space telescope imaging spectrograph survey of far
... coronal (T > 106 K) forbidden lines in a sample of 29 F–M dwarfs, giants, and supergiants. Measuring coronal lines in the 1150–1700 Å band with STIS has important advantages of superior velocity resolution and an absolute wavelength calibration compared with using the Chandra or XMM-Newton grating ...
... coronal (T > 106 K) forbidden lines in a sample of 29 F–M dwarfs, giants, and supergiants. Measuring coronal lines in the 1150–1700 Å band with STIS has important advantages of superior velocity resolution and an absolute wavelength calibration compared with using the Chandra or XMM-Newton grating ...
A" Light," Centrally-Concentrated Milky Way Halo?
... halo was selected to have a quiet merger history, and the high resolution region was resampled with 13 million dark matter particles and an equal number of gas particles, for a mass resolution of mDM = 9.8 × 104 M⊙ and mSPH = 2 × 104 M⊙ , and a gravitational softening of 120 pc (physical). Star part ...
... halo was selected to have a quiet merger history, and the high resolution region was resampled with 13 million dark matter particles and an equal number of gas particles, for a mass resolution of mDM = 9.8 × 104 M⊙ and mSPH = 2 × 104 M⊙ , and a gravitational softening of 120 pc (physical). Star part ...
Formation and evolution of planetary systems in presence of highly
... whose orbital angular momentum vector is mis-aligned with respect to the stellar rotation axis (Fabrycky & Tremaine 2007). The presence of such objects has been confirmed via observations of the Rossiter-McLaughlin effect (McLaughlin 1924), leading to a notion that Kozai cycles with tidal friction ar ...
... whose orbital angular momentum vector is mis-aligned with respect to the stellar rotation axis (Fabrycky & Tremaine 2007). The presence of such objects has been confirmed via observations of the Rossiter-McLaughlin effect (McLaughlin 1924), leading to a notion that Kozai cycles with tidal friction ar ...
Massive Star Formation - Max-Planck
... Across the universe, massive stars play dominant roles in terms of their feedback and their synthesis and dispersal of heavy elements. Achieving a full theoretical understanding of massive star formation is thus an important goal of contemporary astrophysics. This effort can also be viewed as a majo ...
... Across the universe, massive stars play dominant roles in terms of their feedback and their synthesis and dispersal of heavy elements. Achieving a full theoretical understanding of massive star formation is thus an important goal of contemporary astrophysics. This effort can also be viewed as a majo ...
Models for circumstellar nebulae around red and blue supergiants
... Classification and evolution Stars spend most of their life in the Main Sequence (MS). In this stage of their evolution the source of energy production is the fusion of hydrogen into helium in their core. This energy escapes from the star in the form of radiation and, to a minor fraction, in the for ...
... Classification and evolution Stars spend most of their life in the Main Sequence (MS). In this stage of their evolution the source of energy production is the fusion of hydrogen into helium in their core. This energy escapes from the star in the form of radiation and, to a minor fraction, in the for ...
radioactive 26a1 in the galaxy: observations versus theory
... the interstellar medium of our Galaxy and in external galaxies as well [ 1601. In the vast majority of cases observations reveal only elemental abundances, through electromagnetic transitions in the atomic shells. However, it is individual isotopes, not elements, that participate in nuclear reaction ...
... the interstellar medium of our Galaxy and in external galaxies as well [ 1601. In the vast majority of cases observations reveal only elemental abundances, through electromagnetic transitions in the atomic shells. However, it is individual isotopes, not elements, that participate in nuclear reaction ...
Galaxies
... A poor, irregular cluster of about 40 galaxies The diameter is about 1 Mpc (mega parsec) The largest is M31, the Andromeda Galaxy The Milky Way is in the second place Both Milky Way and M31 are surrounded by a number of small satellite galaxies ...
... A poor, irregular cluster of about 40 galaxies The diameter is about 1 Mpc (mega parsec) The largest is M31, the Andromeda Galaxy The Milky Way is in the second place Both Milky Way and M31 are surrounded by a number of small satellite galaxies ...
The ionized gas in the central region of NGC 5253
... the ESO pipeline tasks gimasterbias, gimasterflat and giwavecalibration. In particular, fifteen bias frames were used for the masterbias creation while six and three continuum lamp exposures were needed for the creation of the L385.7 and L427.2 masterflats, respectively. In order to remove the cosmi ...
... the ESO pipeline tasks gimasterbias, gimasterflat and giwavecalibration. In particular, fifteen bias frames were used for the masterbias creation while six and three continuum lamp exposures were needed for the creation of the L385.7 and L427.2 masterflats, respectively. In order to remove the cosmi ...
The asymmetric nuclear region of M83 and its off
... The data were reduced with the standard SINFONI pipeline, which was developed by ESO and the Max-Planck-Institut für extraterrestrische Physik. The default procedure included corrections for pixel non-linearity, distortion and wavelength calibration. Flux calibration as well as telluric feature corr ...
... The data were reduced with the standard SINFONI pipeline, which was developed by ESO and the Max-Planck-Institut für extraterrestrische Physik. The default procedure included corrections for pixel non-linearity, distortion and wavelength calibration. Flux calibration as well as telluric feature corr ...
- Philsci
... A number of caveats apply, and it is best to introduce them straightaway. The case study is, of course, open to alternative interpretations. It is employed as an argument in two different senses. First, the case study exemplifies the thesis that fictional assumptions play an inferential role in mod ...
... A number of caveats apply, and it is best to introduce them straightaway. The case study is, of course, open to alternative interpretations. It is employed as an argument in two different senses. First, the case study exemplifies the thesis that fictional assumptions play an inferential role in mod ...
A SPECTROSCOPIC STUDY OF A LARGE SAMPLE OF WOLF-RAYET GALAXIES
... hence cannot be distinguished from other WR stars in low-resolution spectra. Additionally, WNE stars are not as luminous as WNL stars in the optical range. The WR star lifetime in the WNE stage is short compared to that in the WNL stage for nearly all metallicities and progenitor star masses (Maeder ...
... hence cannot be distinguished from other WR stars in low-resolution spectra. Additionally, WNE stars are not as luminous as WNL stars in the optical range. The WR star lifetime in the WNE stage is short compared to that in the WNL stage for nearly all metallicities and progenitor star masses (Maeder ...
Open access
... to the required diameter of the large telescope. In addition to providing the required spatial resolution, this technique can also allow to strongly reduce the stellar emission by combining the light from two telescopes in phase opposition (so that a dark fringe appears on the line of sight). This t ...
... to the required diameter of the large telescope. In addition to providing the required spatial resolution, this technique can also allow to strongly reduce the stellar emission by combining the light from two telescopes in phase opposition (so that a dark fringe appears on the line of sight). This t ...
Maximum Mass Restraint of Neutron Stars
... the core it begins accumulating until it reaches approximately 1.44 solar masses. At this point degeneracy pressures can no longer support the core and the process of star collapse begins. Core collapse is a rather violent process and is caused by the production of gamma rays within the core. Throug ...
... the core it begins accumulating until it reaches approximately 1.44 solar masses. At this point degeneracy pressures can no longer support the core and the process of star collapse begins. Core collapse is a rather violent process and is caused by the production of gamma rays within the core. Throug ...
Chapter: The Evolution of Binary Systems
... than 10 before helium ignition and again after helium burning, it is much more likely that RLOF starts after the star has continued its main-sequence phase (this assumes a logarithmically flat initial period distribution). On the other hand, since a star spends most of its life on the main sequence, ...
... than 10 before helium ignition and again after helium burning, it is much more likely that RLOF starts after the star has continued its main-sequence phase (this assumes a logarithmically flat initial period distribution). On the other hand, since a star spends most of its life on the main sequence, ...
Z - STScI
... Zampieri et al., Nomoto et al - low luminosity SNe form black-holes No evidence so far of the branching at high luminosity Detailed comparison with models now possible ...
... Zampieri et al., Nomoto et al - low luminosity SNe form black-holes No evidence so far of the branching at high luminosity Detailed comparison with models now possible ...
sBzKs
... E(B-V)~0.40, average SFR ~ 190 Mo/yr, typical stellar mass ~1011 Mo, and ~solar metallicity. The high SFRs, large masses and high metallicities of sBzKs suggest that these z~2 star forming galaxies are the precursors of z=1 passive EROs and z=0 early-type galaxies. ...
... E(B-V)~0.40, average SFR ~ 190 Mo/yr, typical stellar mass ~1011 Mo, and ~solar metallicity. The high SFRs, large masses and high metallicities of sBzKs suggest that these z~2 star forming galaxies are the precursors of z=1 passive EROs and z=0 early-type galaxies. ...
Multi-dimensional models of circumstellar shells around evolved
... the stellar winds. For GRBs this is more difficult to observe, as the high energy photons from the GRB and its afterglow will ionize the surrounding gas to a very high degree (Prochaska et al. 2007), though the presence of dust in the CSM may compensate for this to some extent (Robinson et al. 2010) ...
... the stellar winds. For GRBs this is more difficult to observe, as the high energy photons from the GRB and its afterglow will ionize the surrounding gas to a very high degree (Prochaska et al. 2007), though the presence of dust in the CSM may compensate for this to some extent (Robinson et al. 2010) ...
3 science case - Giant Magellan Telescope Organization
... quality probes of the physical properties of gas giant planets. Nearby field stars, stellar associations, and star-forming regions provide good targets for direct detection of terrestrial and gas giant planets. At distances of 50-100 pc, the TW Hya (10 Myr), η Cha (10 Myr) and Tuc-Hor (30 Myr) assoc ...
... quality probes of the physical properties of gas giant planets. Nearby field stars, stellar associations, and star-forming regions provide good targets for direct detection of terrestrial and gas giant planets. At distances of 50-100 pc, the TW Hya (10 Myr), η Cha (10 Myr) and Tuc-Hor (30 Myr) assoc ...
Chapter 6 in the LSST Science Book
... have begun bound to one another, and both may be on their first approach to the Milky Way, not already bound to it. Attempts to model the motion of the Clouds together with a formation model for the Magellanic Stream in light of the new data (e.g., Besla et al. 2009) are very much works in progress. ...
... have begun bound to one another, and both may be on their first approach to the Milky Way, not already bound to it. Attempts to model the motion of the Clouds together with a formation model for the Magellanic Stream in light of the new data (e.g., Besla et al. 2009) are very much works in progress. ...
A CHANDRA X-RAY STUDY OF THE DENSE GLOBULAR CLUSTER TERZAN... C. O. Heinke, P. D. Edmonds, J. E. Grindlay, and...
... color information did not uncover any promising candidates because of the crowding and overlapping Airy profiles, although it did identify two truly variable stars, one of which was shown to be an RR Lyrae variable. This paper is organized as follows. Section 2.1 describes the observations we used. S ...
... color information did not uncover any promising candidates because of the crowding and overlapping Airy profiles, although it did identify two truly variable stars, one of which was shown to be an RR Lyrae variable. This paper is organized as follows. Section 2.1 describes the observations we used. S ...
Presolar History Recorded in Extraterrestrial Materials
... stars – Red giant stars have exhausted all the hydrogen (Burbidge et al. 1957). Nuclear fusion reactions in stellar in their cores through nuclear reactions, and some of the interiors provide the energy to make stars shine and are H-burning products are brought to the stellar envelope the primary or ...
... stars – Red giant stars have exhausted all the hydrogen (Burbidge et al. 1957). Nuclear fusion reactions in stellar in their cores through nuclear reactions, and some of the interiors provide the energy to make stars shine and are H-burning products are brought to the stellar envelope the primary or ...
On the possibility of a helium white dwarf donor in the presumed
... As noted by Juett et al. (2003) and Nelemans et al. (2004), there is a puzzling contradiction between the characteristics (or mere presence) of these bursts and the suggested hydrogen or helium depletion in the donor stars. The bursts detected from these systems last between 10 and a few hundred sec ...
... As noted by Juett et al. (2003) and Nelemans et al. (2004), there is a puzzling contradiction between the characteristics (or mere presence) of these bursts and the suggested hydrogen or helium depletion in the donor stars. The bursts detected from these systems last between 10 and a few hundred sec ...
Exploring Strange New Worlds: From Giant Planets to Super Earths
... habitable planets populated by advanced civilizations engaged in interstellar trade and !conflict. !Back in our real universe, Earth-like planets and alien life have proved elusive. !Has science fiction led us astray? !NASA recently launched a new space-borne telescope, Kepler, dedicated to discover ...
... habitable planets populated by advanced civilizations engaged in interstellar trade and !conflict. !Back in our real universe, Earth-like planets and alien life have proved elusive. !Has science fiction led us astray? !NASA recently launched a new space-borne telescope, Kepler, dedicated to discover ...
ASTRONOMY AND ASTROPHYSICS Elemental abundances of
... provided a coverage from 5465 — 8180 Å. The overlap of the spectra of the blue and red channel amounts to at least 20 Å around λ = 5500 Å. The slit width was fixed to 1.00 76 projected on the sky for both channels and a fixed position angle of PA = 0◦ . For all exposures the hour angle of the qua ...
... provided a coverage from 5465 — 8180 Å. The overlap of the spectra of the blue and red channel amounts to at least 20 Å around λ = 5500 Å. The slit width was fixed to 1.00 76 projected on the sky for both channels and a fixed position angle of PA = 0◦ . For all exposures the hour angle of the qua ...
Variability of young solar-type stars: Spot cycles, rotation
... affect the conditions in the circumstellar space and are important considerations for the interaction of a star and its planetary system (Vidotto et al., 2015). Coupling of the magnetic field with the strong stellar wind is also responsible for transferring angular momentum away from the star, leading ...
... affect the conditions in the circumstellar space and are important considerations for the interaction of a star and its planetary system (Vidotto et al., 2015). Coupling of the magnetic field with the strong stellar wind is also responsible for transferring angular momentum away from the star, leading ...
Planetary nebula
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.