IRC −10414: a bow-shock-producing red supergiant star
... Most runaway OB stars, like the majority of massive stars residing in their parent clusters, go through the red supergiant (RSG) phase during their lifetimes. Nonetheless, although many dozens of massive runaways were found to be associated with bow shocks, only two RSG bow-shock-producing stars, Be ...
... Most runaway OB stars, like the majority of massive stars residing in their parent clusters, go through the red supergiant (RSG) phase during their lifetimes. Nonetheless, although many dozens of massive runaways were found to be associated with bow shocks, only two RSG bow-shock-producing stars, Be ...
Masses, Radii, and Equation of State of Neutron Stars
... condensates in such matter; the isospin symmetry energy that defines the energy difference between normal and neutron-rich matter and, ultimately, the ability to calculate matter in β-equilibrium from first principles; and the role and reliability of calculations of n-body interactions. Despite the ...
... condensates in such matter; the isospin symmetry energy that defines the energy difference between normal and neutron-rich matter and, ultimately, the ability to calculate matter in β-equilibrium from first principles; and the role and reliability of calculations of n-body interactions. Despite the ...
Heating and Cooling of Neutron Star Crusts
... turn, determines how the crust cools after the outburst. The primary sources of heating in the crust come from electron captures throughout the crust and pycnonuclear reactions in the inner crust. Preliminary work has been done to calculate the depth and thickness of these reaction layers using a ne ...
... turn, determines how the crust cools after the outburst. The primary sources of heating in the crust come from electron captures throughout the crust and pycnonuclear reactions in the inner crust. Preliminary work has been done to calculate the depth and thickness of these reaction layers using a ne ...
A Theory of Extrasolar Giant Planets
... Our theory starts with the assumption that EGP's have been somehow formed from an initially gaseous, high-entropy state. Current theoretical models for forming giant planets require relatively rapid accretion of large amounts of protoplanetary disk gas onto a core of rocky and icy material (Podolak, ...
... Our theory starts with the assumption that EGP's have been somehow formed from an initially gaseous, high-entropy state. Current theoretical models for forming giant planets require relatively rapid accretion of large amounts of protoplanetary disk gas onto a core of rocky and icy material (Podolak, ...
Massive Star Formation - Max-Planck
... plotted here), although denser examples have been found in Henize 2-10 (Santangelo et al., 2009). The 13 CO-defined clouds of RomanDuval et al. (2010) are indicated, along with HCO+ clumps of Barnes et al., (2011), including G286.21+0.17 (Barnes et al., 2010). Along with G286, the BGPS clumps (Ginsb ...
... plotted here), although denser examples have been found in Henize 2-10 (Santangelo et al., 2009). The 13 CO-defined clouds of RomanDuval et al. (2010) are indicated, along with HCO+ clumps of Barnes et al., (2011), including G286.21+0.17 (Barnes et al., 2010). Along with G286, the BGPS clumps (Ginsb ...
YELLOW SUPERGIANTS IN THE ANDROMEDA GALAXY (M31)
... we have color coded them for clarity; the corresponding initial mass is shown in the same color. The two solid vertical lines denote the yellow supergiant region, which we define as having effective temperatures between 4800 K and 7500 K. We see that in most cases the models predict a short pass thr ...
... we have color coded them for clarity; the corresponding initial mass is shown in the same color. The two solid vertical lines denote the yellow supergiant region, which we define as having effective temperatures between 4800 K and 7500 K. We see that in most cases the models predict a short pass thr ...
EL CVn-type binaries - Discovery of 17 helium white dwarf
... core. The mass of the hydrogen layer depends on the total mass and composition of the star (Nelson et al. 2004), but is typically 0.001 – 0.005M⊙ , much greater than for typical white dwarfs (hydrogen layer mass < 10−4 M⊙ ). The preHe-WD then evolves at nearly constant luminosity towards higher effe ...
... core. The mass of the hydrogen layer depends on the total mass and composition of the star (Nelson et al. 2004), but is typically 0.001 – 0.005M⊙ , much greater than for typical white dwarfs (hydrogen layer mass < 10−4 M⊙ ). The preHe-WD then evolves at nearly constant luminosity towards higher effe ...
Simulating the outer layers of Procyon A: a comparison with the Sun
... part of the SAL is in an optically thin region, the photons can more readily carry away excess internal energy from the temperature fluctuations, than they can in optically thick regions. As it loses its excess internal energy at a greater rate compared with its surroundings, the fluctuation is said ...
... part of the SAL is in an optically thin region, the photons can more readily carry away excess internal energy from the temperature fluctuations, than they can in optically thick regions. As it loses its excess internal energy at a greater rate compared with its surroundings, the fluctuation is said ...
Munshi_washington_0250E_12611
... effect is smaller in more massive halos, where baryon loss due to feedback is less (see also Sawala et al. (2012)). The dashed horizontal line marks the ratio if halos had a 100% baryon loss. Middle Panel: Estimated vs. True Stellar Mass as a function of halo mass. The stellar mass using artificial ...
... effect is smaller in more massive halos, where baryon loss due to feedback is less (see also Sawala et al. (2012)). The dashed horizontal line marks the ratio if halos had a 100% baryon loss. Middle Panel: Estimated vs. True Stellar Mass as a function of halo mass. The stellar mass using artificial ...
Spectroscopic Studies of Evolved Stars and Planetary Nebulae
... maser intensity with pulsation phase has been investigated across all sources for the first time. Comparing these masers with model atmospheres constrains the formation region to between 2 and 4 stellar radii. CO in the circumstellar envelope of II Lup has been modelled using the radiative transfer ...
... maser intensity with pulsation phase has been investigated across all sources for the first time. Comparing these masers with model atmospheres constrains the formation region to between 2 and 4 stellar radii. CO in the circumstellar envelope of II Lup has been modelled using the radiative transfer ...
Neutron Stars in Compact Binary Systems: From the equation of
... has substantial uncertainty. Many equations of state have been proposed based on different models of the underlying physics. These predict various quantities, such as the maximum stable mass, which allow them to be ruled out by astronomical measurements. This thesis presents a natural way to write a ...
... has substantial uncertainty. Many equations of state have been proposed based on different models of the underlying physics. These predict various quantities, such as the maximum stable mass, which allow them to be ruled out by astronomical measurements. This thesis presents a natural way to write a ...
An Optical Study of Young Stellar Clusters
... ESO/MPI 2.2-m telescope at La Silla Observatory, I study the systematic effects that bias the derivation of stellar parameters of pre-main sequence (PMS) stars. I derive the new H-R diagram of the entire region, and assign masses and ages to all the members. The age is found to be ∼ 2 − 3 Myr, older ...
... ESO/MPI 2.2-m telescope at La Silla Observatory, I study the systematic effects that bias the derivation of stellar parameters of pre-main sequence (PMS) stars. I derive the new H-R diagram of the entire region, and assign masses and ages to all the members. The age is found to be ∼ 2 − 3 Myr, older ...
Stellar Wind Mechanisms and Instabilities
... One of the great astronomical discoveries of the latter half of the past century was the realization that nearly all stars lose mass through a more or less continuous surface outflow called a “stellar wind”. While it was long apparent that stars could eject material in dramatic outburts like novae o ...
... One of the great astronomical discoveries of the latter half of the past century was the realization that nearly all stars lose mass through a more or less continuous surface outflow called a “stellar wind”. While it was long apparent that stars could eject material in dramatic outburts like novae o ...
EXTREMELY EXTENDED DUST SHELLS AROUND EVOLVED
... 2.1 The Hertzsprung-Russell Diagram: a plot of the Luminosity or Absolute magnitude (vertical axis) vs. Surface temperature, Spectral type or color (e.g. B−V color band; horizontal axis). Both scales are logarithmic (except in magnitudes, which is intrinsically logarithmic) and temperature is increa ...
... 2.1 The Hertzsprung-Russell Diagram: a plot of the Luminosity or Absolute magnitude (vertical axis) vs. Surface temperature, Spectral type or color (e.g. B−V color band; horizontal axis). Both scales are logarithmic (except in magnitudes, which is intrinsically logarithmic) and temperature is increa ...
Star Captures by Quasar Accretion Disks: A Possible Explanation of
... disks around black holes is supplied by stars that plunge through the disk. Stars in the central part of the host galaxy are randomly perturbed to highly radial orbits, and as they repeatedly cross the disk they lose orbital energy by drag, eventually merging into the disk. Requiring the rate of ste ...
... disks around black holes is supplied by stars that plunge through the disk. Stars in the central part of the host galaxy are randomly perturbed to highly radial orbits, and as they repeatedly cross the disk they lose orbital energy by drag, eventually merging into the disk. Requiring the rate of ste ...
The Formation and Early Evolution of Young Massive Clusters
... We review the formation and early evolution of the most massive (> few 104 M⊙ ) and dense (radius of a few pc) young stellar clusters, focusing on the role that studies of these objects in our Galaxy can play in our understanding of star and planet formation as a whole. Comparing the demographics of ...
... We review the formation and early evolution of the most massive (> few 104 M⊙ ) and dense (radius of a few pc) young stellar clusters, focusing on the role that studies of these objects in our Galaxy can play in our understanding of star and planet formation as a whole. Comparing the demographics of ...
400 YEARS OF STELLAR ROTATION - DFTE
... S01: Pre-main Sequence and Low Mass Stars (chair: Alejandra Recio-Blanco) 09:00 - 09:45 Jerome Bouvier (invited review): Angular momentum evolution of solar-type stars, low-mass stars and brown dwarfs: observations and models 09:45 - 10:05 Silvia Alencar (invited): Magnetometry of T Tauri Stars, dyn ...
... S01: Pre-main Sequence and Low Mass Stars (chair: Alejandra Recio-Blanco) 09:00 - 09:45 Jerome Bouvier (invited review): Angular momentum evolution of solar-type stars, low-mass stars and brown dwarfs: observations and models 09:45 - 10:05 Silvia Alencar (invited): Magnetometry of T Tauri Stars, dyn ...
THE UV-OPTICAL GALAXY COLOR-MAGNITUDE DIAGRAM. III
... The NUV r color of galaxies, and to a lesser extent Mr , is affected by dust extinction as well as stellar age (e.g., Johnson et al. 2007a, 2007b; Wyder et al. 2007). We therefore construct an extinction-corrected Hess function in order to determine the number density of transition galaxies. We do ...
... The NUV r color of galaxies, and to a lesser extent Mr , is affected by dust extinction as well as stellar age (e.g., Johnson et al. 2007a, 2007b; Wyder et al. 2007). We therefore construct an extinction-corrected Hess function in order to determine the number density of transition galaxies. We do ...
Fundamental properties of core-collapse Supernova and GRB
... RSG phase. The models predict that core-collapse SN occur after the WR phase, and are of the type Ibc (Georgy et al. 2012, 2009). However, this scenario has yet to be observationally confirmed, specially because WR stars have not been directly detected as SN Ibc progenitors yet (Smartt 2009; Eldridg ...
... RSG phase. The models predict that core-collapse SN occur after the WR phase, and are of the type Ibc (Georgy et al. 2012, 2009). However, this scenario has yet to be observationally confirmed, specially because WR stars have not been directly detected as SN Ibc progenitors yet (Smartt 2009; Eldridg ...
space telescope imaging spectrograph survey of far
... and an absolute wavelength calibration compared with using the Chandra or XMM-Newton grating spectrometers to observe permitted transitions of the same ion stages in the kilovolt X-ray region. Fe xii 1242, 1349 (T 2 106 K) and Fe xxi 1354 (107 K) are well known from solar studies and have bee ...
... and an absolute wavelength calibration compared with using the Chandra or XMM-Newton grating spectrometers to observe permitted transitions of the same ion stages in the kilovolt X-ray region. Fe xii 1242, 1349 (T 2 106 K) and Fe xxi 1354 (107 K) are well known from solar studies and have bee ...
1. introduction 2. disk surface stability: outer disk - CRyA-UNAM
... surface temperatures T that declined with increasing radius R more slowly than the T P R~3@4 predicted by simple optically thick, Ñat disk models, whether powered by steady accretion (Lynden-Bell & Pringle 1974) or irradiation (Adams , Lada, & Shu 1987). Kenyon & Hartmann (1987) showed that the requ ...
... surface temperatures T that declined with increasing radius R more slowly than the T P R~3@4 predicted by simple optically thick, Ñat disk models, whether powered by steady accretion (Lynden-Bell & Pringle 1974) or irradiation (Adams , Lada, & Shu 1987). Kenyon & Hartmann (1987) showed that the requ ...
CHARACTERIZING THE COOL KOIs. III. KOI 961: A SMALL STAR
... and not a giant based on the shallowness of the CO absorption band, and we reported an effective temperature of 3200 ± 50 K and an overall metallicity ([M/H]) of −0.33 ± 0.12 using the spectroscopic indices and calibrations of Rojas-Ayala et al. (2011, hereafter RA11). KOI 961 was the coolest M dwar ...
... and not a giant based on the shallowness of the CO absorption band, and we reported an effective temperature of 3200 ± 50 K and an overall metallicity ([M/H]) of −0.33 ± 0.12 using the spectroscopic indices and calibrations of Rojas-Ayala et al. (2011, hereafter RA11). KOI 961 was the coolest M dwar ...
ACCELERATION DUE TO GRAVITY OF A RAPIDLY ROTATING
... In this chapter I am going to introduce a basic overview about neutron stars and their physical properties and the geometrical representation that we are going to use in this thesis. The ultimate goal is to calculate the acceleration due to gravity at the surface of rotating, relativistic neutron st ...
... In this chapter I am going to introduce a basic overview about neutron stars and their physical properties and the geometrical representation that we are going to use in this thesis. The ultimate goal is to calculate the acceleration due to gravity at the surface of rotating, relativistic neutron st ...
γ Doradus pulsation in two pre-main sequence stars discovered by
... The young open cluster NGC 2264 (α2000 = 6h 41m , δ2000 = +9◦ 53 ) has been studied frequently in all wavelength regimes in the past. It is located in the Monoceros OB1 association about 30 pc above the galactic plane and has a diameter of ∼39 arcmin. Sung et al. (1997) reported a cluster distance ...
... The young open cluster NGC 2264 (α2000 = 6h 41m , δ2000 = +9◦ 53 ) has been studied frequently in all wavelength regimes in the past. It is located in the Monoceros OB1 association about 30 pc above the galactic plane and has a diameter of ∼39 arcmin. Sung et al. (1997) reported a cluster distance ...
A large-scale CO survey of the Rosette Molecular Cloud: assessing
... limb brightening on their edge facing the O stars. By consideration of the full data cube, we identify three distinct spatiovelocity structures: (1) relatively compact regions with broad line wings, identified as compact or well-collimated HV flows, frequently associated with bright IRAS sources; (2 ...
... limb brightening on their edge facing the O stars. By consideration of the full data cube, we identify three distinct spatiovelocity structures: (1) relatively compact regions with broad line wings, identified as compact or well-collimated HV flows, frequently associated with bright IRAS sources; (2 ...