The recent star-formation history of the Large and Small Magellanic
... coupled. They found a quiescent epoch from 12 to 5 Gyr ago and star-formation peaks at 2 Gyr, 500 Myr, 100 Myr, and 12 Myr. The study of the spatial distribution of clusters as well as starformation rates are also equally interesting. A study of the distribution of the bar cluster population in the ...
... coupled. They found a quiescent epoch from 12 to 5 Gyr ago and star-formation peaks at 2 Gyr, 500 Myr, 100 Myr, and 12 Myr. The study of the spatial distribution of clusters as well as starformation rates are also equally interesting. A study of the distribution of the bar cluster population in the ...
PDF hosted at the Radboud Repository of the Radboud University
... Single carbon-oxygen white dwarfs are not formed at masses larger than 1.2M , and the majority are born at masses considerably lower than that, typically around ∼ 0.6M (Homeier et al. 1998). However, type Ia supernovae likely originate from carbon-oxygen white dwarfs at or close to the Chandrasekh ...
... Single carbon-oxygen white dwarfs are not formed at masses larger than 1.2M , and the majority are born at masses considerably lower than that, typically around ∼ 0.6M (Homeier et al. 1998). However, type Ia supernovae likely originate from carbon-oxygen white dwarfs at or close to the Chandrasekh ...
Properties of White Dwarfs, Teacher Guide
... Some background: Sirius is a nearby star – only 9 light-years away. All stars in our Galaxy orbit the Galactic barycenter, so they are all moving. Astronomers detect and track the motion of stars relative to our Sun. There are two motions that can be measured: radial velocity (in the line of sight) ...
... Some background: Sirius is a nearby star – only 9 light-years away. All stars in our Galaxy orbit the Galactic barycenter, so they are all moving. Astronomers detect and track the motion of stars relative to our Sun. There are two motions that can be measured: radial velocity (in the line of sight) ...
ROSAT Ian R. Stevens* and David K. Strickland*
... We note that the detection of a broad He II l4686 feature can be difficult even with high signal-to-noise ratio (S/N) data. This does mean that our sample of WR galaxies will tend to be rather heterogenous. Future studies will have to focus on broader samples of starburst galaxies and starburst regi ...
... We note that the detection of a broad He II l4686 feature can be difficult even with high signal-to-noise ratio (S/N) data. This does mean that our sample of WR galaxies will tend to be rather heterogenous. Future studies will have to focus on broader samples of starburst galaxies and starburst regi ...
Time Variation of Kepler Transits Induced By Stellar Rotating Spots
... to the stellar rotation. Assuming a single spot darker than the stellar disc, spot crossing by the planet can induce measured positive (negative) TTV, if the crossing occurs in the first (second) half of the transit. On the other hand, the motion of the spot towards (away from) the center of the ste ...
... to the stellar rotation. Assuming a single spot darker than the stellar disc, spot crossing by the planet can induce measured positive (negative) TTV, if the crossing occurs in the first (second) half of the transit. On the other hand, the motion of the spot towards (away from) the center of the ste ...
Gent 12 - Newcastle University eTheses
... horizontally 1×1 kpc2 and vertically 2 kpc, symmetric about the galactic mid-plane. They routinely span gas number densities 10−5 –102 cm−3 , temperatures 10–108 K, speeds up to 103 km s−1 and Mach number up to 25. Radiative cooling is applied from two widely adopted parameterizations, and compared ...
... horizontally 1×1 kpc2 and vertically 2 kpc, symmetric about the galactic mid-plane. They routinely span gas number densities 10−5 –102 cm−3 , temperatures 10–108 K, speeds up to 103 km s−1 and Mach number up to 25. Radiative cooling is applied from two widely adopted parameterizations, and compared ...
Tidal Effects on the Oort Cloud Comets and Dynamics of the Sun in
... The Solar System presents a complex dynamical structure and is not isolated from the Galaxy. In particular the comet reservoir of our planetary system, the Oort cloud, is extremely sensitive to the the galactic environment due to its peripheral collocation inside the Solar System. In this framework, ...
... The Solar System presents a complex dynamical structure and is not isolated from the Galaxy. In particular the comet reservoir of our planetary system, the Oort cloud, is extremely sensitive to the the galactic environment due to its peripheral collocation inside the Solar System. In this framework, ...
Unfolding the Milky Way bulge - International Max Planck Research
... 5.7 Difference between the AKs values obtained in this work and those of Schlegel 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 ...
... 5.7 Difference between the AKs values obtained in this work and those of Schlegel 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 mass distribution and lifetime of prestellar cores in perseus
... very red sources that are likely to be embedded in the millimeter cores detected with Bolocam. For the following we will use the term ‘‘candidate protostar’’ in general to encompass candidate Class 0 and Class I objects (André et al. 1993; Lada & Wilking 1984), although more evolved sources may be ...
... very red sources that are likely to be embedded in the millimeter cores detected with Bolocam. For the following we will use the term ‘‘candidate protostar’’ in general to encompass candidate Class 0 and Class I objects (André et al. 1993; Lada & Wilking 1984), although more evolved sources may be ...
Galaxies - hwchemistry
... • To hold stars in such small, short-period orbits, the centers of galaxies must contain masses of a million to a few billion solar masses. • Yet, no object is visible. – The evidence seems to require that the nuclei of galaxies contain supermassive black holes. – You have learned that Milky Way con ...
... • To hold stars in such small, short-period orbits, the centers of galaxies must contain masses of a million to a few billion solar masses. • Yet, no object is visible. – The evidence seems to require that the nuclei of galaxies contain supermassive black holes. – You have learned that Milky Way con ...
MULTI-FREQUENCY TIME VARIABILITY OF ACTIVE GALACTIC NUCLEI RITABAN CHATTERJEE
... In an active galactic nucleus (AGN), the central region of a galaxy is brighter than the rest of the galaxy and sometimes ∼10,000 times as bright as an average galaxy. The extremely high luminosities of AGNs are thought to be produced by the accretion of matter onto a supermassive black hole (1 mill ...
... In an active galactic nucleus (AGN), the central region of a galaxy is brighter than the rest of the galaxy and sometimes ∼10,000 times as bright as an average galaxy. The extremely high luminosities of AGNs are thought to be produced by the accretion of matter onto a supermassive black hole (1 mill ...
Cepheids
... the first recognized star of this class • Young (< 100 Myr) and massive (3-8 MSun) bright (MV up to -7m) radially pulsating variable stars with strongly regular brightness change (light curves) • Typical Periods of the pulsations: from ~1-3 to ~100 days (follow from P ~ (Gρ)-1/2 expression for free ...
... the first recognized star of this class • Young (< 100 Myr) and massive (3-8 MSun) bright (MV up to -7m) radially pulsating variable stars with strongly regular brightness change (light curves) • Typical Periods of the pulsations: from ~1-3 to ~100 days (follow from P ~ (Gρ)-1/2 expression for free ...
Niraj D. Welikala Thesis - D-Scholarship@Pitt
... and on these scales the density fluctuations are small in size (rms fluctuations of the order ∼ 0.1 at 1 Gpc). However, on scales of the order of 10 Mpc, the density fluctuations are large (∼ 1). The most apparent overdensities are therefore on small scales, less than 10 Mpc which are the typical sc ...
... and on these scales the density fluctuations are small in size (rms fluctuations of the order ∼ 0.1 at 1 Gpc). However, on scales of the order of 10 Mpc, the density fluctuations are large (∼ 1). The most apparent overdensities are therefore on small scales, less than 10 Mpc which are the typical sc ...
High-mass X-ray Binaries: X-raying the winds Ángel Giménez García
... Las líneas espectrales que frecuentemente se observan en HMXBs alrededor de los 67 keV es lo que comúnmente se denomina complejo del Fe. Los rasgos espectrales en este intervalo de energía se atribuyen a líneas de emisión del Fe, las cuales pueden estar producidas por fluorescencia o por recombinaci ...
... Las líneas espectrales que frecuentemente se observan en HMXBs alrededor de los 67 keV es lo que comúnmente se denomina complejo del Fe. Los rasgos espectrales en este intervalo de energía se atribuyen a líneas de emisión del Fe, las cuales pueden estar producidas por fluorescencia o por recombinaci ...
The keV–TeV connection in gamma-ray binaries
... The gamma-ray emission from astrophysical sources is arguably different from the emission in the rest of the electromagnetic spectrum because it cannot be generated by hot matter. High energy gamma radiation is therefore an indication that non-thermal processes, which are able to concentrate a large ...
... The gamma-ray emission from astrophysical sources is arguably different from the emission in the rest of the electromagnetic spectrum because it cannot be generated by hot matter. High energy gamma radiation is therefore an indication that non-thermal processes, which are able to concentrate a large ...
The impact of mass-loss on the evolution and pre
... When extended blue loops or blue ward excursions are produced by enhanced mass-loss, the models predict that a majority of blue (yellow) supergiants are post RSG objects. These post RSG stars are predicted to show much smaller surface rotational velocities than similar blue supergiants on their firs ...
... When extended blue loops or blue ward excursions are produced by enhanced mass-loss, the models predict that a majority of blue (yellow) supergiants are post RSG objects. These post RSG stars are predicted to show much smaller surface rotational velocities than similar blue supergiants on their firs ...
Star formation
Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as ""stellar nurseries"" or ""star-forming regions"", collapse to form stars. As a branch of astronomy, star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process, and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation, another branch of astronomy. Star formation theory, as well as accounting for the formation of a single star, must also account for the statistics of binary stars and the initial mass function.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.