Leakage of ionizing radiation from the nearby galaxy Tololo 1247
... data from the Far Ultraviolet Spectroscopic Explorer (FUSE), and an estimated LyC LyC photon escape fraction (fesc ) is calculated by comparing the emitted flux at 900 Å and 1500 Å. However, this method is generally used for galaxies at higher redshifts, and quite a few assumptions about the prope ...
... data from the Far Ultraviolet Spectroscopic Explorer (FUSE), and an estimated LyC LyC photon escape fraction (fesc ) is calculated by comparing the emitted flux at 900 Å and 1500 Å. However, this method is generally used for galaxies at higher redshifts, and quite a few assumptions about the prope ...
The 3-D shaping of NGC 6741: A massive, fast
... We stress the fundamental difference between our frames, covering 80 echelle orders, and the observing procedure usually adopted for extended objects, inserting an interference filter to isolate a single order. The same is valid for the reduction and investigation methods: so far long-slit echellogra ...
... We stress the fundamental difference between our frames, covering 80 echelle orders, and the observing procedure usually adopted for extended objects, inserting an interference filter to isolate a single order. The same is valid for the reduction and investigation methods: so far long-slit echellogra ...
Characterization of the physical properties of the ROSETTA target
... ROSETTA spacecraft with 67P/C-G. Moreover, this study will provide valuable information on the basic physical properties of the nucleus of JFCs and their dust environment far away from the Sun, helping to understand if 67P/C-G behaves as a typical Jupiter family comet or not. The observations were c ...
... ROSETTA spacecraft with 67P/C-G. Moreover, this study will provide valuable information on the basic physical properties of the nucleus of JFCs and their dust environment far away from the Sun, helping to understand if 67P/C-G behaves as a typical Jupiter family comet or not. The observations were c ...
The Lupus clouds - European Southern Observatory
... determinations agree on a smaller range, between 140 pc and 240 pc. Such a range is still uncomfortably large, as it implies an uncertainty by a factor near 3 in important quantities that depend on the square of the distance, such as the mass of clouds and cores or the luminosity of its member stars ...
... determinations agree on a smaller range, between 140 pc and 240 pc. Such a range is still uncomfortably large, as it implies an uncertainty by a factor near 3 in important quantities that depend on the square of the distance, such as the mass of clouds and cores or the luminosity of its member stars ...
The recent star-formation history of the Large and Small Magellanic
... resolution, we adopt a different method. In this method, we estimated the age of the last star-formation event (LSFE) in a given region, by identifying the turn-off of the main sequence (MS) in the CMD of the corresponding region. The turn-off identified from the luminosity function (LF) of the MS repr ...
... resolution, we adopt a different method. In this method, we estimated the age of the last star-formation event (LSFE) in a given region, by identifying the turn-off of the main sequence (MS) in the CMD of the corresponding region. The turn-off identified from the luminosity function (LF) of the MS repr ...
Circumstellar Material in Young Stellar Objects
... with the cloud. However, the study of molecular clouds did not reach its full growth until it became possible to observe mm and submm transitions of molecular species such as CO and NH (Cheung et al. 1968; Wilson et al. 1970; Kutner et al. 1977), allowing more detailed studies of the kinematics and ...
... with the cloud. However, the study of molecular clouds did not reach its full growth until it became possible to observe mm and submm transitions of molecular species such as CO and NH (Cheung et al. 1968; Wilson et al. 1970; Kutner et al. 1977), allowing more detailed studies of the kinematics and ...
this article
... paper include contributions from the two satellite [N ii] lines at 6548 and 6584 8. Complete inclusion of these lines in our line filters allows the possibility to later correct for [N ii] contamination when more information is available. Previous work has indicated that the [N ii]/ H ratio varies ...
... paper include contributions from the two satellite [N ii] lines at 6548 and 6584 8. Complete inclusion of these lines in our line filters allows the possibility to later correct for [N ii] contamination when more information is available. Previous work has indicated that the [N ii]/ H ratio varies ...
arXiv:astro-ph/0702414v1 15 Feb 2007
... to treat the radiation transfer of resonance lines, both numerically (e.g., Auer 1968; Adams 1972; Ahn et al. 2001; Richling 2003; Hansen & Oh 2006; Verhamme et al. 2006) and analytically (e.g., Osterbrock 1962; Neufeld 1990). Neutral hydrogen absorbs and re-emits Lyα photons in random directions. A ...
... to treat the radiation transfer of resonance lines, both numerically (e.g., Auer 1968; Adams 1972; Ahn et al. 2001; Richling 2003; Hansen & Oh 2006; Verhamme et al. 2006) and analytically (e.g., Osterbrock 1962; Neufeld 1990). Neutral hydrogen absorbs and re-emits Lyα photons in random directions. A ...
Constraints on the physical properties and chemical evolution of star
... constrain the physical properties and chemical enrichment of the gas in galaxies at all cosmic epochs. This is important, because galaxies are being detected at always higher redshift and upcoming observations with large telescopes, such as the James Webb Space Telescope, will gather high-quality sp ...
... constrain the physical properties and chemical enrichment of the gas in galaxies at all cosmic epochs. This is important, because galaxies are being detected at always higher redshift and upcoming observations with large telescopes, such as the James Webb Space Telescope, will gather high-quality sp ...
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 ...
the nuclear reddening curve for active galactic nuclei and the shape
... to affect the spectral shape, so the intrinsic matches cannot be perfect for that reason alone. However, the averaging within the composites will greatly reduce the last problem. Note that our subsamples are matched in radio lobe power. We also determined the reddening curve for the broad-line regio ...
... to affect the spectral shape, so the intrinsic matches cannot be perfect for that reason alone. However, the averaging within the composites will greatly reduce the last problem. Note that our subsamples are matched in radio lobe power. We also determined the reddening curve for the broad-line regio ...
Unfolding the Milky Way bulge - International Max Planck Research
... et al. (1998), as a function of Galactic latitude, for 1000 randomly distributed 30′ × 30′ regions between (−8◦ < b < −1◦ ). . . . . . . . . . . . . . . . . . . . 5.8 The upper panel shows the inner ∼ ±2◦ region around the Galactic plane of our VVV extinction map. AKs values are based on Cardelli et ...
... et al. (1998), as a function of Galactic latitude, for 1000 randomly distributed 30′ × 30′ regions between (−8◦ < b < −1◦ ). . . . . . . . . . . . . . . . . . . . 5.8 The upper panel shows the inner ∼ ±2◦ region around the Galactic plane of our VVV extinction map. AKs values are based on Cardelli et ...
Star Formation in the Orion Nebula II: Gas, Dust, Proplyds and
... Orion Nebula and the Orion Nebula Cluster (ONC). The recently formed hot stars of the ONC photoionize the surrounding gas. The gas is only partially confined by overlying neutral material, resulting in an ionization front developing on the face of the molecular cloud. The shock produced by the ioniz ...
... Orion Nebula and the Orion Nebula Cluster (ONC). The recently formed hot stars of the ONC photoionize the surrounding gas. The gas is only partially confined by overlying neutral material, resulting in an ionization front developing on the face of the molecular cloud. The shock produced by the ioniz ...
The VIMOS Ultra-Deep Survey (VUDS): Fast Increase in the Fraction
... determination relies on the strong assumption that the contamination by low–z interlopers and incompleteness are fully understood and well controlled. The numerator of the fraction is the number of the LBGs that are observed with spectroscopy, and for which a strong Lyα rest–frame Equivalent Width ( ...
... determination relies on the strong assumption that the contamination by low–z interlopers and incompleteness are fully understood and well controlled. The numerator of the fraction is the number of the LBGs that are observed with spectroscopy, and for which a strong Lyα rest–frame Equivalent Width ( ...
Galaxy Assembly through Mergers
... way. I imagine that putting up with me when I started rambling about galaxies was sometimes not easy, but you always listened. I treasure how you always found a way to make me smile and a word to comfort me. Thank you for being my safe haven. My friends have been the backbone of my life, especially ...
... way. I imagine that putting up with me when I started rambling about galaxies was sometimes not easy, but you always listened. I treasure how you always found a way to make me smile and a word to comfort me. Thank you for being my safe haven. My friends have been the backbone of my life, especially ...
- REAL-J
... Change of VV Cephei : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 1 { 4 4680 IGOR M. VOLKOV, KH.F. KHALIULLIN: The Revision of Apsidal Motion in V541 Cyg: no Discrepancy with Theory : : : : : : : : : : : : : : : : : : : : : : : : : : : : : ...
... Change of VV Cephei : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 1 { 4 4680 IGOR M. VOLKOV, KH.F. KHALIULLIN: The Revision of Apsidal Motion in V541 Cyg: no Discrepancy with Theory : : : : : : : : : : : : : : : : : : : : : : : : : : : : : ...
Local Universe Supernovae and Their Host Galaxies
... Observational properties •NOT homogeneous • show H, He, O, Ca …... • from small to huge radio and X-ray emission Interpretation: The core collapse in massive • occur only (!!) stars in spiral (M≥8Mgalaxies endare of aassociated series central ) at theand with star forming nuclear regions burnings w ...
... Observational properties •NOT homogeneous • show H, He, O, Ca …... • from small to huge radio and X-ray emission Interpretation: The core collapse in massive • occur only (!!) stars in spiral (M≥8Mgalaxies endare of aassociated series central ) at theand with star forming nuclear regions burnings w ...
PPT - IAC
... The first extensive CCD morphological studies had appeared: Jewitt et al 1986 ApJ 302, 727 44 PNe (haloes) Chu et al. 1987 ApJS 64, 529 ~100 PNe (multiple-shells) Balick 1987 AJ 94, 671 51 PNe and a morphological sequence (round elliptical butterfly ) linked with the Generalised Interacting Stel ...
... The first extensive CCD morphological studies had appeared: Jewitt et al 1986 ApJ 302, 727 44 PNe (haloes) Chu et al. 1987 ApJS 64, 529 ~100 PNe (multiple-shells) Balick 1987 AJ 94, 671 51 PNe and a morphological sequence (round elliptical butterfly ) linked with the Generalised Interacting Stel ...
Observed emission rates in sprite streamer heads
... we will treat them as point sources. We further note that Gaussian profiles, which fit our streamer head observations well, also fit stars [Keyes, 1971] and are used for that purpose in many astronomical software packages. To obtain brightness the total emission from the streamer head will be derive ...
... we will treat them as point sources. We further note that Gaussian profiles, which fit our streamer head observations well, also fit stars [Keyes, 1971] and are used for that purpose in many astronomical software packages. To obtain brightness the total emission from the streamer head will be derive ...
relative age difference between the metal
... than that of M92 if the absolute age of M92 is taken to be 14 Gyr. This relative age difference between M53 and M92 causes slight differences in the horizontal-branch morphology of these two GCs. Key words: globular clusters: individual: M53, M92 — Hertzsprung-Russell and C-M diagrams — stars: evolu ...
... than that of M92 if the absolute age of M92 is taken to be 14 Gyr. This relative age difference between M53 and M92 causes slight differences in the horizontal-branch morphology of these two GCs. Key words: globular clusters: individual: M53, M92 — Hertzsprung-Russell and C-M diagrams — stars: evolu ...
Thesis
... to their relatively easy detection at every redshift. Since stars form out of cold and dense gas, a comprehensive model for galaxy evolution should explain any observed connection between SFR and the amount and properties of the molecular gas of the interstellar medium (ISM). In proposed models of t ...
... to their relatively easy detection at every redshift. Since stars form out of cold and dense gas, a comprehensive model for galaxy evolution should explain any observed connection between SFR and the amount and properties of the molecular gas of the interstellar medium (ISM). In proposed models of t ...
Contents - arXiv.org
... contains physical information about the lensing system, albeit in a degenerate combination. Assuming that the source distance Ds can be determined from its properties (membership in a stellar system, spectral type and apparent magnitude), we are left with three physical parameters, lens mass M , len ...
... contains physical information about the lensing system, albeit in a degenerate combination. Assuming that the source distance Ds can be determined from its properties (membership in a stellar system, spectral type and apparent magnitude), we are left with three physical parameters, lens mass M , len ...
Lithium abundances in nearby FGK dwarf and subgiant stars
... but an overall picture still needs to be drawn from the wealth of available data. Recently, Ramı́rez et al. (2007) have extended their high resolution spectroscopic study of nearby stars from about 500 to 800 objects (Ramı́rez, Allende Prieto, & Lambert, in preparation, hereafter RAL). Their data ar ...
... but an overall picture still needs to be drawn from the wealth of available data. Recently, Ramı́rez et al. (2007) have extended their high resolution spectroscopic study of nearby stars from about 500 to 800 objects (Ramı́rez, Allende Prieto, & Lambert, in preparation, hereafter RAL). Their data ar ...
Lya escape from z~ 0.03 star-forming galaxies: the dominant role of
... (Osterbrock & Ferland 2006), and the Lyα equivalent width, EW (Lyα), is expected to be in the range 100 − 300 Å for metallicities between Z = 0.020 − 0.004, a normal initial mass function, a constant star formation rate of 1 M⊙ /yr−1 , and ages below 10 Myr (Verhamme et al. 2008). In the case of a ...
... (Osterbrock & Ferland 2006), and the Lyα equivalent width, EW (Lyα), is expected to be in the range 100 − 300 Å for metallicities between Z = 0.020 − 0.004, a normal initial mass function, a constant star formation rate of 1 M⊙ /yr−1 , and ages below 10 Myr (Verhamme et al. 2008). In the case of a ...
Full Text
... Het begint al bij de keuze van het type gerecht. Je laat je leiden door je eigen smaak, maar ook het enthousiasme van anderen kan je al op voorhand doen watertanden. Christoffel, hierin speelde je een uitermate belangrijke rol. Het enthousiasme waarmee je de lessen inleiding tot de sterrenkunde op d ...
... Het begint al bij de keuze van het type gerecht. Je laat je leiden door je eigen smaak, maar ook het enthousiasme van anderen kan je al op voorhand doen watertanden. Christoffel, hierin speelde je een uitermate belangrijke rol. Het enthousiasme waarmee je de lessen inleiding tot de sterrenkunde op d ...
Cosmic distance ladder
The cosmic distance ladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to celestial objects. A real direct distance measurement of an astronomical object is possible only for those objects that are ""close enough"" (within about a thousand parsecs) to Earth. The techniques for determining distances to more distant objects are all based on various measured correlations between methods that work at close distances and methods that work at larger distances. Several methods rely on a standard candle, which is an astronomical object that has a known luminosity.The ladder analogy arises because no one technique can measure distances at all ranges encountered in astronomy. Instead, one method can be used to measure nearby distances, a second can be used to measure nearby to intermediate distances, and so on. Each rung of the ladder provides information that can be used to determine the distances at the next higher rung.