a to z of astronomy
... A relatively dense cloud of interstellar material containing dust particles. The dust particles absorb light from the more distant stars etc, so that the region appears dark compared with its surroundings. The clouds are often of low temperature and contain many molecules. DARK MATTER Material in th ...
... A relatively dense cloud of interstellar material containing dust particles. The dust particles absorb light from the more distant stars etc, so that the region appears dark compared with its surroundings. The clouds are often of low temperature and contain many molecules. DARK MATTER Material in th ...
– 1 – 1. Nucleosynthetic Yields From Various Sources
... the ISM is not large, there are many more AGB stars in a stellar population with a typical IMF than there are SN of any kind. Thus the cumulative effect on the chemical inventory of a galaxy from AGB stars can be large for specific species. Amanada Karakas and John Lattanzio have been working on thi ...
... the ISM is not large, there are many more AGB stars in a stellar population with a typical IMF than there are SN of any kind. Thus the cumulative effect on the chemical inventory of a galaxy from AGB stars can be large for specific species. Amanada Karakas and John Lattanzio have been working on thi ...
ChESS: ChaMP Extended Stellar Survey
... as dM stars based on opti al spe tros opy are shown as the blue histogram. ...
... as dM stars based on opti al spe tros opy are shown as the blue histogram. ...
Accretion and radial disk structure
... dust settling lowers the dust:gas ratio (Mdust/Mgas) in disk surfaces dust-depleted evaporation flows and dust settling leave the midplane behind with high Mdust/Mgas (Throop & Bally 2005) midplane can become gravitational instable (Youdin & Shu 2002) spontaneous formation of km-sized planetes ...
... dust settling lowers the dust:gas ratio (Mdust/Mgas) in disk surfaces dust-depleted evaporation flows and dust settling leave the midplane behind with high Mdust/Mgas (Throop & Bally 2005) midplane can become gravitational instable (Youdin & Shu 2002) spontaneous formation of km-sized planetes ...
ppt - UCL
... • low column density (NH ~ 6 x1019 cm–2 ). The source is also pulsating with P ~ 8.4 s. Until a few years ago two mechanisms were proposed for dim NSs: accretion from the interstellar medium onto an old NS or cooling of a younger object. More recently, based on the similarity of the periods, it has ...
... • low column density (NH ~ 6 x1019 cm–2 ). The source is also pulsating with P ~ 8.4 s. Until a few years ago two mechanisms were proposed for dim NSs: accretion from the interstellar medium onto an old NS or cooling of a younger object. More recently, based on the similarity of the periods, it has ...
Presentation (PowerPoint File)
... II. MICROPHYSICS: GRAVITATIONAL COLLAPSE Paradigm: Inside-out collapse of centrally concentrated core Accretion rate ~ Bonnor-Ebert mass per free-fall time ...
... II. MICROPHYSICS: GRAVITATIONAL COLLAPSE Paradigm: Inside-out collapse of centrally concentrated core Accretion rate ~ Bonnor-Ebert mass per free-fall time ...
4. Star Formation
... Class 0 source (André et al. 2000): – central source, identified either by free-free emission at cm wavelength or outflows – extended envelope in sub-mm and millimetre maps – Lsmm / Lbol > 0.005, for forming solar mass stars this might be equivalent to M∗ < Menv or Tbol < 80K; bolometric temperature ...
... Class 0 source (André et al. 2000): – central source, identified either by free-free emission at cm wavelength or outflows – extended envelope in sub-mm and millimetre maps – Lsmm / Lbol > 0.005, for forming solar mass stars this might be equivalent to M∗ < Menv or Tbol < 80K; bolometric temperature ...
Lecture 11: Stars, HR diagram.
... P: period G: gravitational constant M1: mass of star 1 M2: mass of star 2 ...
... P: period G: gravitational constant M1: mass of star 1 M2: mass of star 2 ...
PowerPoint Presentation - 18. The Bizarre Stellar Graveyard
... • Light is emitted by charged particles moving close to the speed of light around magnetic fields. • Emission (mostly radio) is concentrated at the magnetic poles and focused into a beam. • Whether we see a pulsar depends on the geometry. – if the polar beam sweeps by Earth’s direction once each rot ...
... • Light is emitted by charged particles moving close to the speed of light around magnetic fields. • Emission (mostly radio) is concentrated at the magnetic poles and focused into a beam. • Whether we see a pulsar depends on the geometry. – if the polar beam sweeps by Earth’s direction once each rot ...
Blowin` in the wind: both `negative` and `positive` feedback in an
... radiatively-driven winds are available. We present SINFONI near infrared integral field spectroscopy of XID2028, an obscured, radio-quiet z = 1.59 QSO, in which we clearly resolve a fast (1500 km/s) and extended (up to 13 kpc from the black hole) outflow in the [OIII] lines emitting gas, whose large v ...
... radiatively-driven winds are available. We present SINFONI near infrared integral field spectroscopy of XID2028, an obscured, radio-quiet z = 1.59 QSO, in which we clearly resolve a fast (1500 km/s) and extended (up to 13 kpc from the black hole) outflow in the [OIII] lines emitting gas, whose large v ...
star-formation rate
... Galaxies do not become very red if τ is large because their star formation rate, and thus the fraction of massive blue stars, does not decrease sufficiently. ...
... Galaxies do not become very red if τ is large because their star formation rate, and thus the fraction of massive blue stars, does not decrease sufficiently. ...
Solutions to Homework #6, AST 203, Spring 2012
... Note, that velocity and semimajor axis are not in SI units, so we need to convert, using 1 pc = 3.2 ly = 3 × 1016 m, and 220 km/s = 2.2 × 105 m/s. The enclosed mass at 8kpc is then: M (8kpc) ≈ 2 × 1041 kg = 1011 M . c) Assume that the Milky Way is made up of only luminous matter (stars) and that th ...
... Note, that velocity and semimajor axis are not in SI units, so we need to convert, using 1 pc = 3.2 ly = 3 × 1016 m, and 220 km/s = 2.2 × 105 m/s. The enclosed mass at 8kpc is then: M (8kpc) ≈ 2 × 1041 kg = 1011 M . c) Assume that the Milky Way is made up of only luminous matter (stars) and that th ...
Lectures 6-8: Solar nebula theory
... o Initially, gas and dust with low AM fall to core of cloud. Material with high AM cannot due to centrifugal forces. o As gas and dust fall to equatorial plane, it collides with material falling in other direction => energy of this motion is dissipated as heat. o Consider a parcel of gas which fa ...
... o Initially, gas and dust with low AM fall to core of cloud. Material with high AM cannot due to centrifugal forces. o As gas and dust fall to equatorial plane, it collides with material falling in other direction => energy of this motion is dissipated as heat. o Consider a parcel of gas which fa ...
black holes activity
... -The gas particles in the core and radiation zone ____________ with each other constantly but by the time it get to 200,000 km out it is turned into energy and through convection transferred towards the surface C.What is Granulation? -Looking at the surface of the Sun it looks highly _______________ ...
... -The gas particles in the core and radiation zone ____________ with each other constantly but by the time it get to 200,000 km out it is turned into energy and through convection transferred towards the surface C.What is Granulation? -Looking at the surface of the Sun it looks highly _______________ ...
Stellar-mass Black Hole Formation
... high space velocity > 106 km/s -> NS kick or asymmetric mass ejection ...
... high space velocity > 106 km/s -> NS kick or asymmetric mass ejection ...
Today in Astronomy 102: black hole observations, v.4
... Treaty, the US and USSR each put up satellites with X- and ray detectors to monitor the other’s compliance with the treaty. Immediately these instruments detected many brief, bright bursts of rays, similar to the expectations for above-ground nuclear detonations. Naturally, this worried all con ...
... Treaty, the US and USSR each put up satellites with X- and ray detectors to monitor the other’s compliance with the treaty. Immediately these instruments detected many brief, bright bursts of rays, similar to the expectations for above-ground nuclear detonations. Naturally, this worried all con ...
Lecture 2 - SUNY Oswego
... Pulsation is not due to variations in the rate of energy generation in the core. More to do with the variation of the rate at which this radiation can escape. Early astronomers thought they were binary stars. Harlow Shapley suggested there was an internal “breathing” mechanism. Radial pulsations pro ...
... Pulsation is not due to variations in the rate of energy generation in the core. More to do with the variation of the rate at which this radiation can escape. Early astronomers thought they were binary stars. Harlow Shapley suggested there was an internal “breathing” mechanism. Radial pulsations pro ...
Day_6
... from the observer and Earth out to the stars? Can the observer shown see an object located below the horizon? ...
... from the observer and Earth out to the stars? Can the observer shown see an object located below the horizon? ...
Binary Star Systems
... – Sufficiently close to Earth and the stars are well enough separated that we can see the two stars individually (resolved) in a telescope and track their motion over a period of time ...
... – Sufficiently close to Earth and the stars are well enough separated that we can see the two stars individually (resolved) in a telescope and track their motion over a period of time ...
ASTR-264-Lecture
... Windows are both mirrors and transmitters Rose is red because rose reflects red light 5.2 what is light? Light can either act like a wave or a particle Photons: particles of light Wave: pattern of motion that can carry energy without carrying matter along with it Wavelength: is the distance between ...
... Windows are both mirrors and transmitters Rose is red because rose reflects red light 5.2 what is light? Light can either act like a wave or a particle Photons: particles of light Wave: pattern of motion that can carry energy without carrying matter along with it Wavelength: is the distance between ...
Lect18-4-19-10
... In Einstein’s view, the large mass has distorted the space around it, so that freely falling particles, particles on which no forces additional to gravity are acting, follow paths that are curved by the distortion of the space they are moving through. For Einstein, if we can calculate the curvature ...
... In Einstein’s view, the large mass has distorted the space around it, so that freely falling particles, particles on which no forces additional to gravity are acting, follow paths that are curved by the distortion of the space they are moving through. For Einstein, if we can calculate the curvature ...
ASTRONOMY 301 EXAMPLES OF TEST
... surrounded on three sides by hot, young stars. We would observe (A) that the spectrum of the gas cloud consists of many emission lines. (B) that the spectrum of the gas cloud consists of many absorption lines. (C) that the gas cloud has a black body continuous spectrum that is characteristic of the ...
... surrounded on three sides by hot, young stars. We would observe (A) that the spectrum of the gas cloud consists of many emission lines. (B) that the spectrum of the gas cloud consists of many absorption lines. (C) that the gas cloud has a black body continuous spectrum that is characteristic of the ...
Lecture6
... • As already noted in Section (i), the interstellar matter (ISM) is not uniform, but clumpy. New stars are formed in these clumpy, cool, dense clouds called `dark nebulae’ in or near molecular clouds (cool clouds with CO and H2 molecules). Bursts of protostar formation takes place when these dense r ...
... • As already noted in Section (i), the interstellar matter (ISM) is not uniform, but clumpy. New stars are formed in these clumpy, cool, dense clouds called `dark nebulae’ in or near molecular clouds (cool clouds with CO and H2 molecules). Bursts of protostar formation takes place when these dense r ...
Cygnus X-1
Cygnus X-1 (abbreviated Cyg X-1) is a well-known galactic X-ray source, thought to be a black hole, in the constellation Cygnus. It was discovered in 1964 during a rocket flight and is one of the strongest X-ray sources seen from Earth, producing a peak X-ray flux density of 6977229999999999999♠2.3×10−23 Wm−2 Hz−1 (7003230000000000000♠2.3×103 Jansky). Cygnus X-1 was the first X-ray source widely accepted to be a black hole and it remains among the most studied astronomical objects in its class. The compact object is now estimated to have a mass about 14.8 times the mass of the Sun and has been shown to be too small to be any known kind of normal star, or other likely object besides a black hole. If so, the radius of its event horizon is about 7004440000000000000♠44 km.Cygnus X-1 belongs to a high-mass X-ray binary system about 7019574266339685654♠6070 ly from the Sun that includes a blue supergiant variable star designated HDE 226868 which it orbits at about 0.2 AU, or 20% of the distance from the Earth to the Sun. A stellar wind from the star provides material for an accretion disk around the X-ray source. Matter in the inner disk is heated to millions of degrees, generating the observed X-rays. A pair of jets, arranged perpendicular to the disk, are carrying part of the energy of the infalling material away into interstellar space.This system may belong to a stellar association called Cygnus OB3, which would mean that Cygnus X-1 is about five million years old and formed from a progenitor star that had more than 7001400000000000000♠40 solar masses. The majority of the star's mass was shed, most likely as a stellar wind. If this star had then exploded as a supernova, the resulting force would most likely have ejected the remnant from the system. Hence the star may have instead collapsed directly into a black hole.Cygnus X-1 was the subject of a friendly scientific wager between physicists Stephen Hawking and Kip Thorne in 1975, with Hawking betting that it was not a black hole. He conceded the bet in 1990 after observational data had strengthened the case that there was indeed a black hole in the system. This hypothesis has not been confirmed due to a lack of direct observation but has generally been accepted from indirect evidence.