scholarly journals A HIGHLY ECCENTRIC 3.9 MILLISECOND BINARY PULSAR IN THE GLOBULAR CLUSTER NGC 6652

2015 ◽  
Vol 807 (2) ◽  
pp. L23 ◽  
Author(s):  
Megan E. DeCesar ◽  
Scott M. Ransom ◽  
David L. Kaplan ◽  
Paul S. Ray ◽  
Aaron M. Geller
1991 ◽  
Vol 374 ◽  
pp. L41 ◽  
Author(s):  
T. A. Prince ◽  
S. B. Anderson ◽  
S. R. Kulkarni ◽  
A. Wolszczan

1988 ◽  
Vol 132 ◽  
pp. 525-530
Author(s):  
Raffaele G. Gratton

The use CCD detectors has allowed a major progress in abundance derivations for globular cluster stars in the last years. Abundances deduced from high dispersion spectra now correlates well with other abundance indicators. I discuss some problems concerning the derivation of accurate metal abundances for globular clusters using high dispersion spectra from both the old photographic and the most recent CCD data. The discrepant low abundances found by Cohen (1980), from photographic material for M71 giants, are found to be due to the use of too high microturbulences.


1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.


2000 ◽  
Vol 120 (4) ◽  
pp. 1884-1891 ◽  
Author(s):  
F. Grundahl, ◽  
D. A. VandenBerg, ◽  
R. A. Bell, ◽  
M. I. Andersen, ◽  
P. B. Stetson
Keyword(s):  

1999 ◽  
Vol 118 (3) ◽  
pp. 1245-1251 ◽  
Author(s):  
Jeffery A. Brown ◽  
George Wallerstein ◽  
Guillermo Gonzalez

1998 ◽  
Vol 115 (4) ◽  
pp. 1500-1515 ◽  
Author(s):  
Robert P. Kraft ◽  
Christopher Sneden ◽  
Graeme H. Smith ◽  
Matthew D. Shetrone ◽  
Jon Fulbright

1999 ◽  
Vol 513 (2) ◽  
pp. 733-751 ◽  
Author(s):  
Arunav Kundu ◽  
Bradley C. Whitmore ◽  
William B. Sparks ◽  
F. Duccio Macchetto ◽  
Stephen E. Zepf ◽  
...  

1996 ◽  
Vol 165 ◽  
pp. 313-319
Author(s):  
Mark H. Finger ◽  
Robert B. Wilson ◽  
B. Alan Harmon ◽  
William S. Paciesas

A “giant” outburst of A 0535+262, a transient X-ray binary pulsar, was observed in 1994 February and March with the Burst and Transient Source Experiment (BATSE) onboard the Compton Gamma-Ray Observatory. During the outburst power spectra of the hard X-ray flux contained a QPO-like component with a FWHM of approximately 50% of its center frequency. Over the course of the outburst the center frequency rose smoothly from 35 mHz to 70 mHz and then fell to below 40 mHz. We compare this QPO frequency with the neutron star spin-up rate, and discuss the observed correlation in terms of the beat frequency and Keplerian frequency QPO models in conjunction with the Ghosh-Lamb accretion torque model.


2020 ◽  
Vol 496 (1) ◽  
pp. 638-648 ◽  
Author(s):  
Timo L R Halbesma ◽  
Robert J J Grand ◽  
Facundo A Gómez ◽  
Federico Marinacci ◽  
Rüdiger Pakmor ◽  
...  

ABSTRACT We investigate whether the galaxy and star formation model used for the Auriga simulations can produce a realistic globular cluster (GC) population. We compare statistics of GC candidate star particles in the Auriga haloes with catalogues of the Milky Way (MW) and Andromeda (M31) GC populations. We find that the Auriga simulations do produce sufficient stellar mass for GC candidates at radii and metallicities that are typical for the MW GC system (GCS). We also find varying mass ratios of the simulated GC candidates relative to the observed mass in the MW and M31 GCSs for different bins of galactocentric radius metallicity (rgal–[Fe/H]). Overall, the Auriga simulations produce GC candidates with higher metallicities than the MW and M31 GCS and they are found at larger radii than observed. The Auriga simulations would require bound cluster formation efficiencies higher than 10 per cent for the metal-poor GC candidates, and those within the Solar radius should experience negligible destruction rates to be consistent with observations. GC candidates in the outer halo, on the other hand, should either have low formation efficiencies, or experience high mass-loss for the Auriga simulations to produce a GCS that is consistent with that of the MW or M31. Finally, the scatter in the metallicity as well as in the radial distribution between different Auriga runs is considerably smaller than the differences between that of the MW and M31 GCSs. The Auriga model is unlikely to give rise to a GCS that can be consistent with both galaxies.


2021 ◽  
Author(s):  
Mark Gieles ◽  
Denis Erkal ◽  
Fabio Antonini ◽  
Eduardo Balbinot ◽  
Jorge Peñarrubia

Sign in / Sign up

Export Citation Format

Share Document