English
Related papers

Related papers: Using globular clusters to test gravity in the wea…

200 papers

We collected radial velocities of more than 50.000 individual stars in 156 Galactic globular clusters (GGC) and matched them with HST photometry and Gaia DR2 proper motions. This allowed us to derive the GGC's mean proper motions and space…

Astrophysics of Galaxies · Physics 2020-03-18 Michael Hilker , Holger Baumgardt , Antonio Sollima , Andrea Bellini

Using a recent homogeneous sample of 40 high quality velocity dispersion profiles for Galactic globular clusters, we study the low gravitational acceleration regime relevant to the outskirts of these systems. We find that a simple empirical…

Astrophysics of Galaxies · Physics 2020-01-08 X. Hernandez , A. J. Lara-D.

Measurements of the surface brightness distribution and of the velocity dispersion profile have been so far used to infer the inner dynamics of globular clusters. We show that those observations do not trace back the dark matter potentially…

Astrophysics · Physics 2007-05-23 Francois Roueff , Pierre Salati , Richard Taillet

We use recently compiled position and velocity data for the globular cluster and planetary nebula subsystems in NGC 5128, the nearby giant elliptical, to search for evidence of past dwarf-satellite accretion events. Beyond a 10 arcmin (~11…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Kristin A. Woodley , William E. Harris

We present a detailed analysis of the kinematics of the Galactic globular cluster NGC 6397 based on more than ~18,000 spectra obtained with the novel integral field spectrograph MUSE. While NGC 6397 is often considered a core collapse…

Aims: We present the first in-depth study of the kinematic properties and derive the structural parameters of NGC 4372 based on the fit of a Plummer profile and a rotating, physical model. We explore the link between internal rotation to…

In the context of theories of gravity modified to account for the observed dynamics of galactic systems without the need to invoke the existence of dark matter, a prediction often appears regarding low acceleration systems: wherever $a$…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 X. Hernandez , M. A. Jimenez

We present velocity dispersion measurements of 14 globular clusters in NGC 5128 (Centarus A) obtained with the MIKE echelle spectrograph on the 6.5m Magellan Clay telescope. These clusters are among the most luminous globular clusters in…

Astrophysics · Physics 2009-11-10 Paul Martini , Luis C. Ho

In this paper we have examined the internal dynamics of the globular cluster NGC 362. A V band surface brightness profile (SBP) was constructed from CCD images, and, after it was determined that the cluster is not post core-collapse, fit…

Astrophysics · Physics 2009-10-22 P. Fischer , D. L. Welch , M. Mateo , P. Côté

B,V CCD frames have been used to derive surface brightness profiles for NGC 3201 out to ~18 arcmin. A total of 857 radial velocities with median precision ~1 km/s for 399 member giants have been used to trace the velocity dispersion profile…

Astrophysics · Physics 2009-10-28 Patrick Cote , Douglas L. Welch , Philippe Fischer , K. Gebhardt

We use the recent measurement of the velocity dispersion of star-forming, outer-disk knots by Herbert-Fort et al. in the nearly face-on galaxy NGC 628, in combination with other data from the literature, to execute a straightforward test of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Dennis Zaritsky , Dimitrios Psaltis

Over the past couple of years, a number of observational studies have confirmed the flattening of the radial velocity dispersion profiles for stars in various nearby globular clusters. As the projected radial coordinate is increased, a…

Astrophysics of Galaxies · Physics 2015-06-05 X. Hernandez , M. A. Jimenez , C. Allen

We present wide-field spectroscopy of globular clusters around the Leo I group galaxies NGC 3379 and NGC 3384 using the FLAMES multi-fibre instrument at the VLT. We obtain accurate radial velocities for 42 globular clusters (GCs) in total,…

Astrophysics · Physics 2009-11-11 G. Bergond , S. E. Zepf , A. J. Romanowsky , R. M. Sharples , K. L. Rhode

We developed self-consistent dynamical models of stellar systems in the framework of quasi-linear modified Newtonian dynamics (QUMOND). The models are constructed from the anisotropic distribution function of Gunn & Griffin (1979), combined…

Astrophysics of Galaxies · Physics 2023-07-26 A. Sollima , C. Nipoti , F. Calura , R. Pascale , H. Baumgardt

We used a combination of Hubble Space Telescope and ground based data to probe the dynamical state of the low mass Galactic globular cluster NGC 6101. We have re-derived the structural parameters of the cluster by using star counts and we…

Astrophysics of Galaxies · Physics 2015-09-09 E. Dalessandro , F. R. Ferraro , D. Massari , B. Lanzoni , P. Miocchi , G. Beccari

In the context of a project aimed at characterizing the properties of star clusters in the Galactic bulge, here we present the determination of the internal kinematics and structure of the massive globular cluster NGC 6569. The kinematics…

Accurate distances are key to obtaining intrinsic properties of astronomical objects such as luminosity or size. Globular clusters (GCs) follow a well-defined relation between their absolute magnitudes and internal stellar velocity…

Astrophysics of Galaxies · Physics 2023-12-05 Michael A. Beasley , Katja Fahrion , Anastasia Gvozdenko

The millisecond pulsars discovered in globular clusters are diagnostic tools for studying the dynamics of the clusters, the intracluster ionized gas and the evolution of the binaries embedded in the cluster. In the first two years of a…

Astrophysics · Physics 2007-05-23 A. Possenti

We determine the mean velocity dispersion of six Galactic outer halo globular clusters, AM 1, Eridanus, Pal 3, Pal 4, Pal 15, and Arp 2 in the weak acceleration regime to test classical vs. modified Newtonian dynamics (MOND). Owing to the…

Astrophysics of Galaxies · Physics 2015-05-27 Hosein Haghi , Holger Baumgardt , Pavel Kroupa

This study constitutes part of a larger effort aimed at better characterizing the Galactic globular clusters (GGCs) located towards the inner Milky Way bulge and disk. Here, we focus on internal kinematics of nine GGCs, obtained from…

Astrophysics of Galaxies · Physics 2021-01-06 Roger E. Cohen , Andrea Bellini , Mattia Libralato , Matteo Correnti , Thomas M. Brown , Jason S. Kalirai