The Milky Way and Andromeda galaxies in a constrained
... For Milky Way-mass galaxies, the most efficient feedback mechanism is believed to be that produced by stars, via the injection of energy into the interstellar medium during different phases of stellar evolution. In particular, various models for feedback from supernovae (SNe) have been included in simu ...
... For Milky Way-mass galaxies, the most efficient feedback mechanism is believed to be that produced by stars, via the injection of energy into the interstellar medium during different phases of stellar evolution. In particular, various models for feedback from supernovae (SNe) have been included in simu ...
MOLECULAR GAS, KINEMATICS, AND OB STAR FORMATION IN
... observational dataset of CO emission in the galactic disk (Grabelsky et al. 1987; Bronfman et al. 1989; Dame et al. 2001). The beam-size of the antenna in the CO line is 8′ .8, and an angular sampling of 0◦ .125 was adopted. The surveys cover the entire IV galactic quadrant in longitude, and ±2◦ in ...
... observational dataset of CO emission in the galactic disk (Grabelsky et al. 1987; Bronfman et al. 1989; Dame et al. 2001). The beam-size of the antenna in the CO line is 8′ .8, and an angular sampling of 0◦ .125 was adopted. The surveys cover the entire IV galactic quadrant in longitude, and ±2◦ in ...
Measurements of Neutron Star Masses
... the thermal evolution time of the crust, heat transported by electron conduction into the interior, where it is radiated away by neutrinos, creates an isothermal structure [stage (V) in Fig. 1]. The star continuously emits photons, dominantly in x-rays, with an effective temperature Teff that tracks ...
... the thermal evolution time of the crust, heat transported by electron conduction into the interior, where it is radiated away by neutrinos, creates an isothermal structure [stage (V) in Fig. 1]. The star continuously emits photons, dominantly in x-rays, with an effective temperature Teff that tracks ...
The Formation of Primordial Luminous Objects - SLAC
... (ii) Growth rate changes: in general, perturbations grow because of gravity; however, the details of the process change with time, leaving an imprint on the final processed spectrum. The time teq when the matter density becomes larger than the radiation density is particularly important: before teq ...
... (ii) Growth rate changes: in general, perturbations grow because of gravity; however, the details of the process change with time, leaving an imprint on the final processed spectrum. The time teq when the matter density becomes larger than the radiation density is particularly important: before teq ...
POSTERS SESSION I: Atmospheres of Massive Stars
... Independently of the possibility of internally generated fields, there are good reasons to believe that massive stars actually harbour significant magnetic fields of fossil origin. As the ISM itself possesses organized, largescale magnetic fields, it is unavoidable because of magnetic flux conservat ...
... Independently of the possibility of internally generated fields, there are good reasons to believe that massive stars actually harbour significant magnetic fields of fossil origin. As the ISM itself possesses organized, largescale magnetic fields, it is unavoidable because of magnetic flux conservat ...
The star-forming content of the W3 giant molecular cloud
... variations in the stellar IMF (Massey 2003). Turbulent fragmentation models of star formation (e.g. Padoan & Nordlund 2002) predict that complete Salpeterlike mass functions of gravitationally bound dense clumps will form spontanously in molecular clouds with driven turbulence. Such models also sugg ...
... variations in the stellar IMF (Massey 2003). Turbulent fragmentation models of star formation (e.g. Padoan & Nordlund 2002) predict that complete Salpeterlike mass functions of gravitationally bound dense clumps will form spontanously in molecular clouds with driven turbulence. Such models also sugg ...
bars and secular evolution
... Make Sersic fits - take galaxies with n < 2.5 to be disks See mean surface brightness V increase by ~ 2 mag from z = 0.2 to z >1 - good agreement with expectation from theory. Much as expected from passive evolution. Little change in surface density with z, suggests that galaxies increase in size a ...
... Make Sersic fits - take galaxies with n < 2.5 to be disks See mean surface brightness V increase by ~ 2 mag from z = 0.2 to z >1 - good agreement with expectation from theory. Much as expected from passive evolution. Little change in surface density with z, suggests that galaxies increase in size a ...
Five Planets and an Independent Confirmation of
... The linear trend included in the LMMC Keplerian model has a positive slope of about 1.8 m s−1 per year or 16.4 m s−1 over the nine year duration of velocity measurements. This slope is only marginally significant given the large uncertainty in the radial velocity measurements for this star, however ...
... The linear trend included in the LMMC Keplerian model has a positive slope of about 1.8 m s−1 per year or 16.4 m s−1 over the nine year duration of velocity measurements. This slope is only marginally significant given the large uncertainty in the radial velocity measurements for this star, however ...
Next Generation VLA Science White Paper
... The last decades have seen enormous advances in our knowledge of interstellar medium structure in the Milky Way and other galaxies, and with it a better understanding of how stars are born and galaxies grow and die. However, these have come largely from bulk tracers of interstellar gas — tools like ...
... The last decades have seen enormous advances in our knowledge of interstellar medium structure in the Milky Way and other galaxies, and with it a better understanding of how stars are born and galaxies grow and die. However, these have come largely from bulk tracers of interstellar gas — tools like ...
Copyright 2004 Society of Photo-Optical Instrumentation Engineers. This
... of high resolution imaging and spectroscopy over the X-ray band of 0.1 keV – 10 keV. The success of CXO is mainly due to the design and manufacture of its X-ray mirrors – the High Resolution Mirror Assembly (HRMA). At 0.84-m long and 0.6 – 1.2-m in diameters, the surface area of each mirror ranging ...
... of high resolution imaging and spectroscopy over the X-ray band of 0.1 keV – 10 keV. The success of CXO is mainly due to the design and manufacture of its X-ray mirrors – the High Resolution Mirror Assembly (HRMA). At 0.84-m long and 0.6 – 1.2-m in diameters, the surface area of each mirror ranging ...
The Formation of Massive Stars - Max-Planck
... 1000 M (e.g., Beuther et al., 2002a; Williams et al., 2004; Faundez et al., 2004). Massive dense clumps are the main locations where high-mass star formation is taking place. We shall concentrate on the physical properties and evolutionary stages of clumps of dense molecular gas and dust. Most obser ...
... 1000 M (e.g., Beuther et al., 2002a; Williams et al., 2004; Faundez et al., 2004). Massive dense clumps are the main locations where high-mass star formation is taking place. We shall concentrate on the physical properties and evolutionary stages of clumps of dense molecular gas and dust. Most obser ...
Two New Triple Star Systems with Detectable Inner Orbital Motions
... We considered whether the combined and overlaid movement sequences (the three proven components) are visible and predictable. For the inner pair CHR4 Aa,Ab measurements exist from 1984 to 1994. These cover an arc of about 60 degrees and show a well-defined orbital arc. After 1994, the inner system u ...
... We considered whether the combined and overlaid movement sequences (the three proven components) are visible and predictable. For the inner pair CHR4 Aa,Ab measurements exist from 1984 to 1994. These cover an arc of about 60 degrees and show a well-defined orbital arc. After 1994, the inner system u ...
Debris disks and the search for life in the universe Gianni Cataldi
... be the building blocks of planets. By definition, planetesimals are bodies massive enough that their orbital evolution is determined by mutual gravitational interactions, in contrast to smaller dust particles for which aerodynamic interactions with the gas are more important (Armitage 2009). Thus, p ...
... be the building blocks of planets. By definition, planetesimals are bodies massive enough that their orbital evolution is determined by mutual gravitational interactions, in contrast to smaller dust particles for which aerodynamic interactions with the gas are more important (Armitage 2009). Thus, p ...
Structure of the hot object in the symbiotic prototype Z And during its
... UV continuum with an additional attenuation below 1300 Å accompanied by a decline in the radio flux during the 1985 optical maximum. In the line spectrum they measured a broadening of all emission lines with signatures of P-Cygni type profiles for strong resonance lines. Fernández-Castro et al. (19 ...
... UV continuum with an additional attenuation below 1300 Å accompanied by a decline in the radio flux during the 1985 optical maximum. In the line spectrum they measured a broadening of all emission lines with signatures of P-Cygni type profiles for strong resonance lines. Fernández-Castro et al. (19 ...
IR-excesses around nearby Lambda Boo stars are caused by debris
... of a debris disk or interstellar medium (ISM) interaction providing the accreting material. We observe 70 or 100 and 160 µm excess emission around 9 confirmed Lambda Boo stars with the Herschel Space Observatory, to differentiate whether the dust emission is from a debris disk or an ISM bow wave. We ...
... of a debris disk or interstellar medium (ISM) interaction providing the accreting material. We observe 70 or 100 and 160 µm excess emission around 9 confirmed Lambda Boo stars with the Herschel Space Observatory, to differentiate whether the dust emission is from a debris disk or an ISM bow wave. We ...
The MAGNUM survey: positive feedback in the nuclear region of
... integral field observations in the framework of the Measuring Active Galactic Nuclei Under MUSE Microscope (MAGNUM) survey. The data were used to identify regions with different ionization conditions and to map the gas density and the dust extinction. We find evidence for a double-sided ionization c ...
... integral field observations in the framework of the Measuring Active Galactic Nuclei Under MUSE Microscope (MAGNUM) survey. The data were used to identify regions with different ionization conditions and to map the gas density and the dust extinction. We find evidence for a double-sided ionization c ...
The double-pulsar PSR J0737−3039A/B
... PSR B was not detected in the original discovery observation: this is because pulses from the B pulsar are only strong for two short intervals each orbit. The discovery observation happened to be at a time when B pulsed emission is very faint. The first burst of strong emission, centered near orbita ...
... PSR B was not detected in the original discovery observation: this is because pulses from the B pulsar are only strong for two short intervals each orbit. The discovery observation happened to be at a time when B pulsed emission is very faint. The first burst of strong emission, centered near orbita ...
exploring fundamental physics with neutron stars
... known before its launch. With a new generation of telescopes under way, multi-wavelength observations of the sky will surely reveal unknown facets of compact stars. We thus see how observations of several properties of pulsars point to quite extraordinary objects from the astrophysical point of view ...
... known before its launch. With a new generation of telescopes under way, multi-wavelength observations of the sky will surely reveal unknown facets of compact stars. We thus see how observations of several properties of pulsars point to quite extraordinary objects from the astrophysical point of view ...
EXPLORING FUNDAMENTAL PHYSICS WITH NEUTRON STARS
... known before its launch. With a new generation of telescopes under way, multi-wavelength observations of the sky will surely reveal unknown facets of compact stars. We thus see how observations of several properties of pulsars point to quite extraordinary objects from the astrophysical point of view ...
... known before its launch. With a new generation of telescopes under way, multi-wavelength observations of the sky will surely reveal unknown facets of compact stars. We thus see how observations of several properties of pulsars point to quite extraordinary objects from the astrophysical point of view ...
Chandra
... photospheric abundances by selectively removing certain elements (Babel 1995). This paper, however, will focus on high-density, O-star winds, in which momentum sharing is quite efficient. An accelerating wind, by definition, consists of material at a range of velocities. The velocity dispersion in t ...
... photospheric abundances by selectively removing certain elements (Babel 1995). This paper, however, will focus on high-density, O-star winds, in which momentum sharing is quite efficient. An accelerating wind, by definition, consists of material at a range of velocities. The velocity dispersion in t ...
Models of red giants in the CoRoT asteroseismology fields
... and obtained by the other methods (Eqs. (3), (4), and parallax). We also consider extinctions, AV , using Drimmel et al. (2003) as described above, and AV = 0. These results are presented in Figs. 1 and 2. The radii determined with PARAM have the best precision thanks to the Bayesian approach and th ...
... and obtained by the other methods (Eqs. (3), (4), and parallax). We also consider extinctions, AV , using Drimmel et al. (2003) as described above, and AV = 0. These results are presented in Figs. 1 and 2. The radii determined with PARAM have the best precision thanks to the Bayesian approach and th ...
Black holes - Institute of Physics
... Black holes have not yet been seen directly – only by the effect they have on matter nearby, for example, when they co-orbit with a star in a binary system. Material falling towards a black hole heats up to millions of degrees and radiates in the X-ray part of the electromagnetic spectrum. The first ...
... Black holes have not yet been seen directly – only by the effect they have on matter nearby, for example, when they co-orbit with a star in a binary system. Material falling towards a black hole heats up to millions of degrees and radiates in the X-ray part of the electromagnetic spectrum. The first ...
A dearth of dark matter in strong gravitational lenses
... evidence supporting MOND. However, gas-poor early-type systems, ellipticals and S0s, usually miss such a clear tracer of the gravitational acceleration; for such objects the situation has been more confused. An unavoidable prediction of MOND is that in high surface brightness systems, such as lumino ...
... evidence supporting MOND. However, gas-poor early-type systems, ellipticals and S0s, usually miss such a clear tracer of the gravitational acceleration; for such objects the situation has been more confused. An unavoidable prediction of MOND is that in high surface brightness systems, such as lumino ...
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.