|
David Elbaz
David Elbaz is a French novelist and observational astrophysicist, specializing in galaxy formation and evolution. He has been a researcher at the Astrophysics Division (AIM) of the Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA-Saclay) since 1994, where he is currently the Director of Research. He was in charge of directing the "Cosmology and Evolution of Galaxies" laboratory at AIM/CEA-Saclay for about a decade. He has also worked as the scientific advisor to the European Space Agency for the selection of its future space missions (Astronomy Working Group) and was a member of the evaluation committee on space research and exploration for the Centre National d'Etudes Spatiales (CNES) in France. Biography Elbaz's grandparents moved to France from Morocco at the beginning of the 20th century. He was born and raised in the Paris Métro area. He repeated a school year twice in high school. He also attended the École Nationale Supérieure de Physique (ENSP ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paris
Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. Since the 17th century, Paris has been one of the world's major centres of finance, diplomacy, commerce, fashion, gastronomy, and science. For its leading role in the arts and sciences, as well as its very early system of street lighting, in the 19th century it became known as "the City of Light". Like London, prior to the Second World War, it was also sometimes called the capital of the world. The City of Paris is the centre of the Île-de-France region, or Paris Region, with an estimated population of 12,262,544 in 2019, or about 19% of the population of France, making the region France's primate city. The Paris Region had a GDP of €739 billion ($743 billion) in 2019, which is the highest in Europe. According to the Economis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postdoctoral Researcher
A postdoctoral fellow, postdoctoral researcher, or simply postdoc, is a person professionally conducting research after the completion of their doctoral studies (typically a PhD). The ultimate goal of a postdoctoral research position is to pursue additional research, training, or teaching in order to have better skills to pursue a career in academia, research, or any other field. Postdocs often, but not always, have a temporary academic appointment, sometimes in preparation for an academic faculty position. They continue their studies or carry out research and further increase expertise in a specialist subject, including integrating a team and acquiring novel skills and research methods. Postdoctoral research is often considered essential while advancing the scholarly mission of the host institution; it is expected to produce relevant publications in peer-reviewed academic journals or conferences. In some countries, postdoctoral research may lead to further formal qualification ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Observatories Origins Deep Survey
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. GOODS is intended to enable astronomers to study the formation and evolution of galaxies in the distant, early universe. The Great Observatories Origins Deep Survey consists of optical and near-infrared imaging taken with the Advanced Camera for Surveys on the Hubble Space Telescope, the Very Large Telescope and the 4-m telescope at Kitt Peak National Observatory; infrared data from the Spitzer Space Telescope. These are added to pre-existing x-ray data from the Chandra X-ray Observatory and ESAs XMM-Newton, two fields of 10' by 16'; one centered on the Hubble Deep Field North (12h 36m 55s, +62° 14m 15s) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spitzer Space Telescope
The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), was an infrared space telescope launched in 2003. Operations ended on 30 January 2020. Spitzer was the third space telescope dedicated to infrared astronomy, following IRAS (1983) and ISO (1995–1998). It was the first spacecraft to use an Earth-trailing orbit, later used by the Kepler planet-finder. The planned mission period was to be 2.5 years with a pre-launch expectation that the mission could extend to five or slightly more years until the onboard liquid helium supply was exhausted. This occurred on 15 May 2009. Without liquid helium to cool the telescope to the very low temperatures needed to operate, most of the instruments were no longer usable. However, the two shortest-wavelength modules of the IRAC camera continued to operate with the same sensitivity as before the helium was exhausted, and continued to be used into early 2020 in the Spitzer Warm Mission. During the warm missio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luminous Infrared Galaxy
Luminous infrared galaxies or LIRGs are galaxies with luminosities, the measurement of brightness, above . They are also referred to as submillimeter galaxies (SMGs) through their normal method of detection. LIRGs are more abundant than starburst galaxies, Seyfert galaxies and quasi-stellar objects at comparable luminosity. Infrared galaxies emit more energy in the infrared than at all other wavelengths combined. A LIRG's luminosity is 100 billion times that of the Sun. Galaxies with luminosities above are ultraluminous infrared galaxies (ULIRGs). Galaxies exceeding are characterised as hyper-luminous infrared galaxies (HyLIRGs). Those exceeding are extremely luminous infrared galaxies (ELIRGs). Many of the LIRGs and ULIRGs are showing interactions and disruptions. Many of these types of galaxies spawn about 100 new stars a year as compared to the Milky Way which spawns one a year; this helps create the high level of luminosity. Discovery and characteristics Infrared galaxi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star Formation
Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as "stellar nurseries" or "star-forming regions", collapse and form stars. As a branch of astronomy, star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process, and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation, another branch of astronomy. Star formation theory, as well as accounting for the formation of a single star, must also account for the statistics of binary stars and the initial mass function. Most stars do not form in isolation but as part of a group of stars referred as star clusters or stellar associations. Stellar nurseries Interstellar clouds A spiral galaxy like the Milky Way contains stars, stellar remnants, and a diffuse interstellar medium (ISM) of gas and dust. The inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmic Infrared Background
Cosmic infrared background is infrared radiation caused by stellar dust. History Recognizing the cosmological importance of the darkness of the night sky (Olbers' paradox) and the first speculations on an extragalactic background light dates back to the first half of the 19th century. Despite its importance, the first attempts were made only in the 1950-60s to derive the value of the visual background due to galaxies, at that time based on the integrated starlight of these stellar systems. In the 1960s the absorption of starlight by dust was already taken into account, but without considering the re-emission of this absorbed energy in the infrared. At that time Jim Peebles pointed out, that in a Big Bang-created Universe there must have been a cosmic infrared background (CIB) – different from the cosmic microwave background – that can account for the formation and evolution of stars and galaxies. In order to produce today's metallicity, early galaxies must have been signif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Redshift
In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in frequency and energy, is known as a negative redshift, or blueshift. The terms derive from the colours red and blue which form the extremes of the visible light spectrum. In astronomy and cosmology, the three main causes of electromagnetic redshift are # The radiation travels between objects which are moving apart (" relativistic" redshift, an example of the relativistic Doppler effect) #The radiation travels towards an object in a weaker gravitational potential, i.e. towards an object in less strongly curved (flatter) spacetime ( gravitational redshift) #The radiation travels through expanding space ( cosmological redshift). The observation that all sufficiently distant light sources show redshift corresponding to their distance fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectral Energy Distribution
A spectral energy distribution (SED) is a plot of energy versus frequency or wavelength of light (not to be confused with a 'spectrum' of flux density vs frequency or wavelength). It is used in many branches of astronomy to characterize astronomical sources. For example, in radio astronomy they are used to show the emission from synchrotron radiation, free-free emission and other emission mechanisms. In infrared astronomy, SEDs can be used to classify young stellar objects. Detector for spectral energy distribution The count rates observed from a given astronomical radiation source have no simple relationship to the flux from that source, such as might be incident at the top of the Earth's atmosphere. This lack of a simple relationship is due in no small part to the complex properties of radiation detectors. These detector properties can be divided into *those that merely attenuate the beam, including *#residual atmosphere between source and detector, *#absorption in the det ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared Space Observatory
The Infrared Space Observatory (ISO) was a space telescope for infrared light designed and operated by the European Space Agency (ESA), in cooperation with ISAS (now part of JAXA) and NASA. The ISO was designed to study infrared light at wavelengths of 2.5 to 240 micrometres and operated from 1995 to 1998. The €480.1- million satellite was launched on 17 November 1995 from the ELA-2 launch pad at the Guiana Space Centre near Kourou in French Guiana. The launch vehicle, an Ariane 44P rocket, placed ISO successfully into a highly elliptical geocentric orbit, completing one revolution around the Earth every 24 hours. The primary mirror of its Ritchey-Chrétien telescope measured 60 cm in diameter and was cooled to 1.7 kelvins by means of superfluid helium. The ISO satellite contained four instruments that allowed for imaging and photometry from 2.5 to 240 micrometres and spectroscopy from 2.5 to 196.8 micrometers. ESA and the Infrared Processing and Analysis Center m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clarivate Analytics
Clarivate Plc is a British-American publicly traded analytics company that operates a collection of subscription-based services, in the areas of bibliometrics and scientometrics; business / market intelligence, and competitive profiling for pharmacy and biotech, patents, and regulatory compliance; trademark protection, and domain and brand protection. In the academy and the scientific community, Clarivate is known for being the company which calculates the impact factor, using data from its Web of Science product family, that also includes services/applications such as Publons, EndNote, EndNote Click, and ScholarOne. Its other product families are Cortellis, DRG, CPA Global, Derwent, MarkMonitor, CompuMark, and Darts-ip, and also the various ProQuest products and services. Clarivate was formed in 2016, following the acquisition of Thomson Reuters' Intellectual Property and Science Business by Onex Corporation and Baring Private Equity Asia. Clarivate has been g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISI Highly Cited
The Institute for Scientific Information (ISI) was an academic publishing service, founded by Eugene Garfield in Philadelphia in 1956. ISI offered scientometric and bibliographic database services. Its specialty was citation indexing and analysis, a field pioneered by Garfield. Services ISI maintained citation databases covering thousands of academic journals, including a continuation of its longtime print-based indexing service the Science Citation Index (SCI), as well as the Social Sciences Citation Index (SSCI) and the Arts and Humanities Citation Index (AHCI). All of these were available via ISI's Web of Knowledge database service. This database allows a researcher to identify which articles have been cited most frequently, and who has cited them. The database provides some measure of the academic impact of the papers indexed in it, and may increase their impact by making them more visible and providing them with a quality label. Some anecdotal evidence suggests that appearin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
