Dark Matter— More Than Meets The Eye
... dwarf stars too dim to be observed. Or they could be cold planet-like objects with masses about 1/1000 that of the sun. Or maxi- or mini- black holes. Or massive cold gas clouds. All these phenomena are baryonic. There is some observational evidence for the existence of MACHOs. Because they can warp ...
... dwarf stars too dim to be observed. Or they could be cold planet-like objects with masses about 1/1000 that of the sun. Or maxi- or mini- black holes. Or massive cold gas clouds. All these phenomena are baryonic. There is some observational evidence for the existence of MACHOs. Because they can warp ...
CH. 7 - science1d
... the stars. The next nearest star to Earth after the Sun is actually part of a group of three stars that orbit each other. This group is called the Centauri system (Figure 7.8). It lies about 4.3 ly away from the solar system. If it were possible for you to have a cellphone conversation with someone ...
... the stars. The next nearest star to Earth after the Sun is actually part of a group of three stars that orbit each other. This group is called the Centauri system (Figure 7.8). It lies about 4.3 ly away from the solar system. If it were possible for you to have a cellphone conversation with someone ...
powerpoint - Physics @ IUPUI
... • A group at the University of Minnesota discovered a void a BILLION light years across! • This is something we just cannot explain currently as we expect them to be 50-200 million light years in size. ...
... • A group at the University of Minnesota discovered a void a BILLION light years across! • This is something we just cannot explain currently as we expect them to be 50-200 million light years in size. ...
NGC 1808 - Rencontres de Moriond
... + The contribution to soft X-rays might be non-negligible, but is is any case below 30%. + The contribution to hard X-rays is negligible. + The SSC could produce only around 1/50 of the ionizing photons producing the observed emission line spectrum, and no more than 1/10 of the observed FIR luminosi ...
... + The contribution to soft X-rays might be non-negligible, but is is any case below 30%. + The contribution to hard X-rays is negligible. + The SSC could produce only around 1/50 of the ionizing photons producing the observed emission line spectrum, and no more than 1/10 of the observed FIR luminosi ...
Constellation Packet - Mr. Jenkins` Classroom
... It is believed that this constellation was first perceived by the egyptians. They associated its rising with the swelling of the nile, and named the constellation Sirius which represented a big dog. They observed that when Sirius became visible in the east just before the dawn, the overflowing of th ...
... It is believed that this constellation was first perceived by the egyptians. They associated its rising with the swelling of the nile, and named the constellation Sirius which represented a big dog. They observed that when Sirius became visible in the east just before the dawn, the overflowing of th ...
An Eclectic View of our Milky Way Galaxy
... The nature of our Milky Way Galaxy is reexamined from an eclectic point of view. Evidence for a central bar, for example, is not reflected in the distribution of RR Lyrae variables in the central bulge [4,5], and it is not clear if either a 2-armed or 4-armed spiral pattern is appropriate for the sp ...
... The nature of our Milky Way Galaxy is reexamined from an eclectic point of view. Evidence for a central bar, for example, is not reflected in the distribution of RR Lyrae variables in the central bulge [4,5], and it is not clear if either a 2-armed or 4-armed spiral pattern is appropriate for the sp ...
A historical perspective on the discovery of neutron stars
... The central density in white dwarfs was found to be much higher than that in ordinary matter. At such densities atoms are fully ionized and all electrons are free. However electrons are fermions and due to the Pauli exclusion principle (1925), they cannot occupy the same quantum state. Only four mon ...
... The central density in white dwarfs was found to be much higher than that in ordinary matter. At such densities atoms are fully ionized and all electrons are free. However electrons are fermions and due to the Pauli exclusion principle (1925), they cannot occupy the same quantum state. Only four mon ...
Slide 1
... SNe-Ia seen in low-metallicity galaxies, counter to Kobayashi prediction (Prieto+ 2007) CSM found in only 1 SN-Ia (2006X, Patat+ 2007, but see Crotts & Yourdon 2008), not others No clear ID of remaining companion in Tycho (Ruiz-Lapuente+ 2004, Fuhrman 2005, Ihara+ 2007) ...
... SNe-Ia seen in low-metallicity galaxies, counter to Kobayashi prediction (Prieto+ 2007) CSM found in only 1 SN-Ia (2006X, Patat+ 2007, but see Crotts & Yourdon 2008), not others No clear ID of remaining companion in Tycho (Ruiz-Lapuente+ 2004, Fuhrman 2005, Ihara+ 2007) ...
Radiation pressure from massive star clusters as a launching
... sweeps up more gas, and the shell mass Msh (r) increases with increasing radius. The evolution of the optical depth depends on the surface density through the shell, Σsh ≡ Msh (r)/4πr2 ; for a Larson-like GMC density profile ρ(r) ∝ r−1 , Σsh (r) is constant. When the shell, or some part of it, break ...
... sweeps up more gas, and the shell mass Msh (r) increases with increasing radius. The evolution of the optical depth depends on the surface density through the shell, Σsh ≡ Msh (r)/4πr2 ; for a Larson-like GMC density profile ρ(r) ∝ r−1 , Σsh (r) is constant. When the shell, or some part of it, break ...
Think about the universe
... releases vast amounts of energy. enough to be seen with the naked eye. The collapse continues under the influence of gravity, forming visible globules in the nebula cloud. As the globules collapse further, the formation of any original gas A quick glance around the night sky shows us that cloud is a ...
... releases vast amounts of energy. enough to be seen with the naked eye. The collapse continues under the influence of gravity, forming visible globules in the nebula cloud. As the globules collapse further, the formation of any original gas A quick glance around the night sky shows us that cloud is a ...
The Gaseous Halo of NGC 891 Edmund Hodges-Kluck Joel Bregman
... • Is the X-ray metallicity wrong (cf. Li & Wang 2013)? • Are metals in the hot gas depleted onto dust? • Did a small amount of accretion trigger a large amount of star formation (halo may not be in a steady state)? • … are they unrelated? ...
... • Is the X-ray metallicity wrong (cf. Li & Wang 2013)? • Are metals in the hot gas depleted onto dust? • Did a small amount of accretion trigger a large amount of star formation (halo may not be in a steady state)? • … are they unrelated? ...
$doc.title
... Self gravitating sphere (or almost sphere) of gas with a finite definable radius, not easily deformed, not like a cloud in the Earth’s atmosphere Nuclear reactions occur at least to the point where 3 He is produced. radiates energy into the surrounding medium. Jupiter also does this, some internal h ...
... Self gravitating sphere (or almost sphere) of gas with a finite definable radius, not easily deformed, not like a cloud in the Earth’s atmosphere Nuclear reactions occur at least to the point where 3 He is produced. radiates energy into the surrounding medium. Jupiter also does this, some internal h ...
The Circumstellar Medium of Massive Stars in Motion
... enriched matter into the interstellar medium (ISM). They evolve from a hot main sequence star to a more extended red supergiant (RSG) or blue supergiant (BSG), and sometimes to more exotic Wolf–Rayet or Luminous Blue Variable phases1 . These changes induce strong variations in stellar wind propertie ...
... enriched matter into the interstellar medium (ISM). They evolve from a hot main sequence star to a more extended red supergiant (RSG) or blue supergiant (BSG), and sometimes to more exotic Wolf–Rayet or Luminous Blue Variable phases1 . These changes induce strong variations in stellar wind propertie ...
Galactic Archaeology: Current Surveys
... The spectra from the SDSS surveys provide line-of-sight velocities to around 10 km/s. The values of the stellar atmospheric parameters are obtained through a dedicated pipeline (Lee et al. 2008), developed for the broad range of targets and giving metallicity estimates to ∼ 0.2 dex, and for high sig ...
... The spectra from the SDSS surveys provide line-of-sight velocities to around 10 km/s. The values of the stellar atmospheric parameters are obtained through a dedicated pipeline (Lee et al. 2008), developed for the broad range of targets and giving metallicity estimates to ∼ 0.2 dex, and for high sig ...
Chapter 1 Introduction
... Molecular Cloud, and it is a vast reservoir of cold molecular gas and interstellar dust. Although the Orion Nebula is the only molecular cloud visible to the naked eye, similar clouds are numerously scattered throughout the Milky Way and some of them are close enough to Earth, so that they can be st ...
... Molecular Cloud, and it is a vast reservoir of cold molecular gas and interstellar dust. Although the Orion Nebula is the only molecular cloud visible to the naked eye, similar clouds are numerously scattered throughout the Milky Way and some of them are close enough to Earth, so that they can be st ...
Spectral Line VLBI - Australia Telescope National Facility
... • The maser components are extremely small (mas) and narrow (fractions of a km/s) Measure position and velocity of components with great accuracy ...
... • The maser components are extremely small (mas) and narrow (fractions of a km/s) Measure position and velocity of components with great accuracy ...
Toward $ ab\, initio $ extremely metal poor stars
... Bromm 2010; Clark et al. 2011; Greif et al. 2011, 2012). Accretion onto such protostars is eventually limited by radiative feedback (Hosokawa et al. 2011; Stacy, Greif & Bromm 2012; Stacy, Bromm & Lee 2016). The resulting stars should have final masses on the order of a few tens of solar masses. The ...
... Bromm 2010; Clark et al. 2011; Greif et al. 2011, 2012). Accretion onto such protostars is eventually limited by radiative feedback (Hosokawa et al. 2011; Stacy, Greif & Bromm 2012; Stacy, Bromm & Lee 2016). The resulting stars should have final masses on the order of a few tens of solar masses. The ...
printer-friendly version of benchmark
... At this point, the Sun will leave the Main Sequence as the outward pressure from the core decreases and gravitational collapse causes the Sun to contract. As the Sun contracts, the temperature at the core will increase, and when a temperature of around 100,000,000 K has been reached, fusion of heli ...
... At this point, the Sun will leave the Main Sequence as the outward pressure from the core decreases and gravitational collapse causes the Sun to contract. As the Sun contracts, the temperature at the core will increase, and when a temperature of around 100,000,000 K has been reached, fusion of heli ...
sections 12-15 instructor notes
... Wolf Diagrams and Dark Cloud Distances. Wolf diagrams are used to analyze the extinction in dark clouds that are transparent enough to transmit the light of background stars. The technique is to use (m, log π) tables to deduce the Δ(ρk) function for a nearby reference region that is relatively free ...
... Wolf Diagrams and Dark Cloud Distances. Wolf diagrams are used to analyze the extinction in dark clouds that are transparent enough to transmit the light of background stars. The technique is to use (m, log π) tables to deduce the Δ(ρk) function for a nearby reference region that is relatively free ...
Finnish Centre for Astronomy with ESO
... Finland is a member of the European Southern Observatory (ESO) since 2004. ESO is a world leading astronomical research and technology organization, with 15 member states, headquarters in Garching, Germany, and three world-class observatories in Chile. Finnish Centre for Astronomy with ESO (FINCA) i ...
... Finland is a member of the European Southern Observatory (ESO) since 2004. ESO is a world leading astronomical research and technology organization, with 15 member states, headquarters in Garching, Germany, and three world-class observatories in Chile. Finnish Centre for Astronomy with ESO (FINCA) i ...
Abstract - UChicago High Energy Physics
... Neutrinos shape the physical phenomena surrounding compact object mergers, from the dynamics of the disk or hypermassive-neutron star itself [1–4], to the energetic jets, e.g. [5] that may from them. Neutrinos also play an important role in the nucleosynthesis that takes place in and around disks [6 ...
... Neutrinos shape the physical phenomena surrounding compact object mergers, from the dynamics of the disk or hypermassive-neutron star itself [1–4], to the energetic jets, e.g. [5] that may from them. Neutrinos also play an important role in the nucleosynthesis that takes place in and around disks [6 ...
Searching for the Secrets of Massive Star Birth
... galactic interstellar medium (ISM). The first stars to form in the universe were massive. They were responsible for cosmic re-ionization and its initial chemical enrichment. Massive stars continue to power the “galactic ecology”, the cyclic conversion of the ISM into stars, the enrichment of the ISM ...
... galactic interstellar medium (ISM). The first stars to form in the universe were massive. They were responsible for cosmic re-ionization and its initial chemical enrichment. Massive stars continue to power the “galactic ecology”, the cyclic conversion of the ISM into stars, the enrichment of the ISM ...
POISE AND EVOLUTION OF THE GALAXY : STRUCTURE ,
... which might be at the origin of phenomena in astronomy as quizzical as the mysteriously intensely radiating “QUASARS”, that basic astrophysics cannot easily interpret through usual frames. That might be, as well, some origin of the elusive “dark energy”, if not of the unaccountable “dark mass”, acco ...
... which might be at the origin of phenomena in astronomy as quizzical as the mysteriously intensely radiating “QUASARS”, that basic astrophysics cannot easily interpret through usual frames. That might be, as well, some origin of the elusive “dark energy”, if not of the unaccountable “dark mass”, acco ...
Science Grade 08 Unit 11 Exemplar Lesson 02: Classifying Stars
... This unit bundles student expectations that address components and characteristics of the universe. Students learn that stars and galaxies are part of the universe and how they can be classified by their characteristics. Prior to this unit, in Grade 8, students studied the effects resulting from cyc ...
... This unit bundles student expectations that address components and characteristics of the universe. Students learn that stars and galaxies are part of the universe and how they can be classified by their characteristics. Prior to this unit, in Grade 8, students studied the effects resulting from cyc ...
L87 THE b PICTORIS MOVING GROUP B. ZUCkERMAN AND
... Notes.—Units of right ascension are hours, minutes, and seconds, and units of declination are degrees, arcminutes, and arcseconds. (1) On A star zero-age main sequence (Jura et al. 1998). (2) Binary: listed ROSAT flux and LX/Lbol are for the secondary. (3) See Table 2 for additional details. (4) See ...
... Notes.—Units of right ascension are hours, minutes, and seconds, and units of declination are degrees, arcminutes, and arcseconds. (1) On A star zero-age main sequence (Jura et al. 1998). (2) Binary: listed ROSAT flux and LX/Lbol are for the secondary. (3) See Table 2 for additional details. (4) See ...
H II region
An H II region is a large, low-density cloud of partially ionized gas in which star formation has recently taken place. The short-lived blue stars forged in these regions emit copious amounts of ultraviolet light that ionize the surrounding gas. H II regions—sometimes several hundred light-years across—are often associated with giant molecular clouds. The first known H II region was the Orion Nebula, which was discovered in 1610 by Nicolas-Claude Fabri de Peiresc.H II regions are named for the large amount of ionised atomic hydrogen they contain, referred to as H II, pronounced H-two by astronomers (an H I region being neutral atomic hydrogen, and H2 being molecular hydrogen). Such regions have extremely diverse shapes, because the distribution of the stars and gas inside them is irregular. They often appear clumpy and filamentary, sometimes showing bizarre shapes such as the Horsehead Nebula. H II regions may give birth to thousands of stars over a period of several million years. In the end, supernova explosions and strong stellar winds from the most massive stars in the resulting star cluster will disperse the gases of the H II region, leaving behind a cluster of birthed stars such as the Pleiades.H II regions can be seen to considerable distances in the universe, and the study of extragalactic H II regions is important in determining the distance and chemical composition of other galaxies. Spiral and irregular galaxies contain many H II regions, while elliptical galaxies are almost devoid of them. In the spiral galaxies, including the Milky Way, H II regions are concentrated in the spiral arms, while in the irregular galaxies they are distributed chaotically. Some galaxies contain huge H II regions, which may contain tens of thousands of stars. Examples include the 30 Doradus region in the Large Magellanic Cloud and NGC 604 in the Triangulum Galaxy.