Properties of Galactic early-type O
... avoided contamination by the “worm” artifact (Sahnow et al. 2000) by using only the LiF2A spectra on the long-wavelength side (λλ1086-1183 Å) of the spectrum. Finally, the co-added merged spectra were smoothed to a resolution of 30 km s−1 to enhance the signal-to-noise ratio. For HD 66811, we used t ...
... avoided contamination by the “worm” artifact (Sahnow et al. 2000) by using only the LiF2A spectra on the long-wavelength side (λλ1086-1183 Å) of the spectrum. Finally, the co-added merged spectra were smoothed to a resolution of 30 km s−1 to enhance the signal-to-noise ratio. For HD 66811, we used t ...
1 The Hubble Story (10:56)
... versatility has allowed it to make significant contributions to the field. For example, Hubble’s high resolution has been indispensable in the investigation of the gas and dust disks, dubbed proplyds, around the newly born stars in the Orion Nebula. The proplyds may very well be young planetary syst ...
... versatility has allowed it to make significant contributions to the field. For example, Hubble’s high resolution has been indispensable in the investigation of the gas and dust disks, dubbed proplyds, around the newly born stars in the Orion Nebula. The proplyds may very well be young planetary syst ...
A catalogue of the Chandra Deep Field South with multi
... The spectral shapes of the objects in the R-band selected catalogue were measured with a different approach. Photometry in all 17 passbands was done by projecting the object coordinates into the frames of reference of each single exposure and measuring the object fluxes at the given locations. In or ...
... The spectral shapes of the objects in the R-band selected catalogue were measured with a different approach. Photometry in all 17 passbands was done by projecting the object coordinates into the frames of reference of each single exposure and measuring the object fluxes at the given locations. In or ...
Super-Eddington outburst in a binary system: V4641 Sgr Mikhail Revnivtsev, Marat Gilfanov
... super-Eddington accretion • During this episode a powerful expended evelope was formed • When the accretion rate decreased the envelope vanished • X-ray observations support this picture: we have detected the change in the X-ray absorption column, smeared and probably delayed variability of ...
... super-Eddington accretion • During this episode a powerful expended evelope was formed • When the accretion rate decreased the envelope vanished • X-ray observations support this picture: we have detected the change in the X-ray absorption column, smeared and probably delayed variability of ...
Pair instability supernovae: Evolution, explosion, nucleosynthesis
... supernovae are exploding in the visible Universe each second, and at present there are a few of them discovered every day. The average peak luminosity of a supernova competes with that of entire galaxies. Supernovae are the main contributor of heavy elements, energy and momentum to the interstellar ...
... supernovae are exploding in the visible Universe each second, and at present there are a few of them discovered every day. The average peak luminosity of a supernova competes with that of entire galaxies. Supernovae are the main contributor of heavy elements, energy and momentum to the interstellar ...
The Milky Way as a galaxy
... of R D R0 8 kpc. The angle specifies the angular separation of an object in the disk relative to the position of the Sun, as seen from the Galactic center. The distance of an object p with coordinates R; ; z from the Galactic center is then R2 C z2 , independent of . If the matter distribution ...
... of R D R0 8 kpc. The angle specifies the angular separation of an object in the disk relative to the position of the Sun, as seen from the Galactic center. The distance of an object p with coordinates R; ; z from the Galactic center is then R2 C z2 , independent of . If the matter distribution ...
Chapter 10 Formation and evolution of the Local Group
... found closer to the Galaxy/M 31 than gas-rich dwarf irregulars (dIrrs). This is often promoted as evidence of environmental processes due to the massive Galaxy and M 31 driving the evolutionary change between dwarf galaxy types. High Velocity Clouds (HVCs) are likely to be either remnant gas left ov ...
... found closer to the Galaxy/M 31 than gas-rich dwarf irregulars (dIrrs). This is often promoted as evidence of environmental processes due to the massive Galaxy and M 31 driving the evolutionary change between dwarf galaxy types. High Velocity Clouds (HVCs) are likely to be either remnant gas left ov ...
Stellar Populations of Dwarf Elliptical Galaxies: UBVRI Photometry
... Group, dwarf elliptical galaxies out number high luminosity galaxies by a factor of 6 (Mateo 1998), and more than 50% of the galaxies in the Virgo cluster are dEs (Sandage, Binggeli, & Tammann 1985). However, while the clustering properties of dwarf elliptical galaxies appear to be an extension of t ...
... Group, dwarf elliptical galaxies out number high luminosity galaxies by a factor of 6 (Mateo 1998), and more than 50% of the galaxies in the Virgo cluster are dEs (Sandage, Binggeli, & Tammann 1985). However, while the clustering properties of dwarf elliptical galaxies appear to be an extension of t ...
IRAS - the infrared - Imperial College London Astrophysics
... the IRAS all-sky survey of infrared point-sources: white: star-forming regions, blue: red giant stars, green: galaxies. IRAS detected 60,000 dusty, star-forming glaxies over the whole sky. Thessaloniki, Oct 3rd 2009 ...
... the IRAS all-sky survey of infrared point-sources: white: star-forming regions, blue: red giant stars, green: galaxies. IRAS detected 60,000 dusty, star-forming glaxies over the whole sky. Thessaloniki, Oct 3rd 2009 ...
Clusters as laboratories for the study of galaxy evolution
... “On the evolutionary status of early-type galaxies in clusters at z ~ 0.2 I. The Fundamental Plane” – Fritz et al. 2005 MNRAS, 358, 233 Photometry, morphology, and spectra for galaxies in A2390 & A2218 “For the total sample of 34 E+S0 cluster galaxies which enter the FP we deduce only a mild evolut ...
... “On the evolutionary status of early-type galaxies in clusters at z ~ 0.2 I. The Fundamental Plane” – Fritz et al. 2005 MNRAS, 358, 233 Photometry, morphology, and spectra for galaxies in A2390 & A2218 “For the total sample of 34 E+S0 cluster galaxies which enter the FP we deduce only a mild evolut ...
the chandra deep field–north survey. xvii. evolution of
... the temperatures show that a wide range of spectral models can be fitted to the data. In a few cases, additional spectral components that are not statistically significant may be present (see the notes to Table 3). 2.3. X-Ray Variability Since the arrival time for each X-ray event is recorded to wit ...
... the temperatures show that a wide range of spectral models can be fitted to the data. In a few cases, additional spectral components that are not statistically significant may be present (see the notes to Table 3). 2.3. X-Ray Variability Since the arrival time for each X-ray event is recorded to wit ...
Type Ia supernovae as stellar endpoints and cosmological tools
... uest stars (who could have imagined they were distant stellar explosions?) have been surprising humans for at least 950 years, but probably far longer. They amazed and confounded the likes of Tycho, Kepler and Galileo, to name a few. But it was not until the separation of these events into novae and ...
... uest stars (who could have imagined they were distant stellar explosions?) have been surprising humans for at least 950 years, but probably far longer. They amazed and confounded the likes of Tycho, Kepler and Galileo, to name a few. But it was not until the separation of these events into novae and ...
from z=0 to z=1
... 10 times fainter than ULIRGs. 6. LBGs and SCUBA galaxies (UV and IR selected galaxies at z~3) do not overlap with each other very much. SCUBA galaxies have significantly higher SFR, higher attenuation, higher stellar mass, and higher correlation length than LBGs. 7. At intermediate redshifts of z~0. ...
... 10 times fainter than ULIRGs. 6. LBGs and SCUBA galaxies (UV and IR selected galaxies at z~3) do not overlap with each other very much. SCUBA galaxies have significantly higher SFR, higher attenuation, higher stellar mass, and higher correlation length than LBGs. 7. At intermediate redshifts of z~0. ...
Elliptical Galaxies
... obvious symptoms of continuing star formation: no H II regions or young star clusters. They are the simplest galactic systems comprising just a single component, relatively bright in the center but fading rapidly with increasing radius. Elliptical galaxies are found mostly in the denser regions of t ...
... obvious symptoms of continuing star formation: no H II regions or young star clusters. They are the simplest galactic systems comprising just a single component, relatively bright in the center but fading rapidly with increasing radius. Elliptical galaxies are found mostly in the denser regions of t ...
here - NASA/IPAC Extragalactic Database
... equilibrium, and are physically the largest stars: if you place one of the biggest at the center of the solar system, its photosphere would end somewhere between the orbits of Jupiter and Saturn. As Wolf-Rayets (WRs) they are little more than stripped stellar cores with such strong stellar winds tha ...
... equilibrium, and are physically the largest stars: if you place one of the biggest at the center of the solar system, its photosphere would end somewhere between the orbits of Jupiter and Saturn. As Wolf-Rayets (WRs) they are little more than stripped stellar cores with such strong stellar winds tha ...
Document
... Jet (~ continuous flow of emission) close to source Knots with “empty space” further out Only in the past 10 years that we have Realised that outflows can extend for many parsecs 1pc ~ 3 X 1013 km ~ 3.26 light years ~ 206265 AU Can outflows be larger than their parent cloud? ...
... Jet (~ continuous flow of emission) close to source Knots with “empty space” further out Only in the past 10 years that we have Realised that outflows can extend for many parsecs 1pc ~ 3 X 1013 km ~ 3.26 light years ~ 206265 AU Can outflows be larger than their parent cloud? ...
Final Stages of Stellar Evolution - supernovae and the synthesis of
... Nucleosynthesis Revision of Nucleosynthesis up to Iron Nuclear Synthesis of Heavy Elements ...
... Nucleosynthesis Revision of Nucleosynthesis up to Iron Nuclear Synthesis of Heavy Elements ...
Jul y 10-12,
... A handful of Galactic High Mass X-ray Binaries have been observed to emit radiation at very high energies (MeV-TeV), dubbed gamma-ray binaries. This poster will review the importance of multiwavelength observations for understanding two of these systems, HD 259440 and LS 5039. For HD 259440, detecti ...
... A handful of Galactic High Mass X-ray Binaries have been observed to emit radiation at very high energies (MeV-TeV), dubbed gamma-ray binaries. This poster will review the importance of multiwavelength observations for understanding two of these systems, HD 259440 and LS 5039. For HD 259440, detecti ...
A Spectroscopically Confirmed Excess of 24 micron Sources in a
... understanding the interplay between galaxy evolution and environment is to study galaxy groups because: 1) most galaxies in the local universe are in groups (e.g. Geller & Huchra 1983); and 2) hierarchical structure formation predicts that galaxy clusters assemble from the merger and accretion of sm ...
... understanding the interplay between galaxy evolution and environment is to study galaxy groups because: 1) most galaxies in the local universe are in groups (e.g. Geller & Huchra 1983); and 2) hierarchical structure formation predicts that galaxy clusters assemble from the merger and accretion of sm ...
Infrared Properties of Star-Forming Dwarf Galaxies. I. Dwarf Irregular
... According to Kunth & Östlin (2000), the origin of the concepts of ‘‘compact galaxies’’ and ‘‘blue compact galaxies’’ (BCGs) is due to Zwicky (1965). Those BCGs that are less luminous than MB 17 are commonly referred to as ‘‘blue compact dwarfs.’’ BCDs include gas, stars, and usually starburst re ...
... According to Kunth & Östlin (2000), the origin of the concepts of ‘‘compact galaxies’’ and ‘‘blue compact galaxies’’ (BCGs) is due to Zwicky (1965). Those BCGs that are less luminous than MB 17 are commonly referred to as ‘‘blue compact dwarfs.’’ BCDs include gas, stars, and usually starburst re ...
Satellite galaxies in hydrodynamical simulations of Milky Way sized
... Collisionless simulations of the CDM cosmology predict a plethora of dark matter substructures in the halos of Milky Way sized galaxies, yet the number of known luminous satellites galaxies is very much smaller, a discrepancy that has become known as the ‘missing satellite problem’. The most massive ...
... Collisionless simulations of the CDM cosmology predict a plethora of dark matter substructures in the halos of Milky Way sized galaxies, yet the number of known luminous satellites galaxies is very much smaller, a discrepancy that has become known as the ‘missing satellite problem’. The most massive ...
Lecture 2
... spacially resolved kinematic structure of most of the gas…which resides in the cold phase” (Carilli & Blain ...
... spacially resolved kinematic structure of most of the gas…which resides in the cold phase” (Carilli & Blain ...
Iowa - LIGO
... an extra +43”/century compared to Newton’s theory Mercury's elliptical path around the Sun shifts slightly with each orbit such that its closest point to the Sun (or "perihelion") shifts forward with each pass. ...
... an extra +43”/century compared to Newton’s theory Mercury's elliptical path around the Sun shifts slightly with each orbit such that its closest point to the Sun (or "perihelion") shifts forward with each pass. ...
An Expanded View of the Universe
... have been prototyped, will be completed by the end of 2011. During this phase, the project placed contracts with industry and institutes in Europe amounting to about 60 million euros. In addition to these design activities, more than 30 European scientific institutes and high-tech companies studied ...
... have been prototyped, will be completed by the end of 2011. During this phase, the project placed contracts with industry and institutes in Europe amounting to about 60 million euros. In addition to these design activities, more than 30 European scientific institutes and high-tech companies studied ...
Chemical abundances and winds of massive stars in M31: a Btype
... versus 0.3 for HD 92809). Our study represents the first detailed, chemical model atmosphere analysis for either a B-type supergiant or a Wolf –Rayet (WR) star in Andromeda, and shows the potential of how such studies can provide new information on the chemical evolution of galaxies and the evolutio ...
... versus 0.3 for HD 92809). Our study represents the first detailed, chemical model atmosphere analysis for either a B-type supergiant or a Wolf –Rayet (WR) star in Andromeda, and shows the potential of how such studies can provide new information on the chemical evolution of galaxies and the evolutio ...
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.