File 11 - School of Astronomy, IPM
... • Based on photographic images in the blue emphasises star formation (not mass distribution) High z galaxies sample the rest frame UV. • Requires reasonably good spatial resolution across the galaxy ( 20 elements) progressively more difficult for cz > 8000 km/s from ground. To summarise, three kinds ...
... • Based on photographic images in the blue emphasises star formation (not mass distribution) High z galaxies sample the rest frame UV. • Requires reasonably good spatial resolution across the galaxy ( 20 elements) progressively more difficult for cz > 8000 km/s from ground. To summarise, three kinds ...
talk
... GMRT HI images HST V and I band optical images ► TRGB distance (accuracy of ~ 10%) known for most galaxies First large sample of faint dwarfs with accurate distances ...
... GMRT HI images HST V and I band optical images ► TRGB distance (accuracy of ~ 10%) known for most galaxies First large sample of faint dwarfs with accurate distances ...
Stellar populations in the nuclear regions of nearby radio galaxies
... the variations are correlated with the position at which the telescope is pointing. Since flat-fielding is crucial for the reddest wavelengths, where the sky lines are most prominent, after every exposure of 20–30 min we acquired a flat-field in the same position of the telescope as the one for whic ...
... the variations are correlated with the position at which the telescope is pointing. Since flat-fielding is crucial for the reddest wavelengths, where the sky lines are most prominent, after every exposure of 20–30 min we acquired a flat-field in the same position of the telescope as the one for whic ...
2. The Anatomy of Stellar Life and Death
... with a very similar scaling of the mass of protostars. The observations were done in the millimeter (microwave) range where the dusty material comprising the nebula is transparent. This allowed detailed observations of the internal structure of the nebula. Beuther’s and Schilke’s work revealed a neb ...
... with a very similar scaling of the mass of protostars. The observations were done in the millimeter (microwave) range where the dusty material comprising the nebula is transparent. This allowed detailed observations of the internal structure of the nebula. Beuther’s and Schilke’s work revealed a neb ...
Black Holes
... The puzzle of supermassive black holes While the formation of stellar-mass black holes is fairly well understood, it is not clear how black holes as massive as a million to a billion times the mass of the Sun could have formed and have already been in place at a time when the Universe was less than ...
... The puzzle of supermassive black holes While the formation of stellar-mass black holes is fairly well understood, it is not clear how black holes as massive as a million to a billion times the mass of the Sun could have formed and have already been in place at a time when the Universe was less than ...
In 1929, the astronomer Edwin Hubble observed that the light from
... Scientists use a radio telescope to measure the wavelength of the radio waves emitted from the galaxy in part (b) as the waves reach the Earth. The scientists measure the wavelength as 25.2 metres. The effect causing this observed increase in wavelength is called red-shift. (i) ...
... Scientists use a radio telescope to measure the wavelength of the radio waves emitted from the galaxy in part (b) as the waves reach the Earth. The scientists measure the wavelength as 25.2 metres. The effect causing this observed increase in wavelength is called red-shift. (i) ...
Test 4 Review Clicker Questions
... a) they generate energy partly through H to He fusion like stars. b) they show spectra similar to extremely bright O stars. c) their luminosity varies like eclipsing binary stars. d) in short exposure photographs, their images appear stellar. e) they are dense concentrations of millions of stars. ...
... a) they generate energy partly through H to He fusion like stars. b) they show spectra similar to extremely bright O stars. c) their luminosity varies like eclipsing binary stars. d) in short exposure photographs, their images appear stellar. e) they are dense concentrations of millions of stars. ...
Slide 1
... signal emitted by a pulsar is complicated by the Doppler motion of the Earth and by the frequency dispersion in the pulse arrival times. Averaging over many pulses gives clear pulse and interpulse profiles. However, individual pulses are very variable and variations in the flux can be observed on ti ...
... signal emitted by a pulsar is complicated by the Doppler motion of the Earth and by the frequency dispersion in the pulse arrival times. Averaging over many pulses gives clear pulse and interpulse profiles. However, individual pulses are very variable and variations in the flux can be observed on ti ...
The new X-ray universe
... of sources) and at the known distance of M82 this implied that it was “ultraluminous” (Lx >1039 erg s–1; the source in M82 varies up 1041 erg s–1). While the existence of such objects was hinted at by earlier missions, a substantial number have now been found in Chandra and XMM observations of nearb ...
... of sources) and at the known distance of M82 this implied that it was “ultraluminous” (Lx >1039 erg s–1; the source in M82 varies up 1041 erg s–1). While the existence of such objects was hinted at by earlier missions, a substantial number have now been found in Chandra and XMM observations of nearb ...
Video Lesson Information Astronomy: Observations & Theories Astronomy 1
... This lesson describes the fascinating objects that remain after the deaths of large stars—neutron stars and black holes. Gamma-ray bursts and hypernovae are presented as some of the most energetic objects in the universe. Lesson 12 - Our Galaxy: The Milky Way Most discussions of galaxies begin with ...
... This lesson describes the fascinating objects that remain after the deaths of large stars—neutron stars and black holes. Gamma-ray bursts and hypernovae are presented as some of the most energetic objects in the universe. Lesson 12 - Our Galaxy: The Milky Way Most discussions of galaxies begin with ...
Joint formation of QSOs and spheroids: QSOs as clocks of star
... Direct and indirect observational evidence leads to the conclusion that high-redshift QSOs did shine in the core of early-type protogalaxies during their main episode of star formation. Exploiting this fact, we derive the rate of formation of this kind of stellar system at high redshift by using the ...
... Direct and indirect observational evidence leads to the conclusion that high-redshift QSOs did shine in the core of early-type protogalaxies during their main episode of star formation. Exploiting this fact, we derive the rate of formation of this kind of stellar system at high redshift by using the ...
Chapter 25 - Haiku Learning
... mass. The hottest blue stars are about 50 times more massive than the sun, while the coolest red stars are only 1/10 as massive. Therefore, on the H-R diagram, the main-sequence stars appear in decreasing order, from hotter, more massive blue stars to cooler, less massive red stars. Above and to the ...
... mass. The hottest blue stars are about 50 times more massive than the sun, while the coolest red stars are only 1/10 as massive. Therefore, on the H-R diagram, the main-sequence stars appear in decreasing order, from hotter, more massive blue stars to cooler, less massive red stars. Above and to the ...
The Submillimeter Frontier: A Space Science Imperative
... fluctuations and their growth. Many are very dusty, with star formation obscured by very local dust from young hot stars and supernovae. Interstellar shocks reprocess the dust. Some heavy elements enrich the newly ionized intergalactic medium, driven by high pressures and outflows from small galaxie ...
... fluctuations and their growth. Many are very dusty, with star formation obscured by very local dust from young hot stars and supernovae. Interstellar shocks reprocess the dust. Some heavy elements enrich the newly ionized intergalactic medium, driven by high pressures and outflows from small galaxie ...
ch19
... Early attempts to locate our solar system produced erroneous results. The main problem was that interstellar extinction allows one to only see the nearby stars and makes distant objects appear dimmer. The key to finding our location in the galaxy is locating bright objects out of the plane of the ga ...
... Early attempts to locate our solar system produced erroneous results. The main problem was that interstellar extinction allows one to only see the nearby stars and makes distant objects appear dimmer. The key to finding our location in the galaxy is locating bright objects out of the plane of the ga ...
1e 1048.1−5937, xte j1810−197 and 4u 0142+61
... Anomalous X-ray pulsars (AXPs) are objects (commonly believed to be neutron stars) with high X-ray luminosity (greater than can be explained through spindown alone, hence “anomalous”), X-ray pulsations and a rapid spin-down rate. Many of these objects also experience periods of intense X-ray burstin ...
... Anomalous X-ray pulsars (AXPs) are objects (commonly believed to be neutron stars) with high X-ray luminosity (greater than can be explained through spindown alone, hence “anomalous”), X-ray pulsations and a rapid spin-down rate. Many of these objects also experience periods of intense X-ray burstin ...
Starburst Galaxies - Beck-Shop
... The young stars, that can now be seen directly, have masses ranging from 0.08 solar masses (the brown dwarf limit) to slightly over 100 solar masses (beyond which stars become unstable). By far the majority of stars though are at the low-mass end of this range – 80% have masses less than that of the ...
... The young stars, that can now be seen directly, have masses ranging from 0.08 solar masses (the brown dwarf limit) to slightly over 100 solar masses (beyond which stars become unstable). By far the majority of stars though are at the low-mass end of this range – 80% have masses less than that of the ...
PoS(EVN 2014)058 - Proceeding of science
... The Cygnus OB2 Radio Survey (COBRaS) is an e-MERLIN Legacy project awarded a total allocation of 252 hours at C-band and 42 hours at L-band to study the Cygnus OB2 association. The aim of this project is to exploit the high-resolution capability and tremendous sensitivity of eMERLIN to assemble the ...
... The Cygnus OB2 Radio Survey (COBRaS) is an e-MERLIN Legacy project awarded a total allocation of 252 hours at C-band and 42 hours at L-band to study the Cygnus OB2 association. The aim of this project is to exploit the high-resolution capability and tremendous sensitivity of eMERLIN to assemble the ...
Dust and molecular gas in the most distant quasars
... detections show FIR excesses in their SEDs. • The MAMBO undetected quasars at z~6: – The average FIR-to-radio SED is consistent with the templates of local optical quasars. – The average FIR to AGN-bolometric luminosity ratio follows the trend defined by local PG quasars. ...
... detections show FIR excesses in their SEDs. • The MAMBO undetected quasars at z~6: – The average FIR-to-radio SED is consistent with the templates of local optical quasars. – The average FIR to AGN-bolometric luminosity ratio follows the trend defined by local PG quasars. ...
argo and other tidal structures around the milky way
... closer to the Sun than the maximum H I asymmetries at the lines of sight where the disk warp is larger. Moreover, there is no stellar overdensity counterpart of the northern hemisphere H I warp in our data. From these facts, we conclude that both CMa and Argo overdensities are not signatures of the ...
... closer to the Sun than the maximum H I asymmetries at the lines of sight where the disk warp is larger. Moreover, there is no stellar overdensity counterpart of the northern hemisphere H I warp in our data. From these facts, we conclude that both CMa and Argo overdensities are not signatures of the ...
X-ray Astronomy and the search for Black Holes
... • The hard X-rays are thin thermal emissions, i.e., from plasma accreting onto the white dwarf – Are our inference for very massive white dwarfs correct? ...
... • The hard X-rays are thin thermal emissions, i.e., from plasma accreting onto the white dwarf – Are our inference for very massive white dwarfs correct? ...
Lecture notes 18: Galaxies and galaxy clusters
... Lecture notes 18: Galaxies and galaxy clusters Immanuel Kant (1724–1824) and Thomas Wright (1711–1786) were among the first to recocnize the possibility that the Milky Way was indeed a stellar disk where the Sun was but one of many. Kant went on to propose that if the Milky Way were limited then perh ...
... Lecture notes 18: Galaxies and galaxy clusters Immanuel Kant (1724–1824) and Thomas Wright (1711–1786) were among the first to recocnize the possibility that the Milky Way was indeed a stellar disk where the Sun was but one of many. Kant went on to propose that if the Milky Way were limited then perh ...
151 - ESO
... During one of these pulsations the size of the star also changes. The radius of the star can alter with 10-20%. Harvard astronomer Miss Henrietta Leavitt was the first person to determine distances using Cepheids. Therefor in 1912 she made it possible to prove that “spiral-nebulas” (?) are independe ...
... During one of these pulsations the size of the star also changes. The radius of the star can alter with 10-20%. Harvard astronomer Miss Henrietta Leavitt was the first person to determine distances using Cepheids. Therefor in 1912 she made it possible to prove that “spiral-nebulas” (?) are independe ...
Gamma-ray burst
Gamma-ray bursts (GRBs) are flashes of gamma rays associated with extremely energetic explosions that have been observed in distant galaxies. They are the brightest electromagnetic events known to occur in the universe. Bursts can last from ten milliseconds to several hours. The initial burst is usually followed by a longer-lived ""afterglow"" emitted at longer wavelengths (X-ray, ultraviolet, optical, infrared, microwave and radio).Most observed GRBs are believed to consist of a narrow beam of intense radiation released during a supernova or hypernova as a rapidly rotating, high-mass star collapses to form a neutron star, quark star, or black hole. A subclass of GRBs (the ""short"" bursts) appear to originate from a different process – this may be due to the merger of binary neutron stars. The cause of the precursor burst observed in some of these short events may be due to the development of a resonance between the crust and core of such stars as a result of the massive tidal forces experienced in the seconds leading up to their collision, causing the entire crust of the star to shatter.The sources of most GRBs are billions of light years away from Earth, implying that the explosions are both extremely energetic (a typical burst releases as much energy in a few seconds as the Sun will in its entire 10-billion-year lifetime) and extremely rare (a few per galaxy per million years). All observed GRBs have originated from outside the Milky Way galaxy, although a related class of phenomena, soft gamma repeater flares, are associated with magnetars within the Milky Way. It has been hypothesized that a gamma-ray burst in the Milky Way, pointing directly towards the Earth, could cause a mass extinction event.GRBs were first detected in 1967 by the Vela satellites, a series of satellites designed to detect covert nuclear weapons tests. Hundreds of theoretical models were proposed to explain these bursts in the years following their discovery, such as collisions between comets and neutron stars. Little information was available to verify these models until the 1997 detection of the first X-ray and optical afterglows and direct measurement of their redshifts using optical spectroscopy, and thus their distances and energy outputs. These discoveries, and subsequent studies of the galaxies and supernovae associated with the bursts, clarified the distance and luminosity of GRBs. These facts definitively placed them in distant galaxies and also connected long GRBs with the explosion of massive stars, the only possible source for the energy outputs observed.