WTS-1 b: the fi rst extrasolar planet detected in the WFCAM Transit
... Example of the telluric lines in the observed spectra . TELL REMOV: telluric-free spectra . . . . . . . . . . . . CRs filtered spectra with COSMIC REMOV . . . . . . . Correlation function computed with rv.fxcor . . . . All the 64 raw RV values related to each single order Raw RV values related to al ...
... Example of the telluric lines in the observed spectra . TELL REMOV: telluric-free spectra . . . . . . . . . . . . CRs filtered spectra with COSMIC REMOV . . . . . . . Correlation function computed with rv.fxcor . . . . All the 64 raw RV values related to each single order Raw RV values related to al ...
The UKIRT Infrared Deep Sky Survey ZY JHK Photometric System
... shallow survey that will cover 4000 deg2 from within the footprint of the SDSS, in the four bands Y JHK. The depth, K = 18.4, will be some 3 mag. deeper than 2MASS. The Deep Extragalactic Survey (DXS), is of intermediate depth, K = 21.0, and will cover 35 deg2 in J and K. The deepest survey is the U ...
... shallow survey that will cover 4000 deg2 from within the footprint of the SDSS, in the four bands Y JHK. The depth, K = 18.4, will be some 3 mag. deeper than 2MASS. The Deep Extragalactic Survey (DXS), is of intermediate depth, K = 21.0, and will cover 35 deg2 in J and K. The deepest survey is the U ...
The effect of dark matter capture on binary stars
... This work has led to a number of interesting conclusions: (1) Binary stars, due to their orbital motion, can produce more collisions that result in initially bound orbits. However, the gravitational interaction with two masses quickly scatters nearly all WIMPs out of the system. The few that survive ...
... This work has led to a number of interesting conclusions: (1) Binary stars, due to their orbital motion, can produce more collisions that result in initially bound orbits. However, the gravitational interaction with two masses quickly scatters nearly all WIMPs out of the system. The few that survive ...
Physical Processes in the Interstellar Medium
... converging flows generate regions of high density. These localized enhancements can be sufficiently large for gravitational instability to set in. The subsequent evolution now depends on the competition between collapse and dispersal. The same random flows that create high-density regions in the fir ...
... converging flows generate regions of high density. These localized enhancements can be sufficiently large for gravitational instability to set in. The subsequent evolution now depends on the competition between collapse and dispersal. The same random flows that create high-density regions in the fir ...
Models for circumstellar nebulae around red and blue supergiants
... 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 form of stellar wind. Depending on the initial mass, stars have different properties during their MS stage. If the main sequenc ...
... 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 form of stellar wind. Depending on the initial mass, stars have different properties during their MS stage. If the main sequenc ...
Evidence of suppression of star formation by quasar
... then massive, early-type galaxies will be gas-poor and passively aging, while younger galaxies, typically lower-mass, late-type galaxies will still have enough star formation material and appear much bluer. Generally, two modes of such AGN feedback have been identified. During the kinetic mode, also ...
... then massive, early-type galaxies will be gas-poor and passively aging, while younger galaxies, typically lower-mass, late-type galaxies will still have enough star formation material and appear much bluer. Generally, two modes of such AGN feedback have been identified. During the kinetic mode, also ...
Improving Galactic Center Astrometry by Reducing the Effects of
... Observations of M92 were made from 2007 June to 2009 May using the AO system on the W. M. Keck II 10 m telescope with the facility near-infrared camera NIRC2 (PI: K. Matthews). Aside from the 2007 July data set, these observations were obtained upon completion of our primary science program for the ...
... Observations of M92 were made from 2007 June to 2009 May using the AO system on the W. M. Keck II 10 m telescope with the facility near-infrared camera NIRC2 (PI: K. Matthews). Aside from the 2007 July data set, these observations were obtained upon completion of our primary science program for the ...
The birth rate of subluminous and overluminous type Ia supernovae
... Pakmor et al. (2010) also made a BPS study about 1991bg-like events based on their merging model from equal-mass DD systems, where the components are both massive and the mass ratio is only slightly less than one, i.e. the primary masses are in the range of 0.85–1.05 M with a mass ratio of 0.9 < q ...
... Pakmor et al. (2010) also made a BPS study about 1991bg-like events based on their merging model from equal-mass DD systems, where the components are both massive and the mass ratio is only slightly less than one, i.e. the primary masses are in the range of 0.85–1.05 M with a mass ratio of 0.9 < q ...
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 ...
the optical colors of giant elliptical galaxies and their metal
... elliptical galaxies and their metal-rich GCs are known to exhibit supersolar α/Fe ratios (e.g., Trager et al. 2000; Puzia et al. 2006). Figure 3 shows Hβ versus [MgFe]′ for the GCs in NGC 4472 from Cohen et al. (2003), subdivided into blue and red GCs. As the uncertainties are significant for the in ...
... elliptical galaxies and their metal-rich GCs are known to exhibit supersolar α/Fe ratios (e.g., Trager et al. 2000; Puzia et al. 2006). Figure 3 shows Hβ versus [MgFe]′ for the GCs in NGC 4472 from Cohen et al. (2003), subdivided into blue and red GCs. As the uncertainties are significant for the in ...
Libra - www.BahaiStudies.net
... Iota Librae is a complex multiple star, 377 light-years from Earth, with both optical and true binary components. The Visible at latitudes between +65° and −90°. primary appears as a blue-white star of magnitude 4.5; it is a Best visible at 21:00 (9 p.m.) during the month of June. binary star indivi ...
... Iota Librae is a complex multiple star, 377 light-years from Earth, with both optical and true binary components. The Visible at latitudes between +65° and −90°. primary appears as a blue-white star of magnitude 4.5; it is a Best visible at 21:00 (9 p.m.) during the month of June. binary star indivi ...
Here
... n(cm−3 ) is the average H2 number density in the clouds, and Tb (K) is the intrinsic (rest-frame) brightness temperature of the CO line. Mgas is in M⊙ and L′CO is in K km s−1 pc2 (Dickman, Snell & Schloerb 1987; Solomon et al. 1987). This is the physical basis for deriving gas mass from CO luminosit ...
... n(cm−3 ) is the average H2 number density in the clouds, and Tb (K) is the intrinsic (rest-frame) brightness temperature of the CO line. Mgas is in M⊙ and L′CO is in K km s−1 pc2 (Dickman, Snell & Schloerb 1987; Solomon et al. 1987). This is the physical basis for deriving gas mass from CO luminosit ...
doctoral thesis (Dissertation)
... molecular clouds. Along the galactic equator these clouds are seen as black spots, obscuring the light of background stars. They are relatively cool with temperatures of ten Kelvin in the interior to thousand Kelvin at the outer boundaries, where they are illuminated by other stars. One example of s ...
... molecular clouds. Along the galactic equator these clouds are seen as black spots, obscuring the light of background stars. They are relatively cool with temperatures of ten Kelvin in the interior to thousand Kelvin at the outer boundaries, where they are illuminated by other stars. One example of s ...
THE GREAT AGN DEBATE `AGN VS STARBURST
... gas and cause it to fall inward, greatly accelerating the normal process by which interstellar clouds collapse and form stars’ (Weaver, 2007) When quasars we discovered in 1963 scientists struggled to explain these bright and very distant objects. One of the first theories to gain momentum was the s ...
... gas and cause it to fall inward, greatly accelerating the normal process by which interstellar clouds collapse and form stars’ (Weaver, 2007) When quasars we discovered in 1963 scientists struggled to explain these bright and very distant objects. One of the first theories to gain momentum was the s ...
Oxygen, magnesium and chromium isotopic ratios of
... Abstract—Oxygen isotopic measurements of 20 spinel (MgAl2O4) grains from the CM2 meteorite Murray (average diameter 0.45 m), seven spinel grains from ordinary chondrites (OC, 0.3 to 2 m) and three spinel grains from the CI chondrite Orgueil (0.4 to 0.7 m) have revealed large anomalies and thus es ...
... Abstract—Oxygen isotopic measurements of 20 spinel (MgAl2O4) grains from the CM2 meteorite Murray (average diameter 0.45 m), seven spinel grains from ordinary chondrites (OC, 0.3 to 2 m) and three spinel grains from the CI chondrite Orgueil (0.4 to 0.7 m) have revealed large anomalies and thus es ...
Star formation in luminous quasar host galaxies at z = 1–2 ⋆
... A key observable is the level of star formation present in quasar host galaxies when compared to inactive galaxies of the same mass at the same epoch. In this paper, we aim to explore the level of star formation in our z ≈ 1 and 2 quasar samples, originally imaged in the rest-frame optical using HST ...
... A key observable is the level of star formation present in quasar host galaxies when compared to inactive galaxies of the same mass at the same epoch. In this paper, we aim to explore the level of star formation in our z ≈ 1 and 2 quasar samples, originally imaged in the rest-frame optical using HST ...
Astronomy Astrophysics Spectral energy distributions of an AKARI-SDSS-GALEX sample of galaxies
... parameter is calculated and the estimated value of the parameter and its error correspond to the mean and standard deviation of this distribution. Models are generated with a stellar population synthesis code, assuming a particular star formation history and dust attenuation scenario. The energetic ...
... parameter is calculated and the estimated value of the parameter and its error correspond to the mean and standard deviation of this distribution. Models are generated with a stellar population synthesis code, assuming a particular star formation history and dust attenuation scenario. The energetic ...
SDSS J105754. 25+ 275947.5: a period
... The white dwarf and donor masses were found to be Mw = 0.800 ± 0.015 M⊙ and Md = 0.0436 ± 0.0020 M⊙ , respectively. A temperature Tw = 13300 ± 1100 K and distance d = 367 ± 26 pc of the white dwarf were estimated through fitting model atmosphere predictions to multicolour fluxes. The mass of the whi ...
... The white dwarf and donor masses were found to be Mw = 0.800 ± 0.015 M⊙ and Md = 0.0436 ± 0.0020 M⊙ , respectively. A temperature Tw = 13300 ± 1100 K and distance d = 367 ± 26 pc of the white dwarf were estimated through fitting model atmosphere predictions to multicolour fluxes. The mass of the whi ...
The enigmatic pair of dwarf galaxies Leo IV and Leo V: coincidence
... tural properties of these newly discovered dwarf galaxies based on SDSS data have revealed that they are, as a class, more elongated than their brighter counterparts (Martin et al. 2008b), indicating that some systems may be tidally disrupted by the MW. It is as yet unclear whether these objects rep ...
... tural properties of these newly discovered dwarf galaxies based on SDSS data have revealed that they are, as a class, more elongated than their brighter counterparts (Martin et al. 2008b), indicating that some systems may be tidally disrupted by the MW. It is as yet unclear whether these objects rep ...
thesis
... impact on our understanding of the formation and evolution of stars and planetary systems. Space-based observatories, such as IRAS, ISO, and Spitzer, have opened up the infrared spectral window, which have allowed the investigation of interstellar clouds as birth-places of stars, and the study of ci ...
... impact on our understanding of the formation and evolution of stars and planetary systems. Space-based observatories, such as IRAS, ISO, and Spitzer, have opened up the infrared spectral window, which have allowed the investigation of interstellar clouds as birth-places of stars, and the study of ci ...
High energy processes in young stellar objects and high-mass X
... 4.4 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5.1 Gamma rays coming from a massive YSO . . . . . . . . . . . . . . 4.5.2 T-Tauri stars in Monoceros R2 as possible gamma- ...
... 4.4 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5.1 Gamma rays coming from a massive YSO . . . . . . . . . . . . . . 4.5.2 T-Tauri stars in Monoceros R2 as possible gamma- ...
Spiral arm structures revealed in the M31 galaxy
... to be natural within framework of magneto-gravitational instability scenario (Franco et. al. 2002, Lee et al. 2004, Mouschovias et al. 2009). If the wave extremes lie at extreme distances from the M31 plane, then the distances of their centers from the M31 plane can be estimated to be about 50–100 p ...
... to be natural within framework of magneto-gravitational instability scenario (Franco et. al. 2002, Lee et al. 2004, Mouschovias et al. 2009). If the wave extremes lie at extreme distances from the M31 plane, then the distances of their centers from the M31 plane can be estimated to be about 50–100 p ...
... the formation of a disk around these stars. Non-radial pulsations (nrp) and stellar activity of magnetic origin combined to the near break-up rotational velocity have been proposed as mechanisms that could give rise to the additional amount of momentum needed to cause mass ejection. Rivinius et al. ...
on the evolution of anomalous x-ray pulsars and soft gamma
... We show that the period clustering of anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs), their X-ray luminosities, ages, and statistics can be explained with fall back disks with large initial specific angular momentum. The disk evolution models are developed by comparison to self-s ...
... We show that the period clustering of anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs), their X-ray luminosities, ages, and statistics can be explained with fall back disks with large initial specific angular momentum. The disk evolution models are developed by comparison to self-s ...
Multiple Jets from the High-Mass (Proto) stellar Cluster AFGL5142
... Similar to other massive star forming regions (Beuther et al. 2004a,b), multiple molecular lines are detected in the AFGL 5142 region. We detect 22 spectral lines/components from 12 CO, 13 CO, C18 O, CH3 CN, CH3 OH, SO, HNCO, OCS and H13 2 CO molecules (see Table 2). The energy levels of the lines r ...
... Similar to other massive star forming regions (Beuther et al. 2004a,b), multiple molecular lines are detected in the AFGL 5142 region. We detect 22 spectral lines/components from 12 CO, 13 CO, C18 O, CH3 CN, CH3 OH, SO, HNCO, OCS and H13 2 CO molecules (see Table 2). The energy levels of the lines r ...
Main sequence
In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell. Stars on this band are known as main-sequence stars or ""dwarf"" stars.After a star has formed, it generates thermal energy in the dense core region through the nuclear fusion of hydrogen atoms into helium. During this stage of the star's lifetime, it is located along the main sequence at a position determined primarily by its mass, but also based upon its chemical composition and other factors. All main-sequence stars are in hydrostatic equilibrium, where outward thermal pressure from the hot core is balanced by the inward pressure of gravitational collapse from the overlying layers. The strong dependence of the rate of energy generation in the core on the temperature and pressure helps to sustain this balance. Energy generated at the core makes its way to the surface and is radiated away at the photosphere. The energy is carried by either radiation or convection, with the latter occurring in regions with steeper temperature gradients, higher opacity or both.The main sequence is sometimes divided into upper and lower parts, based on the dominant process that a star uses to generate energy. Stars below about 1.5 times the mass of the Sun (or 1.5 solar masses (M☉)) primarily fuse hydrogen atoms together in a series of stages to form helium, a sequence called the proton–proton chain. Above this mass, in the upper main sequence, the nuclear fusion process mainly uses atoms of carbon, nitrogen and oxygen as intermediaries in the CNO cycle that produces helium from hydrogen atoms. Main-sequence stars with more than two solar masses undergo convection in their core regions, which acts to stir up the newly created helium and maintain the proportion of fuel needed for fusion to occur. Below this mass, stars have cores that are entirely radiative with convective zones near the surface. With decreasing stellar mass, the proportion of the star forming a convective envelope steadily increases, whereas main-sequence stars below 0.4 M☉ undergo convection throughout their mass. When core convection does not occur, a helium-rich core develops surrounded by an outer layer of hydrogen.In general, the more massive a star is, the shorter its lifespan on the main sequence. After the hydrogen fuel at the core has been consumed, the star evolves away from the main sequence on the HR diagram. The behavior of a star now depends on its mass, with stars below 0.23 M☉ becoming white dwarfs directly, whereas stars with up to ten solar masses pass through a red giant stage. More massive stars can explode as a supernova, or collapse directly into a black hole.