black hole masses and host galaxy evolution of radio
... We report stellar velocity dispersion measurements for a sample of 28 active galactic nucleus (AGN ) host galaxies, including our previous work. Using the mass-dispersion (M.- ) and the fundamental plane relations, we estimate the black hole mass for a sample of 66 BL Lac objects and investigate th ...
... We report stellar velocity dispersion measurements for a sample of 28 active galactic nucleus (AGN ) host galaxies, including our previous work. Using the mass-dispersion (M.- ) and the fundamental plane relations, we estimate the black hole mass for a sample of 66 BL Lac objects and investigate th ...
Merger of binary neutron stars with realistic equations of state in full
... realistic equations of state are quite different from those in the -law equation of state with 2 (hereafter referred to as the 2 equation of state) which has been widely adopted so far (e.g., [12]).1 It can be expected that these differences will modify the properties of the merger quantita ...
... realistic equations of state are quite different from those in the -law equation of state with 2 (hereafter referred to as the 2 equation of state) which has been widely adopted so far (e.g., [12]).1 It can be expected that these differences will modify the properties of the merger quantita ...
Determination of the position angle of stellar spin axes
... cross-section of the star projected on the sky. The absolute stellar position angle PA star is defined from north to east. The slit is represented by the spatial axis YS , which may not be aligned with the northern axis by an angle PA slit . ψ is the angle formed between the slit axis and the stella ...
... cross-section of the star projected on the sky. The absolute stellar position angle PA star is defined from north to east. The slit is represented by the spatial axis YS , which may not be aligned with the northern axis by an angle PA slit . ψ is the angle formed between the slit axis and the stella ...
Instruments and Methods of Astrophysical X-ray
... with four aligned micro-strip detector and a pressure of ¼ of atmosphere (equivalent to 8 Atm/cm). ...
... with four aligned micro-strip detector and a pressure of ¼ of atmosphere (equivalent to 8 Atm/cm). ...
CPW Science Passage
... Two students discuss the evolution of the Algol system – Algol A, a 3.6-solar-mass MS star; Algol B, a 0.8-solar-mass post-MS star; and Algol C, a 1.7-solar-mass MS star. (One solar mass = the Sun’s mass.) The 3 stars orbit a mutual center of mass, with Algol A and Algol B much closer to each other ...
... Two students discuss the evolution of the Algol system – Algol A, a 3.6-solar-mass MS star; Algol B, a 0.8-solar-mass post-MS star; and Algol C, a 1.7-solar-mass MS star. (One solar mass = the Sun’s mass.) The 3 stars orbit a mutual center of mass, with Algol A and Algol B much closer to each other ...
SGR 1900+14
... neutron star interior so that the surface glows persistently in X-rays, and fractures the crust inducing short, repeated bursts at random intervals. Die rather young; typical ages are ~10000 yrs ...
... neutron star interior so that the surface glows persistently in X-rays, and fractures the crust inducing short, repeated bursts at random intervals. Die rather young; typical ages are ~10000 yrs ...
NGC 6231: a young open cluster under X-rays
... – splitted in six 30ks observations spread over 5 days • One of the deepest exposures towards a young open cluster ...
... – splitted in six 30ks observations spread over 5 days • One of the deepest exposures towards a young open cluster ...
Chapter 5 - Leiden Observatory
... mass. Mass loss from winds, which is substantial e.g. for massive stars and post mainsequence stars, is included. Binary interactions such as mass loss, mass transfer, angular momentum loss, CE, magnetic braking, and gravitational radiation are taken into account with appropriate recipes at every ti ...
... mass. Mass loss from winds, which is substantial e.g. for massive stars and post mainsequence stars, is included. Binary interactions such as mass loss, mass transfer, angular momentum loss, CE, magnetic braking, and gravitational radiation are taken into account with appropriate recipes at every ti ...
Population synthesis for double white dwarfs-II. Semi
... Eddington limit of the accretor (Tutukov & Yungelson 1979). The matter that cannot be accreted is lost from the system, taking along some angular momentum. The binary system may remain stable even though it loses extra angular momentum. However heating of the transferred material, may cause it to ex ...
... Eddington limit of the accretor (Tutukov & Yungelson 1979). The matter that cannot be accreted is lost from the system, taking along some angular momentum. The binary system may remain stable even though it loses extra angular momentum. However heating of the transferred material, may cause it to ex ...
A CHANDRA X-RAY STUDY OF THE DENSE GLOBULAR CLUSTER TERZAN... C. O. Heinke, P. D. Edmonds, J. E. Grindlay, and...
... halo is due to a combination of dust grain scattering and the intrinsic breadth of the point-spread function of the Chandra mirrors.) Nevertheless, the spectacular resolution of Chandra did allow us to identify additional point sources up to 105 times fainter within 1000 of EXO 1745248. The readout ...
... halo is due to a combination of dust grain scattering and the intrinsic breadth of the point-spread function of the Chandra mirrors.) Nevertheless, the spectacular resolution of Chandra did allow us to identify additional point sources up to 105 times fainter within 1000 of EXO 1745248. The readout ...
The Central Star Candidate of the Planetary Nebula Sh2
... are summarised in Fig. 2, which shows a set of four individual lightcurves obtained from three different telescopes. The BOS B, FTS V and LT V datasets are used to reveal the shape of the lightcurve, whereas the overlay between LT V and LT U illustrates the difference in axes scaling between differe ...
... are summarised in Fig. 2, which shows a set of four individual lightcurves obtained from three different telescopes. The BOS B, FTS V and LT V datasets are used to reveal the shape of the lightcurve, whereas the overlay between LT V and LT U illustrates the difference in axes scaling between differe ...
Devil physics The baddest class on campus IB Physics
... Apparent magnitude is based on view from earth Two stars may have the same apparent ...
... Apparent magnitude is based on view from earth Two stars may have the same apparent ...
Identifying Young far from Giant Stars Molecular Clouds
... the electrons in the layer's hydrogen atoms are excited to higher energy levels. However, the electrons are most stable in the ground state and will return to it by releasing Ho: photons in their transitions down, creating strong Ho: emission lines (Jensen 2001). These additional photons from the di ...
... the electrons in the layer's hydrogen atoms are excited to higher energy levels. However, the electrons are most stable in the ground state and will return to it by releasing Ho: photons in their transitions down, creating strong Ho: emission lines (Jensen 2001). These additional photons from the di ...
Pulsed Accretion in the Young Binary &
... onto the central star, resulting in initially massive disks being reduced to relatively low fractional levels over the course of 10 Myr or less. Accretion would also be enhanced by a smaller binary separation and a smaller orbital period (Ostriker et al. 1992). But recently, White and Ghez (2001) fo ...
... onto the central star, resulting in initially massive disks being reduced to relatively low fractional levels over the course of 10 Myr or less. Accretion would also be enhanced by a smaller binary separation and a smaller orbital period (Ostriker et al. 1992). But recently, White and Ghez (2001) fo ...
Cluster formation in molecular clouds – I. Stellar populations, star
... feedback from stars with pre-stellar evolution and those without it. The authors found that there was not a significant difference between the two cases. Since the cluster will be actively accreting gas until feedback effects stop the inflow, any added mass has to be dealt with accordingly. This gas ...
... feedback from stars with pre-stellar evolution and those without it. The authors found that there was not a significant difference between the two cases. Since the cluster will be actively accreting gas until feedback effects stop the inflow, any added mass has to be dealt with accordingly. This gas ...
PS1-12SK IS A PECULIAR SUPERNOVA FROM A HE
... transient with properties that indicate atypical star formation in its host galaxy cluster or pose a challenge to popular progenitor system models for this class of explosion. The optical spectra of PS112sk classify it as a Type Ibn SN (c.f. SN 2006jc), dominated by intermediate-width (3 × 103 km s− ...
... transient with properties that indicate atypical star formation in its host galaxy cluster or pose a challenge to popular progenitor system models for this class of explosion. The optical spectra of PS112sk classify it as a Type Ibn SN (c.f. SN 2006jc), dominated by intermediate-width (3 × 103 km s− ...
Deexcitation NSS 2004
... Only for some elements K lines can be detected (Mg, Al, Si, S, Ca, Ti, and Fe) ...
... Only for some elements K lines can be detected (Mg, Al, Si, S, Ca, Ti, and Fe) ...
A Study of the Nature and Representative Features of Supernova
... The nature of supernovae was not initially understood. They were referred to as “guest stars” and seen as omens in a variety of cultures in Asian and European countries. Approximately 231 confirmed nearby (Galactic) supernovae remnants exist, with a few dozen other heavily suspected. For a listing a ...
... The nature of supernovae was not initially understood. They were referred to as “guest stars” and seen as omens in a variety of cultures in Asian and European countries. Approximately 231 confirmed nearby (Galactic) supernovae remnants exist, with a few dozen other heavily suspected. For a listing a ...
Abstracts - Physics of Evolved Stars 2015
... and planetary-nebula stages. AGB stars lose most of their stellar envelope in the form of a gaseous and dusty stellar wind. This wind eventually grows to such high mass-loss rates that the central star becomes entirely enshrouded by a dense, dusty superwind. Before reaching such high massloss rates, ...
... and planetary-nebula stages. AGB stars lose most of their stellar envelope in the form of a gaseous and dusty stellar wind. This wind eventually grows to such high mass-loss rates that the central star becomes entirely enshrouded by a dense, dusty superwind. Before reaching such high massloss rates, ...
Galactic chemical evolution of heavy elements: from Barium to
... as the difference between its solar abundance and its s-contribution given by the Galactic chemical evolution model at the epoch of the solar system formation. We compare our results with spectroscopic abundances of elements from Ba to Eu at various metallicities (mainly from F and G stars) showing ...
... as the difference between its solar abundance and its s-contribution given by the Galactic chemical evolution model at the epoch of the solar system formation. We compare our results with spectroscopic abundances of elements from Ba to Eu at various metallicities (mainly from F and G stars) showing ...
models for low-mass x-ray binaries in the elliptical
... 1037 ergs s1), pointing to a different LMXB formation mechanism in GCs. The natural question that arises is whether (1) all LMXBs were formed in GCs through dynamical interactions and some eventually escaped or some GCs dissolved in the field, or (2) field LMXBs were born in situ through binary evo ...
... 1037 ergs s1), pointing to a different LMXB formation mechanism in GCs. The natural question that arises is whether (1) all LMXBs were formed in GCs through dynamical interactions and some eventually escaped or some GCs dissolved in the field, or (2) field LMXBs were born in situ through binary evo ...
Cygnus X-1
Cygnus X-1 (abbreviated Cyg X-1) is a well-known galactic X-ray source, thought to be a black hole, in the constellation Cygnus. It was discovered in 1964 during a rocket flight and is one of the strongest X-ray sources seen from Earth, producing a peak X-ray flux density of 6977229999999999999♠2.3×10−23 Wm−2 Hz−1 (7003230000000000000♠2.3×103 Jansky). Cygnus X-1 was the first X-ray source widely accepted to be a black hole and it remains among the most studied astronomical objects in its class. The compact object is now estimated to have a mass about 14.8 times the mass of the Sun and has been shown to be too small to be any known kind of normal star, or other likely object besides a black hole. If so, the radius of its event horizon is about 7004440000000000000♠44 km.Cygnus X-1 belongs to a high-mass X-ray binary system about 7019574266339685654♠6070 ly from the Sun that includes a blue supergiant variable star designated HDE 226868 which it orbits at about 0.2 AU, or 20% of the distance from the Earth to the Sun. A stellar wind from the star provides material for an accretion disk around the X-ray source. Matter in the inner disk is heated to millions of degrees, generating the observed X-rays. A pair of jets, arranged perpendicular to the disk, are carrying part of the energy of the infalling material away into interstellar space.This system may belong to a stellar association called Cygnus OB3, which would mean that Cygnus X-1 is about five million years old and formed from a progenitor star that had more than 7001400000000000000♠40 solar masses. The majority of the star's mass was shed, most likely as a stellar wind. If this star had then exploded as a supernova, the resulting force would most likely have ejected the remnant from the system. Hence the star may have instead collapsed directly into a black hole.Cygnus X-1 was the subject of a friendly scientific wager between physicists Stephen Hawking and Kip Thorne in 1975, with Hawking betting that it was not a black hole. He conceded the bet in 1990 after observational data had strengthened the case that there was indeed a black hole in the system. This hypothesis has not been confirmed due to a lack of direct observation but has generally been accepted from indirect evidence.