◽

10.1039/c4sc02685c ◽

2015 ◽

Vol 6 (1) ◽

pp. 190-196 ◽

Cited By ~ 192

Author(s):

Elisa A. Paoli ◽

Federico Masini ◽

Rasmus Frydendal ◽

Davide Deiana ◽

Christian Schlaup ◽

...

Keyword(s):

Oxygen Evolution ◽

State Of The Art ◽

The State ◽

Order Of Magnitude ◽

Magnitude Improvement

Well-defined mass-selected Ru and RuO2nanoparticles exhibit an order of magnitude improvement in the oxygen evolution activity, relative to the state-of-the-art, with a maximum at around 3–5 nm.

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High-Density Memristor-CMOS Ternary Logic Family

10.36227/techrxiv.12598559 ◽

2020 ◽

Author(s):

Xiaoyuan Wang ◽

Pengfei Zhou ◽

Jason Eshraghian ◽

Chih-Yang Lin ◽

Herbert Ho-Ching Iu ◽

...

Keyword(s):

Indium Tin Oxide ◽

Practical Implementation ◽

Switching Speed ◽

High Data ◽

Fast Switching ◽

Data Density ◽

Order Of Magnitude ◽

High Transconductance ◽

Logic Functions ◽

Magnitude Improvement

<div>This paper presents the first experimental demonstration</div><div>of a ternary memristor-CMOS logic family. We systematically</div><div>design, simulate and experimentally verify the primitive</div><div>logic functions: the ternary AND, OR and NOT gates. These are then used to build combinational ternary NAND, NOR, XOR and XNOR gates, as well as data handling ternary MAX and MIN gates. Our simulations are performed using a 50-nm process which are verified with in-house fabricated indium-tin-oxide memristors, optimized for fast switching, high transconductance, and low current leakage. We obtain close to an order of magnitude improvement in data density over conventional CMOS logic, and a reduction of switching speed by a factor of 13 over prior state-of-the-art ternary memristor results. We anticipate extensions of this work can realize practical implementation where high data density is of critical importance.</div>

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Detection and Quantification of 7-Hydroxydehydroepiandrosterone Epimers in Three Body Fluids

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20020010 ◽

2002 ◽

Vol 67 (1) ◽

pp. 10-18 ◽

Cited By ~ 1

Author(s):

Richard Hampl ◽

Martin Hill ◽

Luboslav Stárka

Keyword(s):

Healthy Subjects ◽

Serum Levels ◽

Body Fluids ◽

Gas Chromatography Mass Spectrometry ◽

Specific Radioimmunoassay ◽

Order Of Magnitude ◽

Three Body ◽

First Time ◽

Nanomolar Range ◽

Detection And Quantification

3β,7α-Dihydroxyandrost-5-en-17-one (1) (7α-OH-DHEA) and its 7β-hydroxy epimer 2 (7β-OH-DHEA) - 7α- and 7β-hydroxydehydroepiandrosterone - were detected and quantified in three human body fluids: in blood serum, saliva and ejaculate. Specific radioimmunoassay and gas chromatography-mass spectrometry have been used. For the first time the data on changes of these dehydroepiandrosterone metabolites are reported for a representative group of healthy subjects of both sexes (172 females and 217 males) during the life span. The serum levels of both 7-hydroxydehydroepiandrosterone epimers in serum and also in semen were in the low nanomolar range, while concentrations by one order of magnitude lower were found in saliva, but still within the detection limit. The results will serve as a basis for comparative studies of 7-hydroxydehydroepiandrosterone levels under various pathophysiological conditions, with a particular respect to autoimmune disorders.

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State-of-the-Art Char Production with a Focus on Bark Feedstocks: Processes, Design, and Applications

Processes ◽

10.3390/pr9010087 ◽

2021 ◽

Vol 9 (1) ◽

pp. 87

Author(s):

Ali Umut Şen ◽

Helena Pereira

Keyword(s):

State Of The Art ◽

Lignocellulosic Materials ◽

Heating Rates ◽

Production Methods ◽

Slow Pyrolysis ◽

Production Studies ◽

Lignocellulosic Feedstocks ◽

Thermochemical Method ◽

Superior Surface ◽

First Time

In recent years, there has been a surge of interest in char production from lignocellulosic biomass due to the fact of char’s interesting technological properties. Global char production in 2019 reached 53.6 million tons. Barks are among the most important and understudied lignocellulosic feedstocks that have a large potential for exploitation, given bark global production which is estimated to be as high as 400 million cubic meters per year. Chars can be produced from barks; however, in order to obtain the desired char yields and for simulation of the pyrolysis process, it is important to understand the differences between barks and woods and other lignocellulosic materials in addition to selecting a proper thermochemical method for bark-based char production. In this state-of-the-art review, after analyzing the main char production methods, barks were characterized for their chemical composition and compared with other important lignocellulosic materials. Following these steps, previous bark-based char production studies were analyzed, and different barks and process types were evaluated for the first time to guide future char production process designs based on bark feedstock. The dry and wet pyrolysis and gasification results of barks revealed that application of different particle sizes, heating rates, and solid residence times resulted in highly variable char yields between the temperature range of 220 °C and 600 °C. Bark-based char production should be primarily performed via a slow pyrolysis route, considering the superior surface properties of slow pyrolysis chars.

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UV Inscription and Pressure Induced Long-Period Gratings through 3D Printed Amplitude Masks

Sensors ◽

10.3390/s21061977 ◽

2021 ◽

Vol 21 (6) ◽

pp. 1977

Author(s):

Ricardo Oliveira ◽

Liliana M. Sousa ◽

Ana M. Rocha ◽

Rogério Nogueira ◽

Lúcia Bilro

Keyword(s):

State Of The Art ◽

Low Cost ◽

Resonance Wavelength ◽

Complex Structures ◽

Pressing Method ◽

Long Period ◽

Long Period Gratings ◽

3D Printed ◽

Mechanical Pressing ◽

First Time

In this work, we demonstrate for the first time the capability to inscribe long-period gratings (LPGs) with UV radiation using simple and low cost amplitude masks fabricated with a consumer grade 3D printer. The spectrum obtained for a grating with 690 µm period and 38 mm length presented good quality, showing sharp resonances (i.e., 3 dB bandwidth < 3 nm), low out-of-band loss (~0.2 dB), and dip losses up to 18 dB. Furthermore, the capability to select the resonance wavelength has been demonstrated using different amplitude mask periods. The customization of the masks makes it possible to fabricate gratings with complex structures. Additionally, the simplicity in 3D printing an amplitude mask solves the problem of the lack of amplitude masks on the market and avoids the use of high resolution motorized stages, as is the case of the point-by-point technique. Finally, the 3D printed masks were also used to induce LPGs using the mechanical pressing method. Due to the better resolution of these masks compared to ones described on the state of the art, we were able to induce gratings with higher quality, such as low out-of-band loss (0.6 dB), reduced spectral ripples, and narrow bandwidths (~3 nm).

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Electro-Quasistatic Animal Body Communication for Untethered Rodent Biopotential Recording

Scientific Reports ◽

10.1038/s41598-021-81108-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Shreeya Sriram ◽

Shitij Avlani ◽

Matthew P. Ward ◽

Shreyas Sen

Keyword(s):

Lower Energy ◽

Sensor Node ◽

State Of The Art ◽

The Body ◽

Animal Body ◽

Current State ◽

Communication Modalities ◽

First Time ◽

Biopotential Recording

AbstractContinuous multi-channel monitoring of biopotential signals is vital in understanding the body as a whole, facilitating accurate models and predictions in neural research. The current state of the art in wireless technologies for untethered biopotential recordings rely on radiative electromagnetic (EM) fields. In such transmissions, only a small fraction of this energy is received since the EM fields are widely radiated resulting in lossy inefficient systems. Using the body as a communication medium (similar to a ’wire’) allows for the containment of the energy within the body, yielding order(s) of magnitude lower energy than radiative EM communication. In this work, we introduce Animal Body Communication (ABC), which utilizes the concept of using the body as a medium into the domain of untethered animal biopotential recording. This work, for the first time, develops the theory and models for animal body communication circuitry and channel loss. Using this theoretical model, a sub-inch$$^3$$ 3 [1″ × 1″ × 0.4″], custom-designed sensor node is built using off the shelf components which is capable of sensing and transmitting biopotential signals, through the body of the rat at significantly lower powers compared to traditional wireless transmissions. In-vivo experimental analysis proves that ABC successfully transmits acquired electrocardiogram (EKG) signals through the body with correlation $$>99\%$$ > 99 % when compared to traditional wireless communication modalities, with a 50$$\times$$ × reduction in power consumption.

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