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Related papers: Deep HST Imaging in NGC 6397: Stellar Dynamics

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We have performed a search for halo white dwarfs as high proper motion objects in a second epoch WFPC2 image of the Groth-Westphal strip. We identify 24 high proper motion objects with mu > 0.014 ''/yr. Five of these high proper motion…

Astrophysics · Physics 2009-11-07 Cailin A. Nelson , Kem H. Cook , Tim S. Axelrod , Jeremy R. Mould , Charles Alcock

Context: In the last six years, the VVV survey mapped 562 sq. deg. across the bulge and southern disk of the Galaxy. However, a detailed study of these regions, which includes $\sim 36$ globular clusters (GCs) and thousands of open clusters…

We study the kinematics and dynamics of the globular cluster system of NGC 1399, the central galaxy of the Fornax cluster. The observational data consists of medium resolution spectra, obtained at the Very Large Telescope. Our sample…

We use deep multi-epoch PSF photometry taken with the Visible and Infrared Survey Telescope for Astronomy (VISTA) to measure and analyze the proper motions of stars within the Galactic globular cluster 47 Tucanae (47 Tuc, NGC 104). The…

We present results from the volume-complete spectroscopic survey of 0.1-0.3M$_\odot$ M dwarfs within 15pc. This work discusses the active sample without close binary companions, providing a comprehensive picture of these 123 stars with…

Solar and Stellar Astrophysics · Physics 2023-06-28 Emily K Pass , Jennifer G Winters , David Charbonneau , Jonathan M Irwin , Amber A Medina

Deep Hubble Space Telescope (HST) observations with WFPC2 of the nearby globular cluster NGC 6752 have allowed us to obtain accurate photometry for the cluster white dwarfs (WD). A sample of local WDs of known trigonometric parallax and…

We present a study of the white dwarf (WD) cooling sequence of the globular cluster 47 Tucanae (47 Tuc or NGC 104) using deep infrared observations with the James Webb Space Telescope (JWST). By combining these data with ultra-deep optical…

Solar and Stellar Astrophysics · Physics 2025-06-27 M. Salaris , M. Scalco , L. R. Bedin , S. Cassisi

Intermediate mass black holes (10$^3$-10$^5$ M$_\odot$) in the center of dwarf galaxies are believed to be analogous to growing Active Galactic Nuclei (AGN) in the early Universe. Their characterization can provide insight about the early…

We measure how the slope $\alpha$ of the stellar mass function (MF) changes as a function of clustercentric distance $r$ in five Galactic globular clusters and compare $\alpha(r)$ to predictions from direct $N$-body star cluster…

We present deep and accurate photometry (F435W, F625W, F658N) of the Galactic Globular Cluster Omega Cen collected with the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope (HST). We identified ~ 6,500 white dwarf…

High-precision proper motions of the globular cluster 47 Tuc have allowed us to measure for the first time the cluster rotation in the plane of the sky and the velocity anisotropy profile from the cluster core out to about 13'. These…

Astrophysics of Galaxies · Physics 2017-08-09 A. Bellini , P. Bianchini , A. L. Varri , J. Anderson , G. Piotto , R. P. van der Marel , E. Vesperini , L. L. Watkins

We present stellar proper motions in the Galactic bulge from the Sagittarius Window Eclipsing Extrasolar Search (SWEEPS) project using ACS/WFC on HST. Proper motions are extracted for more than 180,000 objects, with >81,000 measured to…

We present the first detailed study of the behaviour of the stellar proper motion across the entire Galactic Anti-centre area visible in the Sloan Digital Sky Survey data. We use recalibrated SDSS astrometry in combination with positions…

Astrophysics of Galaxies · Physics 2017-11-01 T. J. L. de Boer , V. Belokurov , S. E. Koposov

As part of the ESO-VLT Multi-Instrument Kinematic Survey (MIKiS) of Galactic globular clusters, we present a detailed investigation of the internal kinematics of NGC 5986. The analysis is based on about 300 individual radial velocities of…

We present the most extensive combined photometric and spectroscopic study to date of the enormous globular cluster (GC) system around M87, the central giant elliptical galaxy in the nearby Virgo cluster. Using observations from DEIMOS and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Jay Strader , Aaron Romanowsky , Jean Brodie , Lee Spitler , Michael Beasley , Jacob Arnold , Naoyuki Tamura , Ray Sharples , Nobuo Arimoto

We report results of the Chandra deep imaging observation of the closest post-core collapse globular cluster, NGC 6397. Some 25 sources are detected within 2 arcmin of the cluster center of which about 20 are likely cluster members with L_x…

Astrophysics · Physics 2009-11-07 J. E. Grindlay , C. O. Heinke , P. D. Edmonds , S. S. Murray , A. M. Cool

Using astrometric techniques developed by Anderson et al., we determine proper motions (PMs) in 14.60 arcmin X 16.53 arcmin area of the kinematically "thick-disk" globular cluster M12. The cluster's proximity and sparse nature makes it a…

Astrophysics of Galaxies · Physics 2018-10-17 Devesh P. Sariya , Ing-Guey Jiang , R. K. S. Yadav

We present measurements of positions and relative proper motions in the 30 Doradus region of the Large Magellanic Cloud (LMC). We detail the construction of a single-epoch astrometric reference frame, based on specially-designed…

Solar and Stellar Astrophysics · Physics 2015-09-16 I. Platais , R. P. van der Marel , D. J. Lennon , J. Anderson , A. Bellini , E. Sabbi , H. Sana , L. R. Bedin

The abundance of brown dwarfs (BDs) in young clusters is a diagnostic of star formation theory. Here we revisit the issue of determining the substellar initial mass function (IMF), based on a comparison between NGC1333 and IC348, two…

Solar and Stellar Astrophysics · Physics 2015-06-17 Aleks Scholz , Vincent Geers , Paul Clark , Ray Jayawardhana , Koraljka Muzic

We present proper motions for $>$40 stars at projected distances $\leq1.2''$ from Sagittarius A* (Sgr A*). We find evidence on a $\geq2\sigma$ level for radial anisotropy of the cluster of stars within $1''$ of Sgr A*. We find no evidence…

Astrophysics · Physics 2009-11-07 R. Schoedel , R. Genzel , T. Ott , A. Eckart , N. Mouawad , T. Alexander