![Tracers of Discs and Winds around Intermediate and High Mass](http://s1.studyres.com/store/data/017571425_1-2c5c05817095c7a3dd8feea9925a01ac-300x300.png)
Tracers of Discs and Winds around Intermediate and High Mass
... A standard reduction procedure was adopted for all of the data discussed here. The projected image of the slit on the array is curved. This was corrected for using the trace of a bright arc line as a model. This procedure was checked for reliability using fainter night sky lines present on each indi ...
... A standard reduction procedure was adopted for all of the data discussed here. The projected image of the slit on the array is curved. This was corrected for using the trace of a bright arc line as a model. This procedure was checked for reliability using fainter night sky lines present on each indi ...
Spherical planetary nebulae
... It is well known that spherical PNe have a larger average galactic latitude b than that of the other PNe (e.g., Manchado et al. 2000). I now show that the class of spherical PNe, as classified by S97, has also a larger galactic longitude than the other PNe. The 458 PNe (of which 452 with good data a ...
... It is well known that spherical PNe have a larger average galactic latitude b than that of the other PNe (e.g., Manchado et al. 2000). I now show that the class of spherical PNe, as classified by S97, has also a larger galactic longitude than the other PNe. The 458 PNe (of which 452 with good data a ...
Draft paper (submitted to MNRAS)
... From an observational standpoint, deep imaging with the Hubble Space Telescope (HST) has been combined with sophisticated stellar evolution models in order to derive the star formation history (hereafter SFH, for short) of a number of nearby dwarfs (see, e.g., Weisz et al. 2011, and references there ...
... From an observational standpoint, deep imaging with the Hubble Space Telescope (HST) has been combined with sophisticated stellar evolution models in order to derive the star formation history (hereafter SFH, for short) of a number of nearby dwarfs (see, e.g., Weisz et al. 2011, and references there ...
Searching for Planets During Predicted Mesolensing Events: II
... well as MEarth, Kepler and other transit studies. If well designed, the monitoring programs will be guaranteed to either discover planets in orbits with semi-major axes smaller than about two Einstein radii, or else to rule out their presence. Planets on wider orbits may not all be discovered, but i ...
... well as MEarth, Kepler and other transit studies. If well designed, the monitoring programs will be guaranteed to either discover planets in orbits with semi-major axes smaller than about two Einstein radii, or else to rule out their presence. Planets on wider orbits may not all be discovered, but i ...
WTS-1 b: the fi rst extrasolar planet detected in the WFCAM Transit
... Statue of Giordano Bruno . . . . . . . . . . . . . . . . . . . . . . Detection methods: radial velocity and transit . . . . . . . . . . . Detection methods: gravitational microlensing and astrometry . . T-Tauri star . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Snow line . . . . . . . ...
... Statue of Giordano Bruno . . . . . . . . . . . . . . . . . . . . . . Detection methods: radial velocity and transit . . . . . . . . . . . Detection methods: gravitational microlensing and astrometry . . T-Tauri star . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Snow line . . . . . . . ...
the red supergiant content of m31
... luminosities. This separation is only partially reflected in the evolutionary tracks, although that might be due to the mis-match in metallicities between the solar Geneva models and the higher-than-solar metallicity of M31. As the luminosities increase the median spectral type also increases; i.e., ...
... luminosities. This separation is only partially reflected in the evolutionary tracks, although that might be due to the mis-match in metallicities between the solar Geneva models and the higher-than-solar metallicity of M31. As the luminosities increase the median spectral type also increases; i.e., ...
Lecture 9: Supernovae
... The light-curve behaved exactly as expected: after the initial increase, it faded quickly until June 1987. Then it settled into a much slower fade, of about 1% a day, for two years. This corresponds exactly to the laboratory-measured half-life of 56 Co (77 days), which is the result of the (rapid) d ...
... The light-curve behaved exactly as expected: after the initial increase, it faded quickly until June 1987. Then it settled into a much slower fade, of about 1% a day, for two years. This corresponds exactly to the laboratory-measured half-life of 56 Co (77 days), which is the result of the (rapid) d ...
Does feedback help or hinder star formation? The effect of
... After the accretion has finished, the star particles emit ionising radiation using the adaptive ray tracing scheme implemented in Enzo that is described in Abel & Wandelt (2002); Wise & Abel (2011) and based on the HEALPix framework (Górski et al. 2005). Each star particle has an ionising luminosit ...
... After the accretion has finished, the star particles emit ionising radiation using the adaptive ray tracing scheme implemented in Enzo that is described in Abel & Wandelt (2002); Wise & Abel (2011) and based on the HEALPix framework (Górski et al. 2005). Each star particle has an ionising luminosit ...
The Age and Stellar Parameters of the Procyon Binary System
... Procyon B was first detected visually at the end of the 19th century by Schaeberle (1896), and was historically one of the first white dwarfs to be discovered. Even early estimates of the mass (MB ) of the white dwarf component, such as that by Strand (1951), showed that it is much closer to the mea ...
... Procyon B was first detected visually at the end of the 19th century by Schaeberle (1896), and was historically one of the first white dwarfs to be discovered. Even early estimates of the mass (MB ) of the white dwarf component, such as that by Strand (1951), showed that it is much closer to the mea ...
here - ISAS/JAXA
... Evolution of dust emission around PNe, from AKARI/Spitzer to SPICA WISE J180956.27-330500.2: A star possibly ongoing an episodic mass-loss Resolving the mass loss in red supergiants with the Very Large Telescope Interferometer and SPICA Filamentary structure, cores, and young stellar objects in the ...
... Evolution of dust emission around PNe, from AKARI/Spitzer to SPICA WISE J180956.27-330500.2: A star possibly ongoing an episodic mass-loss Resolving the mass loss in red supergiants with the Very Large Telescope Interferometer and SPICA Filamentary structure, cores, and young stellar objects in the ...
Feedback from winds and supernovae in massive stellar clusters – I
... swept-up shell. First, the diffuse X-ray emission in M17 and the Rosette nebula reveals that only a small proportion of the cluster wind energy is radiated in the X-ray, and Townsley et al. (2003) conclude that most of the hot gas must flow without cooling into the wider ISM. This picture is support ...
... swept-up shell. First, the diffuse X-ray emission in M17 and the Rosette nebula reveals that only a small proportion of the cluster wind energy is radiated in the X-ray, and Townsley et al. (2003) conclude that most of the hot gas must flow without cooling into the wider ISM. This picture is support ...
Betelgeuse – Challenging our Understanding for more than 2000
... • Rapid photometric changes are not global • Observed events: large, rapid decrease in RV followed by 0.5 mag decrease in brightness – tend to occur just aher pulsaVon RV minimum – speculate that ma ...
... • Rapid photometric changes are not global • Observed events: large, rapid decrease in RV followed by 0.5 mag decrease in brightness – tend to occur just aher pulsaVon RV minimum – speculate that ma ...
UNIT 4 - Galaxies XIV. The Milky Way A. Structure
... gas and dust in the galaxy - Milky Way has a spiral structure Spiral arms contain gas and dust and is the site for star formation within the galaxy appears bright and blue due to the blue color of high mass stars do not live long so they are concentrated within the spiral arms the galactic bulge is ...
... gas and dust in the galaxy - Milky Way has a spiral structure Spiral arms contain gas and dust and is the site for star formation within the galaxy appears bright and blue due to the blue color of high mass stars do not live long so they are concentrated within the spiral arms the galactic bulge is ...
Detection of [Ne ii] Emission from Young Circumstellar Disks
... six optically thick dust disks observed as part of the FEPS Spitzer Legacy program. In addition, we detect a H i(7-6) emission line at 12.37 µm from the source RX J1852.3-3700. Detections of [Ne ii] lines are favored by low mid–infrared excess emission. Both stellar X–rays and extreme UV (EUV) photo ...
... six optically thick dust disks observed as part of the FEPS Spitzer Legacy program. In addition, we detect a H i(7-6) emission line at 12.37 µm from the source RX J1852.3-3700. Detections of [Ne ii] lines are favored by low mid–infrared excess emission. Both stellar X–rays and extreme UV (EUV) photo ...
The Structure and Evolution of Protoplanetary Disks: an Infrared and
... to understand, as mid-separation binaries truncate each other’s outer disks, drastically decreasing the amount of material available for accretion. Spectroscopic binaries (separation 1 AU) and wide binaries (separation > 100 AU) seem to have little effect on disk lifetimes. 2.2. Disk structure and ...
... to understand, as mid-separation binaries truncate each other’s outer disks, drastically decreasing the amount of material available for accretion. Spectroscopic binaries (separation 1 AU) and wide binaries (separation > 100 AU) seem to have little effect on disk lifetimes. 2.2. Disk structure and ...
Background Information on Galaxy Classification
... universes" -- each one a collection of millions or billions of stars bound together by gravity. Within a few years, he had set up a system to classify them that is still used today, albeit with some modifications and additions. Hubble's system divides galaxies into three basic categories: 1) ellipti ...
... universes" -- each one a collection of millions or billions of stars bound together by gravity. Within a few years, he had set up a system to classify them that is still used today, albeit with some modifications and additions. Hubble's system divides galaxies into three basic categories: 1) ellipti ...
Zinc and chromium abundances in a third
... and with the Hubble Space Telescope (Le Brun et al. 1997), and plausible candidates for the absorbing galaxies have been identified. However, in neither case is a Milky Way-type galaxy indicated. The former appears to be an extended object of low surface brightness and low metallicity ([Zn/H] = −1.2 ...
... and with the Hubble Space Telescope (Le Brun et al. 1997), and plausible candidates for the absorbing galaxies have been identified. However, in neither case is a Milky Way-type galaxy indicated. The former appears to be an extended object of low surface brightness and low metallicity ([Zn/H] = −1.2 ...
AN INITIAL MASS FUNCTION STUDY OF THE DWARF Please share
... stellar masses in newly formed stellar populations, is essential for understanding the evolution and star formation histories of galaxies. Whether it is universal or dependent on environment has been a highly contested issue over the past few years. While IMF measurements in high-density environment ...
... stellar masses in newly formed stellar populations, is essential for understanding the evolution and star formation histories of galaxies. Whether it is universal or dependent on environment has been a highly contested issue over the past few years. While IMF measurements in high-density environment ...
Binocular Certificate Handbook
... Galaxies formed in the early Universe when huge clumps of gas began to aggregate. Their cores generally consist of older suns while the arms of spirals host numerous clusters where new stars are being born. Supernovae enrich the interstellar medium with new elements. Our own galaxy, the Milky Way, i ...
... Galaxies formed in the early Universe when huge clumps of gas began to aggregate. Their cores generally consist of older suns while the arms of spirals host numerous clusters where new stars are being born. Supernovae enrich the interstellar medium with new elements. Our own galaxy, the Milky Way, i ...
O stars with weak winds: the Galactic case - Max-Planck
... the broader the profile, the lower the precision of the fit of the line. The typical error on Teff is usually of ± 2000 K but can be reduced when many optical He lines are available. Note that the errors we give are 2σ errors (we have Teff − error < Teff < Teff + error). We also checked that our fin ...
... the broader the profile, the lower the precision of the fit of the line. The typical error on Teff is usually of ± 2000 K but can be reduced when many optical He lines are available. Note that the errors we give are 2σ errors (we have Teff − error < Teff < Teff + error). We also checked that our fin ...
Gas giants in hot water: inhibiting giant planet
... In Section 2, I estimate the temperature of embedded star clusters, and in Section 3 I estimate their protoplanetary disc temperatures. I then compare the relative importance of cluster irradiation and (1) host star irradiation in passive discs, and (2) accretion power in active discs. Generically, ...
... In Section 2, I estimate the temperature of embedded star clusters, and in Section 3 I estimate their protoplanetary disc temperatures. I then compare the relative importance of cluster irradiation and (1) host star irradiation in passive discs, and (2) accretion power in active discs. Generically, ...
The Recent Star Formation Histories of M81 Group Dwarf Irregular
... very efficient observing strategies (e.g., Caldwell et al. 1998). After the images were processed with the HST pipeline, we performed photometry using DOLPHOT, a version of HSTphot (Dolphin 2000) optimized for ACS observations. Cosmic rays, hot pixel residuals, and extended objects were all rejected ...
... very efficient observing strategies (e.g., Caldwell et al. 1998). After the images were processed with the HST pipeline, we performed photometry using DOLPHOT, a version of HSTphot (Dolphin 2000) optimized for ACS observations. Cosmic rays, hot pixel residuals, and extended objects were all rejected ...
Observed Properties of Exoplanets
... of stars harboring giant planets with M < 13MJup within 5 AU is at least 88/1330 = 6.6%. This is no doubt a lower limit as planets between 3–5 AU are not efficiently detected due to the limited duration, 6–8 years, of our Doppler survey. The 12 stars with two or more planets imply an occurrence rate o ...
... of stars harboring giant planets with M < 13MJup within 5 AU is at least 88/1330 = 6.6%. This is no doubt a lower limit as planets between 3–5 AU are not efficiently detected due to the limited duration, 6–8 years, of our Doppler survey. The 12 stars with two or more planets imply an occurrence rate o ...
PPT
... Jet/Counterjet Asymmetries: Doppler Beaming • For several pulsars, both a jet and a counterjet are observed. - for most, the flux from the counterjet is difficult to measure, both because it is faint and because the surrounding PWN emission is bright ...
... Jet/Counterjet Asymmetries: Doppler Beaming • For several pulsars, both a jet and a counterjet are observed. - for most, the flux from the counterjet is difficult to measure, both because it is faint and because the surrounding PWN emission is bright ...
THE FINAL FATE OF STARS THAT IGNITE NEON AND OXYGEN
... evolutionary channel producing EC-SNe in addition to superAGB stars. These stars would be the most massive progenitors of EC-SNe and would ignite neon and oxygen burning offcenter where the maximum temperature has moved outward as neutrino emission produced a net cooling of the mildly electrondegene ...
... evolutionary channel producing EC-SNe in addition to superAGB stars. These stars would be the most massive progenitors of EC-SNe and would ignite neon and oxygen burning offcenter where the maximum temperature has moved outward as neutrino emission produced a net cooling of the mildly electrondegene ...
Planetary nebula
![](https://commons.wikimedia.org/wiki/Special:FilePath/NGC6543.jpg?width=300)
A planetary nebula, often abbreviated as PN or plural PNe, is a kind of emission nebula consisting of an expanding glowing shell of ionized gas ejected from old red giant stars late in their lives. The word ""nebula"" is Latin for mist or cloud and the term ""planetary nebula"" is a misnomer that originated in the 1780s with astronomer William Herschel because when viewed through his telescope, these objects appeared to him to resemble the rounded shapes of planets. Herschel's name for these objects was popularly adopted and has not been changed. They are a relatively short-lived phenomenon, lasting a few tens of thousands of years, compared to a typical stellar lifetime of several billion years.A mechanism for formation of most planetary nebulae is thought to be the following: at the end of the star's life, during the red giant phase, the outer layers of the star are expelled by strong stellar winds. Eventually, after most of the red giant's atmosphere is dissipated, the exposed hot, luminous core emits ultraviolet radiation to ionize the ejected outer layers of the star. Absorbed ultraviolet light energises the shell of nebulous gas around the central star, appearing as a bright coloured planetary nebula at several discrete visible wavelengths.Planetary nebulae may play a crucial role in the chemical evolution of the Milky Way, returning material to the interstellar medium from stars where elements, the products of nucleosynthesis (such as carbon, nitrogen, oxygen and neon), have been created. Planetary nebulae are also observed in more distant galaxies, yielding useful information about their chemical abundances.In recent years, Hubble Space Telescope images have revealed many planetary nebulae to have extremely complex and varied morphologies. About one-fifth are roughly spherical, but the majority are not spherically symmetric. The mechanisms which produce such a wide variety of shapes and features are not yet well understood, but binary central stars, stellar winds and magnetic fields may play a role.