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The white dwarf cooling sequence of 47 Tucanae
... main-sequence turn-off. Finally, we find that the star formation history of the cluster is compatible with that obtained using main sequence stars, which predict the existence of two distinct populations. Conclusions. We conclude that a correct modeling of the white dwarf population of globular clus ...
... main-sequence turn-off. Finally, we find that the star formation history of the cluster is compatible with that obtained using main sequence stars, which predict the existence of two distinct populations. Conclusions. We conclude that a correct modeling of the white dwarf population of globular clus ...
elt science case
... New observational facilities in the coming decade will try to address these questions. Furthermore, new fundamental question may arise: the evidence for dark energy was found only recently, and it added a new component to the Universe, the biggest component in terms of energy density at low redshift ...
... New observational facilities in the coming decade will try to address these questions. Furthermore, new fundamental question may arise: the evidence for dark energy was found only recently, and it added a new component to the Universe, the biggest component in terms of energy density at low redshift ...
A 6% measurement of the Hubble parameter at ζ ∼ 0.45: direct
... and accurate cosmic chronometers using passively evolving selected galaxies. Recently, the independent analysis of SDSS-DR8 luminous red galaxies by ref. [33] has confirmed that massive and quiescent galaxies can be reliably used as cosmic chronometers. It is important to underline that the main str ...
... and accurate cosmic chronometers using passively evolving selected galaxies. Recently, the independent analysis of SDSS-DR8 luminous red galaxies by ref. [33] has confirmed that massive and quiescent galaxies can be reliably used as cosmic chronometers. It is important to underline that the main str ...
AN INITIAL MASS FUNCTION STUDY OF THE DWARF Please share
... 2.7 ± 0.4 × 104 M (MacKenty et al. 2000; Leitherer et al. 1996) using a Salpeter IMF between 1 and 100 M . Our best estimate, from the best fit from both SLUG and SB99, is 4.2 and 4.8 Myr, respectively, with a corresponding best-fit mass of 9.3 ± 4 and 9.7 ± 3 × 104 M , which is consistent with t ...
... 2.7 ± 0.4 × 104 M (MacKenty et al. 2000; Leitherer et al. 1996) using a Salpeter IMF between 1 and 100 M . Our best estimate, from the best fit from both SLUG and SB99, is 4.2 and 4.8 Myr, respectively, with a corresponding best-fit mass of 9.3 ± 4 and 9.7 ± 3 × 104 M , which is consistent with t ...
Toward $ ab\, initio $ extremely metal poor stars
... We ray-traced ionizing radiation from the star particle to compute the dynamical expansion of the HII region over the star’s lifetime of 3.5 Myr. The ionization state and temperature along each separate ray in the HII region interior were evaluated by interpolating from values pre-computed with the ...
... We ray-traced ionizing radiation from the star particle to compute the dynamical expansion of the HII region over the star’s lifetime of 3.5 Myr. The ionization state and temperature along each separate ray in the HII region interior were evaluated by interpolating from values pre-computed with the ...
Annual Report 2012 - Max Planck Institute for Astrophysics
... directorship of Ludwig Biermann. It was first es- institution of similar size. tablished as an offshoot of the Max-Planck-Institut In recent years, activities at the MPA have difür Physik, which at that time had just moved from versified. They now address a much broader range Göttingen to Munich. In 19 ...
... directorship of Ludwig Biermann. It was first es- institution of similar size. tablished as an offshoot of the Max-Planck-Institut In recent years, activities at the MPA have difür Physik, which at that time had just moved from versified. They now address a much broader range Göttingen to Munich. In 19 ...
The Formation of a Realistic Disk Galaxy in Lambda Dominated
... model can be characterized in terms of the reduction in fluctuations on dwarf-galaxy scales. For our choice of 2 keV neutrinos, the fluctuations on scales smaller than 109.5 M are vastly reduced. We retained the phases of the waves that describe the initial density field. These allowed us to discr ...
... model can be characterized in terms of the reduction in fluctuations on dwarf-galaxy scales. For our choice of 2 keV neutrinos, the fluctuations on scales smaller than 109.5 M are vastly reduced. We retained the phases of the waves that describe the initial density field. These allowed us to discr ...
The Blue Stragglers in M67 and Single
... of stellar clusters cannot include all the light of a stellar population. 3.1. Fitting the Observed SEDs for Brightest Members For all the luminous high membership probability stragglers, among which 24 are classiÐed as blue stragglers (more luminous and bluer than the main-sequence turno† point) as ...
... of stellar clusters cannot include all the light of a stellar population. 3.1. Fitting the Observed SEDs for Brightest Members For all the luminous high membership probability stragglers, among which 24 are classiÐed as blue stragglers (more luminous and bluer than the main-sequence turno† point) as ...
GOMOS data characterisation and error estimation
... of the stars to obtain a good global and temporal coverage. Compared to the Sun, stars are point-like sources, and thus provide an excellent pointing information. The disadvantage compared to the solar occultation is the low signal-to-noise ratio. GOMOS is following about 180 different stars while t ...
... of the stars to obtain a good global and temporal coverage. Compared to the Sun, stars are point-like sources, and thus provide an excellent pointing information. The disadvantage compared to the solar occultation is the low signal-to-noise ratio. GOMOS is following about 180 different stars while t ...
Chemical evolution models for the dwarf spheroidal galaxies Leo 1
... The dSph galaxies Leo 1 and Leo 2 are excellent objects to perform the analysis of isolated systems. They are among the most distant dSph satellites in the Milky Way system (∼270 Kpc and ∼204 Kpc, respectively) and probably free from any presentday dynamical influence from the Milky Way. To understa ...
... The dSph galaxies Leo 1 and Leo 2 are excellent objects to perform the analysis of isolated systems. They are among the most distant dSph satellites in the Milky Way system (∼270 Kpc and ∼204 Kpc, respectively) and probably free from any presentday dynamical influence from the Milky Way. To understa ...
outer-disk populations in ngc 7793: evidence for stellar
... A potentially better analog to NGC 7793 is the equivalent simulation generated to model NGC 300 in Gogarten et al. (2010). This galaxy is another member of the Sculptor Group with mass similar to NGC 7793, although the star formation history (SFH) of the system and the lack of a disk break indicate ...
... A potentially better analog to NGC 7793 is the equivalent simulation generated to model NGC 300 in Gogarten et al. (2010). This galaxy is another member of the Sculptor Group with mass similar to NGC 7793, although the star formation history (SFH) of the system and the lack of a disk break indicate ...
Constraining the Warm Dark Matter Particle Mass through Ultra
... Matter (WDM) particle mass mX and compare it with the abundance of ultra-faint galaxies derived from the deepest UV luminosity function available so far at redshift z ≈ 2. The magnitude limit MUV = −13 reached by such observations allows us to probe the WDM mass functions down to scales close to or ...
... Matter (WDM) particle mass mX and compare it with the abundance of ultra-faint galaxies derived from the deepest UV luminosity function available so far at redshift z ≈ 2. The magnitude limit MUV = −13 reached by such observations allows us to probe the WDM mass functions down to scales close to or ...
Title The Correlation between Dispersion Measure and X
... ionized by UV radiation from hot O or B type stars and the shock-heated interior of supernova remnants (SNRs). These sources can contribute significant DM up to a few hundred parsecs per cubic centimeter. At X-ray energies, photons are absorbed mostly by heavy elements in the interstellar gas due to ...
... ionized by UV radiation from hot O or B type stars and the shock-heated interior of supernova remnants (SNRs). These sources can contribute significant DM up to a few hundred parsecs per cubic centimeter. At X-ray energies, photons are absorbed mostly by heavy elements in the interstellar gas due to ...
Deep $ I $-band imaging of $ z=\ mathsf {5.99} $ quasar
... extended X-ray source is statistically significant. It is comprised of 7 counts, which exceeds by far the expected background flux of 0.13 counts. He estimated that the probability of observing 7 photons in a 10 arcsec2 box is 5.8×10−9. What are the chances of observing a galaxy with the given magni ...
... extended X-ray source is statistically significant. It is comprised of 7 counts, which exceeds by far the expected background flux of 0.13 counts. He estimated that the probability of observing 7 photons in a 10 arcsec2 box is 5.8×10−9. What are the chances of observing a galaxy with the given magni ...
Article PDF - IOPscience
... primary concern in astronomy today is determining how galaxies have formed, evolved, and are evolving. The limited progress in our understanding of this is due in no small part to our inability to identify distinct galaxy populations over a range of redshifts based on their fundamental features. If ...
... primary concern in astronomy today is determining how galaxies have formed, evolved, and are evolving. The limited progress in our understanding of this is due in no small part to our inability to identify distinct galaxy populations over a range of redshifts based on their fundamental features. If ...
Molecular Cooling Rates (Neufeld, Lepp and Melnick 1995)
... produce silicate dusts: prominent 9.7 micron emission features Toward the end of the AGB phase, these stars may become carbon-rich and produce carbonaceous dust ...
... produce silicate dusts: prominent 9.7 micron emission features Toward the end of the AGB phase, these stars may become carbon-rich and produce carbonaceous dust ...
an introduction to astrophysics
... Physical quantities, such as mass and position, are commonly represented by algebraic symbols such as m or x. Whenever such symbols are used, it should be recalled that they comprise two parts: a numerical value and an appropriate unit of measurement, such as m = 3.4 kg or x = 6.0 m. The units will ...
... Physical quantities, such as mass and position, are commonly represented by algebraic symbols such as m or x. Whenever such symbols are used, it should be recalled that they comprise two parts: a numerical value and an appropriate unit of measurement, such as m = 3.4 kg or x = 6.0 m. The units will ...
How Massive Single Stars End Their Life - TigerPrints
... and composition at birth and by the history of its mass loss. For single stars, mass loss occurs as a result of stellar winds, for which there exist semiempirical estimates. Thus, within currently existing paradigms for the explosion, the fate of a star of given initial mass and composition is deter ...
... and composition at birth and by the history of its mass loss. For single stars, mass loss occurs as a result of stellar winds, for which there exist semiempirical estimates. Thus, within currently existing paradigms for the explosion, the fate of a star of given initial mass and composition is deter ...
BARS FROM THE INSIDE OUT: AN HST STUDY OF THEIR DUSTY
... strongly barred type and SB(r) the weakest. However, the SB(s) sample does . If only galaxies with include more galaxies with late type and large are included (the range of the SB(r) sample), the mean value of for the SB(s) class decreases to 0.35 (11 galaxies). It would be valuable to revisit the S ...
... strongly barred type and SB(r) the weakest. However, the SB(s) sample does . If only galaxies with include more galaxies with late type and large are included (the range of the SB(r) sample), the mean value of for the SB(s) class decreases to 0.35 (11 galaxies). It would be valuable to revisit the S ...
Spectroscopic Binaries - Thüringer Landessternwarte Tautenburg
... • Spectroscopic binaries are in general important for the determination of fundamental stellar parameters. More important: SB2 stars. Most important: eclipsing SB2 stars. • Composite spectra require, besides the determination of the orbit, the decomposition of the spectra of the components • The inv ...
... • Spectroscopic binaries are in general important for the determination of fundamental stellar parameters. More important: SB2 stars. Most important: eclipsing SB2 stars. • Composite spectra require, besides the determination of the orbit, the decomposition of the spectra of the components • The inv ...
Lithium abundances for 185 main-sequence stars
... resolution spectra of 130 stars and a reanalysis of data for 55 stars from Lambert et al. (1991). The survey takes advantage of improved photometric and spectroscopic determinations of effective temperature and metallicity as well as mass and age derived from Hipparcos absolute magnitudes, offering ...
... resolution spectra of 130 stars and a reanalysis of data for 55 stars from Lambert et al. (1991). The survey takes advantage of improved photometric and spectroscopic determinations of effective temperature and metallicity as well as mass and age derived from Hipparcos absolute magnitudes, offering ...
stellar diameters and temperatures. iii. main-sequence a, f, g
... Cousins (RC IC ), Kron (RK IK ), Sloan (griz), and WISE (W3 W4 ) photometric systems. These relations have an average standard deviation of ∼3% and are valid for stars with spectral types A0–M4. To derive even more accurate relations for Sun-like stars, we also determined these temperature relations ...
... Cousins (RC IC ), Kron (RK IK ), Sloan (griz), and WISE (W3 W4 ) photometric systems. These relations have an average standard deviation of ∼3% and are valid for stars with spectral types A0–M4. To derive even more accurate relations for Sun-like stars, we also determined these temperature relations ...
Active Galactic Nuclei at kiloparsec scales and their cosmological
... found that the incidence of disturbed morphologies is not significantly enhanced over the general population of galaxies (e.g., [12]), leaving secular processes as the most likely triggering mechanism at such luminosities [48]. Thus, it seems that AGN of different luminosities are triggered in diffe ...
... found that the incidence of disturbed morphologies is not significantly enhanced over the general population of galaxies (e.g., [12]), leaving secular processes as the most likely triggering mechanism at such luminosities [48]. Thus, it seems that AGN of different luminosities are triggered in diffe ...
Article PDF - IOPscience
... (PS1) 3p survey offers multi-band, multi-epoch, precise photometry across much of the sky, but a robust identification of RR Lyrae stars in this data set poses a challenge, given PS1ʼs sparse, asynchronous multi-band light curves (12 epochs in each of five bands, taken over a 4.5 year period). We pre ...
... (PS1) 3p survey offers multi-band, multi-epoch, precise photometry across much of the sky, but a robust identification of RR Lyrae stars in this data set poses a challenge, given PS1ʼs sparse, asynchronous multi-band light curves (12 epochs in each of five bands, taken over a 4.5 year period). We pre ...
properties of the high area-to-mass ratio space debris population in
... [2]. The DISCOS catalogue essentially contains the unclassified USSPACECOM space object catalogue. ‘Uncorrelated’ detections correspond to objects which were not found in DISCOS. The solid line indicates the system sensitivity as determined from independent calibration measurements. All magnitudes h ...
... [2]. The DISCOS catalogue essentially contains the unclassified USSPACECOM space object catalogue. ‘Uncorrelated’ detections correspond to objects which were not found in DISCOS. The solid line indicates the system sensitivity as determined from independent calibration measurements. All magnitudes h ...
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.