Binary galaxies

How early could someone have compiled the sort of M/L trends reported in (3) and (4) and shown in Table 1 In principle, shortly before the outbreak of World War II, using the work of Jeans and Kapteyn, or Oort a decade later for the solar neighborhood, Hubble s 1934 discussion of the inner parts of galaxies (16), a rotation curve for the outer parts of M31 that formed part of the PhD dissertation of the late Horace W. Babcock (17), the binary galaxies presented by Holmberg in 1937 (18), also part of his PhD dissertation, and a 1936 study of the Virgo cluster by Sinclair Smith (19), in case you happened not to like Fritz Zwicky, as indeed some of his contemporaries did not. 

Mpc binary galaxies, Local Group, other small groups Virial theorem, X-rays, velocity dispersions of outer satellites, pair-wise velocity differences, approach of M31 (27, 28, 29) 20 - 100 0.02-0.1... 

Final confirmation came from a radio survey of binary galaxies which established redshift differences between pairs grouped around j, 2j and 3j at high confidence levels. 

Ammonia (NH ) is the first binary molecule discovered in outer space of our galaxy, the Milky Way. It may also be the main compound that forms the rings of the planet Saturn. 

Astronomers use a variety of methods to determine the distance to objects in the universe. One of the most effective is the standard candle provided by Type la supemovae. These supemovae originate in a binary star system when a white dwarf star accretes matter from its companion. When the white dwarf reaches the Chandrasekhar limit of 1.4 solar masses, a thermonuclear runaway occurs that completely disrupts the star in a cataclysmic explosion that makes the supernova as bright as an entire galaxy. Because Type la supemovae occur in stars with similar masses and because the nuclear burning affects the entire star, they all have essentially the same intrinsic brightness and their apparent brightness observed from Earth can be used to derive the distance to the supernova. 

Even worse, early N-body calculations showed that a very common occurrence in star clusters was the formation of close binary stars— two stars orbiting one another so closely that in some cases they share a common atmosphere. The timestep for the force calculation for these stars has to be very short, because the stars change their positions relative to one another quite rapidly. Additionally, the very small distance between these stars leads to singularities— places where the computations produce values going to infinity. (This happens because when stars are nearly touching, the distance between them is almost zero relative to the size of the entire cluster or galaxy, and this value appears in the denominator of the force equation.)... 

If one uses the cosmic ray energy requirements and the nonthermal radiation as a guideline, then the most powerful accelerators of relativistic particles in the Galaxy should be supernovae and supernova remnants, pulsars, neutron stars in close binary systems, and winds of young massive stars. The total power Lcr needed to maintain the observed energy density of cosmic rays is estimated as 1041 erg/s. For the acceleration by a supernovae, this estimate... 

We consider the following data sets GRB, SN la, SN Ib/c, X-ray binaries, models of DM distribution in galaxies. Each data set of galactocentric offsets is normalized by typical galaxy radius (r = R/Rgaiaxy X which is usually equal to optical radius (Rgaiaxy — Rapt)- Data on GRB offset errors also avaible. 

Forty years later, measurements of masses of galaxies from rotation curves, binary pairs, cluster velocity dispersions, and other indicators had accumulated to the point where two brief 1974 reviews by an Estonian trio (3) and an American trio (4) tipped the consensus of the community in favor of... 

The synthesis of 26A1 in secondary components of close binaries was found to deserve special attention. The reason is that for 26 Al, as it is /J-unstable with a mean life time of 1.03 106yr (ti/2 = 7.2 105 yr), not only the amount which is synthesised matters, but also the time of the synthesis. The 7-ray line emission from the decay of 26Al in the Galaxy is observed. However, we can only see the decay of 26 Al nuclei in the interstellar medium the decay inside stars is unobservable. Therefore, the 26Al which is observed... 

The crucial distinction between supernovae of types la and Ib/c is that the latter occur near star formation sites and have never been observed in giant elliptical galaxies. Consequently they are associated with core-collapse explosions in massive or intermediate mass stars which have already lost their hydrogen envelopes. Possible candidates include Wolf-Rayet stars and hydrogen-deficient binaries [126,129]. 

Let us now have a physical point of view. In our galaxy a majority of stars are binary stars. If then a weak binary star meets a strong binary star, an ordinary motion of exchange type can easily disrupt the weak binary and lead to the formation of a triple system with the strong binary. That new-born triple system has generally a Hill-type stability and if its motion is of the second oscillating type (which usually requires a large inclination) it will lead to a collision of the two stars of the binary... The probability of this phenomenon is of the order of the ratio of the inner period (that of the close binary) to the outer period (that of the third body). 

How can a new triple system be born Consider our galaxy, with many single stars but with a majority of Binary systems. When a weak binary meets a strong binary, an ordinary motion of exchange type can easily disrupt the weak binary and form a new born triple system. 

---