Showing papers in "Experimental Astronomy in 2021"
University of Manchester1, University of Oxford2, University of Paris-Sud3, New York University4, University of California, Berkeley5, Lawrence Berkeley National Laboratory6, University of Bonn7, University of Ferrara8, INAF9, Sapienza University of Rome10, DSM11, University of New South Wales12, University of Maryland, College Park13, Institute for Advanced Study14, York University15, Goddard Space Flight Center16, KEK17, RWTH Aachen University18, Paris-Sorbonne University19, University of Amsterdam20, Institut d'Astrophysique de Paris21, University of La Laguna22, Spanish National Research Council23, Johns Hopkins University24, Russian Academy of Sciences25, Max Planck Society26
TL;DR: In this paper, the authors highlight the unique science opportunities using spectral distortions of the cosmic microwave background (CMB) for further understanding of inflation, recombination, reionization and structure formation as well as dark matter and particle physics.
Abstract: This Voyage 2050 paper highlights the unique science opportunities using spectral distortions of the cosmic microwave background (CMB). CMB spectral distortions probe many processes throughout the history of the Universe, delivering novel information that complements past, present and future efforts with CMB anisotropy and large-scale structure studies. Precision spectroscopy, possible with existing technology, would not only provide key tests for processes expected within the cosmological standard model but also open an enormous discovery space to new physics. This offers unique scientific opportunities for furthering our understanding of inflation, recombination, reionization and structure formation as well as dark matter and particle physics. A dedicated experimental approach could open this new window to the early Universe in the decades to come, allowing us to turn the long-standing upper distortion limits obtained with COBE/FIRAS some 25 years ago into clear detections of the expected standard distortion signals and also challenge our current understanding of the laws of nature.
63 citations
University of Milan1, Heidelberg University2, Johns Hopkins University3, University of Florida4, University of Zurich5, Autonomous University of Madrid6, Columbia University7, Georgia Institute of Technology8, European Space Agency9, University of Helsinki10, Institute of Space Technology11, University of Stavanger12, Harvard University13, CERN14, Dublin City University15, Peking University16, Institut d'Astrophysique de Paris17, University College Dublin18, University of California, Berkeley19
TL;DR: In this paper, a space-based interferometer was proposed to survey the GW sky in the milli-Hz to μ-Hz frequency range, bracketed in between the LISA and pulsar timing arrays.
Abstract: We propose a space-based interferometer surveying the gravitational wave (GW) sky in the milli-Hz to μ-Hz frequency range. By the 2040s, the μ-Hz frequency band, bracketed in between the Laser Interferometer Space Antenna (LISA) and pulsar timing arrays, will constitute the largest gap in the coverage of the astrophysically relevant GW spectrum. Yet many outstanding questions related to astrophysics and cosmology are best answered by GW observations in this band. We show that a μ-Hz GW detector will be a truly overarching observatory for the scientific community at large, greatly extending the potential of LISA. Conceived to detect massive black hole binaries from their early inspiral with high signal-to-noise ratio, and low-frequency stellar binaries in the Galaxy, this instrument will be a cornerstone for multimessenger astronomy from the solar neighbourhood to the high-redshift Universe.
55 citations
Goddard Space Flight Center1, Queen Mary University of London2, INAF3, University of Edinburgh4, Imperial College London5, Institut d'Astrophysique de Paris6, Albert Einstein Institution7, Columbia University8, University of Oslo9, University of Oxford10, Autonomous University of Madrid11, University of Florida12, Academy of Sciences of the Czech Republic13, Peking University14, Swansea University15, University of California, Berkeley16
TL;DR: In this paper, an observatory with arcminute precision or better could be realized within the Voyage 2050 program by creating a large baseline interferometer array in space and would have transformative scientific potential.
Abstract: Since the very beginning of astronomy the location of objects on the sky has been a fundamental observational quantity that has been taken for granted. While precise two dimensional positional information is easy to obtain for observations in the electromagnetic spectrum, the positional accuracy of current and near future gravitational wave detectors is limited to between tens and hundreds of square degrees, which makes it extremely challenging to identify the host galaxies of gravitational wave events or to detect any electromagnetic counterparts. Gravitational wave observations provide information on source properties that is complementary to the information in any associated electromagnetic emission. Observing systems with multiple messengers thus has scientific potential much greater than the sum of its parts. A gravitational wave detector with higher angular resolution would significantly increase the prospects for finding the hosts of gravitational wave sources and triggering a multi-messenger follow-up campaign. An observatory with arcminute precision or better could be realised within the Voyage 2050 programme by creating a large baseline interferometer array in space and would have transformative scientific potential. Precise positional information of standard sirens would enable precision measurements of cosmological parameters and offer new insights on structure formation; a high angular resolution gravitational wave observatory would allow the detection of a stochastic background and resolution of the anisotropies within it; it would also allow the study of accretion processes around black holes; and it would have tremendous potential for tests of modified gravity and the discovery of physics beyond the Standard Model.
33 citations
Johns Hopkins University1, University of Southampton2, Perimeter Institute for Theoretical Physics3, Sapienza University of Rome4, Instituto Superior Técnico5, Université libre de Bruxelles6, University of Lethbridge7, University of Tübingen8, Autonomous University of Madrid9, ETH Zurich10, Massachusetts Institute of Technology11, Georgia Institute of Technology12, Albert Einstein Institution13, Academy of Sciences of the Czech Republic14, University of Florida15, University of Paris16, University of Nottingham17, Aristotle University of Thessaloniki18, University of Glasgow19, Kuwait University20, University College Dublin21, University of Texas at Austin22
TL;DR: The LIGO/Virgo interferometers are the gravitational-wave equivalent of Galileo's telescope as discussed by the authors, and they have a staggering discovery potential, and they will address fundamental open questions in physics and astronomy.
Abstract: Black holes are unique among astrophysical sources: they are the simplest macroscopic objects in the Universe, and they are extraordinary in terms of their ability to convert energy into electromagnetic and gravitational radiation. Our capacity to probe their nature is limited by the sensitivity of our detectors. The LIGO/Virgo interferometers are the gravitational-wave equivalent of Galileo’s telescope. The first few detections represent the beginning of a long journey of exploration. At the current pace of technological progress, it is reasonable to expect that the gravitational-wave detectors available in the 2035-2050s will be formidable tools to explore these fascinating objects in the cosmos, and space-based detectors with peak sensitivities in the mHz band represent one class of such tools. These detectors have a staggering discovery potential, and they will address fundamental open questions in physics and astronomy. Are astrophysical black holes adequately described by general relativity? Do we have empirical evidence for event horizons? Can black holes provide a glimpse into quantum gravity, or reveal a classical breakdown of Einstein’s gravity? How and when did black holes form, and how do they grow? Are there new long-range interactions or fields in our Universe, potentially related to dark matter and dark energy or a more fundamental description of gravitation? Precision tests of black hole spacetimes with mHz-band gravitational-wave detectors will probe general relativity and fundamental physics in previously inaccessible regimes, and allow us to address some of these fundamental issues in our current understanding of nature.
30 citations
TL;DR: The AMBITION project as discussed by the authors is a mission to return the first-ever cryogenically stored sample of a cometary nucleus, that has been proposed for the ESA Science Programme Voyage 2050.
Abstract: We describe the AMBITION project, a mission to return the first-ever cryogenically- stored sample of a cometary nucleus, that has been proposed for the ESA Science Programme Voyage 2050. Comets are the leftover building blocks of giant planet cores and other planetary bodies, and fingerprints of Solar System’s formation pro- cesses. We summarise some of the most important questions still open in cometary science and Solar System formation after the successful Rosetta mission. We show that many of these scientific questions require sample analysis using techniques that are only possible in laboratories on Earth. We summarize measurements, instrumen- tation and mission scenarios that can address these questions. We emphasize the need for returning a sample collected at depth or, still more challenging, at cryogenic tem- peratures while preserving the stratigraphy of the comet nucleus surface layers. We provide requirements for the next generation of landers, for cryogenic sample acqui- sition and storage during the return to Earth. Rendezvous missions to the main belt comets and Centaurs, expanding our knowledge by exploring new classes of comets, are also discussed. The AMBITION project is discussed in the international context of comet and asteroid space exploration.
25 citations
Université Paris-Saclay1, INAF2, Technical University of Denmark3, Ioffe Institute4, Netherlands Institute for Space Research5, University of Coimbra6, Paris Diderot University7, University College Dublin8, Clemson University9, Spanish National Research Council10, Max Planck Society11, Istituto Nazionale di Fisica Nucleare12, Goddard Space Flight Center13, University of Tokyo14, University of Mainz15, Royal Institute of Technology16, Autonomous University of Barcelona17, University of Geneva18, University College London19, Polish Academy of Sciences20, University of California, Berkeley21
TL;DR: In this paper, the authors stress the importance of a medium-size (M-class) space mission, dubbed "ASTROMEV", to detect MeV photons in space with high efficiency and low background.
Abstract: The energy range between about 100 keV and 1 GeV is of interest for a vast class of astrophysical topics. In particular, (1) it is the missing ingredient for understanding extreme processes in the multi-messenger era; (2) it allows localizing cosmic-ray interactions with background material and radiation in the Universe, and spotting the reprocessing of these particles; (3) last but not least, gamma-ray emission lines trace the formation of elements in the Galaxy and beyond. In addition, studying the still largely unexplored MeV domain of astronomy would provide for a rich observatory science, including the study of compact objects, solar- and Earth-science, as well as fundamental physics. The technological development of silicon microstrip detectors makes it possible now to detect MeV photons in space with high efficiency and low background. During the last decade, a concept of detector (“ASTROGAM”) has been proposed to fulfil these goals, based on a silicon hodoscope, a 3D position-sensitive calorimeter, and an anticoincidence detector. In this paper we stress the importance of a medium size (M-class) space mission, dubbed “ASTROMEV”, to fulfil these objectives.
19 citations
University of Amsterdam1, Netherlands Institute for Space Research2, Fudan University3, Centre national de la recherche scientifique4, Roma Tre University5, Academy of Sciences of the Czech Republic6, INAF7, University of Colorado Boulder8, University of Erlangen-Nuremberg9, Goddard Space Flight Center10, University of Tübingen11, University of Oxford12, Massachusetts Institute of Technology13, Open University14, Leibniz Institute for Astrophysics Potsdam15, Polish Academy of Sciences16, University of Leicester17
TL;DR: X-ray interferometry (XRI) as discussed by the authors was proposed to reveal the universe at high energies with ultra-high spatial resolution, enabling imaging and imaging-spectroscopy of (for example) X-ray coronae of nearby accreting supermassive black holes (SMBH) and the SMBH shadow.
Abstract: We propose the development of X-ray interferometry (XRI), to reveal the Universe at high energies with ultra-high spatial resolution. With baselines which can be accommodated on a single spacecraft, XRI can reach 100 μ as resolution at 10 A (1.2 keV) and 20 μ as at 2 A (6 keV), enabling imaging and imaging-spectroscopy of (for example) X-ray coronae of nearby accreting supermassive black holes (SMBH) and the SMBH ‘shadow’; SMBH accretion flows and outflows; X-ray binary winds and orbits; stellar coronae within ∼ 100 pc and many exoplanets which transit across them. For sufficiently luminous sources XRI will resolve sub-pc scales across the entire observable Universe, revealing accreting binary SMBHs and enabling trigonometric measurements of the Hubble constant with X-ray light echoes from quasars or explosive transients. A multi-spacecraft ‘constellation’ interferometer would resolve well below 1 μ as, enabling SMBH event horizons to be resolved in many active galaxies and the detailed study of the effects of strong field gravity on the dynamics and emission from accreting gas close to the black hole.
17 citations
University of New Hampshire1, University College London2, Northumbria University3, Queen Mary University of London4, Belgian Institute for Space Aeronomy5, Peking University6, University of Tokyo7, Uppsala University8, University of Arizona9, University of Delaware10, Austrian Academy of Sciences11, Katholieke Universiteit Leuven12, University of Cambridge13, National Institute of Information and Communications Technology14, University of California, Berkeley15, University of Cologne16, University of Calabria17, Imperial College London18, Academy of Sciences of the Czech Republic19, Max Planck Society20
TL;DR: The analysis of astrophysical processes at these scales lies at the heart of the field of electron-astrophysics and is the fundamental research priority encapsulating the conversion of plasma-flow and electromagnetic energies into particle energy, either as heat or some other form of energisation as discussed by the authors.
Abstract: A grand-challenge problem at the forefront of physics is to understand how energy is transported and transformed in plasmas. This fundamental research priority encapsulates the conversion of plasma-flow and electromagnetic energies into particle energy, either as heat or some other form of energisation. The smallest characteristic scales, at which electron dynamics determines the plasma behaviour, are the next frontier in space and astrophysical plasma research. The analysis of astrophysical processes at these scales lies at the heart of the field of electron-astrophysics. Electron scales are the ultimate bottleneck for dissipation of plasma turbulence, which is a fundamental process not understood in the electron-kinetic regime. Since electrons are the most numerous and most mobile plasma species in fully ionised plasmas and are strongly guided by the magnetic field, their thermal properties couple very efficiently to global plasma dynamics and thermodynamics.
17 citations
17 citations
TL;DR: In this paper, the authors argue for a new small/medium space mission dedicated to gathering high-precision, high-cadence, long photometric series in dense stellar fields.
Abstract: In the last decade, the Kepler and CoRoT space-photometry missions have demonstrated the potential of asteroseismology as a novel, versatile and powerful tool to perform exquisite tests of stellar physics, and to enable precise and accurate characterisations of stellar properties, with impact on both exoplanetary and Galactic astrophysics. Based on our improved understanding of the strengths and limitations of such a tool, we argue for a new small/medium space mission dedicated to gathering high-precision, highcadence, long photometric series in dense stellar fields. Such a mission will lead to breakthroughs in stellar astrophysics, especially in the metal poor regime, will elucidate the evolution and formation of open and globular clusters, and aid our understanding of the assembly history and chemodynamics of the Milky Way’s bulge and few nearby dwarf galaxies.
16 citations
TL;DR: In this paper, the authors presented the system design of the SARAS 3 version of the receiver, which includes Dicke switching, double differencing and optical isolation for improved accuracy.
Abstract: SARAS is an ongoing experiment aiming to detect the redshifted global 21-cm signal expected from Cosmic Dawn (CD) and the Epoch of Reionization (EoR). Standard cosmological models predict the signal to be present in the redshift range $z \sim $
6–35, corresponding to a frequency range 40–200 MHz, as a spectral distortion of amplitude 20–200 mK in the 3 K cosmic microwave background. Since the signal might span multiple octaves in frequency, and this frequency range is dominated by strong terrestrial Radio Frequency Interference (RFI) and astrophysical foregrounds of Galactic and Extragalactic origin that are several orders of magnitude greater in brightness temperature, design of a radiometer for measurement of this faint signal is a challenging task. It is critical that the instrumental systematics do not result in additive or multiplicative confusing spectral structures in the measured sky spectrum and thus preclude detection of the weak 21-cm signal. Here we present the system design of the SARAS 3 version of the receiver. New features in the evolved design include Dicke switching, double differencing and optical isolation for improved accuracy in calibration and rejection of additive and multiplicative systematics. We derive and present the measurement equations for the SARAS 3 receiver configuration and calibration scheme, and provide results of laboratory tests performed using various precision terminations that qualify the performance of the radiometer receiver for the science goal.
TL;DR: In this paper, a superconducting magnetic spectrometer was proposed as mission in the context of the European Space Agency's Voyage2050 long-term plan, which would extend by about two orders of magnitude the separation between charged particles/anti-particles, making it uniquely suited for addressing and potentially solving some of the most puzzling issues of modern cosmology.
Abstract: Multimessenger astrophysics is based on the detection, with the highest possible accuracy, of the cosmic radiation. During the last 20 years, the advent space-borne magnetic spectrometers in space (AMS-01, Pamela, AMS-02), able to measure the charged cosmic radiation separating matter from antimatter, and to provide accurate measurement of the rarest components of Cosmic Rays (CRs) to the highest possible energies, have become possible, together with the ultra-precise measurement of ordinary CRs. These developments started the era of precision Cosmic Ray physics providing access to a rich program of high-energy astrophysics addressing fundamental questions like matter-antimatter asymmetry, indirect detection for Dark Matter and the detailed study of origin, acceleration and propagation of CRs and their interactions with the interstellar medium. In this paper we address the above-mentioned scientific questions, in the context of a second generation, large acceptance, superconducting magnetic spectrometer proposed as mission in the context of the European Space Agency’s Voyage2050 long-term plan: the Antimatter Large Acceptance Detector In Orbit (ALADInO) would extend by about two orders of magnitude in energy and flux sensitivity the separation between charged particles/anti-particles, making it uniquely suited for addressing and potentially solving some of the most puzzling issues of modern cosmology.
Kapteyn Astronomical Institute1, Tel Aviv University2, ASTRON3, Eindhoven University of Technology4, INAF5, Arizona State University6, University of Colorado Boulder7, Indian Institute of Technology Indore8, Radboud University Nijmegen9, University of Cambridge10, Delft University of Technology11, California Institute of Technology12, University of Groningen13, Stockholm University14, Imperial College London15, Raman Research Institute16, Institut d'Astrophysique de Paris17, University of Oxford18, Curtin University19, Open University of Israel20
TL;DR: It is concluded that only a space- or lunar-based radio telescope, shielded from the Earth’s radio-frequency interference (RFI) signals and its ionosphere, enable the 21-cm signal from the Dark Ages to be detected.
Abstract: Neutral hydrogen pervades the infant Universe, and its redshifted 21-cm signal allows one to chart the Universe. This signal allows one to probe astrophysical processes such as the formation of the first stars, galaxies, (super)massive black holes and enrichment of the pristine gas from z~6 to z~30, as well as fundamental physics related to gravity, dark matter, dark energy and particle physics at redshifts beyond that. As one enters the Dark Ages (z>30), the Universe becomes pristine. Ground-based low-frequency radio telescopes aim to detect the spatial fluctuations of the 21-cm signal. Complementary, global 21-cm experiments aim to measure the sky-averaged 21-cm signal. Escaping RFI and the ionosphere has motivated space-based missions, such as the Dutch-Chinese NCLE instrument (currently in lunar L2), the proposed US-driven lunar or space-based instruments DAPPER and FARSIDE, the lunar-orbit interferometer DSL (China), and PRATUSH (India). To push beyond the current z~25 frontier, though, and measure both the global and spatial fluctuations (power-spectra/tomography) of the 21-cm signal, low-frequency (1-100MHz; BW~50MHz; z>13) space-based interferometers with vast scalable collecting areas (1-10-100 km2), large filling factors (~1) and large fields-of-view (4pi sr.) are needed over a mission lifetime of >5 years. In this ESA White Paper, we argue for the development of new technologies enabling interferometers to be deployed, in space (e.g. Earth-Sun L2) or in the lunar vicinity (e.g. surface, orbit or Earth-Moon L2), to target this 21-cm signal. This places them in a stable environment beyond the reach of most RFI from Earth and its ionospheric corruptions, enabling them to probe the Dark Ages as well as the Cosmic Dawn, and allowing one to investigate new (astro)physics that is inaccessible in any other way in the coming decades. [Abridged]
TL;DR: The results of this study confirm the feasibility of using CeBr3 scintillator, SiPMs, and SIPHRA in future space missions.
Abstract: Recent advances in silicon photomultiplier (SiPM) technology and new scintillator materials allow for the creation of compact high-performance gamma-ray detectors which can be deployed on small low-cost satellites. A small number of such satellites can provide full sky coverage and complement, or in some cases replace the existing gamma-ray missions in detection of transient gamma-ray events. The aim of this study is to test gamma-ray detection using a novel commercially available CeBr3 scintillator combined with SiPM readout in a near-space environment and inform further technology development for a future space mission. A prototype gamma-ray detector was built using a CeBr3 scintillator and an array of 16 J-Series SiPMs by ON Semiconductor. SiPM readout was performed using SIPHRA, a radiation-tolerant low-power integrated circuit developed by IDEAS. The detector was flown as a piggyback payload on the Advanced Scintillator Compton Telescope balloon flight from Columbia Scientific Balloon Facility. The payload included the detector, a Raspberry Pi on-board computer, a custom power supply board, temperature and pressure sensors, a Global Navigation Satellite System receiver and a satellite modem. The balloon delivered the detector to 37 km altitude where its detection capabilities and readout were tested in the radiation-intense near-space environment. The detector demonstrated continuous operation during the 8-hour flight and after the landing. It performed spectral measurements in an energy range of 100 keV to 8 MeV and observed the 511 keV gamma-ray line arising from positron annihilation in the atmosphere with full width half maximum of 6.8%. During ascent and descent, the detector count rate peaked at an altitude of 16 km corresponding to the point of maximum radiation intensity in the atmosphere. Despite several engineering issues discovered after the flight test, the results of this study confirm the feasibility of using CeBr3 scintillator, SiPMs, and SIPHRA in future space missions.
Lund University1, Leiden University2, University of Copenhagen3, University College London4, Dresden University of Technology5, INAF6, University of Warsaw7, University of Cambridge8, Max Planck Society9, Spanish National Research Council10, University of Ljubljana11, Leibniz Institute for Astrophysics Potsdam12, Institute for Advanced Study13, University of Texas at Austin14, Australian National University15, UK Astronomy Technology Centre16, University of the Western Cape17
TL;DR: The era of all-sky space space astrometry began with the Hipparcos mission in 1989 and provided the first very accurate catalogue of apparent magnitudes, positions, parallaxes and proper motions of 120 000 bright stars at the milliarcsec (or microarcsec per year) accuracy level as mentioned in this paper.
Abstract: The era of all-sky space astrometry began with the Hipparcos mission in 1989 and provided the first very accurate catalogue of apparent magnitudes, positions, parallaxes and proper motions of 120 000 bright stars at the milliarcsec (or milliarcsec per year) accuracy level. Hipparcos has now been superseded by the results of the Gaia mission. The second Gaia data release contained astrometric data for almost 1.7 billion sources with tens of microarcsec (or microarcsec per year) accuracy in a vast volume of the Milky Way and future data releases will further improve on this. Gaia has just completed its nominal 5-year mission (July 2019), but is expected to continue in operations for an extended period of an additional 5 years through to mid 2024. Its final catalogue to be released $\sim $
2027, will provide astrometry for $\sim $
2 billion sources, with astrometric precisions reaching 10 microarcsec. Why is accurate astrometry so important? The answer is that it provides fundamental data which underpin much of modern observational astronomy as will be detailed in this White Paper. All-sky visible and Near-InfraRed (NIR) astrometry with a wavelength cutoff in the K-band is not just focused on a single or small number of key science cases. Instead, it is extremely broad, answering key science questions in nearly every branch of astronomy while also providing a dense and accurate visible-NIR reference frame needed for future astronomy facilities.
TL;DR: In this article, the authors present the scientific motivation for future space tests of the equivalence principle, and in particular the universality of free fall, at the 10− 17 level or better.
Abstract: We present the scientific motivation for future space tests of the equivalence principle, and in particular the universality of free fall, at the 10− 17 level or better. Two possible mission scenarios, one based on quantum technologies, the other on electrostatic accelerometers, that could reach that goal are briefly discussed. This publication is a White Paper written in the context of the Voyage 2050 ESA Call for White Papers.
INAF1, Netherlands Institute for Space Research2, University of Palermo3, Technion – Israel Institute of Technology4, University of Michigan5, Durham University6, Xiamen University7, Aix-Marseille University8, University of Rome Tor Vergata9, Columbia University10, University of Maryland, College Park11, University of Tokyo12
TL;DR: In this article, the authors highlight the most important open astrophysical problems that will be central in the next decades and for which a deep understanding of the Universe's wandering metals, their physical and kinematical states, and their chemical composition represents the only viable solution.
Abstract: Metals form an essential part of the Universe at all scales. Without metals we would not exist, and the Universe would look completely different. Metals are primarily produced via nuclear processes in stars, and spread out through winds or explosions, which pollute the surrounding space. The wanderings of metals in-and-out of astronomical objects are crucial in determining their own evolution and thus that of the Universe as a whole. Detecting metals and assessing their relative and absolute abundances and energetics can thus be used to trace the evolution of these cosmic components. The scope of this paper is to highlight the most important open astrophysical problems that will be central in the next decades and for which a deep understanding of the Universe’s wandering metals, their physical and kinematical states, and their chemical composition represents the only viable solution. The majority of these studies can only be efficiently performed through High Resolution Spectroscopy in the soft X-ray band.
Shanghai Astronomical Observatory1, Max Planck Society2, Jet Propulsion Laboratory3, Planetary Science Institute4, Nanjing University5, National Central University6, INAF7, Braunschweig University of Technology8, University of Paris9, University of Grenoble10, University of Alicante11, University College London12, Spanish National Research Council13, Aberystwyth University14, Free University of Berlin15, Aalto University16, Chinese Academy of Sciences17, Aix-Marseille University18
TL;DR: The goal of Project GAUSS (Genesis of Asteroids and evolUtion of the Solar System) is to return samples from the dwarf planet Ceres as discussed by the authors, which is the most accessible candidate of ocean worlds and the largest reservoir of water in the inner Solar System.
Abstract: The goal of Project GAUSS (Genesis of Asteroids and evolUtion of the Solar System) is to return samples from the dwarf planet Ceres. Ceres is the most accessible candidate of ocean worlds and the largest reservoir of water in the inner Solar System. It shows active volcanism and hydrothermal activities in recent history. Recent evidence for the existence of a subsurface ocean on Ceres and the complex geochemistry suggest past habitability and even the potential for ongoing habitability. GAUSS will return samples from Ceres with the aim of answering the following top-level scientific questions:
INAF1, Spanish National Research Council2, University of Zurich3, University of Tokyo4, University College London5, University of Tartu6, Heidelberg University7, Netherlands Institute for Space Research8, Leiden University9, Sapienza University of Rome10, European Space Agency11, University of Leeds12, University of Hull13, Joint Institute for Nuclear Astrophysics14, Hungarian Academy of Sciences15, Open University of Israel16
TL;DR: Ariel as discussed by the authors observes a large and diversified population of transiting planets around a range of host star types to collect information on their atmospheric composition, and highlights how Ariel's characteristics make this mission optimally suited to address this very complex problem.
Abstract: The goal of the Ariel space mission is to observe a large and diversified population of transiting planets around a range of host star types to collect information on their atmospheric composition. The planetary bulk and atmospheric compositions bear the marks of the way the planets formed: Ariel’s observations will therefore provide an unprecedented wealth of data to advance our understanding of planet formation in our Galaxy. A number of environmental and evolutionary factors, however, can affect the final atmospheric composition. Here we provide a concise overview of which factors and effects of the star and planet formation processes can shape the atmospheric compositions that will be observed by Ariel, and highlight how Ariel’s characteristics make this mission optimally suited to address this very complex problem.
TL;DR: In this paper, the authors present the first fully automated pipeline for making images from the interferometric data obtained from the upgraded giant metrewave radio telescope (uGMRT) called CAsa Pipeline-cum-Toolkit for Upgraded Giant Metrewave Radio Telescope data REduction -CAPTURE.
Abstract: We present the first fully automated pipeline for making images from the interferometric data obtained from the upgraded Giant Metrewave Radio Telescope (uGMRT) called CAsa Pipeline-cum-Toolkit for Upgraded Giant Metrewave Radio Telescope data REduction - CAPTURE. It is a python program that uses tasks from the NRAO Common Astronomy Software Applications (CASA) to perform the steps of flagging of bad data, calibration, imaging and self-calibration. The salient features of the pipeline are: i) a fully automatic mode to go from the raw data to a self-calibrated continuum image, ii) specialized flagging strategies for short and long baselines that ensure minimal loss of extended structure, iii) flagging of persistent narrow band radio frequency interference (RFI), iv) flexibility for the user to configure the pipeline for step-by-step analysis or special cases and v) analysis of data from the legacy GMRT. CAPTURE is available publicly on github (
https://github.com/ruta-k/uGMRT-pipeline
, release v1.0.0). The primary beam correction for the uGMRT images produced with CAPTURE is made separately available at https://github.com/ruta-k/uGMRTprimarybeam
. We show examples of using CAPTURE on uGMRT and legacy GMRT data. In principle, CAPTURE can be tailored for use with other radio interferometric data.
TL;DR: The ExoClock project as discussed by the authors is an open, integrated and interactive platform with the purpose of producing a confirmed list of ephemerides for the planets that will be observed by Ariel.
Abstract: The Ariel mission will observe spectroscopically around 1000 exoplanets to further characterise their atmospheres. For the mission to be as efficient as possible, a good knowledge of the planets’ ephemerides is needed before its launch in 2028. While ephemerides for some planets are being refined on a per-case basis, an organised effort to collectively verify or update them when necessary does not exist. In this study, we introduce the ExoClock project, an open, integrated and interactive platform with the purpose of producing a confirmed list of ephemerides for the planets that will be observed by Ariel. The project has been developed in a manner to make the best use of all available resources: observations reported in the literature, observations from space instruments and, mainly, observations from ground-based telescopes, including both professional and amateur observatories. To facilitate inexperienced observers and at the same time achieve homogeneity in the results, we created data collection and validation protocols, educational material and easy to use interfaces, open to everyone. ExoClock was launched in September 2019 and now counts over 140 participants from more than 15 countries around the world. In this release, we report the results of observations obtained until the 15h of April 2020 for 120 Ariel candidate targets. In total, 632 observations were used to either verify or update the ephemerides of 84 planets. Additionally, we developed the Exoplanet Characterisation Catalogue (ECC), a catalogue built in a consistent way to assist the ephemeris refinement process. So far, the collaborative open framework of the ExoClock project has proven to be highly efficient in coordinating scientific efforts involving diverse audiences. Therefore, we believe that it is a paradigm that can be applied in the future for other research purposes, too.
University of Grenoble1, University of Sydney2, University of Lisbon3, Centra4, Queen Mary University of London5, Stockholm University6, École Polytechnique Fédérale de Lausanne7, Max Planck Society8, University of Texas at Austin9, University of Geneva10, University of Cologne11, Université Paris-Saclay12, Institut d'Astrophysique de Paris13, California Institute of Technology14, INAF15, Spanish National Research Council16, University of Granada17, University of Vienna18, University of Washington19, University of Bordeaux20, Harvard University21, University of Coimbra22, University of Paris23, University of Colorado Boulder24, Lund University25, University of Turin26, Istituto Nazionale di Fisica Nucleare27, Chalmers University of Technology28, University of Porto29, University of Michigan30, Open University31, University of Edinburgh32, Niels Bohr Institute33, University of Barcelona34, Dresden University of Technology35, University of Strasbourg36, European Space Research and Technology Centre37, Columbia State Community College38, Alenia Aeronautica39, Heidelberg University40, University of Queensland41, Imperial College London42, Planetary Science Institute43, University of Cambridge44, Space Telescope Science Institute45, Rutherford Appleton Laboratory46, University of Warsaw47, Johns Hopkins University48, Kyoto University49
TL;DR: In order to investigate the nature and characteristics of the motions of very faint objects, a flexibly-pointed instrument capable of high astrometric accuracy is an ideal complement to current sky survey telescopes and a unique tool for precision astrophysics.
Abstract: Sky survey telescopes and powerful targeted telescopes play complementary roles in astronomy. In order to investigate the nature and characteristics of the motions of very faint objects, a flexibly-pointed instrument capable of high astrometric accuracy is an ideal complement to current astrometric surveys and a unique tool for precision astrophysics. Such a space-based mission will push the frontier of precision astrometry from evidence of Earth-mass habitable worlds around the nearest stars, to distant Milky Way objects, and out to the Local Group of galaxies. As we enter the era of the James Webb Space Telescope and the new ground-based, adaptive-optics-enabled giant telescopes, by obtaining these high precision measurements on key objects that Gaia could not reach, a mission that focuses on high precision astrometry science can consolidate our theoretical understanding of the local Universe, enable extrapolation of physical processes to remote redshifts, and derive a much more consistent picture of cosmological evolution and the likely fate of our cosmos. Already several missions have been proposed to address the science case of faint objects in motion using high precision astrometry missions: NEAT proposed for the ESA M3 opportunity, micro-NEAT for the S1 opportunity, and Theia for the M4 and M5 opportunities. Additional new mission configurations adapted with technological innovations could be envisioned to pursue accurate measurements of these extremely small motions. The goal of this White Paper is to address the fundamental science questions that are at stake when we focus on the motions of faint sky objects and to briefly review instrumentation and mission profiles.
INAF1, University of Western Australia2, University of Leicester3, University College Dublin4, University of Milano-Bicocca5, Spanish National Research Council6, Sapienza University of Rome7, University of Geneva8, Frankfurt Institute for Advanced Studies9, Trinity College, Dublin10, University of Amsterdam11, University of Paris12, Université Paris-Saclay13, Istanbul University14, Bar-Ilan University15, Max Planck Society16, University of Nova Gorica17, Czech Technical University in Prague18, Kazan Federal University19, Academy of Sciences of the Czech Republic20, University of Copenhagen21, Paris Diderot University22, University of Trieste23, National Tsing Hua University24, University of Zielona Góra25, National and Kapodistrian University of Athens26, University of Ferrara27, University of Calabria28, Taras Shevchenko National University of Kyiv29, National Academy of Sciences of Ukraine30, Peking University31, Chinese Academy of Sciences32, National Central University33, Sejong University34, Centre national de la recherche scientifique35, University College London36, University of Nevada, Las Vegas37
TL;DR: Theseus will play a central role during the 2030s in detecting and localizing the electromagnetic counterparts of gravitational wave and neutrino sources that the unprecedented sensitivity of next generation detectors will discover at much higher rates than the present as mentioned in this paper.
Abstract: Multi-messenger astrophysics is becoming a major avenue to explore the Universe, with the potential to span a vast range of redshifts. The growing synergies between different probes is opening new frontiers, which promise profound insights into several aspects of fundamental physics and cosmology. In this context, THESEUS will play a central role during the 2030s in detecting and localizing the electromagnetic counterparts of gravitational wave and neutrino sources that the unprecedented sensitivity of next generation detectors will discover at much higher rates than the present. Here, we review the most important target signals from multi-messenger sources that THESEUS will be able to detect and characterize, discussing detection rate expectations and scientific impact.
University of Zurich1, University of Oslo2, Centre national de la recherche scientifique3, University of Tokyo4, University College London5, University of Tartu6, University of Oxford7, Netherlands Institute for Space Research8, Leiden University9, University of Cambridge10, ETH Zurich11, University of Toronto12, Open University of Israel13
TL;DR: In this paper, the authors outline the ongoing activities of the interior working group of the Ariel mission, and list the desirable theoretical developments as well as the challenges in linking planetary atmospheres, bulk composition and interior structure.
Abstract: The recently adopted Ariel ESA mission will measure the atmospheric composition of a large number of exoplanets. This information will then be used to better constrain planetary bulk compositions. While the connection between the composition of a planetary atmosphere and the bulk interior is still being investigated, the combination of the atmospheric composition with the measured mass and radius of exoplanets will push the field of exoplanet characterisation to the next level, and provide new insights of the nature of planets in our galaxy. In this white paper, we outline the ongoing activities of the interior working group of the Ariel mission, and list the desirable theoretical developments as well as the challenges in linking planetary atmospheres, bulk composition and interior structure.
Max Planck Society1, University of Paris2, Spanish National Research Council3, Netherlands Institute for Space Research4, Chinese Academy of Sciences5, INAF6, University of Cologne7, California Institute of Technology8, Paris Diderot University9, Kapteyn Astronomical Institute10, Braunschweig University of Technology11, Bundeswehr University Munich12
TL;DR: The velocity-resolved data in these tracers will reveal the detailed dynamics engrained in these processes in a spatially resolved fashion, and will deliver the perfect synergy with ground-based molecular line data for the colder dense gas.
Abstract: The far-infrared (FIR) regime is one of the wavelength ranges where no astronomical data with sub-arcsecond spatial resolution exist. None of the medium-term satellite projects like SPICA, Millimetron, or the Origins Space Telescope will resolve this malady. For many research areas, however, information at high spatial and spectral resolution in the FIR, taken from atomic fine-structure lines, from highly excited carbon monoxide (CO), light hydrides, and especially from water lines would open the door for transformative science. A main theme will be to trace the role of water in proto-planetary discs, to observationally advance our understanding of the planet formation process and, intimately related to that, the pathways to habitable planets and the emergence of life. Furthermore, key observations will zoom into the physics and chemistry of the star-formation process in our own Galaxy, as well as in external galaxies. The FIR provides unique tools to investigate in particular the energetics of heating, cooling, and shocks. The velocity-resolved data in these tracers will reveal the detailed dynamics engrained in these processes in a spatially resolved fashion, and will deliver the perfect synergy with ground-based molecular line data for the colder dense gas.
TL;DR: In this article, the spectral properties of the solar X-ray monitor (XSM) were investigated under various observing conditions, including gain, spectral redistribution function, and effective area, and the capability of the XSM to maintain its spectral performance at high incident flux as well as its dead-time and pile-up characteristics were also investigated.
Abstract: Chandrayaan-2, the second Indian mission to the Moon, carries a spectrometer called the Solar X-ray Monitor (XSM) to perform soft X-ray spectral measurements of the Sun while a companion payload, CLASS, measures the fluorescence emission from the Moon. Together these two payloads will provide quantitative estimates of elemental abundances on the lunar surface. The XSM with its high time cadence and high energy resolution spectral measurements, is also expected to provide significant contributions to solar X-ray studies. For this purpose, the XSM employs a Silicon Drift Detector and carries out energy measurements of incident photons in the 1 – 15 keV range with a resolution of < 180 eV at 5.9 keV, over a wide range of solar X-ray intensities. Extensive ground calibration experiments have been carried out with the XSM using laboratory X-ray sources as well as X-ray beam-line facilities to determine the instrument response matrix parameters required to carry out quantitative spectral analysis. This includes measurements, under various observing conditions, of gain, spectral redistribution function, and effective area. The capability of the XSM to maintain its spectral performance at high incident flux as well as its dead-time and pile-up characteristics have also been investigated. The results of these ground calibration experiments of the XSM payload are presented in this article.
Centre national de la recherche scientifique1, Chalmers University of Technology2, California Institute of Technology3, University of Michigan4, University of Amsterdam5, University of Crete6, Spanish National Research Council7, Cardiff University8, University of Groningen9, Leiden University10, Nicolaus Copernicus University in Toruń11, Paris Diderot University12, Goddard Space Flight Center13, Smithsonian Institution14, Space Telescope Science Institute15, Rutherford Appleton Laboratory16, University of Oxford17, University of Tokyo18
TL;DR: The Origins Space Telescope (Origins) is one of four science and technology definition studies selected by the National Aeronautics and Space Administration (NASA) in preparation of the 2020 Astronomy and Astrophysics Decadal survey as mentioned in this paper.
Abstract: The Origins Space Telescope (Origins) is one of four science and technology definition studies selected by the National Aeronautics and Space Administration (NASA) in preparation of the 2020 Astronomy and Astrophysics Decadal survey in the US. Origins will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. It is designed to answer three major science questions: How do galaxies form stars, make metals, and grow their central supermassive black holes from reionization? How do the conditions for habitability develop during the process of planet formation? Do planets orbiting M-dwarf stars support life? Origins operates at mid- to far-infrared wavelengths from ~ 2.8 μm to 588 μm, and is more than 1000 times more sensitive than prior far-IR missions due to its cold (~ 4.5 K) aperture and state-of-the-art instruments.
TL;DR: The Far Infrared Spectroscopic Surveyor (FIRSS) fulfills the requirements of a dedicated space-borne, far-infrared spectroscopic facility and by exploiting the legacy of recent photometric surveys it seizes the opportunity to shed light on the fundamental building processes of the authors' Universe.
Abstract: We are standing at the crossroads of powerful new facilities emerging in the next decade on the ground and in space like ELT, SKA, JWST, and Athena. Turning the narrative of the star formation potential of galaxies into a quantitative theory will provide answers to many outstanding questions in astrophysics, from the formation of planets to the evolution of galaxies and the origin of heavy elements. To achieve this goal, there is an urgent need for a dedicated space-borne, far-infrared spectroscopic facility capable of delivering, for the first time, large scale, high spectral resolution (velocity resolved) multiwavelength studies of the chemistry and dynamics of the ISM of our own Milky Way and nearby galaxies. The Far Infrared Spectroscopic Surveyor (FIRSS) fulfills these requirements and by exploiting the legacy of recent photometric surveys it seizes the opportunity to shed light on the fundamental building processes of our Universe.
University of Ferrara1, INAF2, University of Milan3, University of Bath4, Liverpool John Moores University5, Brera Astronomical Observatory6, Los Alamos National Laboratory7, Spanish National Research Council8, Northwestern University9, Technical University of Denmark10, University of Coimbra11, Université Paris-Saclay12, Institut d'Astrophysique de Paris13, University of Geneva14, University of Cagliari15, University of Palermo16
TL;DR: The ASTENA (Advanced Surveyor of Transient Events and Nuclear Astrophysics) mission as mentioned in this paper is a mission for the exploration of the GW Universe over a broad frequency range by ground and space interferometers.
Abstract: The coming decades will establish the exploration of the gravitational wave (GW) Universe over a broad frequency range by ground and space interferometers. Meanwhile, wide-field, high-cadence and sensitive surveys will span the electromagnetic spectrum from radio all the way up to TeV, as well as the high-energy neutrino window. Among the numerous classes of transients, γ–ray bursts (GRBs) have direct links with most of the hot topics that will be addressed, such as the strong gravity regime, relativistic shocks, particle acceleration processes, equation of state of matter at nuclear density, and nucleosynthesis of heavy elements, just to mention a few. Other recently discovered classes of transients that are observed throughout cosmological distances include fast radio bursts (FRBs), fast blue optical transients (FBOTs), and other unidentified high-energy transients. Here we discuss how these topics can be addressed by a mission called ASTENA (Advanced Surveyor of Transient Events and Nuclear Astrophysics, see Frontera et al. 18). Its payload combines two instruments: (i) an array of wide-field monitors with imaging, spectroscopic, and polarimetric capabilities (WFM-IS); (ii) a narrow field telescope (NFT) based on a Laue lens operating in the 50–600 keV range with unprecedented angular resolution, polarimetric capabilities, and sensitivity.
PSL Research University1, Université Paris-Saclay2, University of Oxford3, New York University4, Cardiff University5, Lawrence Berkeley National Laboratory6, University of California, Berkeley7, California Institute of Technology8, Delft University of Technology9, Netherlands Institute for Space Research10, University of Bonn11, Cornell University12, INAF13, University of Barcelona14, Centre national de la recherche scientifique15, University of Manchester16, University of Paris17, University of Toronto18, University of Science and Technology of China19, Chinese Academy of Sciences20, Max Planck Society21, Sapienza University of Rome22, University of New South Wales23, Kavli Institute of Nanoscience24, University of Maryland, College Park25, Imperial College London26, Harvard University27, Goddard Space Flight Center28, Ben-Gurion University of the Negev29, RWTH Aachen University30, Perimeter Institute for Theoretical Physics31, University of Ferrara32, University of Porto33, University of Geneva34, European Southern Observatory35, Yale University36, University of California, Los Angeles37, University of La Laguna38, University of British Columbia39, Johns Hopkins University40, University of Oslo41, Indian Institute of Science Education and Research, Pune42, National Institutes of Natural Sciences, Japan43, University of Cambridge44
TL;DR: In this article, the authors proposed a spectro-polarimetric survey of the microwave sky using a broadband polarised imager and a moderate resolution spectroimager at the focus of a 3.5 m aperture telescope.
Abstract: This paper discusses the science case for a sensitive spectro-polarimetric survey of the microwave sky. Such a survey would provide a tomographic and dynamic census of the three-dimensional distribution of hot gas, velocity flows, early metals, dust, and mass distribution in the entire Hubble volume, exploit CMB temperature and polarisation anisotropies down to fundamental limits, and track energy injection and absorption into the radiation background across cosmic times by measuring spectral distortions of the CMB blackbody emission. In addition to its exceptional capability for cosmology and fundamental physics, such a survey would provide an unprecedented view of microwave emissions at sub-arcminute to few-arcminute angular resolution in hundreds of frequency channels, a data set that would be of immense legacy value for many branches of astrophysics. We propose that this survey be carried out with a large space mission featuring a broad-band polarised imager and a moderate resolution spectro-imager at the focus of a 3.5 m aperture telescope actively cooled to about 8K, complemented with absolutely-calibrated Fourier Transform Spectrometer modules observing at degree-scale angular resolution in the 10–2000 GHz frequency range. We propose two observing modes: a survey mode to map the entire sky as well as a few selected wide fields, and an observatory mode for deeper observations of regions of specific interest.