Protoplanetary Disks and their Evolution
... photosphere, λturn−off , and the slope of the infrared excess, αexcess , computed from λturn−off to 24 µm. The census of Class III sources is highly incomplete in optical and infrared catalogs, however, because they lack strong accretion signatures and infrared excesses. Their youth is generally onl ...
... photosphere, λturn−off , and the slope of the infrared excess, αexcess , computed from λturn−off to 24 µm. The census of Class III sources is highly incomplete in optical and infrared catalogs, however, because they lack strong accretion signatures and infrared excesses. Their youth is generally onl ...
Infrared Astronomy
... Humans at normal body temperature, radiate most strongly in the infrared, which is definitely not seen by human eyes. The scientific discovery that the heat we all feel coming from the Sun is largely a radiation beyond the visible red colour of the solar spectrum was made by William Herschel in 1800 ...
... Humans at normal body temperature, radiate most strongly in the infrared, which is definitely not seen by human eyes. The scientific discovery that the heat we all feel coming from the Sun is largely a radiation beyond the visible red colour of the solar spectrum was made by William Herschel in 1800 ...
Gas and Dust Chemistry in Planet-Forming Disks
... disk LkCa 15 and the Herbig Ae disk HD 163296. The deuterium enrichments are similar to that of molecular clouds, hot cores, and comets, consistent with comet formation in the outer regions of disks. The distribution of HDO in LkCa 15 was found to be similar to predictions from chemical models, whic ...
... disk LkCa 15 and the Herbig Ae disk HD 163296. The deuterium enrichments are similar to that of molecular clouds, hot cores, and comets, consistent with comet formation in the outer regions of disks. The distribution of HDO in LkCa 15 was found to be similar to predictions from chemical models, whic ...
Collisional processes in extrasolar planetesimal discs
... represent model fits to these data (see Section 4) that assume that the disc’s spatial distribution is defined by a fit to the 450 µm image (Holland et al. 2002), and that it is comprised of solid grains of 1/3 (by volume) amorphous silicate and 2/3 organic refractory material (e.g. Li & Greenberg 1 ...
... represent model fits to these data (see Section 4) that assume that the disc’s spatial distribution is defined by a fit to the 450 µm image (Holland et al. 2002), and that it is comprised of solid grains of 1/3 (by volume) amorphous silicate and 2/3 organic refractory material (e.g. Li & Greenberg 1 ...
The Early Evolution of Solids in Protoplanetary Disks
... of planets. According to the core accretion scenario, the formation of planets involves a variety of physical mechanisms starting from the coagulation of sub-µm sized particles and going up to the gas-accretion phase leading to the build up of rocky planets and gas giants. The first stages of this p ...
... of planets. According to the core accretion scenario, the formation of planets involves a variety of physical mechanisms starting from the coagulation of sub-µm sized particles and going up to the gas-accretion phase leading to the build up of rocky planets and gas giants. The first stages of this p ...
SPICA Yellow Book
... A complete understanding of the formation and evolution of galaxies, stars and planets can only be reached through the investigation of the cold and obscured parts of the Universe, where the basic processes of formation and evolution occur. Deep exploration of the cold Universe using high spatial re ...
... A complete understanding of the formation and evolution of galaxies, stars and planets can only be reached through the investigation of the cold and obscured parts of the Universe, where the basic processes of formation and evolution occur. Deep exploration of the cold Universe using high spatial re ...
Polarimetry and photometry of the peculiar main
... observed in polarized light (Boehnhardt et al. 2008), over an extented phase-angle range. Although the shape of the polarimetric curve of 2P/Encke resembles to those of asteroids, the numerical values of the polarization minimum, slope, and inversion phase-angle differ remarkably from those of other ...
... observed in polarized light (Boehnhardt et al. 2008), over an extented phase-angle range. Although the shape of the polarimetric curve of 2P/Encke resembles to those of asteroids, the numerical values of the polarization minimum, slope, and inversion phase-angle differ remarkably from those of other ...
A Spitzer mid-infrared spectral survey of mass
... source. Targets were selected to span the long sequence of increasing mass-loss in LIMS which stretches from (J − K , M K ) ∼ (2, − 9) to (7, −4) in Fig. 1(a). [The bright oxygen-rich object near (J − K , M K ) ∼ (1, −10.7) in Fig. 1(b) was not a target but was accidentally observed when Spitzer sel ...
... source. Targets were selected to span the long sequence of increasing mass-loss in LIMS which stretches from (J − K , M K ) ∼ (2, − 9) to (7, −4) in Fig. 1(a). [The bright oxygen-rich object near (J − K , M K ) ∼ (1, −10.7) in Fig. 1(b) was not a target but was accidentally observed when Spitzer sel ...
Polarimetry: a powerful diagnostic tool in astronomy
... show appreciable polarization. For example, synchrotron and cyclotron radiation produce linear and circular polarization respectively. However, it is the polarization produced by material around a star that perhaps provides most current interest. This could be from a protoplanetary disc or a debris ...
... show appreciable polarization. For example, synchrotron and cyclotron radiation produce linear and circular polarization respectively. However, it is the polarization produced by material around a star that perhaps provides most current interest. This could be from a protoplanetary disc or a debris ...
The visibility of Lyman Alpha Emitters: constraining reionization
... as an ambient hot gas containing cold clouds, which provide the reservoir for star formation, with the two phases being in pressure equilibrium; the relative number of stars of different masses is computed using the Salpeter initial mass function (IMF; Salpeter 1955) between 0.1-100M⊙ . The density ...
... as an ambient hot gas containing cold clouds, which provide the reservoir for star formation, with the two phases being in pressure equilibrium; the relative number of stars of different masses is computed using the Salpeter initial mass function (IMF; Salpeter 1955) between 0.1-100M⊙ . The density ...
material safety data sheet
... Collect dry material using a scoop. Avoid actions that cause dust to become airborne. Avoid inhalation of dust and contact with skin. Wear appropriate personal protective equipment as described in Section 8. Scrape up wet material and place in an appropriate container. Allow the material to “dry” be ...
... Collect dry material using a scoop. Avoid actions that cause dust to become airborne. Avoid inhalation of dust and contact with skin. Wear appropriate personal protective equipment as described in Section 8. Scrape up wet material and place in an appropriate container. Allow the material to “dry” be ...
8 Comets: Potential Sources of Prebiotic Molecules for the
... Cometary dust particles disperse more or less rapidly into the interplanetary space, according to their shape, nature and initial velocity. Some of them cross the path of the Earth; if large enough they produce meteors. One can get an idea of cometary dust particles by looking at particles collected ...
... Cometary dust particles disperse more or less rapidly into the interplanetary space, according to their shape, nature and initial velocity. Some of them cross the path of the Earth; if large enough they produce meteors. One can get an idea of cometary dust particles by looking at particles collected ...
Mid-IR Spectra of IRAS 20343+4129 IRS 1 and IRS 3 M.F. Campbell
... found to have a pair of massive clumps oriented ~EW (contours in Fig 1., taken from Palau, 2006). Beuther et al. (2002b) found it to have a massive molecular outflow oriented NS with lobes extended EW, centered roughly between the 1.2mm clumps. Kumar et al. (2002) observed shocked H2 in the 2 m K b ...
... found to have a pair of massive clumps oriented ~EW (contours in Fig 1., taken from Palau, 2006). Beuther et al. (2002b) found it to have a massive molecular outflow oriented NS with lobes extended EW, centered roughly between the 1.2mm clumps. Kumar et al. (2002) observed shocked H2 in the 2 m K b ...
9 The Clearing of Protoplanetary Disks and of the Protosolar Nebula
... 9.1.2 Constraints on the dispersal of the gas component The initial mass and lifetime of gas in circumstellar disks affect both the formation of giant planets as well as the formation of terrestrial planets. According to the widely accepted scenario of giant planet formation, rocky cores need to rea ...
... 9.1.2 Constraints on the dispersal of the gas component The initial mass and lifetime of gas in circumstellar disks affect both the formation of giant planets as well as the formation of terrestrial planets. According to the widely accepted scenario of giant planet formation, rocky cores need to rea ...
Silicon isotopic abundance toward evolved stars and its application
... Vollmer et al. 2008), indicating that the amount of Si isotopes locked in the SiC grains and the SiO group in silicates may be similar; an example are the Orgueil silicate grains shown in Fig. 3. Most of the presolar grains have 29 Si/30 Si ratios around 1.5, but evidence of lower 29 Si/30 Si ratios ...
... Vollmer et al. 2008), indicating that the amount of Si isotopes locked in the SiC grains and the SiO group in silicates may be similar; an example are the Orgueil silicate grains shown in Fig. 3. Most of the presolar grains have 29 Si/30 Si ratios around 1.5, but evidence of lower 29 Si/30 Si ratios ...
21 -26 August University of Exeter
... Investigating the dynamics of the interstellar medium (ISM) is key to gaining insight into the formation of starforming filaments in molecular clouds (MCs). A plethora of numerical and analytical models associate the origin of this filamentary structure to the interplay between self-gravity and magn ...
... Investigating the dynamics of the interstellar medium (ISM) is key to gaining insight into the formation of starforming filaments in molecular clouds (MCs). A plethora of numerical and analytical models associate the origin of this filamentary structure to the interplay between self-gravity and magn ...
Relating dust, gas, and the rate of star formation in M 31
... that in the Galaxy dust and neutral gas are well mixed. In dense clouds of molecular gas mixed with cold dust most of the stars are formed. They subsequently heat the dust and gas in their surroundings and ionize the atomic gas. As the major coolants of the ISM are continuum emission and line emissi ...
... that in the Galaxy dust and neutral gas are well mixed. In dense clouds of molecular gas mixed with cold dust most of the stars are formed. They subsequently heat the dust and gas in their surroundings and ionize the atomic gas. As the major coolants of the ISM are continuum emission and line emissi ...
The Physics and Chemistry of Nebular Evolution
... can make up as much as 80% of the volume of a given meteorite. Chondrules are roughly millimeter-sized, igneous, ferromagnesium silicates that are considered to be evidence for transient heating events in the early solar system (Connolly et al., 2006). In addition to chondrules, refractory objects c ...
... can make up as much as 80% of the volume of a given meteorite. Chondrules are roughly millimeter-sized, igneous, ferromagnesium silicates that are considered to be evidence for transient heating events in the early solar system (Connolly et al., 2006). In addition to chondrules, refractory objects c ...
Chandra Characterization of X-ray Emission in the Young F
... The twin F stars in the HD 113766 system are thus an interesting and useful couple to study. Close enough (separated by only 1.4ʺ, or 170 AU) to be in the same ISM environment, yet far enough separated that they influence each other’s circumstellar environment within 100 AU minimally, and formed at ...
... The twin F stars in the HD 113766 system are thus an interesting and useful couple to study. Close enough (separated by only 1.4ʺ, or 170 AU) to be in the same ISM environment, yet far enough separated that they influence each other’s circumstellar environment within 100 AU minimally, and formed at ...
chapter - Max-Planck-Institut für Astronomie
... Our story reads that once upon a time, it existed an interstellar cloud of gas and dust. Then, about 4.6 billions years ago, one cloud fragment became the Solar System. What happened to that primordial condensation? When, why and how did it happen? Answering these questions involves putting together ...
... Our story reads that once upon a time, it existed an interstellar cloud of gas and dust. Then, about 4.6 billions years ago, one cloud fragment became the Solar System. What happened to that primordial condensation? When, why and how did it happen? Answering these questions involves putting together ...
Physics of the Interstellar Medium
... Interstellar space is filled with a dilute mixture of charged particles, atoms, molecules and dust grains, called the interstellar medium (ISM). The average particle density of the ISM is 1 cm−3 which represents a density lower than can be created on Earth. The ISM therefore represents a fascinating ...
... Interstellar space is filled with a dilute mixture of charged particles, atoms, molecules and dust grains, called the interstellar medium (ISM). The average particle density of the ISM is 1 cm−3 which represents a density lower than can be created on Earth. The ISM therefore represents a fascinating ...
ESA BR-170 - ESA Science
... regions can be probed by looking at the spectra of the molecules in the region (see box about Astronomical Tools). Very often the spectra can only be obtained by observing in the infrared. The reason is that most atoms and molecules emit radiation whose energy corresponds to the infrared range (emit ...
... regions can be probed by looking at the spectra of the molecules in the region (see box about Astronomical Tools). Very often the spectra can only be obtained by observing in the infrared. The reason is that most atoms and molecules emit radiation whose energy corresponds to the infrared range (emit ...
Missions
... regions can be probed by looking at the spectra of the molecules in the region (see box about Astronomical Tools). Very often the spectra can only be obtained by observing in the infrared. The reason is that most atoms and molecules emit radiation whose energy corresponds to the infrared range (emit ...
... regions can be probed by looking at the spectra of the molecules in the region (see box about Astronomical Tools). Very often the spectra can only be obtained by observing in the infrared. The reason is that most atoms and molecules emit radiation whose energy corresponds to the infrared range (emit ...
OXYGEN IN THE SOLAR SYSTEM
... INTRODUCTION Rocky bodies in the Solar System exhibit large variations in 16O relative to both 17O and O rather than the expected mass-dependent trend in which fractional changes in 17O/16O are about half those in 18O/16O (Fig. 1). This anomalous behavior among the isotopes of oxygen in primitive So ...
... INTRODUCTION Rocky bodies in the Solar System exhibit large variations in 16O relative to both 17O and O rather than the expected mass-dependent trend in which fractional changes in 17O/16O are about half those in 18O/16O (Fig. 1). This anomalous behavior among the isotopes of oxygen in primitive So ...
The Circumstellar Environments of Young Stars at AU Scales
... unexpectedly large in the context of then-current disk models of HAeBe objects (e.g., Hillenbrand et al., 1992), which predicted NIR diameter of 0.2 AU based on optically thick, geometrically thin circumstellar disks with a small dust-free inner hole. This conclusion was reinforced by the completed ...
... unexpectedly large in the context of then-current disk models of HAeBe objects (e.g., Hillenbrand et al., 1992), which predicted NIR diameter of 0.2 AU based on optically thick, geometrically thin circumstellar disks with a small dust-free inner hole. This conclusion was reinforced by the completed ...
Cosmic dust
Cosmic dust is dust which exists in space. It is for the most part a type of small dust particles which are a few molecules to 0.1 µm in size. A smaller fraction of all dust in space consists of larger refractory minerals that condensed as matter left the stars. It is called ""stardust"" and is included in a separate section below. The dust density in the local interstellar medium of the Local Bubble is approximately 10−6 × dust grain/m3 with each grain having a mass of approximately 10−17 kg.Cosmic dust can be further distinguished by its astronomical location: intergalactic dust, interstellar dust, interplanetary dust (such as in the zodiacal cloud) and circumplanetary dust (such as in a planetary ring). In the Solar System, interplanetary dust causes the zodiacal light. Sources of Solar System dust include comet dust, asteroidal dust, dust from the Kuiper belt, and interstellar dust passing through the Solar System. The terminology has no specific application for describing materials found on the planet Earth except for dust that has demonstrably fallen to Earth. By one estimate, as much as 40,000 tons of cosmic dust reaches the Earth's surface every year. In October 2011, scientists reported that cosmic dust contains complex organic matter (""amorphous organic solids with a mixed aromatic–aliphatic structure"") that could be created naturally, and rapidly, by stars.On August 14, 2014, scientists announced the collection of possible interstellar dust particles from the Stardust spacecraft since returning to Earth in 2006.