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At least 1,279 records · Page 71

New Approach to Concept Feasibility and Design Studies for Astrophysics Missions

JPL has assembled a team of multidisciplinary experts with corporate knowledge of space mission and instrument development. The advanced Concept Design Team, known as Team X, provides interactive design trades including cost as a design parameter, and advanced visualization for pre-Phase A Studies.

Concept Feasibility Design Studies Team X Astrophy↗

Suborbital Applications in Astronomy and Astrophysics

Suborbital flights providing access to zero-g in a space environment - Demonstrating new technologies in a relevant environment. - Flight testing of individual elements of a constellation. - Raising the TRL of critical technologies for subsystems on future large missions High-altitude balloons (up to ~10 kg payload) -Access to near-space for wavelengths not observable from the ground. -Raising the TRL of critical technologies for subsystems on future large missions. -UV Detector testing.

rockets↗

The Formation of Organic Compounds of Astrobiological Interest by the Irradiation Processing of Astrophysical Ices

Many environments in space contain very low temperature mixed molecular ices that are exposed to ionizing radiation in the form of cosmic rays and high-energy photons. While traditional chemistry would not be expected to occur at the temperatures typical of these ices (T < 50 K), ionizing radiation can break bonds in the original molecules in the ices to form highly reactive ions and radicals. These ions and radicals are subsequently free to react despite the low temperatures of the original ices. Laboratory experiments, many of them carried out at the Astrochemistry Laboratory at NASA-Ames, show that the irradiation of ices made of even simple molecules like H2O, CO, CO2, CH4, NH3, etc. can result in the robust formation of large numbers of far more complex organic compounds. Many of these new products are of direct interest to astrobiology. For example, the irradiation of mixed molecular ices has been shown to produce amino acids, amphiphiles, quinones, sugars, heterocyclic compounds, and nucleobases, all molecular building blocks used by terrestrial life. Insofar as the presence of these materials plays a role in the origin of life on planets, this has profound implications for the potential abundance of life in the universe since these experiments simulate universal conditions that are expected to be found wherever new stars and planets form.

Astrobiology↗

Astrophysics and Technical Study of a Solar Neutrino Spacecraft: NIAC (NASA Innovative Advanced Concepts) Grant - NASA 2018-Phase-1

We report on our study of the design of a neutrino detector, shielding and veto array needed to operate a neutrino detector in space close to the Sun. This study also took into account the expected rates of Galactic gamma and cosmic rays in addition to the particles from the Sun.These preliminary studies show that we can devise a detector such that a small signal of neutrino interactions can be extracted from a large random number of events from the background sources using a double timing method from the conversion electron produced in the neutrino interaction and a secondary delayed signal from the nuclear excited state produced from the initial neutrino interaction; in our case the conversion of Ga 69 or 71 into Ge 69 or 71, but this method could apply to other nuclei with large neutrino cross sections such as Ir 115. Although these types of events need to be above 0.405 megaelectronvolt (MeV) neutrino energy and are only 66 percent of all conversion neutrino interactions on Gallium, this is a small price to pay for an increase of 10,000 by going close to the Sun to enhance the neutrino rate over the background combatorical fake-signal events. The conclusion of this Phase-1 study is very positive in that we can get the backgrounds less than 20 percent fake signals, and in addition to this we have devised another shielding method that makes the Galactic gamma-ray rate a hundred fold less which will make further improvements over these initial estimates. Although these studies are very encouraging it suggests that the next step is a NIAC Phase-II to actually build a test device,measuring basic principles such as light attention within the scintillator with high dopants and to take data in the lab with a cosmic-ray test stand and triggered X-ray source for comparison with simulated expected performance of the detector. This would be the perfect lead into a future proposal beyond a NIAC (NASA Innovative Advanced Concepts) Phase-II for a test flight of a small one-pint detector in orbit of the detector concept beyond Earth outside of the radiation belts.

Astrophysics↗

MAESTRO, CASTRO, and SEDONA -- Petascale Codes for Astrophysical Applications

Performing high-resolution, high-fidelity, three-dimensional simulations of Type Ia supernovae (SNe Ia) requires not only algorithms that accurately represent the correct physics, but also codes that effectively harness the resources of the most powerful supercomputers. We are developing a suite of codes that provide the capability to perform end-to-end simulations of SNe Ia, from the early convective phase leading up to ignition to the explosion phase in which deflagration/detonation waves explode the star to the computation of the light curves resulting from the explosion. In this paper we discuss these codes with an emphasis on the techniques needed to scale them to petascale architectures. We also demonstrate our ability to map data from a low Mach number formulation to a compressible solver.

79 ASTRONOMY AND ASTROPHYSICS↗

Gravitational Wave Cosmology and Astrophysics with Large Spectroscopic Galaxy Surveys

During the next decade, gravitational waves will be observed from hundreds of binary inspiral events. When the redshifts of the host galaxies are known, these events can be used as `standard sirens', sensitive to the expansion rate of the Universe. Measurements of the Hubble constant $H_0$ from standard sirens can be done independently of other cosmological probes, and events occurring at $z<0.1$ will allow us to infer $H_0$ independently of cosmological models. The next generation of spectroscopic galaxy surveys will play a crucial role in reducing systematic uncertainties in $H_0$ from standard sirens, particularly for the numerous `dark sirens' which do not have an electromagnetic counterpart. In combination with large spectroscopic data sets, standard sirens with an EM counterpart are expected to constrain $H_0$ to $\sim 1-2\%$ precision within the next decade. This is competitive with the best estimates of $H_0$ obtained to date and will help illuminate the current tension between existing measurements. Information on the galaxies that host the gravitational wave events will also shed light on the origin and evolution of compact object binaries.

79 ASTRONOMY AND ASTROPHYSICS↗

Astrophysics with Plasmas at High Energy Density

Nuclear reactions and decay processes are the energy source of stars like our sun and cause stellar explosions like novae and supernovae in our universe. They have also been responsible for building our elements since the Big Bang 13.8 billion years ago. In the third minute of our universe, protons and neutrons formed the first light elements such as helium and lithium, which formed the basis for further construction of the elements inside the stars. Observations of old stars show that this chemical development took place across many generations of stars and many different nuclear reaction sequences.

79 ASTRONOMY AND ASTROPHYSICS↗

Gravitational wave cosmology and astrophysics with large spectroscopic galaxy surveys

During the next decade, gravitational waves will be observed from hundreds of binary inspiral events. When the redshifts of the host galaxies are known, these events can be used as `standard sirens', sensitive to the expansion rate of the Universe. Measurements of the Hubble constant H 0 from standard sirens can be done independently of other cosmological probes, and events occurring at $z<0.1$ will allow us to infer H 0 independently of cosmological models. The subsequent generation of spectroscopic galaxy surveys will play a significant role in reducing systematic uncertainties in H 0 from standard sirens, particularly for the numerous `dark sirens' which do not have an electromagnetic counterpart. In combination with large spectroscopic data sets, standard sirens with an EM counterpart are expected to constrain H 0 to ~1-2% precision within the next decade. This is competitive with the best estimates of H 0 obtained to date and will help highlight the current tension between existing measurements. Information on the galaxies that host the gravitational wave events will further shed light on the origin and evolution of compact object binaries.

79 ASTRONOMY AND ASTROPHYSICS↗