Hubble's law, also known as the Hubble–Lemaître law, is the observation in physical cosmology that galaxies are moving away from the Earth at speeds proportional to their distance. In other words, the farther they are the faster they are moving away from Earth. The velocity of the galaxies has been determined by their redshift, a shift of the light they emit toward the red end of the spectrum.
In gamma-ray astronomy, gamma-ray bursts (GRBs) are extremely energetic explosions that have been observed in distant galaxies. They are the brightest and most energetic electromagnetic events known to occur in the universe. Bursts can last from ten milliseconds to several hours. After an initial flash of gamma rays, a longer-lived "afterglow" is usually emitted at longer wavelengths.
Timeline of galaxies, clusters of galaxies, and large-scale structure of the universe
A magnetar is a type of neutron star believed to have an extremely powerful magnetic field (∼109 to 1011 T, ∼1013 to 1015 G). The magnetic-field decay powers the emission of high-energy electromagnetic radiation, particularly X-rays and gamma rays. The theory regarding these objects was proposed by Robert Duncan and Christopher Thompson in 1992, but the first recorded burst of gamma rays thought to have been from a magnetar had been detected on March 5, 1979. During the following decade, the magnetar hypothesis became widely accepted as a likely explanation for soft gamma repeaters (SGRs) and anomalous X-ray pulsars (AXPs). On 1 June 2020, astronomers reported narrowing down the source of fast radio bursts (FRBs), which may now plausibly include "compact-object mergers and magnetars arising from normal core collapse supernovae".
A supermassive black hole is the largest type of black hole, with mass on the order of millions to billions of times the mass of the Sun (M☉). Black holes are a class of astronomical objects that have undergone gravitational collapse, leaving behind spheroidal regions of space from which nothing can escape, not even light. Observational evidence indicates that almost every large galaxy has a supermassive black hole at the galaxy's center. The Milky Way has a supermassive black hole in its Galactic Center, which corresponds to the location of Sagittarius A*. Accretion of interstellar gas onto supermassive black holes is the process responsible for powering active galactic nuclei and quasars.
The James Webb Space Telescope is a joint NASA-ESA-CSA space telescope that is planned to succeed the Hubble Space Telescope as NASA's flagship astrophysics mission. The JWST will provide improved infrared resolution and sensitivity over Hubble, and will enable a broad range of investigations across the fields of astronomy and cosmology, including observing some of the most distant events and objects in the universe, such as the formation of the first galaxies.
The Great Observatories Origins Deep Survey, or GOODS, is an astronomical survey combining deep observations from three of NASA's Great Observatories: the Hubble Space Telescope, the Spitzer Space Telescope, and the Chandra X-ray Observatory, along with data from other space-based telescopes, such as XMM Newton, and some of the world's most powerful ground-based telescopes.
A neutron star merger is a type of stellar collision. It occurs in a fashion similar to the rare brand of type Ia supernovae resulting from merging white dwarfs.
CHEOPS is a European space telescope to determine the size of known extrasolar planets, which will allow the estimation of their mass, density, composition and their formation. Launched on 18 December 2019, it is the first Small-class mission in ESA's Cosmic Vision science programme.
A kilonova is a transient astronomical event that occurs in a compact binary system when two neutron stars or a neutron star and a black hole merge into each other. Kilonovae are thought to emit short gamma-ray bursts and strong electromagnetic radiation due to the radioactive decay of heavy r-process nuclei that are produced and ejected fairly isotropically during the merger process.
In radio astronomy, a fast radio burst (FRB) is a transient radio pulse of length ranging from a fraction of a millisecond to a few milliseconds, caused by some high-energy astrophysical process not yet understood. Astronomers estimate the average FRB releases as much energy in a millisecond as the sun puts out in 3 days. While extremely energetic at their source, the strength of the signal reaching Earth has been described as 1,000 times less than from a mobile phone on the Moon. The first FRB was discovered by Duncan Lorimer and his student David Narkevic in 2007 when they were looking through archival pulsar survey data, and it is therefore commonly referred to as the Lorimer Burst. Many FRBs have since been recorded, including several that have been detected to repeat in seemingly irregular ways. Nonetheless, one FRB has been detected to repeat in a regular way: particularly, FRB 180916 seems to pulse every 16.35 days. Most FRBs are extragalactic, but the first Milky Way FRB was detected by the CHIME radio telescope in April 2020.
The NIRSpec is one of the four scientific instruments which will be flown on the James Webb Space Telescope (JWST). The JWST is the follow-on mission to the Hubble Space Telescope (HST) and is developed to receive more information about the origins of the universe by observing infrared light from the first stars and galaxies. In comparison to HST, its instruments will allow looking further back in time and will study the so-called Dark Ages during which the universe was opaque, about 150 to 800 million years after the Big Bang.
eROSITA is an X-ray instrument built by the Max Planck Institute for Extraterrestrial Physics (MPE) in Germany. It is part of the Russian-German Spektr-RG space observatory, which also carries the Russian telescope ART-XC. It was launched by Roscosmos on 13 July 2019 from Baikonur, and deployed in a 6-month halo orbit around the second Lagrange point (L2).
KELT-9b is an exoplanet—more specifically, an ultra-hot Jupiter—that orbits the late B-type/early A-type star KELT-9, located about 670 light-years from Earth. Detected using the Kilodegree Extremely Little Telescope, KELT-9b was announced in 2016.
GW 170817 was a gravitational wave (GW) signal observed by the LIGO and Virgo detectors on 17 August 2017, originating from the shell elliptical galaxy NGC 4993. The GW was produced by the last minutes of two neutron stars spiralling closer to each other and finally merging, and is the first GW observation which has been confirmed by non-gravitational means. Unlike the five previous GW detections, which were of merging black holes not expected to produce a detectable electromagnetic signal, the aftermath of this merger was also seen by 70 observatories on 7 continents and in space, across the electromagnetic spectrum, marking a significant breakthrough for multi-messenger astronomy. The discovery and subsequent observations of GW 170817 were given the Breakthrough of the Year award for 2017 by the journal Science.
The Experiment to Detect the Global EoR Signature (EDGES) is an experiment and radio telescope located in a radio quiet zone at the Murchison Radio-astronomy Observatory in Western Australia. It is a collaboration between Arizona State University and Haystack Observatory, with infrastructure provided by CSIRO. EoR stands for epoch of reionization, a time in cosmic history when neutral atomic hydrogen gas became ionised due to ultraviolet light from the first stars.
Peter Lawrence Capak is currently the Architect of Perception Systems at the Oculus division of Facebook. His current focus is developing machine perception technologies, sensors, displays, and compute architectures for the next generation of augmented (AR), mixed (MR) and virtual reality (VR) systems. His research has focused on using physical modeling and advanced statistical methods including artificial intelligence and machine learning to extract information from very large multi-wavelength (hyper-spectral) data sets. He has primarily used this to study structure formation in the universe, cosmology, and the nature of dark matter and dark energy.
GRB 190114C was a notable gamma ray burst explosion from a galaxy 4.5 billion light years away (z=0.4245; magnitude=15.60est) near the Fornax constellation, that was initially detected in January 2019. The afterglow light emitted soon after the burst was found to be tera-electron volt radiation from inverse Compton emission, identified for the first time. According to the astronomers, "We observed a huge range of frequencies in the electromagnetic radiation afterglow of GRB 190114C. It is the most extensive to date for a gamma-ray burst." Also, according to other astronomers, "light detected from the object had the highest energy ever observed: 1 Tera electron volt (TeV) -- about one trillion times as much energy per photon as visible light"; another source stated, "the brightest light ever seen from Earth [to date] ... [the] biggest explosion in the Universe since the Big Bang".
